4 Va. Admin. Code § 25-31-460
All intermittent or perennial streams shall be protected from spoil by natural or constructed barriers. Stream channel diversions shall safely pass the peak run-off from a 10-year, 24-hour storm. Stream channel diversions shall be at least equal to the capacity of the unmodified stream channel immediately upstream and downstream of the diversion.
§§ 45.1-161.3 and 45.1-180.3 of the Code of Virginia.
Derived from Virginia Register Volume 19, Issue 24, eff. September 11, 2003; amended, Virginia Register Volume 30, Issue 6, eff. December 19, 2013.