Department of Water Resources
A daily compilation for DWR personnel of significant news articles and comment
April 11, 2008
1. Top Item
Dust Up: All that water, every drop to drink; s there any hope for desalination as a way to get water to a thirsty
Today, McIntyre and Snow discuss the feasibility of filtering ocean water to supply
'The SUV of water'
By Mindy McIntyre
With all the growing limitations on freshwater, it is easy to see why people would look to the
Many people mistakenly consider ocean desalination a harmless way to get water to growing cities without the effects associated with damming rivers and over-pumping groundwater. The truth is, desalination is one of the most harmful and expensive water options in
Consider that ocean desalination is the most energy intensive way to get water. That's right -- it requires more energy to desalinate a gallon of ocean water than it does to pump water from Northern California over a mountain range all the way to
Ocean desalination also requires that massive amounts of sea water, carrying millions of fish, plankton and other ocean life, must be sucked up and filtered everyday -- with 100% fish mortality. Those who care about the ocean know that these types of diversions can destroy miles of already stressed coastal habitats. In fact, people have been working for decades to stop power plants from this kind of water filtration.
Ocean desalination also fails the cost test. It is the most expensive source of new water for
We should also be aware that many of these desalination plants would be owned by private companies, including subsidiaries of multinational corporations. That raises concerns about transparency and accountability.
Locally controlled water conservation, water recycling and brackish water desalination are all far cheaper than ocean desalination. Coincidentally, these options are also less energy- and greenhouse-gas intensive, and less environmentally damaging.
Ocean desalination, quite frankly, is the SUV of water. We have better options. Communities need to decide whether they want their water sources to generate massive amount of greenhouse gas, cost a fortune and destroy the environment. I suspect that in most cases, Californians would reject that offer.
Mindy McIntyre is the Planning and Conservation League's water program manager.
Desalination deserves consideration
By Lester Snow
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Although most experts estimate that desalination will ultimately contribute less than 10% of total water supply needs, this still represents a significant portion of the state's water supply portfolio that can complement other locally developed supplies, conservation and recycling efforts.
The California Water Plan conservatively estimates that 300,000 to 500,000 acre-feet of desalinated water will be available annually by 2030 -- enough to sustain up to 1 million households for a year.
Desalination can provide significant value and numerous benefits including:
* Providing additional water supply.
* Replacing water lost from other sources and relieving drought conditions.
* Enhancing water reliability.
* Reducing groundwater overdraft and restoring use of polluted groundwater.
* Replacing water that can be used for river and stream ecosystem restoration.
During the extended drought of the late 1980s, several communities considered or built desalination facilities along the
Advances in technology during the past few years have helped make seawater a competitive source for drinking water. The cost of desalination has come down from about $1,850 an acre-foot in 1990 to levels competitive with imported water supplies, particularly in
It is important to note that there is an array of desalination projects ranging from brackish desalination (typically mildly salty groundwater) to ocean desalination. Brackish desalination is generally more cost-effective; however, ocean desalination may fit uniquely into a given region's strategy.
Mindy, you are correct in noting that ocean desalination plants may be more environmentally challenging, but work is being done to address these concerns. In fact, some Department of Water Resources grant funds have gone to projects working on state-of-the-art intake facilities, such as the development of beach wells that significantly reduce environmental impacts.
Overall, DWR has made grants of about $46 million for desalination projects, a large portion of the total investment of $260 million in the technology. Recently, the state has funded the development of a California Desalination Planning Handbook, which will help project proponents and communities identify and resolve issues.
Solving
Lester Snow is director of the California Department of Water Resources. #
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