Overview 

The Board of Supervisors voted unanimously in July to approve contracts for engineering and design work related to the rehabilitation of two Cherrystone Creek dams. These two contracts for design and engineering services, which total $1.426 million, are with Schnabel Engineering, a firm that provides geotechnical, dam, and tunnel engineering services.  

These rehabilitation efforts are required due to regulations from the State and Federal governments. 

The United States Natural Resources Conservation Service (NRCS) from the U.S. Department of Agriculture awarded Pittsylvania County two $750,000 grants (plus $40,00 apiece for the grant administration) to cover engineering and design work for Cherrystone Dams 1 and 2a. These grants did not require a local match.

While federal funding is covering approximately 100% of the design and engineering of the two projects, Pittsylvania County, the Town of Chatham, and the Pittsylvania County Soil and Water Conservation District (the local project sponsors) will be responsible for approximately 35% of the construction costs. The NRCS Small Watershed Rehabilitation program will cover the remaining 65%. 

Several different studies and analyses have been done over the past three years to evaluate potential design options. Each one involves multi-million-dollar costs for each of the two dams. The local project sponsors are still determining the exact cost-sharing arrangement for these rehabilitation projects. 

History and Background

During the mid-1960s the U.S. Soil Conservation Service entered into a watershed agreement with Pittsylvania County, the Pittsylvania Soil and Water Conservation District, and the Town of Chatham to conduct studies aimed at alleviating chronic flooding in the Cherrystone Creek Watershed. The agreement was in accordance with The Watershed Protection and Flood Protection Act. The studies ultimately resulted in the construction of two earthen flood control dams in the watershed. Cherrystone Dam No. 1 (Cherrystone) was constructed on Cherrystone Creek and nearby Cherrystone Dam 2A (Roaring Fork) was built on Roaring Fork Creek, a tributary to Cherrystone Creek. 

Since that time the dams have prevented major flooding and damage in the watershed. Cherrystone Dam No.1 is about 57 feet high and 780 feet long and impounds a lake of approximately 120 acres at full pool. Cherrystone Dam No. 2A (Roaring Fork Dam) is about 68 feet high and 400 long and impounds a lake of approximately 45 acres at full pool. 

Why Rehabilitation is Necessary

In 2008, the Virginia Impounding Structure Regulations (dam safety laws) were modified to require that regulated dams undergo a dam break analysis to simulate various failure modes and that emergency action plans be developed to promote public safety in the event of a large spillway release or potential failure of the dam.

The result of the studies indicated that these two dams were not “significant hazards” as originally thought but should be classified as “high hazard.” Consequently, the emergency (auxiliary) spillways for each dam were determined to be undersized and not capable of safely passing the flood requirements for a high hazard dam. Since that time, the Virginia Department of Conservation and Recreation has issued Conditional Operating Certificates for each dam pending studies and a plan to correct the spillway deficiencies providing the dams were otherwise well maintained and inspected per state regulations for high hazard dams. 

Costs and Funding Sources

Federal funding was provided for planning studies covering both dams through the NRCS. Pittsylvania County issued Requests for Proposals (RFPs) for the engineering of both dams. With a recommendation from County staff, the Board of Supervisors issued the contract to Schnabel Engineering for both dams in July of 2022. 

The exact project costs are unknown and dependent on the engineering solutions that are chosen for both dams. Multiple solutions provided through studies so far include price tags of several million for each dam. For instance, one design solution included a total project cost of more than $21 million to complete both dams. Whatever the final costs, 65% will be paid by the NRCS Small Watershed Rehabilitation program should federal funds be appropriated for the work. Local sponsors will be responsible for the balance.