§ 10.1-605. Promulgation of regulations by the Board; guidance document.
A. The Board shall adopt regulations to ensure that impounding structures inthe Commonwealth are properly and safely constructed, maintained andoperated. Dam safety regulations promulgated by the State Water Control Boardshall remain in full force until amended in accordance with applicableprocedures.
B. The Board's Impounding Structure Regulations shall not require anyimpounding structure in existence or under a construction permit prior toJuly 1, 2010, that is currently classified as high hazard, or is subsequentlyfound to be high hazard through reclassification, to upgrade its spillway topass a rainfall event greater than the maximum recorded within theCommonwealth, which shall be deemed to be 90 percent of the probable maximumprecipitation.
Additionally, such an impounding structure shall be determined to be incompliance with the spillway requirements of the regulations provided that(i) the impounding structure will pass two-thirds of the reduced probablemaximum precipitation requirement described in this subsection and (ii) thedam owner certifies annually that such impounding structure meets each of thefollowing conditions:
1. The owner has a current emergency action plan that is approved by theBoard and that is developed and updated in accordance with the regulations;
2. The owner has exercised the emergency action plan in accordance with theregulations and conducts a table-top exercise at least once every two years;
3. The Department has verification that both the local organization foremergency management and the Virginia Department of Emergency Management haveon file current emergency action plans and updates for the impoundingstructure;
4. That conditions at the impounding structure are monitored on a daily basisand as dictated by the emergency action plan;
5. The impounding structure is inspected at least annually by a professionalengineer and all observed deficiencies are addressed within 120 days of suchinspection;
6. The owner has a dam break inundation zone map developed in accordance withthe regulations that is acceptable to the Department;
7. The owner is insured in an amount that will substantially cover the costsof downstream property losses to others that may result from a dam failure;and
8. The owner shall post the dam's emergency action plan on his website, orupon the request of the owner, the Department or another state agencyresponsible for providing emergency management services to citizens agrees topost the plan on its website. If the Department or another state agencyagrees to post the plan on its website, the owner shall provide the plan in aformat suitable for posting.
A dam owner who meets the conditions of subdivisions 1 through 8, but has notprovided record drawings to the Department for his impounding structure,shall submit a complete record report developed in accordance with theconstruction permit requirements of the Impounding Structure Regulations,excluding the required submittal of the record drawings.
C. The Board's regulations shall establish an incremental damage analysisprocedure that permits the spillway design flood requirement for animpounding structure to be reduced to the level at which dam failure shallnot significantly increase downstream hazard to life or property, providedthat the spillway design flood requirement shall not be reduced to below the100-year flood event for high or significant hazard impounding structures, orto below the 50-year flood event for low hazard potential impoundingstructures.
D. The Board shall consider the impact of limited-use or private roadwayswith low traffic volume and low public safety risk that are downstream fromor across an impounding structure in the determination of the hazardpotential classification of an impounding structure.
(1982, c. 583, § 62.1-115.2; 1986, c. 9; 1988, c. 891; 2010, cc. 249, 270.)
§ 10.1-605. Promulgation of regulations by the Board; guidance document.
A. The Board shall adopt regulations to ensure that impounding structures inthe Commonwealth are properly and safely constructed, maintained andoperated. Dam safety regulations promulgated by the State Water Control Boardshall remain in full force until amended in accordance with applicableprocedures.
B. The Board's Impounding Structure Regulations shall not require anyimpounding structure in existence or under a construction permit prior toJuly 1, 2010, that is currently classified as high hazard, or is subsequentlyfound to be high hazard through reclassification, to upgrade its spillway topass a rainfall event greater than the maximum recorded within theCommonwealth, which shall be deemed to be 90 percent of the probable maximumprecipitation.
Additionally, such an impounding structure shall be determined to be incompliance with the spillway requirements of the regulations provided that(i) the impounding structure will pass two-thirds of the reduced probablemaximum precipitation requirement described in this subsection and (ii) thedam owner certifies annually that such impounding structure meets each of thefollowing conditions:
1. The owner has a current emergency action plan that is approved by theBoard and that is developed and updated in accordance with the regulations;
2. The owner has exercised the emergency action plan in accordance with theregulations and conducts a table-top exercise at least once every two years;
3. The Department has verification that both the local organization foremergency management and the Virginia Department of Emergency Management haveon file current emergency action plans and updates for the impoundingstructure;
4. That conditions at the impounding structure are monitored on a daily basisand as dictated by the emergency action plan;
5. The impounding structure is inspected at least annually by a professionalengineer and all observed deficiencies are addressed within 120 days of suchinspection;
6. The owner has a dam break inundation zone map developed in accordance withthe regulations that is acceptable to the Department;
7. The owner is insured in an amount that will substantially cover the costsof downstream property losses to others that may result from a dam failure;and
8. The owner shall post the dam's emergency action plan on his website, orupon the request of the owner, the Department or another state agencyresponsible for providing emergency management services to citizens agrees topost the plan on its website. If the Department or another state agencyagrees to post the plan on its website, the owner shall provide the plan in aformat suitable for posting.
