Accession Number : AD0756156

Title :   Prototype Observations of Snettisham Project Diversion Tunnel, Long Lake, Alaska.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s) : Munsey,Thomas E. ; Neilson,Frank M.

Report Date : APR 1971

Pagination or Media Count : 33

Abstract : The report is concerned with the unlined diversion tunnel that was used to draw down Long Lake to expose the proposed location for an unlined power tunnel to be constructed as part of the Snettisham project about 28 miles southeast of Juneau, Alaska. The object of the study was to compile project data pertaining to diversion tunnel geometry, lake tapping flow characteristics, and the resultant lake drawdown. These data will augment currently available information concerning the hydraulic characteristics of unlined rock tunnels and lake tapping in the United States. Data pertaining to the hydraulic roughness and friction factor for flow through the diversion tunnel are presented and compared with current design practice. General observations of the lake piercing operation, including a sequence of photographs that depict the front of the initial surge from the tunnel, are also presented. It is concluded that lake tapping proved to be a satisfactory means of diversion at the Snettisham project. (Author)

Descriptors :   (*LAKES, DRAINAGE), (*ELECTRIC POWER PRODUCTION, *WATER TUNNELS), UNDERGROUND STRUCTURES, HYDRODYNAMICS, FLUID FLOW, ALASKA

Subject Categories : Hydrology, Limnology and Potamology
      Electric Power Production and Distribution
      Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE