Located 35kms down the coast from Blenheim, a large shallow lake has ponds that develop a deepening pink colour during the summer months. This is Lake Grassmere, Salt Lakes.
Seawater, fresh from the Pacific Ocean, is pumped into Lake Grassmere, the water evaporates and the salt concentration rises. As the water continues to evaporate, salt forms as a crust on the bottom of the ponds, the remaining water is pumped out and the dried salt is harvested, crushed, washed and moved by giant conveyor belts to form huge mounds of sparkling white crystals.
The pink to purple colour of the crystallisation ponds is caused by natural microscopic green algae that change to pink in the high salt concentration. The same phenomena gives the Red Sea its name. There are also small pink shrimps in the water that thrive in this salty environment.
They are easily seen from Highway 1, the colour pink catches your eye, that you JUST have to stop and have a look at what you are seeing!