12 Va. Admin. Code § 5-610-640

Current through Register Vol. 41, No. 6, November 4, 2024

Section 12VAC5-610-640 - Minimum standards for Soil Drainage Management Plans

A. Every SDMP offered in conjunction with a SDMC shall meet the following minimum standards for surface and groundwater management.

B. The SDMP shall provide for:

1. Positive surface grading in the area of a dwelling and subsurface soil absorption area at a minimum of 0.5%;

2. Drainage ditches for diverting surface water and for lowering the seasonal groundwater table which shall:

a. Completely surround the subsurface soil absorption system;

b. Have a minimum grade of 0.2%;

c. Be located 70 feet, +-10 feet from the drainfield; and

d. Have the invert of the ditch placed in a Group I, II or III soil at an elevation so that the normal water surface in the ditch is at least six inches below the invert of the trench of the subsurface soil absorption system;

3. A French drain on one side in lieu of an open drainage ditch on one of the four sides;

4. Diversion ditches or swales shall be:

a. Required where adjacent property is equal to or higher in elevation than the proposed site and the adjacent property may be expected to discharge water onto the proposed site;

b. Designed to meet such site specific individual requirements as the department determines to be necessary;

5. A receiving stormwater and groundwater drainage system which is adequate in capacity so that waters from a proposed site shall be conveyed to it in accordance with the political subdivision's criteria;

6. Diversion ditches, where required, or other ditches to transport stormwater and/or groundwater from a site to a receiving body in accordance with the political subdivision's criteria;

7. Ditches to remain open and not be piped and covered unless approved by appropriate local government official, such approval to be granted only with the concurrence of the department;

8. Only appurtenances to the subsurface soil absorption system shall be constructed within the confines of the perimeter ditches required in paragraph B 2 a, above, except where a French drain is provided on one side; and

9. Lots which shall be a minimum of three acres in size not including swamps or marshland.

12 Va. Admin. Code § 5-610-640

Derived from VR355-34-02 § 3.20, eff. February 5, 1986; amended, eff. May 11, 1988.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.