{"formats":[{"name":"JSON","format":"json","url":"\/downloads\/2025\/code-json\/10.1-605.json"},{"name":"Plain Text","format":"text","url":"\/downloads\/2025\/code-text\/10.1-605.txt"},{"name":"XML","format":"xml","url":"\/downloads\/2025\/code-xml\/10.1-605.xml"},{"name":"HTML","format":"html","url":"\/downloads\/2025\/code-html\/10.1-605.html"}],"law_id":56867,"edition_id":1,"section_id":56867,"structure_id":12975,"section_number":"10.1-605","catch_line":"Promulgation of regulations by the Board; guidance document","history":"1982, c. 583, \u00a7 62.1-115.2; 1986, c. 9; 1988, c. 891; 2010, cc. 249, 270; 2011, c. 323; 2025, cc. 228, 241.","full_text":"A\n\nThe Board shall adopt regulations to ensure that impounding structures in the Commonwealth are properly and safely constructed, maintained and operated. Dam safety regulations promulgated by the State Water Control Board shall remain in full force until amended in accordance with applicable procedures.B\n\nThe Board’s Impounding Structure Regulations shall not require any impounding structure in existence or under a construction permit prior to July 1, 2010, that is currently classified as high hazard, or is subsequently found to be high hazard through reclassification, to upgrade its spillway to pass a rainfall event greater than the maximum recorded within the Commonwealth, which shall be deemed to be 90 percent of the probable maximum precipitation.1\n\nSuch an impounding structure shall be determined to be in compliance with the spillway requirements of the regulations provided that (i) the impounding structure will pass two-thirds of the reduced probable maximum precipitation requirement described in this subsection and (ii) the dam owner certifies annually and by January 15 that such impounding structure meets each of the following conditions:\n\t\t\t\ta. The owner has a current emergency action plan that is approved by the Board and that is developed and updated in accordance with the regulations;\n\t\t\t\tb. The owner has exercised the emergency action plan in accordance with the regulations and conducts a table-top exercise at least once every two years;\n\t\t\t\tc. The Department has verification that both the local emergency management coordinator and the Virginia Department of Emergency Management have on file current emergency action plans and updates for the impounding structure;\n\t\t\t\td. That conditions at the impounding structure are monitored on a daily basis and as dictated by the emergency action plan;\n\t\t\t\te. The impounding structure is inspected at least annually by a professional engineer and all observed deficiencies are addressed within 120 days of such inspection;\n\t\t\t\tf. The owner has a dam break inundation zone map developed in accordance with the regulations that is acceptable to the Department;\n\t\t\t\tg. The owner is insured in an amount that will substantially cover the costs of downstream property losses to others that may result from a dam failure; and\n\t\t\t\th. The owner shall post the dam’s emergency action plan on his website, or upon the request of the owner, the Department or another state agency responsible for providing emergency management services to citizens agrees to post the plan on its website. If the Department or another state agency agrees to post the plan on its website, the owner shall provide the plan in a format suitable for posting.2\n\nA dam owner who meets the conditions of subdivisions 1 a through 1 h, but has not provided record drawings to the Department for his impounding structure, shall submit a complete record report developed in accordance with the construction permit requirements of the Impounding Structure Regulations, excluding the required submittal of the record drawings.3\n\nA dam owner who fails to submit certifications required by subdivisions 1 a through 1 h in a timely fashion shall not enjoy the presumption that such impounding structure is deemed to be in compliance with the spillway requirements of the Board’s Impounding Structure Regulations (4VAC50-20).4\n\nAny dam owner who has submitted the certifications required by subdivisions 1 a through 1 h shall make (i) such certifications, (ii) the emergency action plan required by subdivision 1 a, and (iii) the certificate of insurance required by subdivision 1 g available, upon request and within five business days, to any person. A dam owner may comply with the requirements of this subdivision by providing the same information on a website and directing the requestor to such website. A dam owner who fails to comply with this