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Lost River Site 16

Comprehensive dam design services meet highest safety standards and growing water needs. 
  • Lost River Site 16 Dam riser structure-Gannett Fleming

    The dam’s riser structure is designed to convey all flow up to the 100-year frequency storm.

  • Lost River Site 16 sub-surface exploration-Gannett Fleming

    Our geotechnical team performed sub-surface exploration of the Lost River site to evaluate foundation conditions.

U.S. Department of Agriculture/West Virginia Natural Resources Conservation Service

Hardy County, West Virginia

Our Role
Planning, Design Engineer, Hydrogeology, Environmental.

Construction Cost
$29.3 million
New Construction
In Progress
  • Planning-level investigations support environmental impact statement
  • Dam design meets Natural Resources Conservation Service design standards
  • Environmental and permitting support move project toward completion.

To control flood damage in West Virginia’s Lost River Watershed, Gannett Fleming is performing planning-level studies to support an environmental impact statement and the design of a 100-foot-high, zoned earthfill dam. The reservoir created by the proposed dam also will provide 400 acre-feet of water supply storage and recreational benefits.

In addition to providing comprehensive dam design services, Gannett Fleming is assisting with complex environmental and permitting issues. When completed, this structure will protect the community from the loss of life and property caused by flooding. 

What We Did

Gannett Fleming provided hydraulic analysis, surveying, environmental studies, and preliminary and final design for the multi-purpose dam. With a 2,000-foot-long, zoned earth embankment, the dam will feature a principal spillway with a riser structure and principal spillway conduit and an auxiliary spillway cut into rock. The structure is designed to retard the runoff from a 100-year frequency storm without discharge occurring in the auxiliary spillway. Our team designed it to pass the Freeboard Hydrograph without overtopping the dam and provide adequate water supply storage to withstand the drought of record.

Additional services included aerial and ground surveys and mapping, subsurface exploration, laboratory testing of soil and rock samples, design of the dam and ancillary facilities, analysis of the auxiliary spillway using the Water Resource Site Analysis Computer Program, preparation of contract drawings and specifications, construction cost estimating, and support services during construction. We are assisting the Natural Resources Conservation Service with permit application support, including consultation on environmental issues.

Key Features

  • 100-foot-high, 2,000-foot-long earth/rock dam
  • Reinforced concrete riser principal spillway
  • 48-inch diameter pre-stressed concrete conduit
  • Reinforced concrete impact basin
  • 360-foot-wide earth/rock cut emergency spillway.

Sustainability Features & Outcomes

  • Safe yield study evaluated water supply options for worst drought of record
  • Maximized use of onsite soil and rock material to construct the new dam.

Similar Projects: Water/Wastewater: Dams & Levees, Water/Wastewater: Drinking Water, Engineering, Geotechnical, Water Resources: Safe Yield & Water Supply Investigations, Water/Wastewater: Water Resources, Engineering: Water/Wastewater