Rock work on lake's dam now complete
Work on refurbishing the erosion protection layer at Lake Pukaki is now complete.
Stage one of the work involved replenishing and rebuilding the erosion protection rock layer on the upstream side of the dam.
The erosion protection rock, which is also called "rip rap", stops the waves from eroding the dam face.
A spokesperson for Meridian said a decent northwest storm can pack some punchy waves and without the rock protection, the dam face would be susceptible to erosion.
"When the dam was originally constructed, more than 60,000 square metres of rock was required," she said.
"Some of the rock was made up of random, large [bigger than two metres in diameter], car-sized rocks and the first stage of the work was to fill the gaps in the existing rip rap."
The work was done with two diggers tracking along the dam face, breaking up the large rocks and then pushing them back into place amongst the existing rip rap. Stage two involved adding more rock to the dam to bring the level of the rip rap protection up to the crest line.
With the rock work now complete, Pukaki dam is set up for a further 40-plus years of operation, without fear of wave action on the erosion protection rock layer.
- © Fairfax NZ News