The Native American Affairs Office in the Commissioner's Office provides the overall lead for Reclamation's Native American Program.
Reclamation Assistance to BIA Safety of Dams Program
Safety of Dams Modifications – Parmelee Dam
Rosebud Indian Reservation
April 26, 2004
Team Leader: John Wilson 303-445-3018
Parmelee Dam is an earthfill embankment located on the Rosebud Indian Reservation, South Dakota. The original dam was constructed in 1968, and was determined to be in need of Safety of Dams (SOD) modifications in 1991 due to the structure’s inability to pass the inflow design flood and concerns regarding the potential for piping of embankment materials. In addition, the original outlet works was inoperable and was determined to require repair.
The SOD modifications consisted of four components; modification of the spillway, repair and modification of the outlet works, construction of a toe drain system, and relocation of the population at risk. The final design drawings and specifications were completed in May 2002. Modification of the service spillway consisted of removing the existing spillway and replacing it with a larger box culvert structure that is designed to safely accommodate the 50-year flood. The SOD modifications to the outlet works included replacement of the intake structure, installing an HDPE liner within the original CMP and grouting it in place, constructing a new gate stem, and building a concrete gate house. A perforated HDPE toe drain surrounded by filter sand and gravel was constructed along the downstream toe to safely collect and control seepage through the embankment and/or foundation, and prevent piping of fine-grained soils. In order to prevent loss of life from dam failure or large spillway releases, the three residences located within the floodplain downstream of the dam were removed and new mobile homes were purchased and placed a safe elevation above the flood level.
The construction contract was awarded on July 24, 2002, and all work was completed on April 30, 2003. Construction Management services were provided by Reclamation, and a Final Construction Report was issued in March 2004. Concrete placement during the winter required covering and heating. Thermal blankets, tents and heaters were used to maintain temperatures at 50 degrees Fahrenheit for 72 hours following each placement. Heating was also required to maintain appropriate temperatures during backfill grouting of the outlet works. A final walk-through was performed on April 29, 2003, and the contractor was given final completion on April 30, 2003.
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