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Item R3 R.3 County �� � .�� �y,4 ' �, "tr, BOARD OF COUNTY COMMISSIONERS Mayor Michelle Coldiron,District 2 �1 `ll Mayor Pro Tem David Rice,District 4 -Ile Florida.Keys ��� � � Craig Cates,District 1 Eddie Martinez,District 3 w Mike Forster,District 5 County Commission Meeting September 15, 2021 Agenda Item Number: R.3 Agenda Item Summary #3610 BULK ITEM: No DEPARTMENT: Planning/Environmental Resources TIME APPROXIMATE: STAFF CONTACT: Michael Roberts (305) 289-2502 1:30 public hearing AGENDA ITEM WORDING: A Public Hearing to Consider Adoption of an Ordinance by the Monroe County Board of County Commissioners Amending Monroe County Land Development Code ("LDC") Chapter 114, Article I, Section 114-2 ("Level of Service Standards") to Update Stormwater Quality Performance Standards; LDC Section 114-3 ("Surface Water Management Criteria") to Require Net Improvement in Stormwater Quality While Providing Flexibility in Achieving Stormwater Quality Standards and Providing Updates to the Stormwater Manual and Layman's Brochure to Incorporate New Approaches for Managing Stormwater; LDC Section 114- 13 ("Fences") to Complement the Clarity of Existing/Pre-Existing Legislative and Regulatory Intent and Providing Criteria for Retaining Walls; Chapter 114, Article IV("Landscaping")to Complement the Clarity of Existing/Pre-Existing Legislative and Regulatory Intent and Providing for Updated Species Lists; LDC Section 114-163 ("Waterfront Lighting") to Complement the Clarity of Existing/Pre-Existing Legislative and Regulatory Intent; and LDC Section 114-164 ("Nonconforming Lighting") Complement the Clarity of Existing/Pre-Existing Legislative and Regulatory Intent. ITEM BACKGROUND: In October 2019, Monroe County received a Community Planning Technical Assistance grant from the Department of Economic Opportunity ("DEO"). The grant required Monroe County to update the Monroe County Land Development Code ("LDC" or"Code") for the management of stormwater and to update two supporting guidance documents to be used by both County regulators and design professionals working within the County. Focusing on options to eliminate or reduce off-property discharges to decrease discharge(s) to nearshore waters is a principal purpose of updating Monroe County's Code(s). In 1994, Monroe County developed a Manual of Stormwater Management Practices ("Manual") to accompany Monroe County's stormwater management ordinance. The Manual provided Best Management Practices ("BMPs") that were appropriate for the time. The Manual had not been updated since 1994 and no longer reflected considerable advancements in stormwater management BMPs and standards. In conjunction with the Manual, Monroe County developed a Layman's Brochure ("Brochure") that provided guidelines for incorporation of BMPs in the preparation of site plans for single-family and duplex lots. Packet Pg. 3390 R.3 The work provided for through the above-referenced grant included updates to the Manual and Brochure and for revisions for changes to LDC Sections 114-2(a)(5) and 114-3 in accordance with Monroe County Comprehensive Plan ("Comprehensive Plan" or"CP")Policy 1001.1.3. Policy 1001.1.3 Monroe County shall maintain, implement, review and update, as necessary, the County's stormwater management regulations and Stormwater Master Plan. All improvements for replacement, expansion or increase in capacity of drainage facilities shall conform to the adopted level of service criteria pursuant to Policy 1001.1.1. The updated Manual and Brochure were presented to the Monroe County Board of County Commissioners ("BOCC", "Monroe County", or "County") at the BOCC's duly noticed, regularly scheduled June 17, 2020, public meeting, along with the proposed amendment(s) to the Land Development Code. The amendment(s) currently proposed shall implement these updated documents by reference through the LDC. In addition to the changes regarding stormwater, the Monroe County Planning and Environmental Resources Department ("Department") professional staff are proposing additional amendment(s) to LDC Chapter 114 complement the existing/pre-existing clarity of Code text in several areas, including but not limited to fences, landscaping, adding criteria for retaining walls, etc. Community Meeting and Public Participation/Input In accordance with LDC Section 102-159(b)(3), a virtual community meeting was held on September 23, 2020, to receive public input. There were 24 attendees, inclusive of nine members of the Department's professional staff. Based upon public input received at and subsequent to that first community meeting, a second community meeting was held on November 4, 2020. Attendance at this meeting consisted of 12 members of the public and eight members of the Department's professional staff. Development Review Committee and Public Participation/Input On March 23, 2021, the Monroe County Development Review Committee ("DRU) conducted a virtual public meeting to review and receive public input. Planning Commission The Monroe County Planning Commission ("Planning Commission" or "PC") considered the proposed amendment(s) at a duly noticed regularly scheduled public meeting held on April 28, 2021. The Planning Commission requested certain revisions to the proposed amendment(s) and tabled the item to a future meeting; those recommendations included the following: 1. Revise language in LDC Section 114-2(5) to reference the new Florida Statute regarding storm-water level of service ("LOS"). State water quality criteria is codified at 62-302.500 Florida Administrative Code. The Department's professional staff have provided this reference in the Code language. 2. LDC Section 114-13 in re:fence height ought to be left at highest grade, and also develop additional language to address conflicts with other required fencing and more extreme issues. The Planning and Environmental Resources Department's professional staff have removed the reference to lowest existing grade; however, the Department's professional staff have Packet Pg. 3391 R.3 not found any conflicts or other extreme issues within LDC Chapter 114-13. 3. LDC Section 114-100(a)(13), remove the prohibition on turf in required landscape areas. LDC Section 114-100(a)(13) has been deleted as requested. 4. LDC Section 114-106,provide additional landscaping incentives. The Department's professional staff have added the following recommendation for additional water conservation incentives: In addition to the Low Impact Development ("LID') strategies outlined in LDC Section 114-100, the addition of managed cisterns or rain barrels may be incorporated into the site stormwater management facilities. A site's storm water retention requirements may be reduced by the capacity volume of plumbed and managed systems that provide irrigation and/or other non potable applications. The Planning Commission considered the proposed amendments as revised above at a duly noticed public meeting held on July 20, 2021, and recommended approval to the Monroe County BOCC. PREVIOUS RELEVANT BOCC ACTION: September 2, 2015: The Monroe County BOCC held public hearings to review and discuss proposed amendments to the Monroe County Land Development Code to be consistent with the transmitted Monroe County Year 2030 Comprehensive Plan, the results of the Comprehensive Plan Technical Document Update, the adopted 2012 Evaluation and Appraisal Report ("EAR"), and the 2014 Evaluation and Appraisal Notification Letter. Chapters reviewed at the September public hearing included, inter alia, Chapter 114 ("Development Standards") and Chapter 118 ("Environmental Protection"). March 1, 2016: At a special public meeting, the Monroe County BOCC held the first of two public hearings to consider adoption of the Monroe County 2030 Comprehensive Plan and the proposed amendments to the Monroe County Land Development Code to be consistent with the Monroe County Year 2030 Comprehensive Plan. April 13, 2016: At a special public meeting, the Monroe County BOCC adopted Ordinance No. 006- 2016, amending the Monroe County Land Development Code to be consistent with the transmitted Monroe County Year 2030 Comprehensive Plan, the results of the Comprehensive Plan Technical Document Update, the adopted 2012 EAR, and the 2014 Evaluation and Appraisal Notification Letter. June 17, 2020: At a duly advertised regularly scheduled public meeting, the BOCC was presented with updates to the Manual of Stormwater Management Practices and Layman's Brochure as well as the recommended revisions to the Monroe County Land Development Code as related to Packet Pg. 3392 R.3 stormwater. CONTRACT/AGREEMENT CHANGES: None STAFF RECOMMENDATION: Approval DOCUMENTATION: Ordinance 2019-183 Staff Report- Chapter 114 amendments Manual of Stormwater Management Practices - March 2020 Layman's Brochure - March 2020 FINANCIAL IMPACT: Effective Date: NA Expiration Date: NA Total Dollar Value of Contract: NA Total Cost to County: NA Current Year Portion: NA Budgeted: NA Source of Funds: NA CPI: NA Indirect Costs: NA Estimated Ongoing Costs Not Included in above dollar amounts: NA Revenue Producing: No If yes, amount: Grant: County Match: Insurance Required: N/A Additional Details: NA REVIEWED BY: Emily Schemper Completed 08/31/2021 3:49 AM Peter Morris Completed 08/31/2021 4:48 PM Purchasing Completed 08/31/2021 4:52 PM Budget and Finance Completed 08/31/2021 4:53 PM Maria Slavik Completed 08/31/2021 5:52 PM Liz Yongue Completed 08/31/2021 6:08 PM Board of County Commissioners Pending 09/15/2021 9:00 AM Packet Pg. 3393 R.3.a 2 3 4 % 5 r 6 MONROE COUNTY, FLORIDA 7 MONROE COUNTY BOARD OF COUNTY COMMISSIONERS 8 ORDINANCE NO. -2021 9 10 AN ORDINANCE BY THE MONROE COUNTY BOARD OF COUNTY 0. 11 COMMISSIONERS AMENDING MONROE COUNTY LAND DEVELOPMENT > 12 CODE CHAPTER 114, ARTICLE I, SECTION 114-2 "LEVEL OF SERVICE 13 STANDARDS" TO UPDATE STORMWATER QUALITY PERFORMANCE 14 STANDARDS; SECTION 114-3 "SURFACE WATER MANAGEMENT 15 CRITERIA" TO REQUIRE NET IMPROVEMENT IN STORMWATER 16 QUALITY WHILE PROVIDING FLEXIBILITY IN ACHIEVING 17 STORMWATER QUALITY STANDARDS AND PROVIDE UPDATES TO THE 18 STORMWATER MANUAL AND LAYMAN'S BROCHURE TO 19 INCORPORATE NEW APPROACHES FOR MANAGING STORMWATER; c 20 SECTION 114-13 "FENCES" TO REFINE CODE LANGUAGE TO BETTER 21 CLARIFY REQUIREMENTS AND PROVIDE CRITERIA FOR RETAINING 22 WALLS; CHAPTER 114, ARTICLE IV "LANDSCAPING" TO REFINE CODE c 23 LANGUAGE TO BETTER CLARIFY REQUIREMENTS AND UPDATE LISTS 24 OF SPECIES; SECTION 114-163 "WATERFRONT LIGHTING" TO REFINE 25 CODE LANGUAGE TO BETTER CLARIFY REQUIREMENTS;AND SECTION 26 114-164 "NONCONFORMING LIGHTING" TO REFINE CODE LANGUAGE 27 TO BETTER CLARIFY REQUIREMENTS; PROVIDING FOR 4 28 SEVERABILITY; PROVIDING FOR REPEAL OF CONFLICTING 29 PROVISIONS; PROVIDING FOR TRANSMITTAL TO THE STATE LAND 30 PLANNING AGENCY AND THE SECRETARY OF STATE; PROVIDING FOR 31 AMENDMENT TO AND INCORPORATION IN THE MONROE COUNTY 32 LAND DEVELOPMENT CODE; PROVIDING FOR AN EFFECTIVE DATE. 33 34 35 WHEREAS, the Board of County Commissioners of Monroe County, Florida, constitutes the 36 local legislature of Monroe County, Florida; and 37 E 38 WHEREAS, at a special meeting of the Monroe County Board of County Commissioners 39 ("BOCC", "Monroe County", or the"County")held on April 16, 2016,the BOCC adopted Ordinance No. 40 006-2016, amending the Monroe County Land Development Code ("Land Development Code", "LDC", 41 or"Code"); and 42 Ord.No. -2021 Page 1 of 30 Packet Pg. 3394 R.3.a I WHEREAS, this LDC amendment implements the Monroe County Comprehensive Plan's 2 ("Comprehensive Plan" or "CP") Goals, Objectives, and Policies by, inter alia, removing eliminable 3 ostensible internal inconsistencies and buttressing the clarity of the existing/pre-existing legislative and 4 regulatory intent of the sections of subsections of this Land Development Code Chapter; and 5 6 WHEREAS, Comprehensive Plan Policy 101.10.3 requires Monroe County to maintain 7 stormwater management regulations, which shall require that all improvements for replacement, 0 8 expansion or increase in capacity of drainage facilities conform with the adopted level of service standards 9 pursuant to Comprehensive Plan Policy 1001.1.1; and E 10 2 11 WHEREAS, Comprehensive Plan Policy 1001.1.1 requires Monroe County to review the > 12 standards for detention and retention volumes for surface water to ensure they achieve minimum water 13 quality standards; and 14 15 WHEREAS, Monroe County's Manual of Stormwater Management Practices and the County's 16 associated Layman's Brochure were updated under Florida Department of Economic Opportunity 0) 17 ("DEO") Community Planning Technical Assistance Grant Agreement No. P0363; and 2 18 2 19 WHEREAS, the Monroe County Planning and Environmental Resources Department 20 ("Department") held community meetings on September 23, 2020, and on November 4, 2020, to review 0 21 the proposed amendments and to receive public input; and 22 u 23 WHEREAS, the Monroe County Development Review Committee ("DRC") held an advertised 24 public meeting on March 23, 2021, to consider adoption of proposed Land Development Code 0 25 amendment(s), and provided for further public participation and input; and N 4 26 27 WHEREAS, the Monroe County Planning Commission ("Planning Commission" or "PC") held a 28 a duly noticed public hearing on April 28, 2021, to review and consider the proposed amendment(s) and 0) 29 to provide for public comment; and t 30 cu 31 WHEREAS, the Planning Commission furnished recommendations for changes to the proposed 32 amendment(s) and consonantly recommended for the Department's professional staff to undertake such 9 33 additional revisions and to schedule a second public hearing for further public comment; and 0 34 35 WHEREAS, the Planning Commission held a duly noticed public hearing on July 20, 2021, to 36 review and consider the proposed amendment(s)with the requested changes and adopted Resolution P08- 37 21, recommending BOCC approval of the proposed amendment(s); and 38 39 WHEREAS, at a duly noticed regularly scheduled public meeting held on September 15, 2021, 40 the Monroe Board of County Commissioners held a public hearing, considered the Monroe County 41 Planning and Environmental Resources Department's professional staff report,provided an opportunity 42 for public participation and comment in accordance with the requirements of local, state, and federal 43 law; and Ord.No. -2021 Page 2 of 30 Packet Pg. 3395 R.3.a 1 2 WHEREAS, based upon the foregoing, the Board of County Commissioners of Monroe County, 3 Florida, hereby makes the following findings of fact and conclusions of law: 4 5 1. The proposed amendment(s) is/are consistent with the Goals, Objectives and Policies of the 6 Monroe County Year 2030 Comprehensive Plan; and 7 2. The proposed amendment(s) is/are consistent with the Principles for Guiding Development for 8 the Florida Keys Area of Critical State Concern, Section 380.0552(7), Florida Statutes; and is 9 3. The proposed amendment(s) is/are consistent with Part 11 of Chapter 163,Florida Statutes; and 10 4. The proposed amendment(s)is/are necessary and in furtherance of the constitutional, statutory, 2 11 and local police power(s) of Monroe County, Florida; 12 13 -� 14 NOW, THEREFORE, BE IT ORDAINED BY THE BOARD OF COUNTY 15 COMMISSIONERS OF MONROE COUNTY, FLORIDA, THAT: 16 17 Section 1. Recitals and Legislative Intent. The foregoing prefatory recitals, including but is 18 not limited this ordinance's title, are true and correct, and are hereby incorporated as if fully stated herein. 2 19 0 20 Section 2. The Monroe County Land Development Code is hereby amended as follows 21 (deletions are sue; additions are underlined): 0 22 Sec. 114-2. Adequate Facilities and Review Procedures. 23 (a) Level of Service Standards (LOS). All development shall be served by adequate public facilities in 0 24 accordance with the following standards: 0 25 26 (5) Drainage/stormwater. E 27 Treatment and disposal facilities shall be designed to meet the design and performance 28 standards established in Rule 62-302.500, F.A.C. and the current edition of the County's 29 Manual of Stormwater Management Practices, and either demonstrate that post development 30 total nitrogen and total phosphorous loads are less than pre-development loads to the receiving 31 water body (net improvement) or demonstrate a ninety five percent (95%) reduction in 32 stormwater total nitrogen load and total phosphorus load. Treatment and disposal facilities 33 must be designed and operated so that off-site discharges meet State water quality E 34 standards, as set forth in Rule 62-302.500, F.A.C. 35 36 Sec. 114-3. Surface Water Management Criteria. 37 (a) Intent. It is the intent of this section to establish guidelines and criteria for the safe management Ord.No. -2021 Page 3 of 30 Packet Pg. 3396 R.3.a I and disposal of stormwater runoff from developed areas that will minimize or eliminate any 2 resultant adverse impacts on the surface water, groundwater, and other natural resources of the 3 county. These guidelines consider the effects of sea level rise and encourage the use of low impact 4 development and new stormwater management aproaches that eliminate off-property discharges. 5 These procedures are intended to assist in protection of the vital water resources of the Florida 6 Keys, including the reservoir of freshwater on Big Pine Key and the near shore waters of the Gulf 7 of Mexico, Florida Bay and the Atlantic Ocean. 0 8 (b) Applicability. Projects discharging to impaired waters or to Outstanding Florida Waters (OFW) 9 are subject to additional requirements for mitigation of pollutant loads. Single-family and duplex E 10 residences are required to observe best management practices (BMP's) as identified in the 0 W 11 sections of the current edition of the c-County's inManual of ;�Stormwater wManagement > 12 pfractices clearly labeled as applicable to single-family and duplex residences and are subject 13 only to the criteria,administrative procedures, and maintenance/retrofitting requirements identified 14 in subsection (d) of this section and other applicable provisions of the Comprehensive Plan and 15 this Land Development Code. All other applications for a county building permit are subject to 16 all the criteria established in this section, except those identified in subsection (c). Except as W 17 specifically exempted in subsection(c)below, 18 are development that is nonconforming to the surface water management criteria standards of 19 this article ._e shall be brought into compliance with the criteria of this Section 114-3 sej-ec4 20 t rho 0 or�� PSeeti r 114 110 er 21 (c) Exemptions. Notwithstanding any other provisions of this Land Development Code, the following 2 22 activities are exempt from the requirements of this section, unless otherwise required by State or 23 Federal Law: 0 24 (1) Maintenance work on existing mosquito drainage structures for public health and welfare 25 purposes,provided that the activities do not increase peak discharge rate or pollution load; E 26 (2) Routine maintenance and minor modification of existing impervious area other than single r_ 27 family and duplex residences provided it meets one of the following conditions: E �t 28 a. The maintenance does not increase the existing impervious conditions of the site; or 29 b. The proposed maintenance is certified by a licensed engineer demonstrating that the 9 30 maintenance will not increase the design peak discharge rate, volume pollution load of 0 31 stormwater runoff, or impervious coverage of the site; or 32 C. The placement of a new structure does not change the designed peak discharge rate, E 33 volume or pollution load, or increase impervious coverage of site area of stormwater 34 runoff from the site. 35 (3) Emergencies requiring immediate action to prevent material harm or danger to persons when 36 obtaining a permit is impractical and would cause undue hardship in protection of property 37 from fire, violent storms, hurricanes, or other hazards. A report of the emergency action shall Ord.No. -2021 Page 4 of 30 Packet Pg. 3397 R.3.a I be made to the county administrator as soon as practicable. All emergency action shall also be 2 temporary in nature and be reversed or appropriately remedied after the emergency has passed; 3 (4) Single-family and duplex residences built on individual lots that are part of an existing 4 subdivision, provided a stormwater management system approved by the Monroe County 5 Growth Management Division or South Florida Water Management District is in place, and is 6 provided as part of the application materials; t� 7 (5) Maintenance, repair, or installation of underground or overhead utility facilities, such as, but 8 not limited to,pipes, conduits and vaults, including replacing the ground surface with in-kind 0 9 material or materials with similar runoff characteristics; > 10 (6) Installation of a new or replacement of an existing public drainage system, public combined 11 sewer,public sanitary sewer, or public water supply system; 12 (7) Road and parking lot maintenance limited to the following activities: 13 a. Pothole and square cut patching; r_ 14 b. Overlaying existing asphalt or concrete or impervious brick pavement with asphalt or 15 concrete without expanding the area of coverage; 16 C. Shoulder grading; 17 d. Reshaping or regrading drainage ditches; 18 e. Crack sealing; and 19 f. Vegetation maintenance. 0 20 (d) Single-family and duplex residences. a� 21 (1) Criteria. All water quantity and water-quality criteria as per subsections 1 and (f)(2) of 22 this section. E e( 23 (2) Administrative procedures. At building permit review, stormwater management criteria will 24 be applied, generally to assess the applicant's compliance with these criteria through the 25 implementation of best management practices. An applicant's stormwater management plan 26 must comply with the criteria listed in subsection(f)(-2)of this section ^r, i *he altefa tiN,, and 27 follow the guidelines outlined in the document entitled Layman's Brochure s 28 distributed by the county. E 29 (3) Lot coverage expansion/retrofitting requirements. Those existing single-family and duplex lot 30 owners wishing to expand impervious area shall bring the increase in impervious area into 31 compliance with this section. Any substantial improvements shall be brought into compliance 32 with the applicable provisions of the land development regulations in accordance with Section 33 114-3(f)(1) and 114-3(f)(2)i ^ er-da*ee w4h Seetio 114 3 (e) Ord.No. -2021 Page 5 of 30 Packet Pg. 3398 R.3.a I (e) General criteria. 2 (1) Water management areas. Such areas shall be legally reserved to and maintained by the 3 operational entity and be dedicated on the plat, deed restriction, or easements. Any change in 4 the use of the property must comply with this regulation and any other requirements of the 5 Comprehensive Plan and this Land Development Code. Stormwater management areas shall 6 be connected to a public road or other location from which operation and maintenance means 7 of access are legally and physically available to the operational entity, in accordance with �? 8 county land development regulations governing subdivision of land. 0. c 9 (2) Environmental impacts. All surface water management plans shall be reviewed by the staff to 10 evaluate anticipated impacts of the proposed work on the environment of the county. The a 11 following environmental features, among others, shall be used by the staff in evaluating r- 12 impacts: 13 a. Wetlands; c 14 b. Water bodies (including determination of discharge to impaired waters or OFW); 0) 15 C. Intermittent(seasonally wet)ponds; 0 16 d. Mixed upland and wetland systems; 17 e. Pinelands; 18 f. Dunes/beach berms; 19 g. Hammock areas; 20 h. Uplands areas; and 21 i. Preferred habitat of rare and endangered plant and animal species. 