Hegan, B.D. 1973 Geology of the proposed dam sites, Esk Valley project. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 193 31 p.
Abstract: The Esk Valley Project is a proposal to realign State Highway 5 from Eskdale to Wairoa and State Highway 5 from Eskdale to Titiokura. As the new highway alignment crosses the Esk River and several of its tributaries as well as the Waikoau River, it is suggested in the proposal that earth dams should be constructed at the crossings. Apart from carrying the highway these dams would be used to control flood waters and to supply water for industry adjacent to Napier. Although several alternative alignments are suggested this report deals only with the proposed dam sites on the computer-chosen alignment (see figure 1). In the computer alignment both S.H. 2 and S.H. 5 follow the true right hand side of the Esk River from Eskdale to a point immediately North of Deep Stream where S.H. 5 branches off to the north-west towards Titiokura. S.H. 2 continues in a north-easterly direction towards Wairoa and crosses the Esk River bypassing the Waikoau and passes into the Waikoau Catchment. Five earth dams are envisaged along the computer alignment located at Ruatoiti Stream, Otakowai Stream, Deep Stream, the Esk River and the Waikoau River (see figure 1). This report deals with the geology at the proposed dam sites, sources of borrow material for the earth dams and slope stability in the vicinity of the dam sites. (auth)