Story: Salt

How salt water is concentrated (2nd of 2)

How salt water is concentrated

Sea water is pumped into Lake Grassmere’s main lake (700 hectares), which has no stopbanks. When the water reaches twice its normal salt content, it is pumped into a series of preliminary concentration ponds (500 hectares) and then into final concentration ponds (80 hectares). Four deep storage ponds (20 hectares) hold the strong brines over winter. The following spring these brines are pumped back into the concentration ponds. After two or three years of this cycle the brine is strong enough to be pumped into the crystallisation ponds (93 hectares) from which the salt is harvested. The reconcentration ponds (40 hectares) are used for bringing rain-diluted brine back to full strength, and the wash ponds (8 hectares) are used for washing the salt after harvest and for rewashing stockpiled salt during refining.

Using this item

Te Ara - The Encyclopedia of New Zealand

This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.

Source: Dominion Salt

All images & media in this story

How to cite this page:

Carl Walrond, 'Salt - Early industry at Lake Grassmere', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/diagram/4333/how-salt-water-is-concentrated (accessed 12 December 2019)

Story by Carl Walrond, published 12 Jun 2006