0 22 (3) Legal operational entity requirements. a� 23 a. An acceptable, responsible entity that agrees to operate and maintain the surface water a� 24 management system shall be identified in the building permit application. The entity must 25 be provided with sufficient ownership so that it has control over all water management 26 facilities authorized. The following are examples of entities that are acceptable: 27 1. Governmental agencies; 28 2. Nonprofit corporations, including homeowners associations, property owners a� 29 associations, condominium owners associations, or master associations; or E 30 3. The property owner as permittee, or his successors, if the property is wholly owned 31 by the permittee and is intended to be so retained. 32 b. The entity must provide legally binding written documentation that it will accept the 33 operation and maintenance of all surface water management systems prior to approval. Ord.No. -2021 Page 6 of 30 Packet Pg. 3399 R.3.a 1 (4) Water quality considerations. All new surface water management systems shall be evaluated 2 based on the ability of the system to prevent degradation of receiving waters. All new surface 3 water management systems shall be designed to either: 4 a. Meet net improvement criteria as defined in Section 114-2(a)(5); or 5 b. Reduce the post-development annual average stormwater for both total nitrogen load and u 6 total phosphorus load by 95%. 7 8 9 Fier-ida waters shall pr-evide greater- tfeatment in aeeer-da*ee w4h Seetieff 40E 4.091, FAG, 0. 10 11 �T.,I��pendi 'E,' as listed inS4seetien (f)(2) •�SectF6s a*d the abilit-f to „f.ffl � 12 13 14 15 16 2 17 (5) Water quantity considerations. All new stormwater management systems shall be evaluated 0 18 on the ability of the system to prevent flooding of on-site structures, adjacent properties,roads, 19 and road rights-of-way based upon antecedent rainfall conditions. 0 20 (f) Technical criteria. 21 (1) Water quantity. c, 0 22 a. Discharge. Off-site discharge is limited to amounts that will not cause adverse off-site 23 impacts. E 24 These amounts are: E e( 25 1. Historic discharges based on natural site drainage patterns; or 26 2. Amounts determined in previous South Florida Water Management District or the 27 county permit actions. 28 b. Drainage and flood protection criteria. The surface water management system shall be a 29 designed using a 24-hour rainfall duration and 25-year return frequency in computing 30 allowable off-site discharge rate. Flood protection and floodplain encroachment standards 31 shall be those established in the Monroe County Land Development Regulations and 32 Comprehensive Plan. If post-development conditions are such that a volume greater than 33 the retention and/or detention volume required for stormwater management is already 34 being retained on site, that condition shall be maintained. Ord.No. -2021 Page 7 of 30 Packet Pg. 3400 R.3.a 1 (2) Water quality. 2 a. Degradation of receiving water quality prohibited. n-eets-shall be designed so t44 3 , 4 62 302.530 a*d RAe 62 330.010. Projects shall demonstrate either of the following: 5 1. Meet net improvement criteria, or 0 6 2. Reduce the post-development annual average stormwater for both total nitrogen 7 load and total phosphorus load by 95%. 0. c 8 9 10 12 b. Presumption of Compliance. Projects designed, constructed, operated, and maintained in 13 accordance with the BMPs requirements found in the current edition of the Manual of 14 Stormwater Management Practices are presumed to be in compliance with the requirements 15 of this article. 0 16 1. Requirements for submittal include a stormwater pollution prevention plan, an 17 operational phase pollution prevention plan, site-specific water quality evaluation, 0 18 grading plan (including sufficient topographic information), and all other 19 requirements by permitting agencies 20 21 1 22 23 24 mop impei44oHs „fa ,mot of 40 ,mot , ����• Treatment veltime _ {aefe feeo (aefe feeo o o Ord.No. -2021 Page 8 of 30 Packet Pg. 3401 R.3.a 1 2 3 E A site speeif e pelt4a t leading a*alys-r�fo t �i initial r, a ^yea 4 ee tions;- 5 ° 6 0 7 8 9 0 i.ors ^�� o water-^ .,�;� in�i.o ro o bod y^a.,will be ^ s; a a o,o . 2 10 a 11 12 13 14 0 15 16 rotorti^r i,aete ti^r 17 42_For the purposes of this Section, the term "disturbed area" includes the entire lot, 0 18 except that the areas covered by the following BMPs 19 shall be subtracted from the calculation of disturbed area: 20 i. Forested upland areas/vegetative buffer strips (both natural and manmade) 21 which will be retained intact and over or through which vehicular access or 0 22 travel is not possible and will not occur; and 23 ii. Open water surfaces and wetlands (salt marsh, buttonwood, mangroves, or 24 freshwater marsh habitat types). E 25 It will be the responsibility of the applicant to affirmatively demonstrate that the 0) 26 BMPs used for the project are designed, constructed, 27 and maintained properly. 28 -5-3. For the purposes of this section, the term "discharging directly to sensitive waters" 29 means the discharge of runoff via a pipe or channel outfall to the near shore waters, E 30 including canals,for which there is no intervening stormwater treatment system such 31 as those listed in subsection (g)(2)b.3. of this section. Sensitive receiving waters are 32 defined as: class I waters,class II waters,class III waters,outstanding Florida waters, 33 impaired water bodies as defined by 62-303, F.A.C., and/or canals connecting with 34 these waters. Ord.No. -2021 Page 9 of 30 Packet Pg. 3402 R.3.a 1 6. Treatment storage r-eeevefy shall be estifn4ed tising a safety faeter- of tw 3 7.Pf-aetention tfeatment yeltifnes-shall be offlii a allowing bypass r roFscefffis 4 . 5 (3) Construction considerations. u 0 U 6 After complying with the water quantity and water quality criteria provisions of this section as 7 applicable, if discharge structures are necessary, the following design construction E 8 considerations shall apply: 0 9 a. Discharge structures. 10 1. All design discharges from the site shall be made through and controlled by 11 structural discharge facilities. Earth berms shall be used only to disperse or collect r- 12 sheet flows from or to ditches, swales, or other water channels, served by discharge 13 structures. 2 0 14 15 �2. Discharge structures shall include gratings for safety and maintenance purposes. E 16 Regularly-scheduled removal of trash is mandatory ' 0 17 system diseb..Fge into s,,,-F ee z .,to ,,EV „tsta*ding state wateFEi. � r 18 43. Discharge structures shall include systems that would allow discharge from other 19 than the top or bottom of the water column and shall include a cleanable jump area 20 for the sediment removal. Discharge structures from areas with greater than 50 0 21 percent impervious area or systems with inlets in paved areas shall include a baffle, 22 skimmer, or other mechanism suitable for preventing oil and grease from 23 discharging to and/or from retention/detention areas. a� 24 -5-4. Direct discharges, such as through culverts, storm drains, or weir structures, will 25 normally be allowed to receive waters which by virtue of their large capacity and 0) 26 configuration, are easily able to absorb concentrated discharges. Such receiving 27 waters might include existing storm sewer systems and manmade ditches, canals, 28 the bay, channels, and the ocean. 29 6-.5. Indirect discharges, such as overflow and spreader swales, are required where the 30 receiving water or its adjacent supporting ecosystem might be degraded by a direct 31 discharge. The discharge structure would therefore discharge into the overflow, 32 spreader Swale, or other channel,which in turn would release the water to the actual 33 receiving water. Such receiving waters might include marshes,wetland,salt marshes 34 and land naturally receiving overland sheet flow. 35 b. Dry retentionld e* areas (not applicable to natural or mitigation wetland areas). Ord.No. -2021 Page 10 of 30 Packet Pg. 3403 R.3.a I 1. Dry retention/detentien areas shall allow for the return of the groundwater level in 2 the area to the control elevation. 3 2. On-site mosquito control ditches or other appropriate features for such purpose 4 shall be incorporated into the design of dry retention/detention areas. 5 3. The design of dry retention/detentien areas shall incorporate considerations for 6 regular maintenance and vegetation harvesting procedures. 0 7 C. Wet retentionld e* areas. 8 1. Dimensional criteria(as measured at or from the control elevation). 0. c 9 i. Depth. A minimum of 20 percent of the area shallower than six feet is 10 required. 11 ii. Side slopes for purposes of public safety, water quality enhancement and 12 maintenance. All wet retention/detentien areas shall have side slopes no 13 steeper than 4:1 (horizontal/vertical) out to a depth of two feet below the is 14 control elevation, or an equivalent substitute. Side slopes shall be topsoiled, 2 15 nurtured or planted from two feet below to one foot above control elevation 0 16 to promote vegetation growth. Littoral zone vegetation growth survival shall 17 be a condition for operation permit issuance. er 18 2. Support facility design criteria. Perimeter maintenance and operation easements of 19 ten feet (minimum preferable) width at slopes no steeper than 4:1 20 (horizontal/vertical) should be provided beyond the control elevation water line. 21 Control elevations must be set so as not to cause flooding in roadways and to protect 22 road subgrades. 23 d. Impervious areas.Runoff shall be discharged from impervious surfaces through retention r_ 24 areas, detention devices, filtering and cleansing devices, and/or subjected to some type E 25 of best management practice (BMP)prior to discharge from the project site. For projects 26 that include substantial paved areas, such as shopping centers, large highway r_ 27 intersections with frequently stopped traffic, and high-density developments,provisions 28 shall be made for the removal of oil, grease, and sediment from stormwater prior to 29 discharge into the receiving waters of a watercourse. 30 e. Stagnant water conditions. Configurations that create stagnant water conditions shall not E 31 be allowed. 32 (g) Stormwater management plans.It is the responsibility of the applicant to include in the stormwater 33 management plan for the development sufficient information for the Planning Director or designee 34 to evaluate the environmental and stormwater discharge characteristics of the affected areas, the 35 potential and predicted impacts of the proposed activity on community waters, and the effectiveness Ord.No. -2021 Page 11 of 30 Packet Pg. 3404 R.3.a I and acceptability of those measures proposed by the applicant for reducing adverse impacts. The 2 stormwater management plan shall contain maps, charts, graphs, tables, photographs, narrative 3 descriptions, calculations, explanations, and citations to supporting references, and any additional 4 information deemed necessary by the Planning Director. The stormwater management plan must be 5 sealed by an engineer registered in the state with experience in stormwater management and drainage 6 design. 0 7 (h) Manual iin br-o,.h....e of sStormwater i*Management pPractices and Layman's Brochure. 8 (1) The Planning and Environmental Resources Department staff shall compile a mManual of 0 9 sStormwater +Management pPractices for the guidance of persons preparing stormwater > 10 management plans and designing or operating stormwater management systems. The Manual 11 of Stormwater_Management Practices (March 2020) and Layman's Brochure (March 2020) 12 shall be the primary implementation tool and shall be updated 13 periodically to reflect the most current and effective practices. Thy Manual o 0 14 Stormwater Management Practices and Layman's Brochure shall be made available to the 15 public. 2 C 0 16 (2) The Manual of Stormwater Management Practices shall include guidance and a� 17 specifications for the preparation of stormwater management plans. Acceptable techniques for 18 obtaining, calculating, and presenting the information required in the stormwater management 19 plans shall be described. 20 (3) The Manual of Stormwater Management Practices and Layman's Brochure br-E)ehtffe 21 shall include guidance for acceptable best management practices (BMP's) for stormwater 22 management systems for single-family and duplex residences. It shall address the condition 23 that improvements to the land may result in water improvement,thereby creating surface water E 24 over land that would otherwise not be wetland. E 25 (4) The Manual of Stormwater Management Practices and Layman's Brochure knee e 26 shall include guidance in the selection of environmentally sound practices for the management r_ 27 of stormwater and the control of erosion and sedimentation. The development and use of 28 techniques that emphasize the use of natural systems shall be encouraged. 29 (5) The Manual of Stormwater Management Practices shall also establish minimum 30 specifications for the construction of stormwater management facilities. Construction 31 specification shall be established in accordance with sound engineering practices. 32 (6) The Planning and Environmental Resources Department shall submit the Manual of 33 Stormwater Management Practices and subsequent revisions of it to the BOCC for 34 review and approval. The Manual of Stormwater Management Practices may also be Ord.No. -2021 Page 12 of 30 Packet Pg. 3405 R.3.a I submitted for review to the Florida Department of Environmental Protection's Nonpoint 2 Source Management Section in Tallahassee,Florida,and the South Florida Water Management 3 District. 4 (7) Adherence to these regulations shall be based on the guidelines outlined in the Manual o 5 Stormwater Management Practices. 0 6 (i) Administration. 7 (1) Permit application procedures. The stormwater management plan shall be submitted as part of 8 an application for development approval outlined in this Code, unless otherwise herein 9 exempted. All conditions, approvals, and fees shall apply. 10 (2) Plan adherence. The applicant shall be required to adhere to the plans as approved and 11 permitted. Any changes or amendments to the individual stormwater management plan must 12 be approved by the Planning and Environmental Resources Department prior to construction. 13 (3) If required, a permit from the South Florida Water Management District must be obtained prior r- 14 to final concurrency determination. a� 15 (j) Maintenance and inspection. c 16 (1) The installed systems required by these regulations shall be maintained by the owner or 17 approved operating entity, except that the county may select certain systems for county 18 maintenance. The selection of critical areas and/or structures to be maintained by the county 0 19 shall be recommended to the BOCC by the Planning Director and the County Engineer. All 4 20 areas and/or structures to be maintained by the county must be dedicated to the county by plat W 21 or separate instrument and accepted by the BOCC. The systems to be maintained by the owner 22 or approved operating entity shall have adequate access and easements to permit the county E 23 right of entry to inspect and, if necessary, to take corrective action should the owner fail to 24 maintain the systems to be maintained by him. The Planning Director shall give such owner 25 written notice of the nature of corrective action necessary. Should the owner fail, within 30 26 days from the date of the notice to take corrective action the BOCC may take the necessary 0 Y Y rY 27 corrective action and place a lien on the property of the owner to recover the costs thereof. a� 28 (2) The applicant shall arrange with the Planning Director for scheduling the following inspections U 29 (these inspections may be scheduled along with other required inspections): 30 a. Erosion and sediment control inspection. As necessary during and after construction to 31 ensure effective control of erosion and sedimentation. Control measures shall be installed 32 and stabilized around the perimeter of the construction are-between ee y waters and *y 33 Ord.No. -2021 Page 13 of 30 Packet Pg. 3406 R.3.a I b. Dewatering inspection. As necessary before and during construction to ensure effective 2 control and discharge of water that must be removed from a construction area. 3 C. Bury inspections. Prior to the burial of any underground drainage structure. 4 d. Final inspection. When all work, including installation of all stormwater management 5 system facilities, has been completed. 6 The Code Compliance Officer who inspects the work shall either approve it or notify the 7 applicant in writing in what respects there has been a failure to comply with the requirements 8 of the approved permit. Any portion of the work that does not comply shall be corrected by the r_ 9 permittee within a time frame deemed reasonable by the Planning Director depending on the 0. 10 time needed to correct the violation and the effect of the violation on water and habitat quality, 6 11 or the applicant shall be subject to the penalty provisions of subsection (k) of this section. 12 There shall be a fee for inspections as established by the BOCC, and no certificates of -� 13 occupancy shall be issued without approval of the Planning Director. 14 (k) Enforcement and penalties. 0 15 (1) Enforcement. If the Planning Director determines that the project is not being carried out in 2 16 accordance with the approved plan or if any project subject to these regulations is being carried 0 17 out without a permit he is authorized to: a, 18 a. Issue written notice to the applicant that specifies the nature and location of the alleged c 19 noncompliance and includes a description of the remedial actions necessary to bring the 20 project into compliance; and 21 b. Direct the Building Official to issue stop-work orders directing the applicant or persons 22 in possession to cease and desist all or any portion of the work that violates the provisions 23 of these regulations until the remedial work is completed. The applicant shall then bring 24 the project into compliance or be subject to denial of certificate of occupancy for the E 25 proj ect. 26 Any order issued pursuant to this subsection not adequately addressed within ten working days 27 shall be forwarded to the Code Compliance Department. With the exception of single-family 28 and duplex residences,the Planning Director shall require a sealed, as-built topographic survey 29 detailing the completed stormwater management system of the development. 30 (2) Penalties. Penalties will be assessed pursuant to F.S. Chapter 163. a 31 (1) Appeals. Any person aggrieved by the action of any official charged with the enforcement of these 32 regulations as the result of the disapproval of a properly filed permit application,issuance of a written 33 notice of violation, or an alleged failure to properly enforce these regulations in regard to a specific 34 application, shall have the right to appeal the action to the Planning Commission pursuant to Section 35 102-185. Ord.No. -2021 Page 14 of 30 Packet Pg. 3407 R.3.a I * * * 2 3 Sec. 114-13. Fences and Walls. 4 It is the purpose of this section to regulate fences and walls in order to protect the public health, safety and 5 welfare. 6 (a) Height. In general, all fences and walls shall be measured from the highest finished elevation 0 7 adjacent to the fence and shall not exceed six feet in height. 8 (1) For any parcel of land with access to U.S. 1, any property with access to an arterial road and/or 0 9 any property developed with a nonresidential use, fences shall not exceed three (3) feet in 10 height within a clear sight triangle as defined in Section 114-201; 11 (2) For any parcel of land located along US 1 or adjacent to the intersection of any two public 12 roads, fences shall not exceed three (3) feet in height within a clear sight triangle as defined in 13 section 114-201 and/or according to FDOT and national American Association of State 14 Highway and Transportation Officials (AASHTO) standards, whichever is more restrictive; 15 (3) For any parcel of land developed with a single-family residential residence and on a local road, 16 fences located within a clear sight triangle as defined in Section 114-201 may exceed three (3) 0 17 feet in height if located a minimum of ten (10) feet from the edge of pavement of the road,the 0 18 sidewalk or the bike path, whichever is closest to the property line. On unpaved streets, the 19 distance shall be measured from the approximate edge of the cleared right-of-way, 20 (4) A fence shall not exceed four(4)feet in height within any front yard setback or within any side 0 21 yard setback that overlaps with a front yard setback, as required pursuant to Chapter 131, 22 except as follows: 23 a. Within all land use (zoning) districts, fences of up to five (5) feet in height may be 24 permitted if constructed of chain-link, a four-foot solid fence with a one-foot lattice or 25 louvre top, or another material that does not impair visibility. Construction details and 26 materials for fences, other than chain-link, must be approved by the Planning Director; E 27 b. Within all land use (zoning) districts, driveway gates no wider than twelve (12)feet maX 28 be permitted up to six (6) feet in height provided the gates meet setback and sightline 29 requirements, et 30 C. Within the Airport(AD), Commercial 1 (C1), Commercial 2 (C2), Commercial Fishing 31 Area (CFA), Commercial Fishing Special District(CFSD), Commercial fishing Village 32 (CFV), Destination Resort (DR), Industrial (1), Maritime Industries (MI), Mixed Use 33 (MU), Recreational Vehicle (RV), Suburban Commercial (SC) and Urban Commercial 34 (UC) Land Use(Zoning)Districts,fences of up to six(6)feet in height may be permitted, 35 provided the fences are not located within clear sight triangles as defined in Section 114- E 36 201 and/or according to FDOT and national AASHTO standards, whichever is more 37 restrictive; 38 d. Within the Improved Subdivision (IS), Native Area (NA), Sparsely Settled (SS), 39 Suburban Residential(SR)and Suburban Residential Limited(SR-L)Land Use(Zoning) 40 Districts, fences of up to six (6) feet in height may be permitted, provided that no other 41 residentially developed property is located within 200 feet of the subject property and 42 provided the fences are not located within clear sight triangles as defined in Section 114- Ord.No. -2021 Page 15 of 30 Packet Pg. 3408 R.3.a 1 201 and/or according to FDOT and national AASHTO standards, whichever is more 2 restrictive; 3 e. Notwithstanding the provisions of(a)(4) and (a)(4)c. of this section, on Stock Island and 4 on Key Haven,fences of up to six(6)feet may be permitted,provided they are not located 5 within clear sight triangles as defined in section 114-201 and/or according to FDOT and 6 national AASHTO standards, whichever is more restrictive. In addition, parcels of land 7 on Stock Island and Key Haven that are developed with single family dwellings may u 8 incorporate entry features of greater than six (6) feet within fences, provided all of the 0 9 following design criteria are met: 10 1. The entry feature is defined as a continuous fence or gate, or combination thereof, 0. c 11 located contiguous to and on both sides of the main access (driveway) to the 12 property which is designed and intended to control and/or demarcate the access to 13 the property. An "entry feature" includes all walls, buttresses, guy wires, integral 14 signs and decorative features attached thereto up to a maximum width of 12 feet, 15 or 15 percent of the lot width whichever is greater, a maximum height of ten (10) 16 feet, and four(4)feet in depth or six(6)percent of the lot depth whichever is greater 17 as measured from the front property line; and 18 2. The entry feature shall not be located in any side yard setback required pursuant to 0 19 Section 131-1; and 0 20 3. The entry feature shall be compatible with the existing development in the a� 21 immediate vicinity, shall be in harmony with the general appearance and character 22 of the community, and shall not be otherwise detrimental to the public welfare; and 0 23 4. The entry feature shall be designed and arranged on the site in a manner that 24 minimizes aural and visual impact on the adjacent structures while affording the 25 applicant a reasonable use of the land; and 26 5. The entry feature shall require a building permit for its construction and in addition 27 to the normal building permit application requirements, the application shall 0 28 include a scaled site plan and elevations for the entry feature that shows the height, 29 width and length of each element of the entry feature applied for, including any 30 decorative or non-functional elements; and identification of the materials 31 composing each element of the structure (e.g. wire, stone, chain-link, wood, etc.). E 32 (5) When it is necessary to use a fence to contain athletic activity, the fence may be erected to a 33 maximum of twelve (12) feet in height, if constructed of chain-link or another material that 34 does not impair visibility and is designed in accordance with the community character as 35 determined by the Planning Director; 36 37 (6) When it is necessary to use a fence to contain a public use for safety and/or security purposes E 38 (i.e. high voltage substations, pumping stations, public wastewater treatment facilities), the 39 fence may be erected to a maximum height provided in national, state or otherwise recognized 40 industry code, if it is designed in accordance with community character as determined by the 41 Planning Director. 