subdivision shall be subject to a civil penalty pursuant to § 10.1-609.C\n\nThe Board’s regulations shall establish an incremental damage analysis procedure that permits the spillway design flood requirement for an impounding structure to be reduced to the level at which dam failure shall not significantly increase downstream hazard to life or property, provided that the spillway design flood requirement shall not be reduced to below the 100-year flood event for high or significant hazard impounding structures, or to below the 50-year flood event for low hazard potential impounding structures.D\n\nThe Board shall consider the impact of limited-use or private roadways with low traffic volume and low public safety risk that are downstream from or across an impounding structure in the determination of the hazard potential classification of an impounding structure.","order_by":null,"text":{"0":{"id":208285,"text":"The Board shall adopt regulations to ensure that impounding structures in the Commonwealth are properly and safely constructed, maintained and operated. Dam safety regulations promulgated by the State Water Control Board shall remain in full force until amended in accordance with applicable procedures.","type":"section","prefixes":["A"],"prefix":"A","entire_prefix":"A","prefix_anchor":"A","level":1,"next_prefix":"B"},"1":{"id":208286,"text":"The Board’s Impounding Structure Regulations shall not require any impounding structure in existence or under a construction permit prior to July 1, 2010, that is currently classified as high hazard, or is subsequently found to be high hazard through reclassification, to upgrade its spillway to pass a rainfall event greater than the maximum recorded within the Commonwealth, which shall be deemed to be 90 percent of the probable maximum precipitation.","type":"section","prefixes":["B"],"prefix":"B","entire_prefix":"B","prefix_anchor":"B","level":1,"prior_prefix":"A","next_prefix":"B1"},"2":{"id":208287,"text":"Such an impounding structure shall be determined to be in compliance with the spillway requirements of the regulations provided that (i) the impounding structure will pass two-thirds of the reduced probable maximum precipitation requirement described in this subsection and (ii) the dam owner certifies annually and by January 15 that such impounding structure meets each of the following conditions:\n\t\t\t\ta. The owner has a current emergency action plan that is approved by the Board and that is developed and updated in accordance with the regulations;\n\t\t\t\tb. The owner has exercised the emergency action plan in accordance with the regulations and conducts a table-top exercise at least once every two years;\n\t\t\t\tc. The Department has verification that both the local emergency management coordinator and the Virginia Department of Emergency Management have on file current emergency action plans and updates for the impounding structure;\n\t\t\t\td. That conditions at the impounding structure are monitored on a daily basis and as dictated by the emergency action plan;\n\t\t\t\te. The impounding structure is inspected at least annually by a professional engineer and all observed deficiencies are addressed within 120 days of such inspection;\n\t\t\t\tf. The owner has a dam break inundation zone map developed in accordance with the regulations that is acceptable to the Department;\n\t\t\t\tg. The owner is insured in an amount that will substantially cover the costs of downstream property losses to others that may result from a dam failure; and\n\t\t\t\th. The owner shall post the dam’s emergency action plan on his website, or upon the request of the owner, the Department or another state agency responsible for providing emergency management services to citizens agrees to post the plan on its website. If the Department or another state agency agrees to post the plan on its website, the owner shall provide the plan in a format suitable for posting.","type":"section","prefixes":["B","1"],"prefix":"1","entire_prefix":"B1","prefix_anchor":"B1","level":2,"prior_prefix":"B","next_prefix":"B2"},"3":{"id":208288,"text":"A dam owner who meets the conditions of subdivisions 1 a through 1 h, but has not provided record drawings to the Department for his impounding structure, shall submit a complete record report developed in accordance with the construction permit requirements of the Impounding Structure Regulations, excluding the required submittal of the record drawings.","type":"section","prefixes":["B","2"],"prefix":"2","entire_prefix":"B2","prefix_anchor":"B2","level":2,"prior_prefix":"B1","next_prefix":"B3"},"4":{"id":208289,"text":"A