Exam 17: Water Use and Management

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By comparison, both projects have the same purpose. That is to divert or transfer water from one region to another. In California, there is plentiful rainfall in the north, so excess water is pumped to the south. In China, it is the reverse. Southern China has plentiful water and will be pumping it to the north where it is scarcer.
In California, much of the original project was done rather underhandedly. In the early 1900s, land in northern California was quietly purchased by persons in power in Los Angeles. Eventually, they controlled over 90% of the water rights in the Owens Valley area of northern California. They built a huge aqueduct and transported the water to the south. So much water was transferred that the Owens River became dry for much of its course and Owens Lake, which was fed by the river, completely disappeared. In the 1940s, even more water was needed, so sources even further north were tapped to increase the supply. Another lake in this area lost half of its volume. This had serious environmental effects by decimating the population of brine shrimp that lived in the lake. This in turn decreased the number of waterbirds that relied on the shrimp as a food source. After many years of legal issues, the California Water Resources Board ruled in 1994 that LA must allow some water to replenish Lake Mono (the second lake affected). By 2014, the lake must be returned to its 1964 level. Some increase has been seen so far. The ecology also seems to be recovering slowly in this area.
In China, a huge multi-year, multi-billion dollar project is now underway to transfer water from southern to northern China. This will involve not one, but three separate routes to transfer the water to the needed regions. There are many problems and issues that will need to be dealt with. One issue is that water polluted by sewage and industrial waste is being transferred. Even though some areas are extremely dry, they are reluctant to accept this water. One of the routes will be extremely expensive and probably will not reach completion until at least 2050. This route will tunnel through mountains and over deep canyons. In addition, if global warming melts all of Tibet's glaciers, it may not be feasible in the long run. Environmental scientists worry that drawing from the Yangtze River will only worsen its pollution problems. Drawing water away from rivers on which millions rely only makes pollution problems worse. Downstream wetlands may also dry up, and ocean circulation may even be affected.