42 43 (b) Setbacks. In general, notwithstanding the setback requirements in Section 131-1, fencing may be 44 located anywhere on the property, including the property line, except as follows: Ord.No. -2021 Page 16 of 30 Packet Pg. 3409 R.3.a 1 (1) The use of a fence shall not negate bufferyard requirements and standards. The clearing of 2 existing native vegetation to locate a fence in the bufferyard shall only be permitted to facilitate 3 the construction of fences located along the inside or outside edge of the required bufferyard. 4 (2) The construction of fences shall not result in or cause any tree abuse. 5 (3) No fence shall be placed so as to extend into or through any wetlands or water bodies, or extend 6 beyond the mean high tide line on any property, except that on marginal docks as described in 7 Section 118-12, fences may extend out to the waterward face of the marginal dock and for u 8 security at public airports in the Airport(AD) Land Use (Zoning) District. 0 9 (4) In no event shall fences be approved if they restrict fire and emergency access to individual or 10 adjacent properties. 11 (5) Additional setback requirements for Big Pine Key and No Name Key are provided in 0. c 12 subsection (c) of this section. 13 (c) Additional requirements for Big Pine Key and No Name Key as required by LCP, HCP and ITP for 14 Big Pine Key and No Name Key. The purpose of this subsection is to recognize and provide for the 15 particular habitat needs of the Florida Key Deer (Odocoileus virginianus clavium) on Big Pine Key 16 and No Name Key so that deer movement throughout Big Pine Key and No Name Key is not 17 hindered while allowing for reasonable use of minimal fencing for the purposes of safety and 18 protection of property. In addition to all other standards set forth in this section, all fences located 0 19 on Big Pine Key and No Name Key shall meet the standards of this subsection as listed below: 0 20 (1) In the Improved Subdivision (IS) Land Use (Zoning) District, fences shall be set back as 21 follows: 0 er 22 a. On canal lots, fences shall be set back at least 15 feet from the edge of abutting street 23 rights-of-way; and built to the edge of all other property lines or as approved through 24 a U.S. Fish and Wildlife Service coordination letter; and 25 b. On all other lots, fences shall be set back at least 15 feet from the edge of abutting 0 26 street rights-of-way, at least five feet from side property lines and at least ten feet 27 from the rear property line, or as approved through a U.S. Fish and Wildlife Service E 28 coordination letter. 29 (2) In land use (zoning) districts other than Improved Subdivision (IS),fences may enclose up 30 to a maximum of and not to exceed the net buildable area of the parcel only. 31 (3) Enclosure of the freshwater wetlands by fences is prohibited. 32 (4) All fences shall be designed and located such that Key Deer access to native habitat, 33 including pinelands, hammocks, beach berms, salt marshes, buttonwoods and mangroves 34 is maintained wherever possible. 35 (5) All fences shall be designed and located such that Key Deer corridors, as identified by the E 36 U.S. Fish and Wildlife Service, shall be maintained. 37 (6) Fences shall not be permitted without a principal use except where the enclosed area 38 consists of disturbed lands or disturbed land with exotics. 39 (7) Fences are not permitted on Tier 1 lands except as authorized by the U.S. Fish and Wildlife 40 Service, and fencing required for safely purposes at any location to enclose the immediate 41 impervious area of pools and tennis courts. 42 (8) Fences are not permitted in non-residential areas along U.S. 1. Ord.No. -2021 Page 17 of 30 Packet Pg. 3410 R.3.a 1 (9) Fences existing on the date the LCP was adopted (August 18, 2004) may be replaced in 2 their existing configuration. 3 (d) Retaining Walls. For the purposes of this section, retaining wall is defined as "A wall or similar 4 structural device used at a grade change to hold the soil on the up-hill side from slumping,- sliding, liding, 5 or falling." 6 a.. Retaining walls are subject to the setback and height_ requirements of fences, except that 0 7 no retaining wall shall exceed four feet(4') in height as measured from the lowest existing 8 adjacent _grade. E 9 b. Where more than one retaining wall is necessary, individual retaining walls shall be 10 separated by a space equal to a minimum distance of two times the exposed wall height of 11 the lower wall, however, the minimum separation shall be two feet(2') and the maximum 12 required width shall be five feet (5'). Separation width shall be measured from the back 13 edge of the lower retaining wall to the foremost edge of the immediately succeeding and 14 higher retaining wall. 15 c, Retaining walls, together with any fence, shall not exceed the allowable fence height as 0 16 measured from the lowest adjacent grade. No combination of retaining walls and fences 17 within any setback shall exceed the fence height requirement for that setback as specified r- 18 in Section 114-13(a). m 19 (e) Use. Fences may be allowed as accessory uses/structures within any Land Use(Zoning)District. c 20 Notwithstanding the definition of accessory use in Section 101-1,fences may be allowed without 21 a principal use where upland security is required. u 22 (f) Construction material. Fences may be constructed of natural or manmade materials, including, 23 but not limited to,brick, lumber,stone,metal,plaster,concrete and masonry., *eept fer-413arbed 24 wire and razor wires are prohibited except in the Industrial (1) and Airport(AD) Land Use 0 25 (Zoning) Districts. 26 27 (g) Attachments to fences. No attachments to fences shall be allowed. The only exception shall be a 28 maximum of two electrical lights attached to the fence per driveway. Such lights shall not exceed E 29 two feet in height above the maximum height limit of the fence. These lights shall comply with 30 all outdoor lighting requirements of Article VI of this chapter. 31 32 (h) Required permit. All fences shall be constructed pursuant to a building permit issued by the 33 county building department and, if applicable, according to the requirements of the HCP/ITP. 34 35 (1) Limited clearing. To allow construction of fences and gates, limited clearing may be permitted E 36 if the following design standards have been met: 37 (1) Such limited clearing does not occur in scenic highway corridors as defined and required in 38 Section 114-125; 39 (2) Limited clearing shall not remove native vegetation that would provide for the minimum 40 buffer required in Section 114-124; and 41 (3) Existing native trees ea*epies within hardwood and pineland hammocks are not removed. Ord.No. -2021 Page 18 of 30 Packet Pg. 3411 R.3.a 1 0) Maintenance. All fences shall be maintained in good repair at all times. 2 3 4 Sec. 114-100. Required Landscaping. u 0 5 (a) All off-street parking areas containing more than six (6) spaces shall be landscaped in accordance 6 with the following standards: 0. c 7 (1) Interior landscaping shall be installed in landscape areas designated for the purposes of 8 controlling traffic,providing shade, screening unnecessary views into and within the vehicular 9 use areas, and separating parking circulation and service areas. 10 (2) Parking lots shall be designed to be sustainable and to function as part of the development's 11 stormwater management system, utilizing vegetated islands as bioretention/swale areas, at/or 12 below grade and with curb cuts. Existing natural drainage ways and vegetated channels shall 13 be incorporated into the design, rather than the standard soil mounding, continuous concrete 14 curb and gutter configuration, to decrease flow velocity and allow for stormwater infiltration. 2 15 (3) Landscaping shall be provided in a square footage area equal to a minimum of twenty percent 0 16 (20%)of the gross parking lot area(includes both parking and vehicular use area). Calculations 17 to verify these requirements shall be shown on the landscape plan per Section 114-108. Such 18 required parking lot landscaping area shall be in addition to other required bufferyards. c 19 (4) No required parking lot landscaping area shall have any dimension less than five (5) feet. 20 (5) For all off-street parking areas containing twenty (20) or more spaces a terminal island shall 21 be provided at the end of each row of parking adjacent to the travel lanes or parking aisle 22 serving the parking. 23 (6) Island landscape areas shall be provided for at least every ten (10)parking spaces in a row. 0 24 (7) One (1) tree shall be required for every one thousand (1,000) square feet, or fraction thereof, 25 of gross parking lot area (includes both parking and vehicular use area). Every island shall E 26 have a minimum one (1) canopy tree. 27 (8) Four (4) shrubs gr-etmdeever shall be required for every one thousand (1,000) square feet, or 28 fraction thereof, of gross parking lot area(includes both parking and vehicular use area). 29 (9) 100% of required parking lot landscaping material shall be native species, as meted defined in 30 Section 114-105. 31 (10) A minimum of fifty percent (50%) of the required trees shall be native canopy species, as 32 defined in Section 114-105, and shall have a minimum of twenty (20) feet on-center spacing. 33 (11) A minimum of forty percent(40%) of the required trees shall be native understory species, as 34 defined in Section 114-105. E 35 (12) A maximum of ten percent(10%) of the required trees may be native palm species, as defined c, 36 in Section 114-105. 37 ; 38 gr-ett*deever-s shall be tts-e& 39 (134) Existing native plant material that is retained and meets the planting requirements relative to 40 location, size and species may be counted toward the total planting requirement of this section. Ord.No. -2021 Page 19 of 30 Packet Pg. 3412 R.3.a I (14-5)Landscaping on each island shall be located so as not to cause a traffic hazard. Visibility must 2 be maintained for traffic movements. Shrubs shall not exceed thirty (30) inches in height, and 3 trees shall be kept with at least four(4) feet of clear trunk. 4 5 Sec. 114-101. Commercial Irrigation Standards. u 0 6 All proposed commercial irrigation systems shall meet the requirements of this section. 7 0. c 8 Sec. 114-102. Landscape Installation and Maintenance Criteria. 9 (a) Plant species shall conform at a minimum to the standards for Florida No. 1 or better, as given in 10 "Grades and Standards for Nursery Plant," State Department of Agriculture and Consumer Services, 11 Division of Plant Industry, Tallahassee. All plant material shall be free of disease, invasive pests, 12 and invasive fungi and shall be one of the species shown in Section 114-105 or shall be certified by 13 the county biologist as native 2 14 0 15 (b) All plant material shall be installed in a fashion that ensures the availability of sufficient soil and 16 water to sustain healthy growth. 17 c er 18 (c) All plant material shall be planted with a minimum of six inches of planting soil and mulched to a 19 depth of four inches. All trees shall be properly guyed or staked at the time of planting. u 20 21 (d) All plant material shall be planted in a manner that is not intrusive to utilities or pavement. 22 0 23 (e) Plant material that dies shall be replaced in accordance with the integrity of the approved landscape 24 plan. 25 26 (f) One hundred percent(100%) of the plant material used to satisfy landscaping requirements shall be E 27 native species in accordance with Section 114-105. 28 29 (g) Shrubs and hedges shall be maintained at a height not to exceed three (3) feet if located within the 30 clear sight triangle as defined in Section 114-201. 31 32 (h) Invasive exotic plant species, as defined in Section 101-1, shall not be planted within the County, 33 including but not limited to: E 34 35 (1) Melaleuca, Melaleuca quinquinerva; 36 (2) Australian Pine, Casuarina (Spp.); 37 (3) Brazilian Pepper, Schinus terebinthifolius; 38 (4) Sapodilla, Manilkara zapota, nefth of*he Seye,, ratio Bridge; 39 (5) Latherleaf, Colubrina asiatica, 40 (6) Lead Tree, Leucaena leucocephala, Ord.No. -2021 Page 20 of 30 Packet Pg. 3413 R.3.a 1 (7) Seaside Mahoe, Thespesia populnea, 2 (8) Bowstring Hemp, Sansevieria hyacinthoides;-a*d 3 (9) Beach Naupaka, Scaevola taccada-; and 4 (10) Guinea grass,Panicum maximum 5 6 (i) Hammock species shall not be planted within 500 feet of native pineland communities. 7 8 Sec. 114-104. Street Trees. 0. c 9 All street fronts shall plant native canopy street trees species as listed in Section 114-105 within the 10 primary and secondary front yard setback area as established in Section 131-1. 11 _(a Gumbo limbo (Bursera simaruba) and all palm species shall not be acceptable as a street tree. 12 fl?� Such trees shall , not be intrusive to utilities or pavement, 13 ( Native trees shall be installed pursuant to a landscape plan,with the number of trees to be equal c 14 to at least one (1) canopy tree of at least twelve (12) feet in overall height or a minimum tree 15 caliper dimension of 4three(33)inches ealipe0measured at six (6) inches above grade per one- 2 16 hundred (100) feet of street length, provided that in no event will less than one street tree be 0 17 provided for every parcel. Canopy species that are listed as Threatened, Endangered or 18 Regionally Important in Section 114-105 that are a minimum of eight (8) feet tall are 19 acceptable as a street tree. 0 20 d Native canopy trees installed along the street as landscaping or a buffer and required b Section ). PY g P g Y q Y 21 114-100 or 114-124 may satisfy this requirement. 22 ( Preservation of existing natural native vegetation takes priority and may satisfy this 23 requirement. j 24 _Lf The required amount of street trees pursuant to this section shall be as a condition of the 0 25 issuance of any permit for change of use, expansion, addition or redevelopment. a� 26 Sec. 114-105. Landscaping materials. a� 27 All required landscaping materials shall be of the types and minimum sizes set forth in this section. Canopy 28 trees shall be a minimum of twelve (12) feet in overall height or a minimum tree caliper dimension of 29 three (3) inches (measured at six (6) inches above grade) at the time of installation. Understory trees shall 30 be a minimum of five (5) feet in height. Shrubs shall be a minimum of two (2) feet in height at the time 31 of installation. 32 C = Canopy E 33 U=Understory c, 34 S = Shrub 35 P = Palm 36 G = Ground cover 37 V=Vine 38 ST= Street tree 39 SA = Salt tolerant Ord.No. -2021 Page 21 of 30 Packet Pg. 3414 R.3.a I T= Threatened (Florida) 2 E=Endangered(Florida) 3 RI=Regionally Important 4 5 6 7 8 (a) Native Planting List* 0 9 N NATIVE PLANTING LIST Common Name Latin Name T e Status** ............................................................................................................................................................................................................................................................................................................................................................... .................................................................................................................................................................. c ,. .,n > r Mc.Bahama Cassia . . .Sc.nna xrcana var. S T chapmanii a , a n , a; r, a„ , ; :.............................................................................................................................................:.................................................................................................................................................................................................:.............................................................................................:......................................................................................... Yellowwood, West Indian Zanthoxylum flavum U, ST E satinwoo Be u^.,,a :................................. . . ..........................................................................................:.................................................................................................................................................................................................:........................................................................................ ....................................................................................... Bay Cedar Suriana maritima S, SA RI ............................. ........................................................................................ ........................................................................................................................................................... .................................................................................. .............................................................................. Beautyberry Callicarpa americana . S c ............................................................................._ ......... .......................................................................................................................:...............Black Ironwood Krugiodendron ferreum C, U, ST RI m ..............................................................................................................................................................................................................................................................................................................................................................................................................................................:......................................................................................... Blackhead Pithecellobium keyense U, S T 0 Blacktorch Erithalis fruticosa S T Blolly 1 Guapira discolor U, S, ST, SA Buccaneer p-Ralm....................................................Pseudophoenix sargentii................................................................ C U P E Buttonwood, Silver Conocarpus erectus C, U, S, ST, SA b-Buttonwood ....-................................................................................................................................. c Cabbage palm Sabal palmetto C, U, P, SA y Cat's C-claw Pithecellobium unguis-cati U, S .........................................-....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... a� Christmas b-gerry Lycium carolinianum S, G, SA RI .......................................................................................................................................................................................................................................................................................................................................... -a..............................................................................................:........................................................................................: Cinnamonbark Canella winterana U, S, ST E ...............................................................................................................................................................................................................................................................................................................................................:.............................................................................................:........................................................................................: Coffee c olubrina r, H&A H. Colubrina arborescens C, U, ST E .........................................:................................................................................................................................................................................................................................................................................................ ......................................................... .............................................................................. W Coontie Zamia Wntegrifolia S, G .............................................................................................................................................:................................................................................................................................................................................................................................................................................................................................................................................... Crabwood 4eF6,9qHHS hie; r Gwnnanthes U, ST RI lucida , ..................................................................................................................................................................................................: Cuba cGolubrina Colubrina cubensis U E .........................................................................................................................................:................................................................................................................................................................................................: .................................................................................... ...................................................................._ Cupania Cupaniaglabra U E .... ........................................................................................................... ............................................................... ................................................................................... ..............................................................................Darling pPlum Reynosia septentrionalis U T .............