dam owner who fails to submit certifications required by subdivisions 1 a through 1 h in a timely fashion shall not enjoy the presumption that such impounding structure is deemed to be in compliance with the spillway requirements of the Board’s Impounding Structure Regulations (4VAC50-20).","type":"section","prefixes":["B","3"],"prefix":"3","entire_prefix":"B3","prefix_anchor":"B3","level":2,"prior_prefix":"B2","next_prefix":"B4"},"5":{"id":208290,"text":"Any dam owner who has submitted the certifications required by subdivisions 1 a through 1 h shall make (i) such certifications, (ii) the emergency action plan required by subdivision 1 a, and (iii) the certificate of insurance required by subdivision 1 g available, upon request and within five business days, to any person. A dam owner may comply with the requirements of this subdivision by providing the same information on a website and directing the requestor to such website. A dam owner who fails to comply with this subdivision shall be subject to a civil penalty pursuant to § 10.1-609.","type":"section","prefixes":["B","4"],"prefix":"4","entire_prefix":"B4","prefix_anchor":"B4","level":2,"prior_prefix":"B3","next_prefix":"C"},"6":{"id":208291,"text":"The Board’s regulations shall establish an incremental damage analysis procedure that permits the spillway design flood requirement for an impounding structure to be reduced to the level at which dam failure shall not significantly increase downstream hazard to life or property, provided that the spillway design flood requirement shall not be reduced to below the 100-year flood event for high or significant hazard impounding structures, or to below the 50-year flood event for low hazard potential impounding structures.","type":"section","prefixes":["C"],"prefix":"C","entire_prefix":"C","prefix_anchor":"C","level":1,"prior_prefix":"B4","next_prefix":"D"},"7":{"id":208292,"text":"The Board shall consider the impact of limited-use or private roadways with low traffic volume and low public safety risk that are downstream from or across an impounding structure in the determination of the hazard potential classification of an impounding structure.","type":"section","prefixes":["D"],"prefix":"D","entire_prefix":"D","prefix_anchor":"D","level":1,"prior_prefix":"C"}},"ancestry":[{"id":12975,"edition_id":1,"name":"Dam Safety Act","identifier":"2","label":"article","depth":4,"order_by":1,"parent_id":12894,"metadata":{},"date_created":"2026-06-26 03:44:06","date_modified":"2026-06-26 03:44:06","permalink":{"id":144445,"object_type":"structure","relational_id":12975,"identifier":"2","token":"10.1\/I\/6\/2","url":"\/10.1\/I\/6\/2\/","edition_id":1,"permalink":0,"preferred":1}},{"id":12894,"edition_id":1,"name":"Flood Protection and Dam Safety","identifier":"6","label":"chapter","depth":3,"order_by":1,"parent_id":12893,"metadata":{},"date_created":"2026-06-26 03:43:59","date_modified":"2026-06-26 03:43:59","permalink":{"id":144271,"object_type":"structure","relational_id":12894,"identifier":"6","token":"10.1\/I\/6","url":"\/10.1\/I\/6\/","edition_id":1,"permalink":0,"preferred":1}},{"id":12893,"edition_id":1,"name":"Activities Administered by the Department of Conservation and Recreation","identifier":"I","label":"subtitle","depth":2,"order_by":1,"parent_id":12740,"metadata":{},"date_created":"2026-06-26 03:43:59","date_modified":"2026-06-26 03:43:59","permalink":{"id":143315,"object_type":"structure","relational_id":12893,"identifier":"I","token":"10.1\/I","url":"\/10.1\/I\/","edition_id":1,"permalink":0,"preferred":1}},{"id":12740,"edition_id":1,"name":"Conservation","identifier":"10.1","label":"title","depth":1,"order_by":1,"parent_id":null,"metadata":{},"date_created":"2026-06-26 03:43:51","date_modified":"2026-06-26 03:43:51","permalink":{"id":143313,"object_type":"structure","relational_id":12740,"identifier":"10.1","token":"10.1","url":"\/10.1\/","edition_id":1,"permalink":0,"preferred":1}}],"structure_contents":[{"id":58286,"structure_id":12975,"section_number":"10.1-604","catch_line":" Definitions","url":"\/10.1-604\/","token":"10.1\/I\/6\/2\/10.1-604","metadata":false},{"id":54062,"structure_id":12975,"section_number":"10.1-604.1","catch_line":"Determination of hazard potential classification","url":"\/10.1-604.1\/","token":"10.1\/I\/6\/2\/10.1-604.1","metadata":false},{"id":56867,"structure_id":12975,"section_number":"10.1-605","catch_line":"Promulgation of regulations by the Board; guidance