Lake Grassmere

Lake Grassmere is close to Cook Strait in the northeastern South Island of New Zealand. Lake Grassmere, 25 miles (40 km) south of Blenheim and 6 miles (9.7 km) south of the mouth of the Awatere River, is a shallow lagoon protected from the open sea by a single barrier beach covered by sand dunes. It is on the north-easterly extension of the Ward depression. Covering an area of 17 km², it has no natural inflow and is prone to strong warm winds. Close to the sea, it also has a very high salinity. Because of these geographical characteristics, it is ideal for natural salt extraction. Grassmere has been divided into solar evaporation ponds. Seawater is pumped in, and moved between ponds over several months, increasing in salinity with each...