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................. Everglades velvetseed Guettarda elliptica U, ST RI .......................................................................................................................................................................................................................................................................:............................................................................................;........................................................................................ Fiddlewood Citharexlum spinosum U RIy ................................................................................................................................................................................................................................................................. ...............:.............................................................................................:........................................................................................: ............................................................................................................................................: .......................................................... ....:.............................................................................................:........................................................................................ Florida Eforestiera, Forestiera segregata S RI Florida s-Swampprivet ...........................................:................................................................................................. Florida t-Thatch pP-alm Thrinax radiata U, S, P E ..............................................................................................:.................................................................................................................................................................................................:.............................................................................................:......................................................................................... Florida t-Trema Trema micranthum U, S RI Ord.No. -2021 Page 22 of 30 Packet Pg. 3415 R.3.a Geig er t-Tree Cordia sebestena C U ST RI r ,,,, 1 n r ; , 1nn zz,,,;.,,,.n „z r ffi ......................................................................................................................................................................................................................................................................................................................................................................................................................................... .............................................................................. Inkberry Scaevola phsmieri U, S, SA T ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... Inkwood 1 Exothea paniculata C, ST RI ................................................................................................................................................................................................................................................................................................................................................................................................... Jamaica cC-aper C )uadrella jamaicensis Us C�w&fhH4Hfh'qr Common Name Latin Name T e Status** e yp....................................................... .................................................................................................................... Jamaica d-Dogwood Piscidia piscipula C, ST .....................................................................................................................................................................................................................................................................................................................................................................................:......................................................................................... Joewood 1 Jacquinia keyensis U, S, SA T ......................................................................................................................................................................................................................................: Keys t-Thatch p alm �Leucothrinax morrisii U, S, P T e ..................................:.........................................................................................................................................::................................................................................................................................................................................................................................................................................................................................................. - Lancewood, Jamaica TT Damburneya coriacea C, U, ST RI nectandra Lignum Vitae Guaiacum sanctum U, S, ST E .. .. ....................................................................................................... ................................... ................. .. .... ........................................................... p y � Limber Caper - Cyno)halla flexuosa U ..............................................................................................................................................................................................................................................................................................................................................:............................................................................................ Locustberry B rsonima lucida S T ..................................................................................................................................................................'.............................................................................................................................................................................................................................................................................................................................................................. ...........................................................................................................................................................................:..............................."............:.....:..................:..:........................................................................................ ........................................................................ .............................................................................. ca Maidenbush SHeterosavia bahamensis S E :...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... c Marlberry Ardisia escallonioides U, S c Mastic a t:�t;�r^^���^���IIH Sideroxylon C, ST RI foetidissimum Ma ten s=Ti rcc.l ma h llanthoides SSA T t� Y y Milkbark Drypetes diversifolia C, U, ST E ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... Myrsine Myrsine z�r,,,.; �n �cubana U, S ........................................................................................................................................................................................................................:.....:.................................................................................................................:.............................................................................................:........................................................................................: ..._Paradise tree...................................................................._Simarouba...glauca.................................................................................................._C. S_T.............................................................._RL...................................................................... Pearlberry Vallesia antillana G E ca Pigeon p-Plum Coccoloba diversi olia C.. ST e .............................................................................................................................................................................................................................................................................................................................................:.................................................................................................................................................................................. Pisonia Pisonia rotundata U, S E ....................................................................................................................................................................................................................... ........................................................................................................................................................................................................................................................................................................................................................................................................................................... Poisonwood Metopium toxiferum C, ST 03 .............................................................................................................................................:.......................................................................................................................................................................................................................................................................................... .............................................................................. Pondapple 1 Annona glabra U :.............................................................................................................................................:........................................................................................................................................................................................................................................................................................................................................................................................: Potato Ttree Solanum erianthum U, S .................................................- Prickly a-Apple cCractus Harrisia fragrans S E :........................................-.........................................................................................................................................................................................................................................................................................................................................................................................................................................., Princewood Exostema caribaeum C, U, ST E Randia, White Randia aculeata S ilndigoberry Red s-Stopper Eugenia rhombea S E ...........................:.................................................................................................................:.......................................................................................................................................................................................................................................................................................... .............................................................................. Redbay Persea borbonia C RI ........................................... .................................................................................. .............................................................................. Redberry Stopper Eugenia confusa U, S E .......................................................................................................................................................................................................................................................................................................................................... .................................................................... .............................................................................. Rhacoma Crossopetalum rhacoma U, S T Saffron €lum zz.......................................r�Sideroxylon celastrina U ......... .... . . ............................................................................................................................................................................................................................................................................................ ................................................................................... .............................................................................. Saltbush Baccharis halimifolia C, SA ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... Satinleaf Chrysophyllum oliviforme C, U, ST T ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... Saw almetto Serenoa repens S, P Ord.No. -2021 Page 23 of 30 Packet Pg. 3416 R.3.a ...................................................................................................................................................................................................................................................... Sea IEavendar Heliotrop ium S E gnaphalodes 0 Common Name : Latin Name T e : Status Seagrape Coccoloba uvifera C, S, ST, SA ..............................................................................................................................................................................................................................................................................................................................................................................................................................................:........................................................................................: Seven-y)Lear a4pple Genipa clusiifolia U RI .............................................................................................................................................:...................................................................................................................................................................................................................................................................................................................................................................................... c Shortleaf F-fig Ficus citrifolia C Silver palm Coccothrinax argentata U, S, P T ........................................................................................................................................................................................................................................................ ............................................................................. ................................................................................... .............................................................................. Slash pine Pinus elliottii var. densa C RI ...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................: Snowberry Chiococca alba S, G Soapberry 1 Sapindus saponaria U RI Spanish b ayonet Yucca aloifolia S Spanish s-Stopper Eugenia foetida U, S Spicewood, Pale 1901 Myrcia U, S RI lidflower ............ ................... . . . neopallens e - Strangler fEig Ficus aurea C .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... Strongback Bourreria wtasucculenta U E ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... c ,.�,,.;�, Sweet Acacia 4- Vachelha farnesiana var. 1 U, S RI arne.s iana Tallowwood, Hog plum Ximenia americana U .............................................................................................................................................:..................................................................................................................................................................................................................................................................................................................................................................................... Torchwood Amyris elemifera U RI ..._Wax-Myrtle...............................................................................Myrica cerifera.................................................................................................................0 S .................................................................... e West Indian Cherry Prunus myrtifolia U T N ..................................... ............... ................................................. ........................................ .......... ................................................................................................ ................................................................................... .............................................................................. %17—+ T_A, 'n, T ;l n n T,�," T, 7 ," ................................................................................................................................................................:..........:...................:..................:................................................................................................................................................................................................................................................................................................................ West Indies trema Trema lamarckiana S E White ilronwood Hypelate trifoliata U, ST E .......................................-...................................................................................................,...................................................................................................................................................................................................................................................................................................................................................................................... White s-Stopper Eugenia axillaris U, ST .......................................-....................................................................................................................................................................................................................................................................................................:.............................................................................................:........................................................................................, Bahama w ild coffee Psychotria ligustrifolia S E Wild coffee Psychotria nervosa S Wild dDilly Manilkara jaimiqui subw. U T ema7" InatL7l ,T r : ..................................................................................................................................................................................................: Wild Lantana Lantana involucrata S ............................................................................................................................................. :.............................................................................................................................................................................................................................................................................................:........................................................................................: Wild Lime Zanthoxylum fagara U S RI .................................-..........................................................................................................................................................................................................................................................................................................,..................................................................................................................................................................................... Wild Ramarind, Lysiloma latisiliquum C, ST Lysiloma Willow b�ustic .Srdcl oxylon salici olia C U���rJ��r S-� f > ST *The list is to be used as a representative sampling, and by no means a complete inventory of the species that are native to South Florida or the Florida Keys. For a determination of what constitutes a native plant, contact the County Biologist. Ord.No. -2021 Page 24 of 30 Packet Pg. 3417 R.3.a This list is to be used as a representative sampling, and by no means a complete inventory of threatened, endangered, or regionally important species. Any species listed as threatened, endangered or regionally important under the provisions of the federal Endangered Species Act, and/or Florida Statutes, and/or the Florida Endangered and Threatened Special Act shall be considered as such. ......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... 1 2 3 c 4 The following native plants fna-y be tised in �he swale for- ster-fnwater- management, w4h eensider-ation 5 zn c 6 6 SW ALE T Ti DT ANT-ING LIST*Common Xam � J B.,1,.,m., wild eeffee Bay eedar- CHpi ter,flldp4iflle 0 Fifebtis} r r i Myr-sine eHb sP" G01360�eifs G WfflE myFde A eepKelw th4 are . ive to C.,u4 FIEwid the FIEwid Kffs. For- ., detof ffli,,.,t;.,,, Of „b,.,t � 7 8 (b) List of Trees/Shrubbery/Ground Covers Appropriate for Stormwater Landscaped Areas. 9 10 Examples of Shade Trees/Larger Trees Non-Salt Tolerant 11 12 Common Name Botanical Name Ord.No. -2021 Page 25 of 30 Packet Pg. 3418 R.3.a I Inkwood Exothea paniculata 2 Mastic Mastichodendron foetidissimum 3 Paradise Tree Simaruba lg auca 4 5 Examples of Shade Trees/Larger Trees/ Salt Tolerant 6 7 Common Name Botanical Name u 8 Buttonwood, Green Conocarpus erectus 0 9 Buttonwood, Silver Conocarpus erectus var. sericeus 10 Seagrape Coccoloba uvifera 11 12 Examples of Screening/Small Trees/Shrubbery Non-Salt Tolerant 13 14 Common Name Botanical Name 15 Bahama Senna Senna Mexicana var. chapmanii 16 Blackhead Pithecellobium guadalupense 17 Blolly Guapira discolor 18 Caper, Jamaica Quadrella iamaicensis 19 Cat' s Claw Pithecellobium unguis-cati 2 20 Cinnecord Vachella choriophvlla 0 21 Geiger Cordia sebestena - a� 22 Lignum Vitae Guaiacum sanctum 23 Lime, Wild Zanthoxylum agara 0 24 Locust-berry Bvrsonima Iucida 25 Palm, Silver Coccothrinax ar eg ntata 26 Palm, Florida Thatch Thrinax radiata 27 Palm, Keys Thatch Thrinax morrisii 28 Palm, Silver Coccothrinax argentata 0 29 Pigeon Plum Coccoloba diversi olia 30 Stopper, Spanish ELigenia foetida 31 Stopper, White Eugenia axillaris 32 Sweet Acacia Vachellia famesiana E 33 Wild Cotton Gossypium hirsutum ,- 34 Yellow Elder Tecoma stans 35 36 Examples of Screening/Small Trees/Shrubbery Salt Tolerant 37 38 Common Name Botanical Name 39 Bay Cedar Suriana maritima E 40 Blackbead Pithecellobium guadalupense c, 41 Black Torch Erithalis e ruticos 42 Cafs Claw Pithecellobium unguis-cati 43 Cinnecord Vachella choriophvlla 44 Geiger Cordia sebestena 45 Palm, Silver Coccothrinax aLgentata 46 Sea Lavender Heliotropium gnnaphalodes Ord.No. -2021 Page 26 of 30 Packet Pg. 3419 R.3.a I Seven Year Apple Genipa clusiifolia 2 3 Examples of Ground Covers Non-Salt Tolerant 4 5 Common Name Botanical Name 6 Blue Porterweed Stachytarpheta Iamaicensis 7 Golden Creeper Ernodea littoralis 8 Lantana Lantana involucrata c c, 9 Wild Lily Hvmenocallis kevensis 10 Keys Railroad vine Ipomoea pes-caprae 11 Sea Ox-eye Daisy Borrichia frutescens 0 12 Sea Ox-eye Daisy Borrichia arborescens 13 Sesuvium Sesuvium portulacastrum or S. maritimum 14 15 16 Examples of Ground Covers Salt Tolerant 17 18 Common Name Botanical Name 2 19 Batis Batis maritima 0 20 Beach Pea Canavalia maritima a� 21 Cord Grass Spartina bakeri 22 Glass Wort Salicornia ambigua c 23 Golden Creeper Ernodea littoralis 24 Lily, Keys Hvmenocallis kevensis 25 Railroad vine Ipomoea pes-caprae 26 Salt Grass Distichlis spicata 27 Sea Oats Uniola paniculata c N 28 Sea Ox-eye Daisy Borrichia frutescens 29 Sea Ox-eye Daisy Borrichia arborescens 30 Seashore Dropseed Sporobolus vir ink icus 31 Sesuvium Sesuvium portulacastrum or S. maritimum 32 33 The list is to be used as a representative sampling and by no means a complete inventory of the species 34 that are native to South Florida or the Florida Keys. For a determination of what constitutes a native plant, 35 additional species that may be appropriate to use in stormwater landscaped areas, or potential sight line 36 conflicts, contact the County Biologist. 