News Reservoir Doc Feb 17 Dredging Facts

DREDGING the SOUTH FORK RIVANNA RESERVOIR Basic Information Did you know the following facts about dredging the SFRR? FACT: Dredging as a stand-alone project cannot satisfy the safe yield deficit. FACT: The major factor in determining estimated dredging costs are: composition of the sediments, location of the sediments, location for sediment dewatering, and sediment disposal and marketability. FACT: Hydraulic dredging could be used as a least disruptive form of dredging. FACT: Approximately 545 MG of sediment has been deposited in the SFRR since 1966. FACT: Based on continued sedimentation there will be approximately 1,302 MG of sediment in SFRR in 2055. FACT: Approximately 1,050 MG of sediment

would need to be removed to regain the original SFRR useable storage. FACT: Approximately 5,000,000 cubic yards of sediment would need to be removed. Approximately 100,000 cubic yards annually for 50 years. FACT: Approximately 67 truckloads per day would need to be hauled. FACT: The estimated volume of material would cover the playing field of Scott Stadium at UVA to a depth of about 26 feet each year. FACT: Estimates are that for a 50/50% (sand: silt/clay) mixture, the dewatering land required is approximately 40 acres. FACT: Estimates are that for a 50/50% (sand: silt/clay) mixture, the approximate total 50year dredging project cost would be between $127,000,000 and $145,000,000. FACT: Cost per gallon to provide 5.5 MGD safe yield from this concept is: $23 - $26. For additional information related to the RWSA Long-Term Community Water

Supply Plan to visit www.rivanna.org