HomeMy WebLinkAboutZTA201300003 Attachment AATTACHMENT A
§ 10.1 -604. Definitions.
"Dam break inundation zone" means the area downstream of a dam that would be inundated or otherwise
directly affected by the failure of a dam.
§ 10.1- 606.2. Mapping of dam break inundation zones.
A. An owner of an impounding structure shall prepare a map of the dam break inundation zone for the
impounding structure in accordance with criteria set out in the Virginia Impounding Structure Regulations
(4VAC 50 -20). Existing maps prepared by the locality in accordance with these regulations may be used
for this purpose.
B. All maps prepared in accordance with subsection A shall be filed with the Department of Conservation
and Recreation and with the offices with plat and plan approval authority or zoning responsibilities as
designated by the locality for each locality in which the dam break inundation zone resides.
C. Owners of impounding structures may be eligible for matching grants of up to 50 percent from the Dam
Safety, Flood Prevention and Protection Assistance Fund and other sources of funding available to the
Director to assist in the development of dam break inundation zone maps and for conducting incremental
damage assessments in accordance with the Virginia Impounding Structure Regulations.
D. All properties identified within the dam break inundation zone shall be incorporated by the owner into
the dam safety emergency action plan of that impounding structure so as to ensure the proper notification
of persons downstream and other affected persons or property owners in the event of an emergency
condition at the impounding structure.
(2008, c. 491.)
§ 10.1- 606.3. Requirement for development in dam break inundation zones.
A. For any development proposed within the boundaries of a dam break inundation zone that has been
mapped in accordance with § 10.1- 606.2, the locality shall, as part of a preliminary plan review pursuant
to § 15.2 -2260, or as part of a plan review pursuant to § 15.2 -2259 if no preliminary review has been
conducted, (i) review the dam break inundation zone map on file with the locality for the affected
impounding structure, (ii) notify the dam owner, and (iii) within 10 days forward a request to the
Department of Conservation and Recreation to make a determination of the potential impacts of the
proposed development on the spillway design flood standards required of the dam. The Department shall
notify the dam owner and the locality of its determination within 45 days of the receipt of the request.
Upon receipt of the Department's determination, the locality shall complete the review in accordance with
§ 15.2 -2259 or 15.2 -2260. If a locality has not received a determination within 45 days of the
Department's receipt of the request, the Department shall be deemed to have no comments, and the
locality shall complete its review. Such inaction by the Department shall not affect the Board's authority to
regulate the impounding structure in accordance with this article.
If the Department determines that the plan of development would change the spillway design flood
standards of the impounding structure, the locality shall not permit development as defined in § 15.2 -2201
or redevelopment in the dam break inundation zone unless the developer or subdivider agrees to alter the
plan of development so that it does not alter the spillway design flood standard required of the
impounding structure or he contributes payment to the necessary upgrades to the affected impounding
structure pursuant to § 15.2- 2243.1.
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The developer or subdivider shall provide the dam owner and all affected localities with information
necessary for the dam owner to update the dam break inundation zone map to reflect any new
development within the dam break inundation zone following completion of the development.
The requirements of this subsection shall not apply to any development proposed downstream of a dam
for which a dam break inundation zone map is not on file with the locality as of the time of the official
submission of a development plan to the locality.
B. The locality is authorized to map the dam break inundation zone in accordance with criteria set out in
the Virginia Impounding Structure Regulations (4VAC 50 -20) and recover the costs of such mapping from
the owner of an impounding structure for which a dam break inundation zone map is not on file with the
locality and a map has not been prepared by the impounding structure owner.
C. This section shall not be construed to supersede or conflict with the authority granted to the
Department of Mines, Minerals and Energy for the regulation of mineral extraction activities in the
Commonwealth as set out in Title 45.1. Nothing in this section shall be interpreted to permit the
impairment of a vested right in accordance with § 15.2 -2307.
(2008, c. 491.)
§ 15.2 -2201. Definitions.
As used in this chapter, unless the context requires a different meaning:
"Development" means a tract of land developed or to be developed as a unit under single ownership or
unified control which is to be used for any business or industrial purpose or is to contain three or more
residential dwelling units. The term "development" shall not be construed to include any tract of land
which will be principally devoted to agricultural production.
§ 15.2 -2241. Mandatory provisions of a subdivision ordinance.