37 38 39 Sec. 114-106. Landscape Incentives. 40 Incentives are provided to increase water conservation, biological diversity, and sustainable landscaping, 41 subject to approval by the County Biologist. The following activities are encouraged: 42 , 43 . Ord.No. -2021 Page 27 of 30 Packet Pg. 3420 R.3.a 1 2 (4)Laj Butterfly gardens consisting of at least two (2) larval host plants, and two (2)nectar source plants 3 shall allow the reduction of one (1) required understory tree. Pursuant to approval from the County 4 Biologist, additional reductions may be allowed for plant species that benefit native butterfly species 5 that are endangered, threatened, or otherwise protected. 6 7 Replacement of turf grass or sod areas with artificial turf or a native plant bed shall allow the u 8 reduction of three (3)required shrubs. 0 9 (c) In addition to the Low Impact Development(LID) strategies outlined in 114-100, the addition of 10 managed cisterns or rain barrels may be incorporated into the site stormwater management E 11 facilities. A site's stormwater retention requirements may be reduced by the capacity volume of 0 12 plumbed and managed systems that provide irrigation and/or other non-potable aplications. 13 14 15 16 17 Sec. 114-163. Waterfront Lighting. 18 19 (a) Outdoor lighting within twenty-five (25) feet of any body of water shall be cutoff lights and shall 0 20 not exceed a height of eighteen (18) feet above grade. 0 21 a� 22 (b) Dock lighting shall comply with the following design criteria: 0 23 (1) Light fixtures shall i*elttde contain recessed light sources or shields; 24 (2) Light source shall consist of yellow bug type bulbs Not e*eeedin g 25 ,: a4ts or low-pressure 25 sodium vapor lamps, not exceeding_ the he equivalent of a 25 watt incandescent bulb; 26 (3) Dock lighting shall consist of low-profile, low-level luminaries no higher than 48 inches off 27 the decking such as low-mounted wall fixtures, low bollards, and dock-level fixtures, so that 0 28 the light source or any reflective surface of the light fixture is not visible from the water; and 29 (4) The use of red or green lights or lights that emit red or green light due to a lens or other method 30 is prohibited_ 31 Sec. 114-164. Nonconforming Lighting. 32 33 When any change of use, redevelopment, or expansion of a use development footprint occurs, the site 34 shall come into compliance with the lighting requirements of this article to the greatest extent practicable, 35 as approved by the Planning Director on a case-by-case basis. 36 37 E 38 39 Section 3. Construction and Interpretation. This ordinance and its interpretation shall be 40 liberally construed and enforced in favor of Monroe County to effectuate its public purpose(s) and 41 policy(ies) of the County. The construction and interpretation of this ordinance and all Monroe County 42 Comprehensive Plan provision(s), Florida Building Code, Florida Statutes, and Monroe County Code(s) 43 provision(s) whose interpretation arises out of, relates to, or is interpreted in connection with this 44 ordinance shall be liberally construed and enforced in favor of Monroe County to effectuate its public Ord.No. -2021 Page 28 of 30 Packet Pg. 3421 R.3.a I purpose(s) and policy(ies) of the County, and shall be construed in favor of the BOCC and such 2 construction and interpretation shall be entitled to great weight in adversarial administrative proceedings, 3 at trial, bankruptcy, and on appeal. 4 5 Section 4. No Liability. Monroe County expressly reserves and in no way shall be deemed to 6 have waived,for itself or for its officer(s), employee(s), or agent(s), any sovereign, governmental, and any 7 other similar defense, immunity, exemption, or protection against any suit, cause-of-action, demand, or u 8 liability. 0 9 10 Section 5. Severability. If any provision of this ordinance, or any part or portion thereof, is 11 held to be invalid or unenforceable by any administrative hearing officer or court of competent 0 12 jurisdiction, the invalidity or unenforceability of such provision, or any part or portion thereof, shall 13 neither limit nor impair the operation, enforceability, or validity of any other provision of this ordinance, 14 or any remaining part(s)or portion(s)thereof. All other provisions of this ordinance, and remaining part(s) 15 or portion(s)thereof, shall continue unimpaired in full force and effect. 16 17 Section 6. Repeal of Inconsistent Provisions. All ordinances in conflict with this ordinance 18 are hereby repealed to the extent of said conflict. The repeal of an ordinance herein shall not repeal the 19 repealing clause of such ordinance or revive any ordinance which has been repealed thereby. 2 20 0 21 Section 7. Transmittal. This ordinance shall be transmitted to the Florida State Land 22 Planning Agency pursuant to Chapter 163 and 380, Florida Statutes. 23 0 24 Section 8. Filin2 and Effective Date. This ordinance shall be filed in the Office of the 25 Secretary of State of Florida, but shall not become effective until a notice is issued by the Florida State 26 Land Planning Agency or Administration Commission finding the amendment in compliance with 27 Chapter 163, F.S., and if challenged until such challenge is resolved. 28 0 29 Section 9. Inclusion in the Land Development Code. The amendment shall be 30 incorporated in the Monroe County Land Development Code. The numbering of the foregoing 31 amendment may be renumbered to conform to the numbering in the Monroe County Land Development 32 Code. 33 < 34 PASSED AND ADOPTED by the Board of County Commissioners of Monroe County, Florida, W 35 at a regular meeting held on the day of 2021. 36 37 Mayor Michelle Coldiron 0 38 Mayor Pro Tem David Rice 39 Commissioner Craig Cates 40 Commissioner Eddie Martinez 41 Commissioner Mike Forster 42 43 44 BOARD OF COUNTY COMMISSIONERS 45 OF MONROE COUNTY, FLORIDA 46 Ord.No. -2021 Page 29 of 30 Packet Pg. 3422 R.3.a 1 2 By: 3 Mayor Michelle Coldiron 4 (SEAL) 5 6 ATTEST: KEVIN MADOK, CLERK APPa TO FORM 8 .. ®, ,. 9 As Deputy Clerk PETER MORRIS ASSISTANT COUNTY ATTORNEY c 8/31/21 0 C 0 0 0 N Ord.No. -2021 Page 30 of 30 Packet Pg. 3423 R.3.b 0 2 i,i fr S{ti r �{ - 1t i, f a\ F l {t¢y r1 ff �i���i, 3u 4 5 MEMORANDUM 6 MONROE COUNTY PLANNING&ENVIRONMENTAL RESOURCES DEPARTMENT 7 8 To: Monroe County Board of County Commissioners 9 10 Through: Emily Schemper, AICP, CFM, Senior Director of Planning & Environmental Resources 11 0 12 From: Michael Roberts, CEP; PWS; Assistant Director—Environmental Resources W 13 14 Date: August 12, 2021 2 15 16 Subject: An ordinance by the Monroe County Board of County Commissioners amending Monroe 17 County Land Development Code: Chapter 114, Article I, Section 114-2 "Level of 18 Service Standards" to update stormwater quality performance standards; Section 114-3 19 "Surface Water Management Criteria"to require net improvement in stormwater quality 2 20 while providing flexibility in achieving stormwater quality standards and provide 21 updates to the Stormwater Manual and Layman's Brochure to incorporate new 0 22 approaches for managing stormwater; Section 114-13 "Fences" to refine code language 23 to better clarify requirements and provide criteria for retaining walls; Chapter 114, 24 Article IV "Landscaping" to refine code language to better clarify requirements and E 25 update lists of species; Section 114-163 "Waterfront Lighting" to refine code language 26 to better clarify requirements; and Section 114-164 "Nonconforming Lighting" to refine E 27 code language to better clarify requirements. (File 2019-183) 28 29 Meeting: September 15, 2021 E 30 31 I. REQUEST E 32 33 Amendments to the Monroe County Land Development Code were adopted in April, 2016 and became 34 effective in February 2017 (Ordinance 006-2016). Upon implementation, the Planning and 35 Environmental Resources Department has identified certain Sections of the amended Code that require 36 revision for purposes of clarity or to better further the Goals, Objectives and Policies of the 37 Comprehensive Plan. The proposed amendments were developed by Staff to: 38 • update stormwater quality performance standards and to correct a scrivener's error; 39 • section 114-3 "surface water management criteria" to require net improvement in stormwater 40 quality while providing flexibility in achieving stormwater quality standards in accordance with 41 Comprehensive Plan policy 1001.1.3 and provide updates to the stormwater manual and M co 42 lyman's brochure to incorporate new approaches for managing stormwater; 43 • section 114-13 "fences"to provide design criteria for retaining walls and to refine code language 44 to better clarify requirements; 45 • chapter 114, article iv "landscaping" to refine code language to better clarify requirements and 46 update lists of species; E 47 • section 114-163 "waterfront lighting"to refine code language to better clarify requirements; and, BOCC Staff Report 8/12/21 Page 1 of 16 File 42019-183 Packet Pg. 3424 R.3.b I • section 114-164"nonconforming lighting"to refine code language to better clarify requirements. 2 0 c, 3 II. BACKGROUND INFORMATION a, 4 5 In October 2019, Monroe County received a Community Planning Technical Assistance grant from the 0 6 Department of Economic Opportunity. The grant required the County to update the Land Development > 7 Code for the management of stormwater and to update two supporting guidance documents to be used 8 by both County regulators and design professionals working within the County. 9 10 The principal purpose of updating the County's codes and guidance materials was to focus on options to 11 eliminate or reduce off-property discharges to decrease discharge to nearshore waters. Monroe County 12 developed a"Manual of Stormwater Management Practices" in 1994 to accompany the Monroe County 13 Stormwater Management Ordinance. The Manual provided Best Management Practices (BMP's) that 0 14 were appropriate for the time. The manual has not been updated since 1994 and no longer reflects r_ 15 advancements in stormwater management practices and standards. In conjunction with the Manual, 2 16 Monroe County developed a"Layman's Brochure" that provided guidelines for incorporation of BMP's 17 in the preparation of site plans for single family and duplex lots. 18 19 The work provided for through the above grant included updates to the Manual and Brochure and 20 revisions for changes to Section 114-2(a)(5) and 114-3 of the Land Development Code in accordance 21 with CP Policy 10001.1.3: 22 0 23 Policy 1001.1.3 24 Monroe County shall maintain, implement, review and update, as necessary, the County's 25 stormwater management regulations and Stormwater Master Plan. All improvements for E 26 replacement, expansion or increase in capacity of drainage facilities shall conform to the 27 adopted level of service criteria pursuant to Policy 1001.1.1. E 28 29 Community Meeting and Public Participation 30 Community Meeting and Public Participation 31 In accordance with LDC Section 102-159(b)(3), a Community Meeting was held virtually on September 32 23, 2020 to provide for public input. There were 24 attendees, inclusive of nine County staff members. 33 Based on public input during and subsequent to the Community Meeting, a second Community Meeting 34 was held on November 4, 2020. Attendance at this meeting consisted of twelve members of the public 35 and eight staff members. 36 37 Members of the public provided comments at both meetings and via e-mail. All written comments are t� 38 provided in Appendix 1. 39 40 Development Review Committee and Public Input 41 42 On March 23,2021 the Development Review Committee(DRC)held a virtual public meeting to review v) 43 the proposed amendments and receive public input. co 44 45 Public InputCD 46 47 Public comments on the proposed amendments to Chapter 114 are provided below with Staff responses. 48 BOCC Staff Report 8/12/21 Page 2 of 16 File 42019-183 Packet Pg. 3425 R.3.b 1 • Is there a minimum threshold for exemptions from stormwater? Ie a shed? 2 • Can a swimming pool be a Swale? There is no minimum threshold proposed for stormwater management. It should be noted E however that new additions and/or accessory structures are only required to treat the new 0 impervious surface. > Pools may not be counted towards swale volumes as the decking/coping of pools is typically above grade and does not allow for the inflow of surface water. 3 0 4 • Fence height— what happens when people fill their property? How does that affect the height 5 measurement? 2 6 7 The height of the fence is measured from the lowest adjacent grade. 8 9 • Coming into compliance with nonconforming buffers (landscape) up to Code —the added cost c 10 to DOT access if they change a use—hard to bring into compliance Where compliance with the buffer requirements present a hardship, a variance may be granted in accordance with Sections 102-186 and 102-187. 14 0 15 • 114-109 — look at non-native trees like Key West that has a heritage tree program (mamey, 16 sapodilla) E 17 18 E 19 Plannin2 Commission < 20 21 The Planning Commission considered the proposed amendments at a regular meeting on April 28,2021. a 22 The Planning Commission requested certain revisions to the proposed amendments and tabled the item 23 to a future meeting. The Planning Commission requested revisions included: E 24 25 1. revise language in Section 114-2(5) to reference the new Florida Statute regarding storm 26 water level of service. 27 28 State water quality criteria is codified at 62-302.500 Florida Administrative Code. Staff has 29 provided this reference in the Code language. 30 31 2. Section 114-13 for fence height to be left at highest grade, and also work on additional 32 language to address conflicts with other required fencing and more extreme issues. 33 v) 34 Staff has removed the reference to lowest existing grade, however staff was not able to identify `o 35 conflicts or other extreme issues within 114-13. 36 37 3. Section 114-100(a)13, remove the prohibition on turf in required landscape areas. 38 39 114-100(a)13 has been deleted as requested. BOCC Staff Report 8/12/21 Page 3 of 16 File 42019-183 Packet Pg. 3426 R.3.b 1 w 2 4. Section 114-106,provide additional landscaping incentives. c 3 4 Staff added the following recommendation for additional water conservation incentives: 5 0. c 6 In addition to the Low Impact Development (LID) strategies outlined in 114-100, the addition 7 of managed cisterns or rain barrels may be incorporated into the site stormwater management 8 facilities. A site's storm water retention requirements may be reduced by the capacity volume 9 ofplumbed and managed systems thatprovide irrigation and/or other non potable applications. 10 11 5. Section 114-128 regarding buffer yard, delete the word "evenly," leave as "distributed" 12 and add reference to the definition showing need to meet the intent of a buffer yard. 13 2 14 Staff made the following revisions to this Section: 0 15 16 The trees, understory and shrubs shall be eve4y distributed throughout the bufferyard area to 17 visibly separate one use from another, shield or block noise, lights or other nuisances . c er 18 19 HOWEVER—based on the absence of bufferyards in the advertising of the first two community 20 meetings, changes to the bufferyard sections have been removed from this amendment and will 21 be processed separately. t� . 0 22 N 23 6. Somewhere with 114-46, any additional incentives for storm water collection and reuse, 24 and a possible way to waive another requirement for that. E 25 26 Staff recommended the following addition to 114-46: 27 28 114-46 (3), In accordance with Section 114-106, the addition of managed cisterns or rain barrels 29 may be incorporated into the site stormwater management facilities. A site's storm water retention 30 requirements may be reduced by the capacity volume of plumbed and managed systems that 31 provide irrigation and/or other non-potable applications. E 32 M er 33 HOWEVER — based on the absence of Section 114-46 in the advertising of the first two 34 community meetings, changes to the bufferyard sections have been removed from this amendment 35 and will be processed separately. ............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... 36 37 The Planning Commission considered the proposed amendments as revised at a regular meeting on July 38 20, 2021 and recommended approval to the Board of County Commissioners, with the exception of the 39 items related to bufferyards and Section 114-46, due to advertising requirements. 40 41 Previous County Action M co 42 On September 2, 2015 the BOCC held public hearings to review and discuss proposed amendments to 43 the Land Development Code to be consistent with the transmitted Monroe County Year 2030 44 Comprehensive Plan, the results of the Comprehensive Plan Technical Document update, the adopted 45 2012 Evaluation and Appraisal Report and the 2014 Evaluation and Appraisal Notification Letter. 46 Chapters reviewed at the September hearing included, among others, 114 Development Standards; and E 47 118 Environmental Protection. BOCC Staff Report 8/12/21 Page 4 of 16 File 42019-183 Packet Pg. 3427 R.3.b I On March 1,2016,at a special public meeting,the BOCC held the first of two public hearings to consider 2 adoption of the Monroe County 2030 Comprehensive Plan and the proposed amendments to the Land 0 3 Development Code to be consistent with the Monroe County Year 2030 Comprehensive Plan. 0) 4 On April 13, 2016 at a special public meeting, the Monroe County Board of County Commissioners r- 5 adopted Ordinance No. 006-2016, amending the Land Development Code to be consistent with the 0 6 transmitted Monroe County Year 2030 Comprehensive Plan, the results of the Comprehensive Plan 7 Technical Document update,the adopted 2012 Evaluation and Appraisal Report and the 2014 Evaluation 8 and Appraisal Notification Letter. 9 0 r- 0 c c N N c M CD co U BOCC Staff Report 8/12/21 Page 5 of 16 File 42019-183 Packet Pg. 3428 (opoo&auwdoIanaa pue,A&unoo aoauoW ay&;o q��aa&deyo o&s&uauwpuawV) s&uawpuawe q��aa&deyo-}aodeN JJe&S£8�-6�OZ:&uOwLIOe&&y co tb a � �'� ou�•o � °� o � ° o a�i o �Y' a°'i " ,� '� � ,j o ;;.� � Y o o � , -a o tb z A. 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M s a d o s w a�.� o > N o oq o Or i3 N w 5 o 0 14 k � e r v w 0 0 0 0 0 0 aw- a a C4❑ � � �v w ^� � � � r-1 r-1 Q L E-, 'Z' '�' O C ti ^W ti 'O U ti U a c Fq Fq z, o N `a iv a o p .ter '3 z a a 'b .. �.°-i O# r�w R.3.b IV. CONSISTENCY WITH THE MONROE COUNTY LAND DEVELOPMENT CODE w 0 U The proposed amendment is consistent with one or more of the required provisions of LDC Section 102- 158(d)(7)(b): c 1. Changed projections (e.g., regarding public service needs) from those on which the text or boundary was based; N/A 2. Changed assumptions (e.g., regarding demographic trends); N/A 3. Data errors, including errors in mapping, vegetative types and natural features described in 2 volume 1 of the plan; 0 Corrections to scientific names of certain plants. 0 4. New issues; N/A 5. Recognition of a need for additional detail or comprehensiveness; or 0 The proposed amendments eliminate redundant or obsolete text,refine code language to better clarify regulatory intent for the benefit of the regulated community and county staff and to strengthen environmental protection in certain areas and provide for advances in storm water management technologies. E e( 6. Data updates; N/A V. CONSISTENCY WITH THE MONROE COUNTY COMPREHENSIVE PLAN, THE PRINCIPLES FOR GUIDING DEVELOPMENT,AND FLORIDA STATUTES. A. The proposed amendment is consistent with the Goals, Objectives and Policies of the Monroe County 2030 Comprehensive Plan. Specifically,it furthers: Policy 101.10.1 Monroe County shall maintain the level of service standards for stormwater management established in Drainage Policy 1001.1.1. These level of service standards ensure that at the time a certificate of M occupancy is issued, adequate stormwater management facilities are available to support the new v) development concurrent with the impacts of such development. Existing development, except single co co family residential built prior to November 16, 1992 shall, to the greatest extent possible, meet the County's best management practices for stormwater management. (See Drainage Objective 100 1.1 C44 and related policies.) a� BOCC Staff Report 8/12//2021 Page 13 of 16 File 42019-183 Packet Pg. 3436 R.3.b Policy 105.1.4 c U Within one(1)year after the adoption of the 2030 Comprehensive Plan,Monroe County shall prepare W redevelopment standards and within one year afterwards, shall amend the LDC to address the large r_ number of nonconforming commercial structures that are non-compliant as to on-site parking, 0 construction and shoreline setbacks, stormwater management, landscaping and buffers. By identifying the existing character and constraints of the different island communities,regulations can be adopted that provide incentives for redevelopment and permit the continuance of businesses while moving towards an integrated streetscape. Policy 1001.1.1 Water Quality Level of Service Standards - Minimum Water Quality: All projects shall be designed so that the discharges will meet Florida State Water Quality/Quantity 0 Standards as set forth in Chapters 62-3 and 62-302.530, F.A.C, incorporated herein by reference. All 0 projects should be designed in accordance with the Florida Department of Transportation and South Florida Water Management District standards and taking into account projections for climate change. [§163.3177(6)(c),F.S.] er Every three years, after the adoption of the 2030 Comprehensive Plan, Monroe County shall review the standards for detention and retention volumes for surface water to ensure they achieve minimum water quality standards. 0 Policy 1001.1.3 n Monroe County shall maintain, implement, review and update, as necessary, the County's stormwater management regulations and Stormwater Master Plan. All improvements for E replacement, expansion or increase in capacity of drainage facilities shall conform to the adopted level of service criteria pursuant to Policy 1001.1.1. N Policy 1001.1.5 Monroe County shall maintain land development regulations which ensure County review of all development permits for compliance with adopted stormwater management design criteria. m [§163.3177(3)(a)3.,F.S.] E er B. The amendments are consistent with the Principles for Guiding Development for the Florida Keys Area, Section 380.0552(7), Florida Statutes. For the purposes of reviewing consistency of the adopted plan or any amendments to that plan with the principles for guiding development and any amendments to the principles, the principles shall be construed as a whole and no specific provision shall be construed or applied in isolation from the other provisions. (a) Strengthening local government capabilities for managing land use and development so that local government is able to achieve these objectives without continuing the area of critical state concern v) designation. M (b) Protecting shoreline and benthic resources, including mangroves, coral reef formations, seagrass beds, wetlands, fish and wildlife, and their habitat. (c) Protecting upland resources, tropical biological communities, freshwater wetlands, native tropical vegetation (for example, hardwood hammocks and pinelands), dune ridges and beaches, wildlife, and their habitat. E BOCC Staff Report 8/12//2021 Page 14 of 16 File 42019-183 Packet Pg. 3437 R.3.b (d) Ensuring the maximum well-being of the Florida Keys and its citizens through sound economic u development. 