Construction work on the Waimea Community Dam in New Zealand is now approximately 80% complete, with 11 months and $40 million of spend remaining, Waimea Water has reported in its quarterly update.

The major dam project located on the Lee River will increase water to aquifers that supply Richmond, Brightwater, Mapua, and other urban areas along the Waimea Plain once complete – which is expected towards the end of 2023.

Waimea Water said that significant milestones have been reached on the project, with the concrete face and concrete parapet wall on top of the crest completed, allowing the mechanical elements on the face, including the intake screens, rails and winch platform to be installed and commissioned in early October 2022.

The spillway chute and flip‐bucket were completed in August 2022. The ogee weir and optimum hydraulic flow was completed in October 2022.   

Construction of the 9m high concrete cut off wall between the spillway flip‐bucket and plunge pool was hampered by flood events back in July and August but construction of the toe berm, drainage weirs and spillway bridge abutment on the downstream side of the embankment continued and all are expected to be completed by the end of 2022.

Upstream of the spillway in the approach channel, work has commenced on constructing the structures to support the geosynthetic liner, is due to be installed during the first calendar quarter (March) of 2023.

On 18 October, the project reached the milestone of closing the first of two culverts to commence the temporary river diversion works. The temporary river diversion works will be completed over the summer, to then allow the reservoir to be closed and commence filling immediately after the seasonal summer demands for water.  

Downstream face, toe berm and spillway pictured in September 2022. Image courtesy of Waimea Water