The US local desalination plants are mainly specialized in the treatment of bitter water. In some regions where water shortage is extremely serious such as Southern California, with the fast demand on water consumption, US government initiated the California water source development plan in 1960 in order to resolve the water shortage problem there. This plan tried to introduce the water from the deltaic area in the upper stream of San Francisco Bay, Northern California to Southern California, with the length of more than 600km and 28 dams and reservoirs and 22 pump stations established. It is the water transmission project with the longest transmission distance and the highest lift in the world. It costs 3.1kw/hr/t to transfer water to Southern California (excluding fresh water treatment), accounting for 2-3% of the power consumption in the whole California. It is the unique user with the largest power consumption in California.
Energy consumption is inevitable whatever water transfer or water making. According to ADC, the sea water desalination technique has become mature and the energy consumption is far lower than the energies cost for the water source development plan of California. Therefore, to establish one sea water desalination plant actually can save the energy consumed by transferring the water to Southern California. On the basis of the above, the US government established Bitter Water and Water Resources Study Technical Center, prepared the law on water resources desalination and carried out the study and development of desalination technique together with the non-governmental enterprises. On the basis that the sea water desalination was highly accepted by the mass with short terms of establishment, stable water supply, mature technique and low price, all states and local governments promoted the scheme where water source is replaced by sea water desalination. There have been altogether 2,563 desalination plants in the US, ranking the first in the world in terms of quantity. The daily output of the desalinated water is 3.6million t, which ranks the 2nd in the world. 80% water generated is used for domestic purpose and the rest 20% for industrial purpose.
Water Transmission Project in Southern California