0 (e) Limiting the adverse impacts of development on the quality of water throughout the Florida Keys. (f) Enhancing natural scenic resources, promoting the aesthetic benefits of the natural environment, and C ensuring that development is compatible with the unique historic character of the Florida Keys. 0. (g) Protecting the historical heritage of the Florida Keys. c a) (h) Protecting the value, efficiency, cost-effectiveness, and amortized life of existing and proposed major > public investments,including: 1. The Florida Keys Aqueduct and water supply facilities; 2. Sewage collection, treatment, and disposal facilities; 3. Solid waste treatment, collection, and disposal facilities; 4. Key West Naval Air Station and other military facilities; 5. Transportation facilities; 0 6. Federal parks,wildlife refuges, and marine sanctuaries; C 7. State parks,recreation facilities, aquatic preserves, and other publicly owned properties; 8. City electric service and the Florida Keys Electric Co-op; and 9. Other utilities, as appropriate. er (1) Protecting and improving water quality by providing for the construction, operation, maintenance, and replacement of stormwater management facilities; central sewage collection; treatment and disposal 2 facilities; and the installation and proper operation and maintenance of onsite sewage treatment and disposal systems. U (j) Ensuring the improvement of nearshore water quality by requiring the construction and operation of wastewater management facilities that meet the requirements of ss. 381.0065(4)(1) and 403.086(10), as applicable, and by directing growth to areas served by central wastewater treatment facilities through permit allocation systems. -a (k) Limiting the adverse impacts of public investments on the environmental resources of the Florida Keys. (1) Making available adequate affordable housing for all sectors of the population of the Florida Keys. (m)Providing adequate alternatives for the protection of public safety and welfare in the event of a natural or manmade disaster and for a postdisaster reconstruction plan. (n) Protecting the public health, safety, and welfare of the citizens of the Florida Keys and maintaining the E Florida Keys as a unique Florida resource. Pursuant to Section 380.0552(7) Florida Statutes, the proposed amendment is not inconsistent with the Principles for Guiding Development as a whole and is not inconsistent with any Principle. VI. PROCESS Land Development Code Amendments may be proposed by the Board of County Commissioners, the Planning Commission,the Director of Planning,private application, or the owner or other person having W a contractual interest in property to be affected by a proposed amendment. The Director of Planning shall review and process applications as they are received and pass them onto the Development Review v) Committee and the Planning Commission. co The Planning Commission shall hold at least one public hearing. The Planning Commission shall reviewCD the application, the reports and recommendations of the Department of Planning & Environmental Resources and the Development Review Committee and the testimony given at the public hearing. The E Planning Commission shall submit its recommendations and findings to the Board of County BOCC Staff Report 8/12//2021 Page 15 of 16 File 42019-183 Packet Pg. 3438 R.3.b Commissioners (BOCC). The BOCC holds a public hearing to consider the adoption of the proposed amendment, and considers the staff report, staff recommendation, Planning Commission 0 recommendation and the testimony given at the public hearing. The BOCC may adopt the proposed w amendment based on one or more of the factors established in LDC Section 102-158(d)(7). r- 0. c VIL STAFF RECOMMENDATION Staff recommends approval of the proposed amendment. 0 r- 0 c c N N c M CO CD cv BOCC Staff Report 8/12//2021 Page 16 of 16 File 42019-183 Packet Pg. 3439 R.3.c 0. C J C tJ C C C � 0 lie 5 CL ?l` E a) PRACTICES MANUAL OF STORMWATER MANAGEMENT C To Be Used In Conjunction With The Monroe 0 County Land Development Code March 2020 Packet Pg. 3440 R.3.c 0. C J C UPDATED MANUAL OF STORMWATER MANAGEMENT PRACTICES C Original Manual published by Monroe County in 1995 — Updates performed by ]ones Edmunds & Associates, Inc. C Prepared for: N Monroe County Department of Planning & Environmental Resources 102050 Overseas Highway Key Largo, Florida 33037 E cv cv Prepared by: Jones Edmunds &Associates, Inc. 2240 Palm Beach Lakes Blvd Suite 300CL West Palm Beach, Florida 33409 a) E Jones Edmunds Project No.: 13015-001-01 c 4- 0 March 2020 Packet Pg. 3441 R.3.c TABLE OF CONTENTS C 1 INTRODUCTION ............................................................................................ 1-1 2 APPLICABILITY............................................................................................. 2-1 3 CONTENTS OF A STORMWATER MANAGEMENT PLAN..................................... 3-1 4 METHODS OF STORMWATER TREATMENT...................................................... 4-1 4.1 Wet Detention ............................................................................................4-2 4.1.1 Definition.............................................................................................4-2 4.1.2 Requirements as Expressed in this Manual ...............................................4-2 4.1.3 Method of Achievement .........................................................................4-3 4.2 Retention...................................................................................................4-3 4.2.1 Definition.............................................................................................4-3 4.2.2 Requirements as Expressed in this Manual ...............................................4-3 4.2.3 Method of Achievement .........................................................................4-3 N 4.3 Low Impact Development or Design ..............................................................4-4 4.3.1 Definition.............................................................................................4-4 4.3.2 Requirements as Expressed in this Ordinance...........................................4-4 4.3.3 Method of Achievement .........................................................................4-5 5 CONTROL STRUCTURES................................................................................. 5-1 cV 5.1 Definition...................................................................................................5-1 5.2 Purpose.....................................................................................................5-1 ' 5.3 Types of Control Structures..........................................................................5-1 6 CRITERIA FOR SINGLE-FAMILY DUPLEX LOTS 6-1 LIST OF FIGURES m Figure 1 Schematics of Four Basic Detention/Retention Stormwater Runoff Management Systems..........................................................................4-2 w Figure 2 Spreader Swale (Indirect Discharge) .....................................................5-2 Figure 3A Orifice Weirs.....................................................................................A1-1 E Figure 3B V-Notched Weir.................................................................................A1-2 Figure 3C Rectangular Weir...............................................................................A1-3 Figure 4A Pollution -Retardant Catch Basin .........................................................A2-2 Figure 4B Pollution- Retardant Catch Basin with Removable Down-turned Pipe........A2-3 Figure 4C Pollution -Retardant Catch Basin with Removable Downturned Pipe .........A2-4 Figure 5 Typical Exfiltration Trench ..................................................................A4-2 13015-001-01 March 2020 Table of Packet Pg. 3442 R.3.c C LIST OF TABLES Table 1 Required Retention Depths for Stormwater Treatment .............................4-4 Table 2 Required Retention Depth for Single Family/Duplex Lots ..........................6-2 APPENDICES Appendix 1 Control Structures C r_ Appendix 2 Catch Basins and Pollutant Retardant Structures Appendix 3 Wet-Detention Facilities C Appendix 4 Dry-Retention Facilities Appendix 5 Stormwater Management Plan Checklist Appendix 6 Sample Calculations for Single Family/Duplex Lots Appendix 7 Bibliography cv CL cv m E 4- 0 13015-001-01 March 2020 Table of Packet Pg. 3443 R.3.c I INTRODUCTION Monroe County has a unique, water-oriented environment and because of the importance of its aquatic environment, both aesthetic and economic, a Stormwater Management Ordinance (hereinafter referred to as the "Ordinance") has been adopted to help protect these resources from the harmful effects of stormwater runoff. Stormwater is the water that results from a rain event. Runoff is defined as the portion of stormwater that does not percolate into the ground, evaporate, and is not intercepted 2 before reaching a stormwater management system. Stormwater runoff from undeveloped lands usually does not present a management problem since it is relatively clean, and the volume usually is minimal. When natural land is converted to some other land uses, stormwater becomes a problem and should be managed. Soil is often paved over and impervious surfaces are created. When impervious surfaces are created, stormwater is no longer able to percolate into the ground and accumulates on the surface causing flooding in some areas. These impervious areas also allow for pollution accumulation, degrading the quality of stormwater runoff and rendering it a pollution source. For these two reasons, flooding (water quantity) and pollution (water quality), stormwater management practices are implemented in developed areas. Stormwater runoff quality varies with land use. A multitude of pollutants exist in stormwater runoff as well as the sources for these pollutants. These pollutants can consist of nutrients, solid waste, litter, lead, petroleum products (from automobiles), chemicals, fertilizers, and herbicides applied to lawns, and atmospheric deposition. Higher nutrient loads are generated by residential and industrial land uses and commercial, mixed urban, and roadways generate higher concentrations of metal contamination. Heavy metals are of `V concern because several are known to be toxic to many aquatic plant and animal species. Motor vehicles and road surfaces are the main sources of heavy metals in stormwater runoff. Nutrients and pesticides from lawn fertilizers and atmospheric deposition can cause algal blooms and similar occurrences if untreated runoff is allowed to enter surface waters. During a rainfall event, stormwater runoff flows over these surfaces, picking up pollutants, CL and carrying them to surface waters. Stormwater not only causes adverse environmental impacts, but economic impacts as well. E An increase in the number of impervious surfaces increases the potential for flooding and property damage. Stormwater can also lead to reduced fisheries production because of the degradation of water quality. For these reasons, stormwater management practices have been implemented throughout Florida and the United States. This manual is designed as a guide to Best Management Practices (BMP's) for stormwater management in Monroe County. A stormwater management practice is one that shapes and improves the quality and C quantity of stormwater runoff being discharged to receiving waters. BMPs for stormwater are those that meet discharge quantity and quality criteria at a minimal cost (Wanielista and Yousef, 1985). Section 114-3 of the Monroe County Code addresses the issue of flood protection and water quantity management. Although this stormwater management ordinance does have general 13015-001-01 March 2020 Intr Packet Pg. 3444 R.3.c criteria for water quantity and flood protection, the purpose is to control stormwater- 0. generated pollution and is water quality based. The practices and procedures described in this manual are those in common usage throughout Florida and also apply to Monroe County. The bibliography at the end of this manual lists some of the relevant sources of additional information on this subject. This manual will be used to review and approve stormwater management systems permitted by the County and will be modified as appropriate technology dictates. C r— C CL cv cv m E 4- 0 13015-001-01 March 2020 Intr Packet Pg. 3445 R.3.0 2 APPLICABILITY This manual is to accompany the Monroe County Stormwater Management Ordinance. This Ordinance was incorporated into the Monroe County Land Development Code by amendment to the Comprehensive Plan. A Stormwater Management Plan will be required as part of all building permit applications (except those projects exempted pursuant to Section 114-3(c) of the Land Development Code). The definitions used in this manual are consistent with those in the Land Development Code and the Monroe County Stormwater Management Ordinance. C CL c N cv cv a) E c 4- 0 13015-001-01 March 2020 App Packet Pg. 3446 R.3.c 3 CONTENTS OF A STORMWATER MANAGEMENT PLAN A stormwater management plan is required pursuant to Section 114-3 (g) of the Land Development Code for those projects not exempted pursuant to Section 114-3 (c). A Plan is to be submitted as part of the Monroe County building permit application. The Plan will indicate how project design will incorporate the required stormwater treatment criteria. The following is an outline of those elements that may be required as part of a stormwater management plan. Appendix 5 contains a check-list of these elements. This will allow County staff to determine which of the elements a specific plan should or should not require for each site. Some of these elements are required for other parts of a County building permit, but also need to be considered as part of the Stormwater Management Plan. In these instances, specific criteria are the same as those already required by the County and are not discussed further in this Manual. C 1. Site Information: a. Detailed location sketch. b. Description of vegetative cover, including wetlands. c. Location and size of preservation or mitigation areas. d. Paving, grading, and drainage plan. e. Vegetation protection plan. f. Soils map and percolation test results. E g. Wet-season water table elevation. < h. Future wet-season water table elevation (30-year). cv i. Description of measures to be used during construction to eliminate adverse off-site `V impacts, such as increased turbidity or siltation, if applicable. j. Recent aerial photograph. k. Map of drainage basin boundaries. I. Map of floodplain and elevations. 2. Master Stormwater Management Plan: CL a. Location of all existing and proposed on-site water bodies, including wetlands. E b. Location of all off-site wetlands, water courses, and waterbodies affected by on-site drainage patterns. c. Location and detail of all major control structures and elevations. Preliminary construction plans may be submitted for conceptual approval. d. Right-of-way and easement locations for stormwater management systems including E all areas reserved for stormwater management purposes. e. Location and size of on-site stormwater management facilities. f. Square footages, acreages, and percentage of property proposed as: (1) Impervious surface (excluding waterbodies). (2) Impervious surface (waterbodies). (3) Pervious surface. (4) Total square footage or acreage of the project site. g. Proposed grading plan. 13015-001-01 March 2020 Contents of a Stormwater Managem Packet Pg. 3447 R.3.c h. Treatment volumes and discharge rates (if applicable) for stormwater runoff. 3. Legal and Institutional Information: a. Entity responsible for operation and maintenance of surface water management system. b. If the operational and maintenance entity is to be a public body, a letter from the public body confirming this must be submitted before staff approval. If the entity is a homeowners' association, documents verifying the existence of such organization and its ability to accept operation and maintenance responsibility must be submitted before staff approval. C CL cv cv m E 4- 0 13015-001-01 March 2020 Contents of a Stormwater Managem Packet Pg. 3448 R.3.0 4 METHODS OF STORMWATER TREATMENT Stormwater treatment facilities are designed to treat stormwater runoff to a level that results in the pollutant loads discharged after development either being less than the pollutant loads discharged before development (a net improvement) or that results in pollutant loads being reduced by 95 percent. The volume to be treated depends on the type of stormwater management facility(ies) used and the land use of the property. The two most commonly used methods of stormwater treatment are wet detention and dry retention. A detention facility collects and temporarily stores a treatment volume to provide for treatment through physical, chemical, or biological processes with subsequent gradual C release of the stormwater to a surface water system. A retention facility is designed to prevent the discharge of a given volume; however, it is slowly released from the facility. A retention or detention facility built above the groundwater table is "dry." A facility with the c bottom below the control elevation is "wet." Figure 1 conceptually illustrates the differences between each. The wet-season water table plays an important part in the functioning of retention systems. To ensure that stormwater practices continue to function, a stormwater design will need to include a determination of the wet-season water table and an estimate C of the future wet-season water table. The future wet-season water table will be assumed to N be increased by the difference in sea level in the year that the wet-season water table determination was made and the projected sea level 30 years after the permitting. The estimated sea level rise projections adopted the Southeast Florida Climate Change Compact must be used for this determination. A newer approach to stormwater management is called Low Impact Development or Design (LID). This approach seeks to replicate a more natural hydrologic function on the landscape and uses a combination of stormwater management practices to meet the objective stated above. Some of these practices include pervious pavement, vegetated swales, vegetated filter strips, bioretention systems, cisterns, and green roofs. cn Very often a stormwater management system incorporates a combination of treatment methods. It is unfeasible to describe all the possible combinations in this manual. The CL criteria for each individual type of treatment is detailed. The intent is to ensure that the proper volume of runoff is treated in an appropriate manner for the land use. References to E guidelines for LID approaches to stormwater management are also provided. °3 Appendices 3 through 6 provide the design criteria for each form of management. E c 4- 0 13015-001-01 March 2020 Methods of Stormwater Tr Packet Pg. 3449 R.3.0 Figure I Schematicsf Four Basic Detention/Retention Stormwater Runoff Management t WET DETENTION BASIN, DRY T ITK) 6 BASIN � CONTRCL,t_E:�, iNF'Low NO OVTFLOw INFLOW TL ` A a EVAPORATION, OE TEN T NSA 4 c c . e OLA4 PERCOLATION Source: Adapted from Whalen and Cullum, 1988. c ..1. WET DETENTION .,1,1 DEFINITION Wet detention is the collection and temporary storage of stormwater runoff—before E controlled discharge into receiving waters—in a permanently wet impoundment in such a < manner as to provide for treatment through physical, chemical, and biological processes cv with subsequent gradual release of the stormwater. A wet detention facility is a basin or pond with a bottom elevation below the wet-season water table or control elevation. ,1,2 REQUIREMEN"T-S As ExPRESSED IN "THIS MANUAL Stormwater designs must demonstrate a net improvement in nutrient loads or a 95 percent reduction in pollutant loads. This can be demonstrated through methods that are accepted 2 CL by the South Florida Water Management District (SFWMD). An example of one of these methods is using BMP Trains, which is freely available from the University of Central Florida 0) Stormwater Management Academy (https:!lstars.library.ucf.edulbmptrains!). m As an alternative to demonstrating net improvement or 95-percent reduction, wet detention with pretreatment that meets the following criteria can be used as a stormwater practice and will be presumed to meet the County stormwater treatment objectives: • Provide a treatment volume sized to the first 1 inch of runoff from the site or the total of 2.5 inches times the percent of impervious area, whichever is greater. • One-half inch of the detained volume must be released through a control structure C within 24 hours. • Wet detention cannot be used as the sole form of stormwater treatment. Projects using wet detention must provide at least 2.5 inch of runoff pre-treatment in dry retention before discharging into a wet detention facility. 13015-001-01 March 2020 Methods of Stormwater Tr Packet Pg. 3450 R.3.0 4.1.3 M THOD OF ACHI V M NT C Man-made lakes or ponds on the site are generally used for wet detention. These lakes or ponds must meet the design criteria in Appendix 3 of this manual. The retention volume can be achieved using the guidelines in Section 4.2 and Section 4.3 of this manual. 4.2 RETENTION ..2.1 DEFINITION c Dry retention is a stormwater system designed to prevent the discharge of a given volume of stormwater runoff into surface waters by complete on-site storage of that volume. A dry- retention facility has a bottom elevation at least 1 foot above the future condition wet- season water table and is usually dry. Stormwater is released only during times of heavy rainfall or flooding. C ..2.2 REQUIREMENTS As ExPRESSED IN THIS MANUAL Stormwater designs must demonstrate a net improvement or a 95 percent reduction in pollutant loads in nutrient loads. This can be demonstrated through methods that are c accepted by the SFWMD. An example of one of these methods is using the BMP Trains, which is freely available from the University of Central Florida Stormwater Management Academy (https://stars.library.ucf.edu/bmptrains/). As an alternative to demonstrating net improvement or 95-percent nutrient load reduction, dry-retention systems that retain the retention depth listed in Table 1 multiplied by the total < project area will be presumed to meet the County stormwater treatment objectives. cV cv 4.2.3 M THOD OF ACHI V M NT Examples of dry-retention facilities include infiltration systems (vegetated swales, bioretention systems), and seepage systems (exfiltration trenches, pervious pavement, exfiltration vaults). Of these two, infiltration systems provide better pollution attenuation. The vegetation takes up a percentage of the nutrients commonly found in stormwater 2 CL runoff. Most heavy metals bind with the soils above the water table, and the potential for them entering the groundwater is reduced. Seepage systems consist of an underground facility which that relies on a mostly outward dispersion of stormwater from the facility to the groundwater. These structures are constructed a minimum of 1 foot above the future wet-season water table. These systems are most suitable for areas where the aquifer has a high transmissivity, such as Monroe County. However, they do not provide the nutrient uptake that is offered with vegetated infiltration systems. Infiltration systems and seepage systems need a highly permeable substratum to allow the stormwater runoff to percolate into the ground. Seepage systems do not require as much land area as infiltration systems, since they can be installed underground. However, the future wet- season water table at the project site must be at least 1 foot below the seepage structure. 