A. A subdivision ordinance shall include reasonable regulations and provisions that apply to or provide:
3. For adequate provisions for drainage and flood control, for adequate provisions related to the failure of
impounding structures and impacts within dam break inundation zones, and other public purposes, and
for light and air, and for identifying soil characteristics;
§ 15.2- 2243.1. Payment by developer or subdivider.
A. If the Department of Conservation and Recreation determines that a plan of development proposed by
a developer or subdivider is wholly or partially within a dam break inundation zone and would change the
spillway design flood standards of an impounding structure pursuant to § 10.1- 606.3, a locality shall
require, prior to its final approval of a subdivision or development, that a developer or subdivider of land
submit an engineering study in conformance with the Virginia Soil and Water Conservation Board's
standards under the Virginia Dam Safety Act (§ 10.1 -604 et seq.) and the Virginia Impounding Structure
Regulations (4 VAC 50 -20). The study shall provide a contract -ready cost estimate for conducting the
upgrades. The Department of Conservation and Recreation shall verify that the study conforms to the
Board's standards. Following receipt of a study, the Department shall have 15 days to determine whether
the study is complete. The Department shall notify the developer or subdivider of any specific deficiencies
that cause the study to be determined to be incomplete. Following a determination that a submission is
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complete, the Department shall notify the developer or subdivider of its approval or denial within 45 days.
Any decision shall be communicated in writing and shall state the reasons for any disapproval.
B. Following the completion of the engineering studies in accordance with subsection A, and prior to any
development within the dam break inundation zone, a locality shall require that a developer or subdivider
of land pay 50 percent of the contract -ready costs for necessary upgrades to an impounding structure
attributable to the development or subdivision, together with administrative fees not to exceed one
percent of the total amount of payment required or $1,000, whichever is less. Necessary upgrades shall
not include costs associated with routine operation, maintenance, and repair, nor shall necessary
upgrades include repairs or upgrades to the impounding structure not made necessary by the proposed
development or subdivision.
C. Where a payment under subsection B is required, such payment shall be made by the developer or
subdivider in accordance with the following provisions:
1. A locality may elect to receive such payment. Upon receipt, payments shall be kept in a separate
account by the locality for each individual improvement project until such time as they are expended for
the improvement project; however, any funds not committed by the dam owner within six years of the time
of deposit shall be refunded to the developer or subdivider. The locality may issue an extension of up to
an additional four years for the use of the funds if the dam owner shows that sufficient progress is being
made to justify the extension and the extension is approved by the Virginia Soil and Water Conservation
Board prior to the expiration of the six -year period. Should the locality be unable to locate the developer
or subdivider following a period of 12 months and the exercise of due diligence, the funds shall be
deposited in the Dam Safety, Flood Prevention and Protection Assistance Fund for the provision of grants
and loans. Any locality maintaining an account in accordance with this section may charge an
administrative fee, not to exceed one percent of the total amount of payment received or $1,000,
whichever is less.
2. If the locality elects not to receive such payment, any payments shall be made to the Dam Safety,
Flood Prevention and Protection Assistance Fund pursuant to § 10.1- 603.19:1. The funds shall be held by
the Virginia Resources Authority for each improvement project until such time as they are expended for
the improvement project; however, any funds not committed by the dam owner within six years of the time
of deposit shall be refunded to the developer or subdivider. The Board may issue an extension of up to an
additional four years for the use of the funds if the dam owner shows that sufficient progress is being
made. Should the Department of Conservation and Recreation be unable to locate the developer or
subdivider following a period of 12 months and the exercise of due diligence, the funds shall be deposited
in the Dam Safety, Flood Prevention and Protection Assistance Fund for the provision of grants and
loans. The Virginia Resources Authority shall not have any liability for the completion of any project
associated with the moneys they manage in the Dam Safety, Flood Prevention and Protection Assistance
Fund.
D. No locality shall be required to assume financial responsibility for upgrades except as an owner of an
impounding structure.
E. The owner of the impounding structure shall retain all liability associated with upgrades in accordance
with § 10.1- 613.4.
(2008, c. 491.)
4VAC50- 20 -40. Hazard potential classifications of impounding structures.
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A. Impounding structures shall be classified in one of three hazard classifications as defined in subsection
B of this section and Table 1.