A dam owner who meets the conditions of subdivisions 1 through 8, but has notprovided record drawings to the Department for his impounding structure,shall submit a complete record report developed in accordance with theconstruction permit requirements of the Impounding Structure Regulations,excluding the required submittal of the record drawings.
C. The Board's regulations shall establish an incremental damage analysisprocedure that permits the spillway design flood requirement for animpounding structure to be reduced to the level at which dam failure shallnot significantly increase downstream hazard to life or property, providedthat the spillway design flood requirement shall not be reduced to below the100-year flood event for high or significant hazard impounding structures, orto below the 50-year flood event for low hazard potential impoundingstructures.
D. The Board shall consider the impact of limited-use or private roadwayswith low traffic volume and low public safety risk that are downstream fromor across an impounding structure in the determination of the hazardpotential classification of an impounding structure.
(1982, c. 583, § 62.1-115.2; 1986, c. 9; 1988, c. 891; 2010, cc. 249, 270.)
§ 10.1-605. Promulgation of regulations by the Board; guidance document.
A. The Board shall adopt regulations to ensure that impounding structures inthe Commonwealth are properly and safely constructed, maintained andoperated. Dam safety regulations promulgated by the State Water Control Boardshall remain in full force until amended in accordance with applicableprocedures.
B. The Board's Impounding Structure Regulations shall not require anyimpounding structure in existence or under a construction permit prior toJuly 1, 2010, that is currently classified as high hazard, or is subsequentlyfound to be high hazard through reclassification, to upgrade its spillway topass a rainfall event greater than the maximum recorded within theCommonwealth, which shall be deemed to be 90 percent of the probable maximumprecipitation.
Additionally, such an impounding structure shall be determined to be incompliance with the spillway requirements of the regulations provided that(i) the impounding structure will pass two-thirds of the reduced probablemaximum precipitation requirement described in this subsection and (ii) thedam owner certifies annually that such impounding structure meets each of thefollowing conditions:
1. The owner has a current emergency action plan that is approved by theBoard and that is developed and updated in accordance with the regulations;
2. The owner has exercised the emergency action plan in accordance with theregulations and conducts a table-top exercise at least once every two years;
3. The Department has verification that both the local organization foremergency management and the Virginia Department of Emergency Management haveon file current emergency action plans and updates for the impoundingstructure;
4. That conditions at the impounding structure are monitored on a daily basisand as dictated by the emergency action plan;
5. The impounding structure is inspected at least annually by a professionalengineer and all observed deficiencies are addressed within 120 days of suchinspection;
6. The owner has a dam break inundation zone map developed in accordance withthe regulations that is acceptable to the Department;
7. The owner is insured in an amount that will substantially cover the costsof downstream property losses to others that may result from a dam failure;and
8. The owner shall post the dam's emergency action plan on his website, orupon the request of the owner, the Department or another state agencyresponsible for providing emergency management services to citizens agrees topost the plan on its website. If the Department or another state agencyagrees to post the plan on its website, the owner shall provide the plan in aformat suitable for posting.
A dam owner who meets the conditions of subdivisions 1 through 8, but has notprovided record drawings to the Department for his impounding structure,shall submit a complete record report developed in accordance with theconstruction permit requirements of the Impounding Structure Regulations,excluding the required submittal of the record drawings.
C. The Board's regulations shall establish an incremental damage analysisprocedure that permits the spillway design flood requirement for animpounding structure to be reduced to the level at which dam failure shallnot significantly increase downstream hazard to life or property, providedthat the spillway design flood requirement shall not be reduced to below the100-year flood event for high or significant hazard impounding structures, orto below the 50-year flood event for low hazard potential impoundingstructures.
D. The Board shall consider the impact of limited-use or private roadwayswith low traffic volume and low public safety risk that are downstream fromor across an impounding structure in the determination of the hazardpotential classification of an impounding structure.
(1982, c. 583, § 62.1-115.2; 1986, c. 9; 1988, c. 891; 2010, cc. 249, 270.)