13015-001-01 March 2020 Methods of Stormwater Tr Packet Pg. 3451 R.3.0 Table q it Retention Depths for Stormwater Treatment 0. Required Retention Depth c Percent Impervious (Inches) 20 1.40 25 1.47 30 1.59 35 1.71 40 1.88 45 2.02 C 50 2.17 55 2.33 60 2.49 c 65 2.65 70 2.81 75 2.99 80 3.16 N 4.3 Low CT DEVELOPMENT OR DESIGN 4.3.1 DEFINITION LID is an approach to stormwater and land use management that aims to replicate a more W natural hydrologic function by promoting infiltration, filtration, storage, and evaporation or CD N stormwater runoff. This approach should focus on conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project's design, especially its landscaping and open space. Stormwater management through LID often includes a treatment train consisting of several different stormwater management practices that combine to meet the stormwater quality objectives for the site. Examples of practices that are often included in LID are: CL • Minimizing clearing, grading, soil disturbance, and compaction on a site. • Minimizing impervious area on site. a) • Pervious pavement. • Shallow bioretention systems. • Vegetated or grassed swales. • Vegetated filter strips. • Minimizing directly connected impervious area. 2 • Cisterns. 4- • Stormwater harvesting. C 4.3.2 REQUIREMEN"T-S As ExPRESSED IN "T-HIS ORDINANCE Using a LID approach for stormwater management is encouraged in Monroe County. E However, stormwater designs must demonstrate a net improvement or 95-percent reduction in pollutant loads. This can be demonstrated through methods that are accepted 13015-001-01 March 2020 Methods of Stormwater Tr Packet Pg. 3452 R.3.0 by SFWMD. An example of one of these methods is using BMP Trains, which is freely 0. available from the University of Central Florida Stormwater Management Academy 0) (https:!lstars.library.ucf.eduZbmptrainsZ). > 4,33 METHOD OF ACHIFVFMENT A LID approach to stormwater management starts during the planning and site evaluation and continues through the selection and design of the most appropriate stormwater treatment practices for the site. The goal of stormwater management should be to retain, detain, recharge, filter, and use as much stormwater as possible on a site. A variety of LID design manuals in Florida describe this approach to stormwater management. These include but are not limited to the following: • Low-Impact Development and Green Infrastructure: Pollution Reduction Guidance for Water Quality in Southeast Florida • Sarasota County Low-Impact Development Guidance Document • Duval County Low-Impact Development Stormwater Manual • Pinellas County Stormwater Manual C The manuals listed above provide design guidelines for a variety of LID stormwater N practices, which include: • Grassed conveyance swales. • Shallow bioretention. • Pervious pavement. W • Stormwater harvesting. • Green roofs. `V • Rainwater harvesting (cisterns). • Detention with biofiltration. Monroe County will generally accept the LID practices and design consideration described in the LID manuals referenced above, although it should be noted that the performance curves and tables provided in these manuals do not necessarily apply to Monroe County's CL hydrologic conditions. Pollutant load reductions will need to be determined by the appropriate Florida-registered and -licensed professional. E E c 4- 0 13015-001-01 March 2020 Methods of Stormwater Tr Packet Pg. 3453 R.3.c 5 CONTROL STRUCTURES 5.1. DEFINITION A control structure is a device through or over which water is discharged from a stormwater management system. Direct discharge occurs when stormwater is released through a control structure to the receiving water body. If the discharge from the stormwater management system is by a means other than a control structure (e.g., sheet flow or ca spreader Swale), it is considered indirect discharge. C C 5.2 PURPOSE The primary purpose of a control structure in a detention facility is to release the calculated runoff volume slowly over a specified period. In a retention facility the control structure allows for volumes in excess of the calculated retention volume to leave the system in a manner that provides for adequate downstream flood protection. CONTROL5.3 TYPES OF T T 0 Direct discharge from a water management facility to the receiving body is usually achieved through control structures such as weirs and orifices. The following criteria must be met for E all methods of direct discharge: 1. Trash-collecting gratings must be on the intake of all structures that discharge to surface < waters. cv 2. Detention facilities must be discharged from the mid-depth of the water column. 3. If the property is greater than 50-percent impervious or contains a system with inlets in paved areas, discharge structures must include a baffle, skimmer, or other suitable mechanism for preventing oil and grease from being discharged. (Appendix 2 describes these mechanisms, which are part of a catch basin). 4. Direct discharge will only be allowed to those areas that by virtue of their large capacity or configuration are able to absorb concentrated discharges. CL When using indirect discharge to release stormwater, a spreader swale is commonly used. The swale is positioned parallel to the receiving body, and the side adjacent to the receiving as body is lower than the side opposite the receiving body. Figure 2 illustrates this form of discharge. The swale allows the water to flow into the receiving body but not flood the adjoining property. This method works well when trying to maintain a proper water level in wetlands that are used for stormwater management. The spreader swale is also a treatment facility for stormwater runoff. Runoff in excess of the first flush is allowed to enter the E wetland system via sheet flow. 4- 0 13015-001-01 March 2020 Control St Packet Pg. 3454 R 3.0 Figure 2 Spreader Swale (Indirect Discharge) 0. c !° tat H- depth of %wale required to treat runolf t t halt rKjh of runoff C CJ C N cv CD cv U CL E 4- 0 13015-001-01 March 2020 Control St Packet Pg. 3455 R.3.0 C 6 CRITERIA FOR SINGLE-FAMILY/DUPLEX LOTS Single family and duplex homes may be exempted from filing a Stormwater Management Plan pursuant to Section 14-3(d), provided guidelines established in the "Layman's Brochure" are used to treat stormwater. The Layman's Brochure and the following design criteria generally use vegetated swales. However, other retention practices may be used. The retention volume specified in these design criteria will provide adequate stormwater treatment on a single-family/duplex lot to meet the criteria of Section 114-3 (f) (2). However, calculations demonstrating a net improvement or 95 percent reduction in nutrient loads may be submitted as an alternative to using the retention volume specified in these design criteria. These stormwater calculations must be completed by an appropriate Florida- registered and -licensed professional. C The retention volume depends on the lot size and the stormwater management system used. Stormwater treatment can also be provided through the use of other retention systems such as pervious pavement, exfiltration trenches, or shallow stormwater vault systems. C Required retention depths for single-family/duplex lost are provided in Table 2. N If swale(s) are used, they must meet the following criteria: E • Runoff from site must be drained to Swale. E • Swale length must be greater than its width. W • Swale side slope must be 4:1 or shallower (horizontal to vertical). • Swale must be placed so that any natural areas to be preserved are not disturbed. • Swale must be at least 6 inches deep. • Swales should be vegetated. If a Swale is not vegetated, then a 6-inch layer of soil amendment formulated to reduce nutrient loading must be installed directly below the v, Swale. Specifications and published nutrient reduction test results for the media must be provided at the time of testing. Examples of acceptable media are NutriGoneTM (distributed by EcoSense International) and Bold and Gold® (distributed by CL Environmental Conservation Solutions) Retention systems must discharge off-site to prevent flooding. For retention systems, a control structure will allow runoff in excess of the volume of the Swale to be discharged to the receiving body. There may be More than one retention system may be present on the property, provided each meets these criteria and the total volume of the swales is at least the calculated volume. Vegetated swales may be incorporated into the set-back criteria required by the Monroe County Code. Appendix 6 contains sample calculations for single- 2 family/duplex lots. Florida-Friendly LandscapingTM is encouraged for vegetated swales. 4- 0 13015-001-01 March 2020 Criteria for Single Family/Du Packet Pg. 3456 R.3.0 Table 2 Required Retention Depth for Slagle Family/Duplex Lots E Effective Impervious Area Required Retention Required Retention c to Disturbed Area Ratio Depth Depth (Step 5) (feet) (inches) 0.20 0.138 1.66 0.25 0.146 1.75 0.30 0.153 1.84 0.35 0.164 1.97 C 0.40 0.177 2.12 0.45 0.188 2.26 C 0.50 0.203 2.44 0.55 0.215 2.58 0.60 0.228 2.74 c 0.65 0.243 2.92 N 0.70 0.256 3.07 0.75 0.271 3.25 0.80 0.286 3.43 CL N E c 4- 0 13015-001-01 March 2020 Criteria for Single Family/Du Packet Pg. 3457 R.3.c 0. C J C tJ C C C r r Appendices N The Appendices contain the specific design criteria for the BMPs discussed in this manual. These E criteria are based on best available knowledge in CN the area of stormwater management. As technology dictates, these criteria will change. CL a) E 4- 0 Packet Pg. 3458 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 1 W N Control Structures a) E 4- 0 Packet Pg. 3459 R.3.0 APPENDIX I — CONTROL STRUCTURES This Appendix contains details on the designs for four types of control structures: a triangular orifice, a circular orifice, a v-notched weir, and a rectangular weir. Orifices and V-notched weirs are generally used with control structures associated with detention facilities. These structures are commonly referred to as bleed-down mechanisms and allow for controlled release of a portion of detained volume over a specified period (usually 1/2 inch in 24 hours). Rectangular weirs are commonly used with detention and retention facilities. In retention facilities, a rectangular weir allows for the runoff in excess of the retained volume to leave the facility. Rectangular weirs serve the same purpose in detention facilities, using a circular or triangular orifice as the bleed -down device. Figures 3A through 3C illustrate these different types of control structures and their use. The retained and detained volumes used in the determination of the dimensions of the control structures are calculated from the equations following each drawing. Figure 3A OrificeWeirs c SY d$ J n � �� R. a' rare , a {T�uX�g � u RIK � . cont conlrol A*X eleval'a -li� VR I A FIE EMU C44 � uv € Trian ,gular Orifice Circular Orifice Q A = 4.8H 3/2 a) Q = discharge (cfs) A= Area of orifice (square feet) H=Head above orifice centroid* (feet) E *Centroid for a circular orifice is the center; centroid for a triangular orifice is two-thirds the distance from the vertex. The first is a circular orifice. As the name and illustration implies, it is a round opening. The bottom of the opening is at the control elevation. In the case of dry detention, the bottom of the circle is at the ground elevation. The most common method for constructing a circular orifice is placing a PVC pipe in the control structure. This pipe then discharges to the E receiving body or to a conveyance system discharging to the receiving body. 13015-001-01 March 2020 Appendix 1 - Control St Packet Pg. 3460 R.3.c The second type of orifice is a triangular orifice which is an inverted triangular opening in 0. the control structure. The vertex of the orifice is at the control elevation. If the facility is a dry detention facility, the vertex is at the ground elevation. For maintenance purposes, the cross-sectional area of the orifice in any control structure must be greater than 6 square inches to ensure that the structure allows for free flow of water and does not become clogged. The above formula is used to calculate the cross- sectional area of the orifice. U The following is an example calculation for an orifice in a control structure which is part of a wet detention facility. The following assumptions are made. • H = 3 feet • One-half inch of retained stormwater = 400,000 ft3 • First, the discharge rate (Q) must be calculated: Q. x ,,how x4 ram,, . , Q-4.63 cfs C Aso 4 i n t r g 4SX3 a, , A-O 6 ft2 < CD cv CD This meets the minimum dimensional criteria for orifices in detention facilities. `V Figure 3B V-Notched Weir CL AIIX 4--control elevation .��'+ '� t ax Gy w xwx a "K 7 M RA n w' w ow Vi Tv..'Nwwf* V-NE oh+ Weir 4— arct r� t 9 nw: C ry t h angle (degrees) Vd t 1 h of detention volurne to be releAse<l trrtlft)' fit-distance from Weir creil to vertex eagle tftt m 7 cubic toot . 10° acre-feet 13015-001-01 March 2020 Appendix 1 - Control St Packet Pg. 3461 R.3.0 V-notched weirs are used with wet- and dry- detention facilities. The configuration of the opening allows for slow discharge of detained water over time. The rate of discharge depends on the angle of the V-notch. When designing a control structure with a V-notch weir, the angle is calculated using the above formula. Vdet refers to 1/2 inch of the detained volume that must be discharged within 24 hours. For maintenance and functional purposes, the angle of the V-notch should not be less than 200 being the minimum to allow for adequate flow of water and to prevent blockage of the weir. C The following is an example calculation for a V-notched weir, which is part of a 2-foot-deep dry-detention facility, making the following assumptions: H 2.0 feet Ideoth of detention I ay) 00 t 1 t , thetirfate, fir° 0'0 t acre (eel r t n (0 2) Il ,r 1- ) r t n M 1 tw01',F 11 r t n 10,0 1 CJ �1 r c N Since the calculated angle is less than 200, and the angle of the V-notch must be at least 200, this facility will need a 200 angle. Because most of the stormwater management facilities reviewed by County staff will be small, calculations in which the angle of the notch is less than 200 will be common. W cv Figure 3C Rectangular Weir cv 0 H gull rt ater level Oc � pb �q-N� `' gy .9 0 CO °"J ' Sj F a;: 1 �.y i v.y Fl Bei nl - �' Efsl4' d. -a " �, `AXE bs�#Yi � ^� ,� o0o CD _ control'10 coil, elevation aMNI f x - zap xx�kR i IKI W_ width of control structure t8 Circular nfic- H distance above control elevation L. needed to retain required volume c 4- A rectangular weir is a structure that allows excess volumes of water to leave a stormwater c management facility. A rectangular weir is used with retention facilities to discharge runoff in excess of the retained volume. A rectangular weir can also be used in conjunction with a detention facility that has an orifice for the delayed release of stormwater runoff. The rectangular weir allows for the discharge of excess runoff during severe rain events. The weir is constructed on top of the control structure. Rectangular weirs are used in areas 13015-001-01 March 2020 Appendix 1 - Control St Packet Pg. 3462 R.3.c where a receiving water body exists for excess runoff or a method of conveying excess 0. runoff to a receiving water body. Control structures can be made of several different types of materials. Those commonly used include concrete, cement, aluminum, and earthen material. Polyvinyl chloride (PVC) pipe is often used as a bleed-down mechanism (circular orifice). All control structures must discharge to a receiving body of water that has the capacity to handle the discharge. If no receiving water body exists adjacent to the stormwater ca management facility, some system for conveying the stormwater must be provided and is commonly done by using swales, culverts, or similar mechanisms. However, an assurance that water will not stand in enclosed structures (i.e., culverts) for extended periods must be provided since this may lead to water quality problems. C C CL cv cv m E 4- 0 13015-001-01 March 2020 Appendix 1 — Control St Packet Pg. 3463 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 2 Catch Basins and Pollutant- Retardant Structures CL a) E 4- 0 Packet Pg. 3464 R.3.0 APPENDIX 2 - CATCH BASINS AND POLLUTANT- RETARDANT STRUCTURES Catch basins are often used to collect stormwater from areas with large percentages of impervious surfaces and convey it to a treatment facility. These structures need to be designed and certified by a professional engineer and be equipped with pollutant -retardant structures. The structures in Figures 4A through 4C will allow for pollution control and sedimentation before discharge to the stormwater treatment facility. In Figure 4A, the a, center column acts as a baffle. Oils, greases, and debris will remain on top of the water column in the right- hand chamber. Only water below the baffle will be able to flow out of c the pipe. In Figures 413 and 4C, the down-turned pipe serves the same purpose. This pipe is removable so it can be cleaned and maintained. Periodic cleaning and maintenance are necessary to prevent clogging, ensure adequate treatment, and prolong the life of the facility. CL N cv cv m E c 4- 0 13015-001-01 March 2020 Appendix 2 — Catch Basins and Pollutant Retardant St Packet Pg. 3465 jo t, L joldeqD ®4 s4uawpuaua ) OZOZ you - s93g3BJd 4u9w96euqAj j94emwjo4S jo ' n :4u9ua o 44 to M Cl) a_ d ' aC U tC c L (Q J—� n � J-� (Q J—� 0 CL .» _0 : (10 U) 71 U) m � V 6cbb IPA U i i N Q Q Q C .. 0 Ll wa 0 Kx o O N 00 V 0 � R.3.0 Figure Pollution- Retardant Catch Basin with Removableto n t rned Pipe c inilet grate ®y W G �qq C q V Grout Connecting � r Ertl ) NOW r a1 1. ! tern ®� r /down-turried Removable N p 1lit detention +at it t .� � CL E �I to a) Notes-, 1. everts -of pipesto be placed to achieve intent of design and to accornodate hydraulic requirements. E c . Adated fromgroard County, 1987. 4- 0 13015-001-01 March 2020 Appendix 2 - Catch Basins and Pollutant Retardant St Packet Pg. 3467 jo t, L joldeqD ®4 s4uawpuaua ) OZOZ you - s93g3BJd 4u9w96euqAj j94emwjo4S jo ' n :4u9ua o 44 co M Cl) a_ d ' aC U tC 4 c ` _0 L G � Y 7 _ a 01 � � c ► +, m ism -r- l' (O U a C Q air Q cr � to Cl- 4,0 oil�" r t��y �,.�..,.'lip��,•� .�, � +� �, m Zo � I a ' Y �r - o N O 0 V 0 � R.3.c 0. C J C tJ C C C r r tJ C N Appendix 3 Wet-Detention Facilities CL a) E 4- 0 Packet Pg. 3469 R.3.0 APPENDIX 3 - WET-DETENTION FACILITIES A wet -detention facility is usually wet and allows for 1/2 inch of the required detained volume (1 inch or the total of 2.5 inches times the percent of impervious area, whichever is greater) to be discharged through a control structure in no less than 24 hours. Catch basins, pipes, swales, or channels are used in areas with large amounts of impervious surface to collect runoff and convey it to the detention facility. The required design criteria of a wet detention facility are detailed below.: C • The lakes must be at least 0.25 acre and be at least 50 feet wide for lakes in excess of 100 feet in length. • Irregularly shaped lakes may be narrower than 50 feet in some portions but should average 50 feet in width. • Projects with single-owner entities or entities with a full-time maintenance staff with obvious interests in maintaining the areas for water quality purposes may have the area and width criteria waived. • The lake slopes should be at least 4:1 (horizontal to vertical), to a depth of 2 feet for safety reasons and to allow a littoral habitat to form. • Discharge should be from the center of the water column. • The control structure is at one point in the detention facility. Trash collection screens are E required on structures discharging to all surface waters. • The control structure must be opposite from where the runoff enters the facility to E prevent hydraulic short-circuiting and ensure full treatment. < cv Wet detention cannot be used as the sole form of stormwater. If wet detention is used, at least 2.5 inches of dry retention must be provided before discharging into a wet-detention facility. CL E c 4- 0 13015-001-01 March 2020 Appendix 3 - Wet-Retention Packet Pg. 3470 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 4 W N Dry-Retention Facilities CL a) E 4- 0 Packet Pg. 3471 R.3.0 APPENDIX 4 - DRY- RETENTION FACILITIES Two types of dry-retention facilities exist — infiltration facilities and seepage facilities. The most common form of infiltration is vegetated swales or basins. Runoff is routed to a vegetated area, either directly or through a catch basin and conveyance system. A control structure, usually a rectangular weir, is at one end of the swale or basin to allow for excess runoff to be discharged to a receiving body. A spreader swale can also be used in conjunction with this form of treatment. This type of discharge is most often used to release water through sheet flow to wetland areas or to prevent erosion. The seepage method of dry retention involves allowing the water to disperse outward from an underground facility. The runoff is routed to a catch basin and is conveyed to a seepage system. Exfiltration trenches are the most commonly used types of seepage systems. They are used in conjunction with catch basins and consist of a perforated pipe surrounded by coarse rock. Figure 5 shows that the system is in the ground, but above the wet-season water table. Water enters the pipe and seeps out. The retained volume will exfiltrate over 1 hour. The length of the pipe is dependent on several factors — the volume of runoff to be c treated, the width of the trench, the depth to the water table, and the hydraulic conductivity N of the soils. When calculating the volume of an exfiltration trench, a safety factor of 2 is used to allow for geologic uncertainties. The formula shown in Figure 5 illustrates how to design an exfiltration trench. An overflow system allowing for volumes in excess of the retained volume is usually located at the end < of the trench opposite the point where the runoff enters the system and discharges to the cv receiving waters. Although exfiltration trenches provide adequate stormwater treatment and allow more land for development, they must be inspected regularly and cleaned from time 2 to time. The pipe can become clogged and not allow proper seepage. When this occurs, the pipe acts like a conduit for untreated stormwater. Ensuring that the catch basins are maintained is one way of preventing failure of the trench. Q Required retention depth is based on Table 1. CL a) E c 4- 0 13015-001-01 March 2020 Appendix 4 - Dry-Retention Packet Pg. 3472 R.3.0 Figure 5 Typical ExIfiltration Trench BACK FILL .a TRENCHmtmmum DEPTH Impt I2 ""ES IPERFORATED miiwll U,M PIPE DIAMETER - - 12 INCHES' P1PC 13EC C MINIMUM TRENCH WIDTH c c N Lm LENGT H OF TRENCH 'RCCIJIREDIFCC" s VOLUME TREATED (ACRE-INCHES)"(FEET) CD We TRENCH WIDTH C44 Ka HYDRAULIC CONDUCTIVITY (CFS/FT—FT�HEAI)�,� cV N10 DEPTH TO, WATER T LC ("FEET) C • NON-SATURATED TRENCH DEPTH (FEET) D SATURATED TRENCH DEPTH (FEET1 CL CLiBIC FOOT 2.75 IIJOARII=IE °' HYDRALXIC CONDUCTIVITY III 15 OBTAMD FROM THE PERCOLATION T iT E c 4- 0 13015-001-01 March 2020 Appendix 4 - Dry-Retention Packet Pg. 3473 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 5 W CD Stormwater Management Plan Checklist N CL a) E 4- 0 Packet Pg. 3474 R.3.0 APPENDIX 5 STORMWATER MANAGEMENT PLAN CHECKLIST Not Required Requ red Sufficient A. Site Information Detailed location sketch c C ® Description of vegetative cover r_ C Location and size of preservation or mitigation areas ® Vegetation protection plan C Soils map ® Percolation test results c Current wet season high water table ® Future wet-season water table .E Measures to be taken to eliminate off-site adverse impacts, such as turbidity, flooding, etc. < cv * Recent aerial photo (if available) Map of drainage basin boundaries * Map of flood pain and elevations B. Master Stormwater Management Plan CL Location of all existing and proposed on-site waterbodies (including wetlands) E Location of all off-site wetlands and waterbodies to be affected by on-site drainage patterns Location of all major control structures and elevations (preliminary,construction plan may be submitted for conceptual review) 4- 0 Right-of-way and easement locations for stormwater management systems, including all areas reserved for stormwater management purposes 13015-001-01 March 2020 Appendix 5 - Stormwater Management Plan Packet Pg. 3475 R.3.0 Not E Required Requ red Sufficient 0. 0) Location and size of on-site water management > facilities Square footages, acreages, and percentage of property proposed as: C • Impervious surface (excluding waterbodies) • Impervious surface (waterbodies) • Pervious surface • Total square footage or acreage of project site ® Proposed grading i plan Treatment volume and discharge rate (if applicable) for stormwater management system C. Legal and Institutional Information C Entity responsible for operation and maintenance of stormwater management facility* * If the operational and maintenance entity is to be a public body, a letter from the public body confirming this must be submitted before staff approval. If the entity is a homeowners'association, documents verifying the existence of such organization and its ability to accept operation and maintenance ability must be submitted before staff approval. cv CL m E c 4- 0 13015-001-01 March 2020 Appendix 5 - Stormwater Management Plan Packet Pg. 3476 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 6 Single-Family/ Duplex Lot CD Sample Calculations CL a) E 4- 0 Packet Pg. 3477 R.3.0 APPENDIX 6 - SINGLE-FAMILY/DUPLEX LOT SAMPLE CALCULATIONS An orifice is a device that allows for discharge from the center of the control structure. Simply put, it is an opening in the structure that lets water slowly pass. Detention facilities use orifices. The rate that water is discharged depends on the cross-sectional area of the orifice. Figure 6 shows the two types of orifices. An 8,000-square-foot lot with a house, deck, and driveway using dry -retention swales: r_ C • House 1,600 square feet (800 directly connected and 800 unconnected) • Driveway 650 square feet • Concrete Patio 840 square feet C Total impervious 3,000 square feet Effective Impervious 2,600 square feet Total lot size 8,000 square feet c N Ration of effective impervious area = 37.5 percent.to lot area 0.33% Since the impervious area is less than 40 percent of the total lot size, the following equation is used: CD • Swale volume (cubic feet) = total lot size (square feet) x 0.415-foot required retention depth (feet) `V • Swale volume = 8,000 x 0.0415.164 • Swale volume = 332 ft3 = 1,312 cubic feet Assuming a 4:1 (horizontal to vertical) slope for the swales to a 1-foot depth, the cross- sectional area (A) of the Swale is 4.0 square feet. CL Therefore, the length of the Swale is determined as follows: • Length of Swale (feet) = volume (A). °3 • Length of Swale = 1,312/4. • Length of Swale = 328 feet. In areas where there is a receiving water body is adjacent to the property, a rectangular weir should be placed at one end of the Swale for discharge of excess runoff. To reduce the E required length of the Swale opportunities to reduce the directly connected impervious area, c replace impervious surfaces with pervious surfaces, and minimize site disturbance could be evaluated. These changes would reduce the required Swale length. 13015-001-01 March 2020 Appendix 6 - Single Family/Duplex Lot Sample Cal Packet Pg. 3478 R.3.c 0. C J C tJ C C C r r tJ C N Appendix 7 W CD CN BibliographyCD a) CD 4- 0 Packet Pg. 3479 R.3.0 Ammon, D.C.,; W.C. Huber, WC; and J.P. Heany, JP. 1981. Wetlands'Use for Water Management in Florida. J. Water Res. Planning Management Div. Proceeding of ASCE 107 (WR2):315-327. Branscome, J,. and R. S. Tomasello, IS. 1988. Field Testing of Exfiltration Systems. South Florida Water Management District, Tech. Pub. 87-5, West Palm Beach, Florida. 50 pp. Camp Dresser and McKee, Inc. (CDM). 1985. An Assessment of Stormwater Management Programs. J.P. Hartiganm, S.V. Plante, L.A. Rosner., Maitland, Florida. c Chesters, G,. and L.J. Schierow, LJ. 1985. A Primer on Nonpoint Pollution. J. Soil Water Conserv. 40(1):9-13. C Cox, J.H. 1985. Overview of BMP's and Urban Stormwater Management. Proceedings: Stormwater Management - "an update' M.P. Wanielista and Y.A. Yousef, Eds. Univ. of Central Florida Environ. Systems Engr. Institute, Pub. #85-1,. Orlando, Florida. c Duval County. Duval County Low-Impact Development Stormwater Manual. Jacksonville, FL Ferrara, R.A. 1982. Stormwater Detention and Nonpoint Source Pollution Control. In the International Symposium on Urban Hydrology, Hydraulics, and Sediment Control, University of Kentucky, Lexington, Kentucky, pp. 91-91. Florida Department of Environmental Protection. 2019. Low-Impact Development and Green Infrastructure: Pollution Reduction Guidance for Water Quality in Southeast Florida. Harper, H.H.,; Y.A. Yousef, YA; and M.P. Wanielista, MP. 1984. Efficiency of Roadside Swales in Removing Heavy Metals from Highway Associated Nonpoint Source Runoff. Conference on Options for Reaching Water Quality Goals, American Water Res. Assoc. Livingston, E.H. 1985. Overview of Stormwater Management. Florida Department of CL Environmental Regulation, Tallahassee, Florida. Mass, R.P.; M.D. Smolen, MD; and S.A. Dressing, SA. 1985. Selecting Critical Areas for E Nonpoint-Source Pollution Control. J. Soil Water Conserv. 40(1):68-71. Mason, Jr., J.M. 1984. Development of a Stormwater Management Plan. In the international symposium on Urban Hydrology, Hydraulics, and Sediment Control, University of Kentucky, Lexington, Kentucky, pp. 201-205. E Sarasota County .2015. Sarasota County Low-Impact Development Guidance Document. c Sarasota FL. South Florida Water Management District (SFWMD). In review. An Assessment of Land Use and Related Stormwater Runoff Quality Treatment Efficiencies Associated with Selected Stormwater Management Systems. Resource Planning Department, West Palm Beach, FL. E 13015-001-01 March 2020 Appendix 7 - Bibli Packet Pg. 3480 R.3.0 South Florida Water Management District (SFWMD). Environmental Resource Permit Applicant's Handbook, Vol II. West Palm Beach, FL. Wanielista, M.P., and Y.A. Yousef, YA. 1985. Overview Stormwater Manage Practices. Proceedings: Stormwater Management - "an update' M.P> Wanielista and Y.A. Yousef, Eds. Univ. of Central Florida, Environ. Systems Engr. Institute, Pub. #85-1., Orlando, Florida. Whalen, P.J. and M.G. Cullum. 1988. As Assessment of Urban Land Use/Stormwater Runoff Quality Relationships and Treatment Efficiencies of Selected Stormwater Management System. Technical Publication 88-9, South Florida Water Management District. West Palm Beach, Florida. C CL N cv cv m E c 4- 0 13015-001-01 March 2020 Appendix 7 — Bibli Packet Pg. 3481 R.3.d c ca c s As s 4{st s � fl� 1! y .F., sG`3 u t � — r P' N Photo Credit:Mayte Santamaria(Monroe Count LAYMAN S BROCHURE N Guidelines for preparation of a site plan for single family and duplex lots in Monroe County 2 CID March 2020 y A. Stormwater Management..-an important element of the site plan ........ 2 , B. Guidelines to prepare your site plan ...................................................... 3C. f Guidelines to address strraetrrarat in your site pl ........... 4 D. Sample construction techniques ........................................................... 7 E. Guidelines for expansion of existing homes............................................ 12 Packet Pg. 3482 R.3.d A. Stormwater Management — an important element of the site WHY all the fuss, you ask?Here's why... 0 Monroe County is home to the Florida Keys, lush islands surrounded by clear, aquamarine waters, and a myriad of 0. c underwater wonders. Most of the year,the Keys enjoy a sunny, near-tropical climate, but there comes a rainy season,from May through October. During these months,frequent thunderstorms last from a few minutes to a few days. Heavy seasonal rains cause stormwater to run off commercial and residential rooftops,yards, and streets.This c stormwater normally collects in the streets and works its way towards the nearest waterway. While street flooding is c a temporary nuisance,the pollutants carried in the stormwater create a less visible but longer lasting effect.These c pollutants include automobile oil and grease, lawn fertilizers and pesticides, a variety of chemicals from commercial/industrial areas, and silt and floating debris from highways. 0 Continued pollution of Florida's coastal area has severely degraded our most valuable resource,the coral reefs. Pollution also has negatively affected the quality and clarity of our waters. It has reduced our fish and wildlife populations. 0 Stormwater running off into the streets also wastes a valuable resource.After the rainy season come the dry months of November through April. With few exceptions, Monroe County's drinking water comes from the mainland via a m single pipeline. In the event of a hurricane, power and this water supply may be discontinued for days. Monroe County has adopted a comprehensive development plan that establishes specific goals for safe CD `-' management and disposal of stormwater and conservation of our water resources.To achieve these goals and to CD N begin reversing the current negative trends,we must significantly reduce the potential pollution from new 2 construction. Our adopted Stormwater Management Ordinance Sec. 114-2 and 114-3 of the Land Development Code establishes guidelines for the safe management and disposal of stormwater runoff from developed areas.The ordinance is ca applicable to all developments and requires that all applications for building permits must contain a stormwater management plan. The guidelines and recommendations in this brochure are designed to help you to address stormwater management in the site plan for your single family or duplex lot.Sample engineering calculations supporting the guidelines of the m brochure are available in the current version of Monroe County' s "Manual of Stormwater Management Practices". 2 Packet Pg. 3483 R.3.d B. Guidelines r site OKAY, what must 1 do to prepare a site plan for my single family or duplex home? 0 In order to prepare a site plan, it is necessary to assess the existing site conditions, evaluate the proposed 0. c improvements and make provisions for stormwater management.This process begins with the collection of site- specific data, by performing a lot survey.The lot survey is then used as a base to locate the proposed improvements and grade the lot in order to control stormwater runoff.The following steps detail the type of data to be collected for the lot survey and the information to be provided in the site plan. 0 STEP ONE—SURVEY DRAWING 2 Obtain a boundary survey and topographic information (either from survey or LiDAR data)for your lot.The survey must be performed by a professional land surveyor licensed to practice in the State of Florida. The survey drawing must provide this information: a. Legal description of lot. b. Property line dimensions, bearings and/or angles. c. Location of existing improvements,to include adjacent street and waterway(if any). d. Three cross-sections, showing elevations from the street, across lot lines and center of the property. e. Location and identification of existing trees. c N f. Location sketch and identification of a nearby Mile Marker g. Scale (1"=10' recommended)and north arrow. m h. LiDAR-based elevations may be used if available. STEP TWO—SITE PLAN CD CN Prepare a site plan showing the proposed improvements, utilities,site grading and landscaping.The site plan,which CDmust meet the guidelines described later in this brochure, should be prepared at a recommended scale of 1"=10' and provide the following information: a. Locations, dimensions, and types of construction materials of the building, roof, patio, screened porch, deck, shed, pool, driveway, septic tank and drainfield. 0 b. Proposed site grading showing existing and proposed elevations and/or contours. c. Proposed drainage directions and areas draining to each retention system. Site grading must drain towards !A retention system. d. Locations, dimensions, and types of materials to be used in landscaping features,such as planters,walks, privacy walls,fences,trees and shrubs. e. A cross-section (elevation view)across the center of the lot showing proposed improvements and site grading. m Packet Pg. 3484 R.3.d C. Guidelines in your site HOW do 1 address stormwater management in my site plan? Much of Monroe County is beautiful and ecologically sensitive to manmade pollutants, many of which are carried to 0. the ocean by stormwater runoff. Monroe County's objective is to keep the resident coral reef,fish, and animals alive and healthy,while allowing you to occupy the same bit of Florida paradise.To achieve this objective, Monroe County requires your new home to meet the following design and construction guidelines: • Preserve Roadside Swales (Plate 2) 1. Maintain the pervious cover of swales. 2. Preserve existing swale elevations. • Reduce Lot Fill (Plate 2) 1. Carefully consider the need to import any fill for the lot. c 2. Limit building pad elevations to eight inches above the adjacent roadway. • Flood Protection (Plate 3) 1. Elevate the first habitable floor above the Federal Emergency Management Agency Base Flood Elevation c using stilt-construction techniques. • Reduce Impervious Surfaces 1. Use pervious materials, such as gravel, pervious pavers on sand, native grasses,grass-covered porous pavement and wood for the construction of other site and landscaping improvements. Florida-Friendly Landscaping'" is encouraged. 2. Do not place impervious layers, such as roofing paper or plastic under paved or landscaped areas. • Conserve Water(Plate 4&5) 1. Use cisterns to collect roof runoff and recycle for non-potable water uses. 2. Use native plant materials for landscaping. • Reduce Direct Discharges to Waterways (Plate 6) 1. Use berms to contain runoff onto adjacent waterways. CD 2. If your lot has an existing bulkhead, lower the adjacent ground to provide a minimum of 6" difference between the finished lot and the top of the bulkhead. • Reduce Discharges to Roadway 2 1. Use berms to contain runoff from lot onto adjacent roadways. 2. Use traffic rated trench drains across driveways to reduce discharges to the roadway.These trench drains should be drained to an onsite retention area.Trench drains are not needed where the driveway is below or at the same elevation as the roadway Swale. • Calculate required retention volume using the following steps: 1. Determine square feet of impervious area on the site that is directly connected to the proposed retention ?� system (typically this would be an onsite Swale). Directly connected would be any area when stormwater runoff passes over less than 20 feet on pervious area (e.g.grassed or landscaped area) before entering the onsite retention system. Pervious pavers would not be considered an impervious area. 2. Determine square feet of impervious area on the site that is unconnected to the proposed retention system and has to drain over 20 feet or more of pervious area before entering the retention system.An example of this would be an area of the roof that is drained from a downspout but flows over 20 feet of landscaped area before reaching the onsite Swale. 3. Calculate the total effective impervious area by summing the directly connected area with half the unconnected area. 4 Packet Pg. 3485 4. Determine the square feet of lot area that is disturbed during construction.This is any area that is accessibl to construction vehicles or construction staff during construction. Undisturbed areas need to be clearly sig posted and taped off during construction. 5. Calculate the ratio of the effective impervious area to the disturbed area. 6. Use Table 1 below to determine the required retention depth.The effective impervious area to the disturbed area ratio from Step 5 should be rounded to the nearest ratio in Table 1. 7. Determine the required retention volume (cubic feet) by multiplying the required retention depth in feet (Step 6) by the disturbed area in square feet (Step 4). 0 U Table 1. Required Retention Depth 0. M � egg s� > 0.20 0.138 1.66 0.25 0.146 1.75 0.30 0.153 1.84 0.35 0.164 1.97 0.40 0.177 2.12 2.26 0.45 0.188 0.50 0.203 2.44 0.55 0.215 2.58 0.60 0.228 2.74 U 0.65 0.243 2.92 N 0.70 0.256 3.07 0.75 0.271 3.25 0.80 0.286 3.43 cv CD cv If swale(s) are used they must meet the following criteria: • Runoff from site must be drained to Swale. • Swale length must be greater than its width. • Swale side slope must be 4:1 or shallower(horizontal to vertical). • Swale must not disturb any natural areas. • Swale must be 6 inches or deeper. ?� • Swales should be vegetated. If a Swale is not vegetated than a 6-inch layer of nutrient sorption soil amendment formulated to reduce nutrient loading must be installed directly below the Swale.Specifications and published nutrient reduction test results for the media must be provided for County review at the time of permitting. Examples of acceptable media are NutriGoneTM (distributed by EcoSense International)and Bold and Gold° (distributed by Environmental Conservation Solutions). m 5 If exfiltration trenches or french drains are used on single-family or duplex lots they must meet the following criteri • Minimum of 8 inches of cover. • Use at least a 4 inch or greater perforated pipe.A prefabricated shallow vault or drainage well may be used. • Inlets to exfiltration system must include a fabric filter. • Exfiltration system must not be within 10 feet of a building. • Exfiltration systems cannot be installed under driveways or other areas that may receive frequent vehicular traffic, unless designed by a Florida-registered and -licensed professional engineer. • Bottom of exfiltration system must be more than 12 inches above the wet season water table. Wet season water table can be determined using the USDA Web Soil Survey(hops.//websoilsurveyr.sc.e ov.usda.gov), SoilWeb app available on Android or iPhone devices,or determined by an appropriate Florida-registered and -licensed professional. • Volume of an exfiltration trench in cubic feet can be approximated as:V= L x W x(D—0.96)x 0.4,where L= e length in feet,W=average trench width, and D=average trench depth in feet. > 'SOP OF PAVEMENT OR FINISHED GRADE - Ca 0 BACKFILL OR EMBANKMENT c '.. GATE - FILTER 0 FABRIC TRENCH ''PERFORATED, REQUIRED I k T OR TREATMENT PIPS TED " ..... VOLUME (RTV) TRENCH WIDTH E RTV RECOVERY W IL INFILTRATIO N SEASONAL II I 'ROUN WATER TABLE( HG CONFINING UI a� TYPICAL "DRY" EXFILTRATION TRENCH X-SECTIO,N 0 Source.Florida Department of Environmental Protection and Water Management Districts ca Environmental Resource Permit Stormwater Quality Applicant's Handbook(March 2010—Draft) ut The following diagrams illustrate the above design and construction guidelines and a sample site plan (Plate 7). If you have other questions, call the Planning and Environmental Resources Department at at 305-289-2500. 6 Packet Pg. 3487 constructionD. Sample N R.3.d Ilk 0 0 Existing Dative Shorefine Vegetation to to Preserved Existing Ground (Plate 1 c N cv CD Pear Setback Building Front Setback cV Swale Swale � Paired Pad Berm 8" Maximum 76ginal tett�ret Peer let Swale %roni lot Swale Deep Minimum Ground Line ,. Deep Minimum eat Existing Native Shoreline Vegetation to be Preserved Lot Grading (Plate 7 Packet Pg. 3488 R.3.d c k Ofeezeway L� Stilt Construction MY 2 0 Existing Native Shorefine Vegetation to be Preserved House Elevation (Plate 3' 0 ��,0 0 W N N --- U - 2 ca Above round Cistern r Existing Iry hor Nn Vegetation to be Preswvod Water Conservation (Plate 4' 8 Packet Pg. 3489 R.3.d C xli . qq�T jI Native Vegetation Existing Native Shorefino Vprr to be Preserved u w 2 c 0 Water Conservation (Plate 5 0 r r — Mangiove, S C) w 0) Berm CD i9> E Bulkhead Qi��x�� Qrrti co y Side and Freer Lot Details (Plate 6 Packet Pg. 3490 R.3.d k u,,to v�y.,..k IV xwwr r:xattn m 1 Lire troe 43 Proposed ._..�... - shruW'24'UNK, 3t corr am r PtAnteci 2'rr nri i II i Row d V N — CANAL".:., 3� I 'errn W i 111 T G.rtra+�ad. f A i u�q -- F 0 i pr pcsod t �.� 43-Nrapc-sda 0 htubwr2 ,,TA IV j - aster gal-i_r9ntaanawrr, Gumbo Lim array planter 2apan to r rmfin r SfTE PLAN r tJ 0 N } LL f Omni 1 'P�ijp drrc� �r b 7,n�1rard Fdge w ave rw�a t Wood of raid g CANAL rE x ififirg elevml 0 n la Grairsrr Cirior*a s as 4`Gae"G�aB 2 a s a' 6'deep ro"'Id CROSS SECTION Ex�sflng Native Shorchne Vegetation to be Preserved (Plate � 10 Packet Pg. 3491 R.3.d --Eximi Gumbo Limbo tree P,ctafr to remain f�����ie« n R �y ���a �� IJ�11 ilfl, 1 �11�1���ill b�aas Swal w #Nay a ,rivaa�uC 1 G) WWA u9 - Ho ROADWAY �_. .._.. Residence �r :vet � � � > Drrvoway m=..4..,... Proposed 41i!FWJ �3 r lovatron a' i Proposed s. 9, u y t $Wii t Thalct,t' 4 F Expou g @ 0 Qs7 o d@ 'r Guar Guartm Urribo tree Elevation ' ` Exacting... cU to rot~norr F iota �_Property Lino �9Nras� Elevation 4'fit" P' P' fTE PLAN � tJ 0 N Proposed Edge od Eavomem CN Elevation Elevahun CD t k P Dootr Swale Drainap Gaiw nun w xnmA Proposed E4ovakfon� o ryDL at 9 ro; �` Boltorn god al tin .1 A LDt Sao aft �a IifftwrvweMa,�.nCaag wig.b9. %„ .a. _ .. E TI A a U rr7ae9s� a ��Ntr=4x,1,&� kwrWe�a C,v °✓ C f � t8 Low Density Foliage Lot N.T.S. Packet Pg. 3492 R.3.d C tan d'5• 1-Exi5fing r m Umbo Irem p9u9F4"Cl r��lF4`rs"cwr9 IF ley a au9r a P:.. �7�aylkatxr �I tM ­ROAD WAY E Br_r�ir ew donre r r d n 6 Sw v lej or,drive only or In roar only 0)Swaps �LrrarY„ w rpropasod ,EmN9rng I Elevation , ` � P rrposoa Elevation 4' " 1 Thatch P MM v p � Vry�/q Proposad remain Gumbo tjmhntr y°tr �6 '11rrurr 8, E. PLAN xi, tdn 0 10 p Properly Line 0 ,ECTp) , r E. sm Guidelines N N N WHAT if 1 just want to expand my home? E Any impervious area expansion of existing lot coverage,that is, roofs, decks, patios, pools, and pavements, must provide for the retention of two and half inches of runoff from the expansion area.Typically,this retention requirement can be met by construction of a shallow Swale alongside the expansion's area. However, other approaches to retaining stormwater on the site will be considered.The following table shows the proportional stormwater retention storage required for every 25 feet of new impervious area: Provisions for swales must be 7 s ®s shown on the site plans submitted with your permit 25 5 application.Just remember, 50 10 you should still follow the steps outlined in this brochure, 75 16 but you don't need to meet all of the design and construction 100 21 criteria required for new 125 26 homes. 150 31 175 36 200 42 12 Packet Pg. 3493