B. For the purpose of this chapter, hazards pertain to potential loss of human life or damage to the
property of others downstream from the impounding structure in event of failure or faulty operation of the
impounding structure or appurtenant facilities. Hazard potential classifications of impounding structures
are as follows:
1. High Hazard Potential is defined where an impounding structure failure will cause probable loss of life
or serious economic damage. "Probable loss of life" means that impacts will occur that are likely to cause
a loss of human life, including but not limited to impacts to residences, businesses, other occupied
structures, or major roadways. Economic damage may occur to, but not be limited to, building(s),
industrial or commercial facilities, public utilities, major roadways, railroads, personal property, and
agricultural interests. "Major roadways" include, but are not limited to, interstates, primary highways, high -
volume urban streets, or other high - volume roadways, except those having an AADT volume of 400
vehicles or less in accordance with 4VAC50- 20 -45.
2. Significant Hazard Potential is defined where an impounding structure failure may cause the loss of life
or appreciable economic damage. "May cause loss of life" means that impacts will occur that could cause
a loss of human life, including but not limited to impacts to facilities that are frequently utilized by humans
other than residences, businesses, or other occupied structures, or to secondary roadways. Economic
damage may occur to, but not be limited to, building(s), industrial or commercial facilities, public utilities,
secondary roadways, railroads, personal property, and agricultural interests. "Secondary roadways"
include, but are not limited to, secondary highways, low- volume urban streets, service roads, or other low -
volume roadways, except those having an AADT volume of 400 vehicles or less in accordance with
4VAC50- 20 -45.
3. Low Hazard Potential is defined where an impounding structure failure would result in no expected loss
of life and would cause no more than minimal economic damage. "No expected loss of life" means no
loss of human life is anticipated.
C. To support the appropriate hazard potential classification, dam break analysis shall be conducted by
the owner's engineer or the department in accordance with one of the following alternatives and utilizing
procedures set out in 4VAC50- 20 -54.
1. The owner of an impounding structure that does not currently hold a regular or conditional certificate
from the board, or the owner of an impounding structure that is already under certificate but the owner
believes that a condition has changed downstream of the impounding structure that may reduce its
hazard potential classification, may request in writing that the department conduct a simplified dam break
inundation zone analysis to determine whether the impounding structure has a low hazard potential
classification. The owner shall pay a fee to the department in accordance with 4VAC50 -20 -395 for
conducting each requested analysis. The department shall address requests in the order received and
shall strive to complete analysis within 90 days; or
2. The owner may propose a hazard potential classification that shall be subject to approval by the board.
To support the proposed hazard potential classification, an analysis shall be conducted by the owner's
engineer and submitted to the department. The hazard potential classification shall be certified by the
owner.
D. Findings of the analysis conducted pursuant to subsection C of this section shall result in one of the
following actions:
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1. For findings by the department resulting from analyses conducted in accordance with subdivision C 1
of this section:
a. If the department finds that the impounding structure appears to have a low hazard potential
classification, the owner may be eligible for general permit coverage in accordance with 4VAC50 -20 -103.
b. If the department finds that the impounding structure appears to have a high or significant hazard
potential classification, the owner's engineer shall provide further analysis in accordance with the
procedures set out in 4VAC50 -20 -54 and this chapter. The owner may be eligible for grant assistance
from the Dam Safety, Flood Prevention and Protection Assistance Fund in accordance with Article 1.2 (§
10.1- 603.16 et seq.) of Chapter 6 of Title 10.1 of the Code of Virginia.
2. For findings by the owner's engineer resulting from analyses conducted in accordance with subdivision
C 2 of this section:
a. If the engineer finds that the impounding structure has a low hazard potential classification, the owner
may be eligible for general permit coverage in accordance with 4VAC50 -20 -103; or
b. If the engineer finds that the impounding structure appears to have a high or significant hazard
potential classification, then the owner shall comply with the applicable certification requirements set out
in this chapter.
E. An incremental damage analysis in accordance with 4VAC50 -20 -52 may be utilized as part of a hazard
potential classification by the owner's engineer.
F. Impounding structures shall be subject to reclassification by the board as necessary.
Statutory Authority
§ 10.1 -605 of the Code of Virginia.
Historical Notes
Derived from VR625 -01 -00 § 1.4, eff. February 1, 1989; amended, Virginia Register Volume 24, Issue 25,
eff. September 26, 2008; Volume 29, Issue 2, eff. November 8, 2012.
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