§ 6.06.03. Contents of the stormwater management plan.

It is the responsibility of an applicant to include in the stormwater management plan required by section 6.06.02 sufficient information for reviewing officials to evaluate the environmental qualities of the affected area, the potential and predicted impacts of the proposed development activity on affected waters, and the effectiveness and acceptability of these measures proposed by the applicant for reducing adverse impacts. The stormwater management plan shall incorporate the following information and reports:

1.

Vicinity sketch and legal description.

2.

Basin and sub-basin boundaries: Including all on-site and off-site areas contributing to the site, and a breakdown of the subarea(s) contributing to each inlet or conveyance in the internal stormwater collection system.

3.

Topographic site data: Showing existing contours and spot elevations. Contours must be shown to the minimum one-foot interval to at least 25 feet outside the project boundaries. The engineer of record must provide the source of such topographic data and certify its currency.

4.

Existing stormwater management system features (ditches, ponds, etc.): Including the location of areas on the site where surface waters collect and percolate into the ground.

5.

Description of all watercourses, water bodies, and wetlands: Locations on or adjacent to the site or into which surface waters flow.

6.

Jurisdictional limits of all on-site wetland systems: The jurisdictional wetland limits must be surveyed and a statement of formal acceptance of the wetland boundaries must be provided by the regulatory agency(ies) that has jurisdictional authority of the wetlands.

7.

Soil information: Information sufficient to evaluate the performance of proposed facilities. Soil classification using the United States Department of Agriculture (USDA), Natural Resource Conservation Service "Soil Survey of Okaloosa County, Florida" may be utilized as a planning guide only. Design features shall be supported by a geotechnical report from a licensed engineer or other professional authorized under Florida Statutes to do such work. The report shall include all parameters that affect the design and recovery of proposed systems, including all elements required below:

a.

Soil investigation—Roadways: The soil investigation report shall include:

i.

Test borings to a minimum depth of four feet below proposed edge of pavement and incorporating a maximum spacing of 500 feet along the roadway centerline.

ii.

Soil boring logs, the existing groundwater table elevation and the estimated seasonal high groundwater table elevation without consideration of drainage improvements that may lower the groundwater.

iii.

In special cases, additional borings may be required to determine the soil classifications predominant to the area.

b.

Soil investigation—Retention/detention areas: The soil investigation report shall include:

i.

A minimum of two test borings per proposed retention/detention facility or two per acre of proposed retention/detention facility, whichever is greater. Borings shall extend to a minimum depth of two feet below the proposed pond bottom or to the water table, whichever is greater;

ii.

Soil boring logs, the existing groundwater table elevation, and the estimated seasonal high groundwater table elevation without consideration of drainage improvements that may lower the groundwater;

iii.

If the analysis of the basin utilizes infiltration to achieve either peak flow attenuation or recovery time, a hydraulic conductivity test at the proposed bottom of the facility.

8.

Flood zone designation: Determined from the flood insurance rate maps (FEMA). Elevations of the flood zone along with the flood hazard boundary shall be delineated.

9.

Proposed development layout with horizontal and vertical controls.

10.

Proposed stormwater management system features: Including, but not limited to, the locations of outfall control structures, weirs, inlets, swales, ponds, conveyance systems, easements, etc.

11.

Design report: Technical narrative and documentation of all drainage calculations.

12.

Revisions made to a phased project.

13.

Erosion and sediment control plan: A plan specifying in detail the type and location of control measures, the stage of development at which they will be put into place or used and provisions for maintenance.

14.

Documentation that all runoff leaving the project utilizes a legal positive outfall.

15.

Any other information that the developer or reviewing officials consider necessary for an evaluation of the proposed development.

(Ord. No. 11-01, § 2, 1-18-11)