Meander Dam: designing a new RCC dam
Client: Rivers & Water Supply Commission (now Tasmanian Irrigation)
Location: Tasmania, Australia
Date: 2001–2008
Innovative design of a new roller-compacted concrete dam and mini-hydropower station, providing reliable irrigation water to a regional farming district
Background
The 50 m high, 43 000 ML Meander Dam in northern Tasmania was planned to provide reliable irrigation water supply for the Meander Valley community to enable expansion of agriculture and increase employment in this regional area. The planned development also included a 2.5 MW mini-hydropower station to produce electricity for up to 5000 homes.
Solution
Entura was intimately involved in the Meander Dam project from feasibility through to completion of construction:
- We assessed the environmental and engineering feasibility of the project during 2001 and 2002, and these results became the basis of the dam’s Development Proposal and Environmental Management Plan.
- We undertook a tender design for the project in 2004 prior to it being awarded as a design and construct contract in late 2005.
- We undertook the detailed design of the dam and associated mini-hydropower station. This included civil and mechanical design and the preparation of a Dam Safety Emergency Plan.
- We designed a number of innovative features of the dam that allowed the construction process to be undertaken in a more efficient manner. These included the design of precast elements for the intake tower, spillway training walls, spillway crest, abutment crest parapets and dam gallery.
- We then provided construction support until the dam and associated works were completed in 2008.
Outcome
Meander Dam was successfully constructed and opened in early 2008, providing irrigation water to the Meander Valley community, and additional power to the Tasmanian grid. It features innovative solutions that can be leveraged in future roller-compacted concrete (RCC) dam projects. These solutions include a secondary spillway to reduce peak flood levels, the use of precast units for upstream and downstream formwork, the use of precast units in spillway training walls and crests, a conveyor system for delivering RCC, a comprehensive RCC quality control system, a cost-effective cranage system and the installation of an upstream membrane.