INVESTIGATIONS AND REMEDIAL WORKS AT DRAKESBROOK DAM IN WESTERN AUSTRALIA

PAPER ABSTRACT

Drakesbrook Dam is a 17m high earthfill embankment constructed in 1931 to provide water for the Waroona Irrigation District, 80km south of Perth. The dam has a storage capacity of 2.30 GL and is classified as a “High A” hazard dam according to ANCOLD Guidelines on Dam Safety Management.

A Dam Safety Review, undertaken in 2001 identified a number of deficiencies associated with the main embankment, outlet works and the main spillway requiring remedial works. Detailed design of these remedial works is currently underway. Challenging features of this project are the design of a liner for the existing curved conduit and the design of a new spillway with an usual drop-type stilling basin.

This paper presents the salient aspects of the remedial works design along with the various design and construction criteria adopted to achieve an economical design of a new spillway and outlet conduit sleeve without compromising the safety of the dam.