§ 5.8. Stormwater management.

5.8.1.

Applicability.

A.

Applicants may be required to provide stormwater management improvements or make other improvements to the existing drainage system to address water quantity concerns, water quality concerns, or both if the proposed development will increase potential flood damages to existing properties or significantly increase pollutant levels in downstream receiving waters.

B.

The need for stormwater management improvements to address offsite impacts must be determined by the county engineering division. The applicant shall be required to provide surety to guarantee completion of required improvements prior to final plat approval.

5.8.2.

Stormwater management program.

A.

Subdivision applications disturbing one (1) or more acres of land or two thousand five hundred (2,500) square feet within the Chesapeake Bay watershed, as well as all modifications to existing stormwater systems shall require the submittal of a stormwater management plan in accordance with the county stormwater management ordinance.

B.

When a separate stand-alone stormwater management plan is not required, the proposed stormwater management improvements must be indicated on the preliminary plat, construction plans, and final plat.

C.

The stormwater management concept plan and stormwater management final plan shall be prepared in accordance with the county stormwater management ordinance.

5.8.3.

Stormwater design standards.

A.

The applicant must provide all necessary information needed to determine what improvements are necessary to properly develop the subject property, including contour intervals, drainage plans and proposed stormwater management improvements.

B.

Stormwater management improvements must be designed and installed in accordance with the Isle of Wight County Stormwater Management Ordinance as well as all other applicable codes and ordinances. Plans for all improvements must include a certification by a properly qualified engineer or surveyor that proposed improvements, when properly installed, will be adequate for proper development and conform to all design standards and requirements.

C.

Piping and modification of streams and other natural watercourses should be minimized and shall be considered on a case-by-case basis to determine if it is necessary and environmentally sound. Such facilities must be designed, constructed and maintained to minimize flooding, protect downslope properties, preserve water quality, and adequately transport existing and projected stormwater flows.

D.

The use of best management practices (BMPs) to manage stormwater is strongly encouraged. Examples of BMPs include: Bioretention and biofiltration, rain gardens, infiltration, detention, and structural controls.

Note: The following table illustrates some (but not all) of the BMPs that may be considered.

Example BMP	Illustration
Rain garden
Roadside Infiltration Swale
Dry Detention Basin
Media Filter

 

F.

When stormwater ponds or management facilities are used, they shall be designed, landscaped, and integrated into the overall site design as a community amenity as follows:

1.

Stormwater retention and detention areas shall meander through the development as a greenbelt, rather than as a single basin. Stormwater retention areas shall be improved so as to be useable and accessible for recreational purposes. Retention areas shall be designed such that when inundated (following a rain event), they shall remain usable for their designated recreational purposes.

G.

Stormwater retention and detention areas shall be designed with a natural character and shall be constructed of natural materials. Terracing, berming, and contouring is required in order to naturalize and enhance the aesthetics of the basin. Such features shall be approved by the subdivision agent. Basin slopes may not exceed a three (3) to one (1) slope and shall be designed to permit ready access for maintenance. In addition, the final design must incorporate child safety features through signage or other appropriate means.

H.

Roadway drainage improvements must be provided in accordance with the VDOT Drainage Handbook. Drainage facilities located within the right-of-way must be approved by the VDOT engineer prior to dedication.

I.

The subdivision agent may require that easements for drainage through adjoining property be provided by the applicant. An access easement that is at least ten (10) feet in width may be required to allow routine maintenance and repairs to stormwater facilities.

5.8.4.

Maintenance and ownership.

A.

Maintenance bond required. .....The applicant shall submit a maintenance bond on a form acceptable to the county until the stormwater facility is turned over to the property owner's association.

B.

Ownership. .....Stormwater facilities shall be owned and maintained by a property owner's association (POA) representing owners of the land within the subdivision. Membership in the association shall be mandatory and automatic for all landowners of the subdivision and their successors. The POA shall have lien authority to ensure the collection of dues from all members.

C.

Maintenance agreement. .....A stormwater management facility maintenance agreement, maintenance easement agreement and formal maintenance covenant shall be submitted and recorded with the clerk's office of the circuit court prior to the issuance of any permits and shall be binding on all subsequent owners of land served by the facility. The stormwater management facility maintenance agreement shall be prepared in accordance with the requirements of the county stormwater management ordinance.

D.

Failure to maintain. .....In the event the POA responsible for maintenance of the stormwater facility fails to maintain all or any portion in reasonable order and condition, the county may assume responsibility for its maintenance and may enter the premises and take corrective action, including the provision of extended maintenance. The costs of such maintenance may be charged to the POA, or to the individual property owners that make up the association, and may include administrative costs and penalties. Such costs shall become a lien on all subdivision properties.