document","url":"\/10.1-605\/","token":"10.1\/I\/6\/2\/10.1-605","metadata":false},{"id":82106,"structure_id":12975,"section_number":"10.1-605.1","catch_line":"Delegation of powers and duties","url":"\/10.1-605.1\/","token":"10.1\/I\/6\/2\/10.1-605.1","metadata":false},{"id":73336,"structure_id":12975,"section_number":"10.1-605.2","catch_line":"Certain regulations affecting impounding structures","url":"\/10.1-605.2\/","token":"10.1\/I\/6\/2\/10.1-605.2","metadata":false},{"id":58996,"structure_id":12975,"section_number":"10.1-605.3","catch_line":"General permit for certain impounding structures","url":"\/10.1-605.3\/","token":"10.1\/I\/6\/2\/10.1-605.3","metadata":false},{"id":69664,"structure_id":12975,"section_number":"10.1-606","catch_line":"Local advisory committee","url":"\/10.1-606\/","token":"10.1\/I\/6\/2\/10.1-606","metadata":false},{"id":54840,"structure_id":12975,"section_number":"10.1-606.1","catch_line":"Repealed","url":"\/10.1-606.1\/","token":"10.1\/I\/6\/2\/10.1-606.1","metadata":false},{"id":79423,"structure_id":12975,"section_number":"10.1-606.2","catch_line":"Mapping of dam break inundation zones","url":"\/10.1-606.2\/","token":"10.1\/I\/6\/2\/10.1-606.2","metadata":false},{"id":81394,"structure_id":12975,"section_number":"10.1-606.3","catch_line":"Requirement for development in dam break inundation zones","url":"\/10.1-606.3\/","token":"10.1\/I\/6\/2\/10.1-606.3","metadata":false},{"id":87482,"structure_id":12975,"section_number":"10.1-606.4","catch_line":"Notice to the public","url":"\/10.1-606.4\/","token":"10.1\/I\/6\/2\/10.1-606.4","metadata":false},{"id":71315,"structure_id":12975,"section_number":"10.1-607","catch_line":"Safety inspections","url":"\/10.1-607\/","token":"10.1\/I\/6\/2\/10.1-607","metadata":false},{"id":68429,"structure_id":12975,"section_number":"10.1-607.1","catch_line":"Criteria for designating a dam as unsafe","url":"\/10.1-607.1\/","token":"10.1\/I\/6\/2\/10.1-607.1","metadata":false},{"id":77589,"structure_id":12975,"section_number":"10.1-608","catch_line":"Unsafe dams presenting imminent danger","url":"\/10.1-608\/","token":"10.1\/I\/6\/2\/10.1-608","metadata":false},{"id":79239,"structure_id":12975,"section_number":"10.1-609","catch_line":"Unsafe dams presenting nonimminent danger; civil penalty","url":"\/10.1-609\/","token":"10.1\/I\/6\/2\/10.1-609","metadata":false},{"id":80418,"structure_id":12975,"section_number":"10.1-609.1","catch_line":"Installation of IFLOWS gauges","url":"\/10.1-609.1\/","token":"10.1\/I\/6\/2\/10.1-609.1","metadata":false},{"id":83779,"structure_id":12975,"section_number":"10.1-609.2","catch_line":"Prohibited vegetation; certain wetland vegetation allowed","url":"\/10.1-609.2\/","token":"10.1\/I\/6\/2\/10.1-609.2","metadata":false},{"id":60640,"structure_id":12975,"section_number":"10.1-610","catch_line":"Right of entry","url":"\/10.1-610\/","token":"10.1\/I\/6\/2\/10.1-610","metadata":false},{"id":65885,"structure_id":12975,"section_number":"10.1-610.1","catch_line":"Monitoring progress of work","url":"\/10.1-610.1\/","token":"10.1\/I\/6\/2\/10.1-610.1","metadata":false},{"id":63179,"structure_id":12975,"section_number":"10.1-611","catch_line":"Dam safety coordination","url":"\/10.1-611\/","token":"10.1\/I\/6\/2\/10.1-611","metadata":false},{"id":54419,"structure_id":12975,"section_number":"10.1-611.1","catch_line":"Soil and Water Conservation District Dam Maintenance, Repair, and Rehabilitation Fund established; Department to manage; Board to expend moneys; regulations","url":"\/10.1-611.1\/","token":"10.1\/I\/6\/2\/10.1-611.1","metadata":false},{"id":64937,"structure_id":12975,"section_number":"10.1-612","catch_line":"Technical Advisory Committee","url":"\/10.1-612\/","token":"10.1\/I\/6\/2\/10.1-612","metadata":false},{"id":67844,"structure_id":12975,"section_number":"10.1-612.1","catch_line":"Temporary stop work order; hearing; injunctive relief","url":"\/10.1-612.1\/","token":"10.1\/I\/6\/2\/10.1-612.1","metadata":false},{"id":72084,"structure_id":12975,"section_number":"10.1-613","catch_line":"Enforcement","url":"\/10.1-613\/","token":"10.1\/I\/6\/2\/10.1-613","metadata":false},{"id":67195,"structure_id":12975,"section_number":"10.1-613.1","catch_line":"Criminal penalties","url":"\/10.1-613.1\/","token":"10.1\/I\/6\/2\/10.1-613.1","metadata":false},{"id":73441,"structure_id":12975,"section_number":"10.1-613.2","catch_line":"Repealed","url":"\/10.1-613.2\/","token":"10.1\/I\/6\/2\/10.1-613.2","metadata":false},{"id":80653,"structure_id":12975,"section_number":"10.1-613.3","catch_line":"No liability of Board, Department, employees, or