AGENDA DATE: 8/1/2018
TITLE:
Title
Update on Dam Safety Program
BODY
SUBJECT/PROPOSAL/REQUEST: Information is provided to familiarize the Board with County activities associated with dam safety.
ITEM TYPE: Consent Information Item
STAFF CONTACT(S): Richardson, Henry, Harper
PRESENTER (S): Greg Harper
LEGAL REVIEW: Not Required
REVIEWED BY: Jeffrey B. Richardson
BACKGROUND: Since the 1980s, the County has been responsible for properly operating and maintaining six dams regulated by the Virginia Department of Conservation and Recreation (DCR). A summary of these dams is included as Attachment A. These dams are earthen dams (as opposed to concrete) and generally located on County-owned properties: Mint Springs Park (2 dams), Chris Greene Lake Park, Walnut Creek Park, and on land adjacent to Monticello High School (Hillcrest Dam). One dam (Lake Hollymead) was accepted by the County to facilitate the acceptance of Timberwood Parkway by the Virginia Department of Transportation.
New DCR rules issued in 2008 require that owners of regulated dams perform an analysis of a dam break, or failure. The analysis involves mapping flood inundations zones to determine what structures (homes, businesses, and roadways) would be affected by a dam break. The purpose of the analysis is to:
* reassess the hazard potential classification of the dam - the hazard potential classification is an indication of the consequences (to life, structures, and property) of a failure and does not characterize the possibility of failure or the integrity of the dam
* determine if the dam has adequate spillway capacity to safely pass the spillway design flood (SDF) - the SDF is the most severe storm a dam must withstand
* update Emergency Action Plans (EAPs) - EAPs include a listing of the downstream structures that would be flooded due to a dam break
* monitor for new development within inundation zones
STRATEGIC PLAN: Infrastructure Investment - Prioritize, plan, and inv...
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