L - Alaska Energy Data Inventory

The construction facility requirements have been reviewed and comparedwith facilities required for similar structures on similar projectssuch as Dworshak, Mica and Oroville. The Trans Alaska Oil Pipelineconstruction camp experience was also reviewed. Diversion tunnels areassumed to be fully lined and rock support assumptions during tunnelinghave been conservative. Careful analyses of means of diversion andprocedures have been made. Contingencies for construction facilitiesare 20 percent.Devil Canyon DamThe total contingencies used for the Devil Ca~yon gravity damestimate are $120,551,000, or 20 percent of the Devil Canyon constructioncosts. Contingencies for all features are the same percentages as forWatana dam for the same reasons, except that contingencies for the maindam, spillway, and auxiliary dam features have been increased to 20percent.Twenty percent contingencies were used for the main dam. Assumptionson foundation excavation and preparation for a gravity dam areconservative. Both abutments are exposed rock. The concrete gravitystructure is relatively simple with known features. Aggregate locationsand quantities available have been established.The auxiliary earthfill and concrete dam was estimated at 20 percentcontingencies. The borrow source is known, partially explored,and quantities determined. This is a simple, uncomplicated structure.Foundation excavation and preparation assumptions are conservative.The total contingencies for the thin arch dam alternate are$103,756,000 or 21.2 percent of the updated total estimated constructioncost of $665,000,000.In general, the contingencies used for this project are based onintensive study and comparison with cost histories and experience withother projects.The Office of Management and Budget (OMB) has questioned the contingenciesused based on a 36 percent overrun on the Snettisham project.The project cost estimate for the Snettisham project was $41,500,000 forfiscal year 1967. the first year of construction. This estimate includedthe Long Lake phase of project development, camp facilities, the transmissionsystem, and related features. The Crater Lake phase of projectdevelopment was added in fiscal year 1973, but design and constructionwere subsequently deferred.B-11