agents","url":"\/10.1-613.3\/","token":"10.1\/I\/6\/2\/10.1-613.3","metadata":false},{"id":58273,"structure_id":12975,"section_number":"10.1-613.4","catch_line":"Liability of owner or operator","url":"\/10.1-613.4\/","token":"10.1\/I\/6\/2\/10.1-613.4","metadata":false},{"id":79781,"structure_id":12975,"section_number":"10.1-613.5","catch_line":"Program administration fees; establishment of Dam Safety Administrative Fund","url":"\/10.1-613.5\/","token":"10.1\/I\/6\/2\/10.1-613.5","metadata":false},{"id":77193,"structure_id":12975,"section_number":"10.1-613.6","catch_line":"Negotiated settlement agreements","url":"\/10.1-613.6\/","token":"10.1\/I\/6\/2\/10.1-613.6","metadata":false}],"previous_section":{"id":54062,"structure_id":12975,"section_number":"10.1-604.1","catch_line":"Determination of hazard potential classification","url":"\/10.1-604.1\/","token":"10.1\/I\/6\/2\/10.1-604.1","metadata":false},"next_section":{"id":82106,"structure_id":12975,"section_number":"10.1-605.1","catch_line":"Delegation of powers and duties","url":"\/10.1-605.1\/","token":"10.1\/I\/6\/2\/10.1-605.1","metadata":false},"metadata":false,"official_url":"https:\/\/law.lis.virginia.gov\/vacode\/10.1-605\/","history_text":"

This law was first created in 1982. The record of its establishment is cataloged in chapter 583 of that year\u2019s edition of \u201cActs of Assembly,\u201d the annual state publication listing all changes made to the Code of Virginia in that year. Unfortunately, the 1982 \u201cActs\u201d aren\u2019t available online. It has been modified 5 times. Those modifications are cataloged by \u201cThe Acts of Assembly,\u201d a state publication, by year and chapter. Those modifications that can be read on the General Assembly\u2019s website will be linked accordingly. Those modifications are as follows: in 1986, chapter 9; in 1988, chapter 891; in 2010, chapters 249<\/a> and 270<\/a>; in 2011, chapter 323<\/a>; in 2025, chapters 228<\/a> and 241<\/a>.<\/p>","references":[{"id":54062,"section_number":"10.1-604.1","catch_line":"Determination of hazard potential classification","order_by":null,"url":"\/10.1-604.1\/"},{"id":82106,"section_number":"10.1-605.1","catch_line":"Delegation of powers and duties","order_by":null,"url":"\/10.1-605.1\/"},{"id":79239,"section_number":"10.1-609","catch_line":"Unsafe dams presenting nonimminent danger; civil penalty","order_by":null,"url":"\/10.1-609\/"}],"refers_to":false,"permalink":{"id":144455,"object_type":"law","relational_id":56867,"identifier":"10.1-605","token":"10.1\/I\/6\/2\/10.1-605","url":"\/10.1-605\/","edition_id":1,"permalink":0,"preferred":1},"url":"\/10.1-605\/","token":"10.1\/I\/6\/2\/10.1-605","dublin_core":{"Title":"Promulgation of regulations by the Board; guidance document","Type":"Text","Format":"text\/html","Identifier":"\u00a7 10.1-605","Relation":"Code of Virginia"},"html":"\n\t\t\t\t\t\t

A.<\/span> The Board<\/span> shall adopt regulations to ensure that impounding structures<\/span> in the Commonwealth are properly and safely constructed, maintained and operated. Dam safety regulations promulgated by the State Water Control Board<\/span> shall remain in full force until amended in accordance with applicable procedures. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

B.<\/span> The Board<\/span>’s Impounding Structure<\/span> Regulations shall not require any impounding structure<\/span> in existence or under a construction<\/span> permit prior to July 1, 2010, that is currently classified as high hazard, or is subsequently found to be high hazard through reclassification, to upgrade its spillway to pass a rainfall event greater than the maximum recorded within the Commonwealth, which shall be deemed to be 90 percent of the probable maximum precipitation. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

1.<\/span> Such an impounding structure<\/span> shall be determined to be in compliance with the spillway requirements of the regulations provided that (i) the impounding structure<\/span> will pass two-thirds of the reduced probable maximum precipitation requirement described in this subsection and (ii) the dam owner<\/span> certifies annually and by January 15 that such impounding structure<\/span> meets each of the following conditions:\n\t\t\t\ta. The owner<\/span> has a current emergency action plan that is approved by the Board<\/span> and that is developed and updated in accordance with the regulations;\n\t\t\t\tb. The owner<\/span> has exercised the emergency action plan in accordance with the regulations and conducts a table-top exercise at least once every two years;\n\t\t\t\tc. The Department<\/span> has verification that both the local emergency management coordinator and the Virginia Department<\/span> of Emergency Management have on file current emergency action plans and updates for the impounding structure<\/span>;\n\t\t\t\td. That conditions at the impounding structure<\/span> are monitored on a daily basis and as dictated by the emergency action plan;\n\t\t\t\te. The impounding structure<\/span> is inspected at least annually by a professional engineer and all observed deficiencies are addressed within 120 days of such inspection;\n\t\t\t\tf. The owner<\/span> has a dam break inundation zone<\/span> map developed in accordance with the regulations that is acceptable to the Department<\/span>;\n\t\t\t\tg. The owner<\/span> is insured in an amount that will substantially cover the costs of downstream property losses to others that may result from a dam failure; and\n\t\t\t\th. The owner<\/span> shall post the dam’s emergency action plan on his website, or upon the request of the owner<\/span>, the Department<\/span> or another state agency responsible for providing emergency management services to citizens agrees to post the plan on its website. If the Department<\/span> or another state agency agrees to post the plan on its website, the owner<\/span> shall provide the plan in a format suitable for posting. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

2.<\/span> A dam owner<\/span> who meets the conditions of subdivisions 1 a through 1 h, but has not provided record drawings to the Department<\/span> for his impounding structure<\/span>, shall submit a complete record report developed in accordance with the construction<\/span> permit requirements of the Impounding Structure<\/span> Regulations, excluding the required submittal of the record drawings. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

3.<\/span> A dam owner<\/span> who fails to submit certifications required by subdivisions 1 a through 1 h in a timely fashion shall not enjoy the presumption<\/span> that such impounding structure<\/span> is deemed to be in compliance with the spillway requirements of the Board<\/span>’s Impounding Structure<\/span> Regulations (4VAC50-20). <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

4.<\/span> Any dam owner<\/span> who has submitted the certifications required by subdivisions 1 a through 1 h shall make (i) such certifications, (ii) the emergency action plan required by subdivision 1 a, and (iii) the certificate of insurance required by subdivision 1 g available, upon request and within five business days, to any person. A dam owner<\/span> may comply with the requirements of this subdivision by providing the same information on a website and directing the requestor to such website. A dam owner<\/span> who fails to comply with this subdivision shall be subject to a civil penalty<\/span> pursuant to § 10.1-609<\/a>. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

C.<\/span> The Board<\/span>’s regulations shall establish an incremental damage analysis procedure that permits the spillway design flood requirement for an impounding structure<\/span> to be reduced to the level at which dam failure shall not significantly increase downstream hazard to life or property, provided that the spillway design flood requirement shall not be reduced to below the 100-year flood event for high or significant hazard impounding structures<\/span>, or to below the 50-year flood event for low hazard potential impounding structures<\/span>. <\/i><\/a><\/p><\/section>\n\t\t\t\t\t\t

D.<\/span> The Board<\/span> shall consider the impact of limited-use or private roadways with low traffic volume and low public safety risk that are downstream from or across an impounding structure<\/span> in the determination of the hazard potential classification of an impounding structure<\/span>. <\/i><\/a><\/p><\/section>","plain_text":" CODE OF VIRGINIA\n\nPROMULGATION OF REGULATIONS BY THE BOARD; GUIDANCE DOCUMENT (\u00a7 10.1-605)\n\nA. The Board shall adopt regulations to ensure that impounding structures in the\nCommonwealth are properly and safely constructed, maintained and operated. Dam\nsafety regulations promulgated by the State Water Control Board shall remain in\nfull force until amended in accordance with applicable procedures.\n\nB. The Board’s Impounding Structure Regulations shall not require any\nimpounding structure in existence or under a construction permit prior to July\n1, 2010, that is currently classified as high hazard, or is subsequently found\nto be high hazard through reclassification, to upgrade its spillway to pass a\nrainfall event greater than the maximum recorded within the Commonwealth, which\nshall be deemed to be 90 percent of the probable maximum precipitation.