Probably the earliest method of production, producing salt from the lake, involves channeling sea water to flow into natural or man-made basins and allowing the water to evaporate using wind and solar energy. The water evaporates in successive ponds until the brine is fully concentrated and salt crystallizes on the floor of the crystallizing ponds. Solar salt plans must be located in areas of low rainfall and high evaporation rates. In Pakistan, for example, this method works well because evaporation exceeds rainfall by a factor of 3:1.