§ 21-161. Stormwater Management.

Stormwater runoff is recognized, both as a valuable natural resource critical to the maintenance of water quantity in the Central Florida lakes, as well as a significant contributor of pollutants which affect the quality of the lake waters. This division is enacted in order to:

•

Control stormwater runoff and prevent or minimize damage to persons or property which may occur as a result of heavy rainfall;

•

Define stormwater management control areas and restrict those activities within the areas that are not compatible with sound stormwater management;

•

Establish runoff limitations in order to ensure suitable treatment and reduction in the amounts of undesirable pollutants discharged to outfalls or receiving waters of those lakes located in the City;

•

Prevent the installation of improvements which adversely affect stormwater management and drainage patterns;

•

Implement a program of stormwater management within the City for the continued projection of a vital natural resource; and

•

Require the treatment of stormwater from redeveloped sites which otherwise would be exempt from State and regional stormwater treatment requirements. For purposes of treatment of stormwater on redeveloped sites, the word treatment shall be defined as the reduction of the pollutants contained in stormwater through detention, retention, filtration or other physical, chemical or biological processes.

(a)

The provisions of this division shall not apply to:

(1)

Bona fide agricultural or forest operations, including land clearing operations in connection therewith; provided, however, if such land is subsequently changed to another type of use, the use of such land shall thenceforth be subject to this division.

(2)

Home gardening or other minor clearing or excavation work not incident to a substantial change in the existing residential use of land which may be reasonably expected not to contribute any substantial amount of on-site generated runoff beyond the boundaries of the property of the residence involved.

(3)

Emergency repairs, on public or private projects, necessary for the preservation of life, health, or property where taken to implement and accomplish the beneficial purposes of this division as set forth herein under such circumstances where it would be impractical to obtain approval from the City Engineer prior to making such emergency repairs.

(4)

Routine maintenance or repair work on public or privately owned portions of a structural stormwater or drainage control system which does not constitute major construction or rebuilding.

(5)

Single-family residential lots where the property owner will reside in the residence upon its completion or completion of any addition thereto.

(6)

Single-family residential lots located outside the one hundred-year floodplain (individual lots only).

(7)

Redeveloped structures which undergo less than fifty (50) percent demolition of their entire footprint area and are adding no new building square footage.

(8)

Redeveloped lots or parcels which are less than one-half acre (21,780 square feet) in size.

(9)

Lots or parcels located within the C-1, Commercial-Downtown zoning district or an approved development with zero lot line requirements.

(10)

Redeveloped lots or parcels that are a part of a regional stormwater treatment system which is designed to treat stormwater to the extent required by the regulations contained in this division.

(b)

Any person proposing development or redevelopment in the City, which is not exempted by section 21-161(a), shall submit, as part of, or attached to, site plans for the proposed development, a stormwater management plan which demonstrates the measures to be implemented by such person for controlling runoff as required under provisions of this division. The site and stormwater management plans shall include information necessary to illustrate the means by which compliance with applicable control standards will be achieved. Approval of the stormwater management plan shall be a condition prior to the issuance of a Development Approval Certificate and/or building permit.

Minimum requirements for supporting documentation that shall be included are:

(1)

The nature and extent of clearing, grading and development operations;

(2)

Contour elevations for existing and post-development conditions;

(3)

Hydrologic engineering analysis of runoff for existing and post-development conditions (drainage calculations);

(4)

The projected sequence of work (for large-scale development projects); and

(5)

Impact upon waterways affected by the proposed development.

(c)

The maximum volume of post-development off-site discharge shall not exceed the pre-development discharge. The post-development peak rate of runoff leaving the site shall not exceed the pre-development peak rate of runoff for the designated storm event.

(d)

The following shall be the maximum allowable rate of runoff under this division.

(1)

All changes to land use resulting in facilities for parking and roadways shall limit the post-development peak rate of runoff to both:

a.

That generated by a pre-development ten-year, 24-hour design storm, and the maximum allowable runoff coefficient for that land use area; and

b.

That allowed by the capacity of the existing system to accommodate the peak runoff without damage to upstream and downstream property.

(2)

All other land use changes shall adhere to subsection 21-161(e)(a.) and (b.) except that the design storm shall be a twenty-five-year, 24-hour design storm.

(e)

The following stormwater treatment standards shall apply for those areas undergoing redevelopment:

(1)

Redeveloped lots or parcels equal to or larger than one-half acre in size (21,780 square feet) but less than two (2) acres in size shall treat one-quarter (¼) inch of runoff from all impervious areas.

(2)

Redeveloped lots or parcels which are two (2) acres or more in size shall treat one-half (½) inch of runoff from impervious areas.

(3)

Redeveloped non-residential and multifamily lots or parcels requiring a State or regional permit shall be required to meet the treatment standards outlined above only for those areas not covered by treatment facilities designed for the project.

(f)

Maintenance requirements. It shall be the duty of the property owner to provide proper maintenance of the stormwater management system so that the system continues to meet the requirements of this section. The City shall have access to inspect stormwater management systems and facilities and to require such maintenance, repair, and replacement of facilities as necessary.

(g)

Stormwater system standards.

(1)

Stormwater systems as required by this chapter shall be designed so as to be readily accessible from rights-of-way, parking lots, courtyards, or other open areas so that maintenance and clean-out of these areas can be easily accomplished.

(2)

The appearance and buffering of stormwater pond areas shall meet the requirements of the City's landscape code.

(3)

Retention areas shall be designed and function to prohibit the abilities of mosquitos to breed and hatch. When soil conditions will permit, dry retention areas shall be utilized.

(Ord. No. O-00-09, 1(Art. 3, 3.05.00), 4-24-00; Ord. No. O-01-06, § 1, 2-26-01; Ord. No. O-17-38 , § 1, 10-23-17)