\n\n 1. Such an impounding structure shall be determined to be in compliance with\n the spillway requirements of the regulations provided that (i) the impounding\n structure will pass two-thirds of the reduced probable maximum precipitation\n requirement described in this subsection and (ii) the dam owner certifies\n annually and by January 15 that such impounding structure meets each of the\n following conditions:\n \t\t\t\ta. The owner has a current emergency action plan that is approved by the\n Board and that is developed and updated in accordance with the regulations;\n \t\t\t\tb. The owner has exercised the emergency action plan in accordance with\n the regulations and conducts a table-top exercise at least once every two\n years;\n \t\t\t\tc. The Department has verification that both the local emergency\n management coordinator and the Virginia Department of Emergency Management\n have on file current emergency action plans and updates for the impounding\n structure;\n \t\t\t\td. That conditions at the impounding structure are monitored on a daily\n basis and as dictated by the emergency action plan;\n \t\t\t\te. The impounding structure is inspected at least annually by a\n professional engineer and all observed deficiencies are addressed within 120\n days of such inspection;\n \t\t\t\tf. The owner has a dam break inundation zone map developed in accordance\n with the regulations that is acceptable to the Department;\n \t\t\t\tg. The owner is insured in an amount that will substantially cover the\n costs of downstream property losses to others that may result from a dam\n failure; and\n \t\t\t\th. The owner shall post the dam’s emergency action plan on his\n website, or upon the request of the owner, the Department or another state\n agency responsible for providing emergency management services to citizens\n agrees to post the plan on its website. If the Department or another state\n agency agrees to post the plan on its website, the owner shall provide the\n plan in a format suitable for posting.\n\n 2. A dam owner who meets the conditions of subdivisions 1 a through 1 h, but\n has not provided record drawings to the Department for his impounding\n structure, shall submit a complete record report developed in accordance with\n the construction permit requirements of the Impounding Structure Regulations,\n excluding the required submittal of the record drawings.\n\n 3. A dam owner who fails to submit certifications required by subdivisions 1 a\n through 1 h in a timely fashion shall not enjoy the presumption that such\n impounding structure is deemed to be in compliance with the spillway\n requirements of the Board’s Impounding Structure Regulations\n (4VAC50-20).\n\n 4. Any dam owner who has submitted the certifications required by subdivisions\n 1 a through 1 h shall make (i) such certifications, (ii) the emergency action\n plan required by subdivision 1 a, and (iii) the certificate of insurance\n required by subdivision 1 g available, upon request and within five business\n days, to any person. A dam owner may comply with the requirements of this\n subdivision by providing the same information on a website and directing the\n requestor to such website. A dam owner who fails to comply with this\n subdivision shall be subject to a civil penalty pursuant to § 10.1-609.\n\nC. The Board’s regulations shall establish an incremental damage analysis\nprocedure that permits the spillway design flood requirement for an impounding\nstructure to be reduced to the level at which dam failure shall not\nsignificantly increase downstream hazard to life or property, provided that the\nspillway design flood requirement shall not be reduced to below the 100-year\nflood event for high or significant hazard impounding structures, or to below\nthe 50-year flood event for low hazard potential impounding structures.\n\nD. The Board shall consider the impact of limited-use or private roadways with\nlow traffic volume and low public safety risk that are downstream from or across\nan impounding structure in the determination of the hazard potential\nclassification of an impounding structure.\n\nHISTORY: 1982, c. 583, \u00a7 62.1-115.2; 1986, c. 9; 1988, c. 891; 2010, cc. 249,\n270; 2011, c. 323; 2025, cc. 228, 241.","edition":{"id":1,"name":"2025","slug":"2025","date_created":"2026-06-21 22:39:22","date_modified":"2026-06-21 22:39:22","current":1,"order_by":1,"last_import":null}}