Agencies | Governor
Virginia Regulatory Town Hall
Department of Conservation and Recreation
Virginia Soil and Water Conservation Board
Impounding Structure Regulations [4 VAC 50 ‑ 20]
This action is exempt from the executive branch review process.
Amend the Impounding Structure Regulations to incorporate the Probable Maximum Flood Study as required by Chapters 475 and 479 of the 2014 General Assembly Session
General Information
Action Summary This action amends 4VAC50-20-50 titled Performance standards required for impounding structures and incorporates by reference the Probable Maximum Study for Virginia (and associated PMP Evaluation Tool and Database) (November 2015). The key elements of this action include: (1) removal of references to the National Weather Service, NOAA, PMP values and inserted references to PMP values “derived from the Probable Maximum Study for Virginia (and associated PMP Evaluation Tool and Database) (November 2015)”; (2) removal of the reference to “flat terrain” from the description of PMP as this set of PMP values does bring orographic variables into the analysis; (3) updating the citation for the Department of Environmental Quality’s Virginia Stormwater Management Program (VSMP) Regulation; and (4) incorporating by reference the PMP Study and Evaluation Tool. This regulatory action is expected to be cost beneficial to dam owners, including local governments.
Chapters Affected Only affects this chapter.
Exempt from APA Yes, this action is exempt from Article II of the APA and executive branch review.
Exempt Citation: §2.2-4006 A of the Code of Virginia
RIS Project Yes  [004564]
New Periodic Review This action will not be used to conduct a new periodic review.
Stages associated with this regulatory action.
Stage ID Stage Type Status
7445 Final Stage complete. This regulation became effective on 03/23/2016.
Contact Information
Name / Title: Lisa McGee  / Policy and Planning Director
Address: 600 East Main Street, 24th Floor
Richmond, VA 23219
Email Address:
Phone: (804)786-4378    FAX: (804)786-6141    TDD: ()-

This person is the primary contact for this agency.