PROVO — The third and final phase of the modification work under way at Deer Creek Dam will likely be done by early winter, according to the Bureau of Reclamation and Provo Water Users Association.

Deer Creek Dam, which is in Provo Canyon, has been undergoing improvements as part of a program that involves regular inspections of dams throughout the 17 Western states to identify and correct deficiencies and improve seismic performance.

The final stage of the seismic work began in October 2007 to improve the spillway control structure and raise the dam crest, which will allow these structures to withstand a large seismic event.

The improvement work at Deer Creek began in June 2004. Several government agencies, including Utah's Department of Transportation, worked together on the project.

To do the construction work, the water level had to be lowered.

The 2008 reservoir level will be kept 40 feet below the normal level until the construction work is completed. Recreational activities will again be available by mid-spring as the reservoir rises, said Keith Denos, PRWUA general manager.

Larger releases from the dam may be necessary in the spring with the current runoff at 111 percent of the average.

Deer Creek Dam is the main feature of the Provo River Project, which was constructed from 1938 to 1941. The structure stores water to provide for the municipal and irrigation needs of large portions of Salt Lake and Utah counties.