Development of Wells Hydroelectric Project

Abstract

The low rock elevation was used to advantage by the development of a nonconventional design where the turbines were deeply submerged such that spillway openings could be located above the turbine water passages and between the generators. By locating fish attraction facilities and fish ladders into the end walls and locating the specially designed switchyard on the top deck, all requirements of a hydroelectric development on the Columbia River were provided in a single structure. Extensive hydraulic model tests were necessary to verify the proposed design especially the effect on turbine operation of the spillway discharging directly above the draft tube outlets. The single concrete structure, located in a flood plain, required minimum cofferdam construction and resulted in a number of advantages, in addition to less cost, as compared to a conventional arrangement. Detailed descriptions of the structural design, fish facilities, earth embankments and construction are contained in companion papers.