6.05.01 - Stormwater Management System Requirements

A complete stormwater management system shall be provided for all areas within the subdivision or development, including lots, streets, and alleys.

A.

The system design shall meet the applicable provisions of the current County codes and ordinances, SFWMD rules and regulations pursuant to Florida Statutes, and the Florida Administrative Code, and any other affected state and federal agencies' rules and regulations in effect at the time of preliminary subdivision plat submission.

B.

Where stormwater runoff from outside the subdivision or development historically passes on, over, or through areas of the subdivision or development, such runoff shall be included in the stormwater system design. The system shall be designed for long life, low cost maintenance by normal methods and provide for optimal on-site detention of stormwater runoff and groundwater recharge in accordance with applicable County and SFWMD regulations.

C.

Any structure with an outside wall which is closer than 10 feet from a side property line shall install properly sized (minimum twenty-four (24)-square inch cross-section) gutters and downspouts to direct stormwater away from neighboring properties and toward front and/or rear swales or retention/detention areas.

D.

In-ground percolation type retention systems such as rock trenches, exfiltration trenches or beds, infiltrator type systems, gallery type systems, etc., shall not be used to achieve water quality retention for residential subdivisions. Rear yard open retention systems shall likewise not be designed to achieve water quality retention on projects submitted after January 1, 2002. All retention systems for projects designed after January 1, 2002, shall be on common property owned and maintained by a homeowners' association or similar entity.

E.

Any canal which forms a part of the public water management system shall be dedicated for care and maintenance per the requirements of the governmental agency which has jurisdiction. Canals located entirely within the subdivision and which do not form a part of the public water management system shall be dedicated to the public, without the responsibility for maintenance, as a drainage easement. A maintenance easement, of a size acceptable to the County Manager or designee or other governmental agency with maintenance responsibility, shall be provided adjacent to the established drainage easement, or the drainage easement created must be of a size suitable for the proposed canal and its maintenance.

F.

Stormwater Retention/Detention Design for Single-Family Dwelling Units, Two-Family Dwelling Units and Duplexes.

1.

Applicability. Any application for a building permit to allow the development or redevelopment of a single-family or two-family dwelling or duplex submitted after July 1, 2008, except for the following conditions:

a.

Any application within the boundaries of development projects that have: (1) been permitted by the South Florida Water Management District for Surface Water Management or Environmental Resource Protection and (2) have a central surface water management collection, storage, treatment and discharge system;

b.

A one-time addition is allowed for certain sized homes, as set forth below; or

c.

An application accompanied by a stormwater management plan, signed and sealed by a registered Florida Professional Engineer.

Table 6.05.01 F.

2.

The maximum allowable ratio of lot coverage and impervious area coverage to the total lot area shall be as provided for in Table 6.05.01 F. unless accompanied by an engineer's analysis as specified below.

a.

The site drainage analysis shall include water quality calculations to SFWMD standards and water quantity calculations done to accommodate the runoff, from area in excess of the above ratio, from a 5-year 1-day storm and shall include a percolation test done by a qualified engineer or technician. If the site will use a drainfield/septic tank for sewage treatment/disposal, the wet season water table calculations for drainage must match that used for the drainfield design.

b.

The application site plan shall list all required separation distances between wells, drainfield systems, and stormwater retention/detention areas. The calculations may be done on the site plan or may be in a separate Engineer's report, but must be signed and sealed by the Engineer.

c.

The water surface area of swimming pools and ponds is not considered as impervious area for the purposes of the calculations in Table 6.05.01 F.

3.

A one-time addition to an existing residence will be allowed after July 1, 2008. The addition will be limited to 3 percent of the lot area up to a maximum of 1,000 square feet as long as that one-time addition does not exceed the area in Table 6.05.01 F. by more than 3 percent of the lot area or more than 1,000 square feet.

G.

The design of the stormwater management system shall fully incorporate the requirements of the Interim Watershed Management regulations of LDC section 3.07.00

(Ord. No. 07-67, § 3.P; Ord. No. 08-10, § 3.D)

6.05.02 - Seawalls and Bulkheads

A.

When authorized, the water side of the concrete seawall cap shall be constructed landward of the property boundary and shall be in accordance with the seawall construction regulations, Collier County Ordinance No. 85-2 [Code ch. 22, art. IX], as amended.

B.

The applicant shall obtain the requisite approval(s) and permit(s) from the Florida Department of Environmental Protection (DEP) and the U.S. Army Corps of Engineers ("COE"), where such approvals are necessary, prior to commencement of construction. A copy of such approval(s) and/or permit(s) must be filed with the County Manager or designee upon receipt.

C.

The construction of seawalls or bulkheads, in association with water management system lake construction under jurisdiction of SFWMD, shall be in compliance with SFWMD criteria.

D.

Best Management Practice (BMP) for single family residential lots employing seawall(s). Coastal canal residential lots bounded by seawall(s) shall provide an infiltration trench adjacent to and along the entire length of the seawall serving the lot perimeter. Infiltration trenches shall be excavated to a width and depth of 2 to 3 feet, lines and secured with a class "C" geotextile filter fabric, or better, and backfilled with clean ¾—1 inch stone. Other agency permitting requirements notwithstanding, infiltration trench characteristics shall be suitable for pretreatment of drainage areas of five (5) acres or less. The infiltration trench shall be directly behind and centered on the 2;inch; weep hole shown on the "Sample Concrete Seawall" detail of the Technical Specifications section of County Ordinance 85-02.

(Ord. No. 07-67, § 3.Q)