                                 CODE OF VIRGINIA

RURAL TIDEWATER LOCALITIES; WATER QUANTITY TECHNICAL CRITERIA; TIERED APPROACH
(§ 62.1-44.15:27.2)

A. For determining the water quantity technical criteria applicable to a land
disturbance equal to or greater than 2,500 square feet but less than one acre,
any rural Tidewater locality may elect to use certain tiered water quantity
control standards based on the percentage of impervious cover in the watershed
as provided in this section. The establishment and conduct of the tiered
approach by the locality pursuant to this section shall be subject to review by
the Department. The Board shall adopt regulations to carry out provisions of
this section.

B. 1. The local governing body shall make, or cause to be made, a watershed map
showing the boundaries of the locality. The governing body shall use the most
recent version of Virginia&#8217;s 6th order National Watershed Boundary Dataset
to show the boundaries of each watershed located partially or wholly within the
locality. The map shall indicate the percentage of impervious cover within each
watershed. Data provided by the Virginia Geographic Information Network (VGIN)
shall be sufficient for the initial determination of impervious cover percentage
at the time of the initial adoption of the map.

   2. The watershed map also shall show locations at which the governing body
   expects or proposes that development should occur and may indicate the
   projected future percentage of impervious cover based on proposed development.
   The governing body may designate certain areas within a watershed in which it
   proposes that denser-than-average development shall occur and may designate
   environmentally sensitive areas in which the energy balance method for water
   quantity management, as set forth in the regulations adopted by the Board
   pursuant to this article, shall apply.

   3. After the watershed map has been made, the governing body may then approve
   and adopt the map by a majority vote of its membership and publish it as the
   official watershed map of the locality. No official watershed map shall be
   adopted by the governing body or have any effect until it is approved by an
   ordinance duly passed by the governing body of the locality after a public
   hearing, preceded by public notice as required by &#xA7; 15.2-2204. Within 30
   days after adoption of the official watershed map, the governing body shall
   cause the map to be filed in the office of the clerk of the circuit court.

   4. At least once each year, the local governing body shall by majority vote
   make additions to or modifications of the official watershed map to reflect
   actual development projects. The governing body shall change the indication on
   the map of the impervious cover percentage within a watershed where the
   percentage has changed and shall update the map and supporting datasets with
   actual development project information, including single-family housing
   projects and any projects covered by the General Permit for Discharges of
   Stormwater from Construction Activities and administered by the Department for
   opt-out localities pursuant to &#xA7; 62.1-44.15:27. The governing body may
   incorporate into the official watershed map the most recent VGIN data,
   including data on state and federal projects that are not reviewed or approved
   by the locality. The governing body shall keep current its impervious cover
   percentage for each watershed located within the locality, as reflected in the
   official watershed map, and shall make the map and such percentages available
   to the public.

   5. The locality shall notify the Department and update the official map within
   12 months of the approval of the development plan for any project that exceeds
   the impervious cover percentage of the watershed in which it is located and
   causes the percentage for that watershed to rise such that the watershed steps
   up to the next higher tier pursuant to subsection C.

   6. No official watershed map or its adopting or amending ordinances shall take
   precedence over any duly adopted zoning ordinance, comprehensive plan, or
   other local land-use ordinance, and in the case of a conflict, the official
   watershed map or ordinance shall yield to such land-use ordinance.

C. When the locality evaluates any development project in a watershed that is
depicted on the official watershed map as having an impervious cover percentage
of:

   1. Less than five percent, the locality shall apply the regulatory minimum
   standards and criteria adopted by the Board pursuant to Article 2.4 (&#xA7;
   62.1-44.15:51 et seq.) and in effect prior to July 1, 2014, for the protection
   of downstream properties and waterways from sediment deposition, erosion, and
   damage due to increases in volume, velocity, and peak flow rate of stormwater
   runoff for the stated frequency storm of 24-hour duration.

   2. Five percent or more but less than 7.5 percent, the locality shall require
   practices designed to detain and release over a 24-hour period the expected
   rainfall resulting from the one year, 24-hour storm, which practices shall be
   exempt from any flow rate capacity and velocity requirements for natural or
   man-made channels.

   3. Seven and one-half percent or more, the locality shall apply the energy
   balance method as set forth in regulations adopted by the Board.

D. The locality shall require that any project whose construction would cause
the impervious cover percentage of the watershed in which it is located to rise,
such that the watershed steps up to the next higher tier, shall meet the current
water quantity technical criteria using the energy balance method or a more
stringent alternative.

HISTORY: 2018, c. 154.