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Dam Advocates Make Case for the Virtual River

Barry Nelson

Posted March 10, 2010

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This story in yesterday’s Los Angeles Times makes a compelling case for what NRDC calls the virtual river – new water supplies that can be tapped without pumping more from our overtaxed rivers. In fact, the dam advocates themselves make this case very persuasively.

As the article points out, some Central Valley growers are quite enthusiastic about the proposed $3.3 billion Temperance Flat Dam on the San Joaquin River.  That's no surprise - the federal water reclamation program has been very generous to its agricultural beneficiaries. As Bettina Boxall points out, after a 60 year interest-free loan provided by federal taxpayers, Central Valley Project growers have repaid only 19 percent of the 1.2 billion dollars they owe the federal government for the construction of the existing project.  (That amounts to a 300 year interest-free loan.  Imagine what your mortgage payment might be if you could get those terms!)  If these farmers could get that kind of financing deal on Temperance Flat Dam, of course they would jump at the opportunity.  But even a casual look at the numbers raises real questions about such an investment.

As grower Harvey Bailey admits in the piece, farmers couldn't pay $1,500 per acre for water from the proposed dam.  At around 3 acre-feet applied per acre of land, that amounts to a per acre-foot cost of about $500.  In reality, the real cost of water from the dam would certainly be far higher.  The Bureau’s estimate of $850 per acre foot is also certainly too low.  In 1994, the Bureau estimated that raising Friant Dam – a very similar storage project – would produce water costing nearly $3,000 per acre-foot.  A realistic low estimate of the true cost of water from Temperance Flat is perhaps $1,000 to $1,500 per acre-foot.  That’s more than 20 times what farmers in the area pay the Bureau of Reclamation for water today.  As Mr. Bailey admits, such a project would only be viable if subsidized by urban taxpayers or water users.  The problem is that the Metropolitan Water District of Southern California, quoted in the article, seems less than enthusiastic about the proposal.  The reasons for this reluctance are many - and persuasive.

First, there’s just not much water there.  For most of the past half century, 60 miles of the San Joaquin River have been literally dry – with every drop of water captured by the existing Friant Dam.  (Today, thanks to an agreement reached by NRDC, the Friant water users and the federal government, restoration flows have begun in the river.  As a result, in most years, Temperance Flat Dam would not produce a drop of water.  In very wet years, some water would be captured; however, on average, this yield is tiny.  It’s hard to justify building a new multi-billion dollar dam when there’s just not much water left to squeeze out of the river.

Second, the alternatives are far cheaper.  At perhaps $1,500 per acre-foot, just about everything would be cheaper than water from Temperance Flat - conservation, water recycling, groundwater clean up and storage, water purchased on the open market, even desalination could cost less.  And the proposed urban subsidy for agricultural water from this project – contemplated by the growers in the Times story – would further raise the cost of water for urban dwellers.

Third, the water from this dam would go to agriculture, not urban water users.  The Bureau of Reclamation owns the current dam on the San Joaquin River. It holds the water rights and is studying Temperance Flat.  Existing Central Valley Project agricultural contractors would expect the lion's share of water from any project.  Even if MWD wanted a piece of the project, getting water from Temperance Flat to Southern California would be a long uphill struggle.

Fourth, with every new groundwater project built in this part of the Central Valley, the tiny amount of water left to capture in the San Joaquin River would shrink.  Even optimists admit that it would likely be 20 years before Temperance Flat could be completed.  By that time, two decades of groundwater development would reduce the already small potential yield of the dam to a trickle.

Fifth, climate change is likely to further shrink the yield of Temperance Flat.  The U.S. Climate Change Science Program has projected that California could be 5-10 percent drier by the middle of the next century.  Clearly, water planners should be careful when considering a potential multi-billion dollar investment to capture the last 5 percent of water on the San Joaquin or any California river.  That water simply might not be there in the future. 

It’s not a surprise that agricultural interests are interested in building more old-fashioned dams in the Central Valley.  This technology served them well in the past.  However, given the issues above, it’s also not a surprise that business leaders, urban water agencies and environmentalists agree that the virtual river is a far better investment.

The only thing the LA Times got wrong in this story was the title – “Another Water Project Could Divide the State.”  When it comes to expensive projects like Temperance Flat Dam, most of the state is united.

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PhilipMar 10 2010 06:43 PM

Neither Sites nor Temperance Flat would do much of anything to increase agricultural supplies overall. There *is* a plausible argument to be made that off-stream storage will allow more efficient capture of water in very wet years, and more flexibility in operating the existing plumbing, so that many environmental objectives could then be be met without affecting agricultural and municipal supplies as badly as they are affected today. (Underground off-stream storage would be less expensive and available sooner, although it would require more energy. How much of such storage is available, and how the supply would be managed, is barely on anyone's radar.)
IMO, trying to sell the purpose of these expensive dams as solely agricultural is a poor idea. They have to be seen as ways to construct a more reliable and environmentally sensitive water system for large parts of the State, not just some farmers. Proponents need to prove that they will do this. Even if they can do so, and nobody wants to pay for them, end of story.

Barry NelsonMar 10 2010 08:33 PM

Philip - Thanks for the comment. Actually, there has been an enormous amount of off-stream storage built in California during the past 15 years -- approximately 6.5 million acre feet of storage capacity. Most of it grounwater storage in Kern County and Southern California, along with the Diamond Valley, Olivenhain and Los Vaqueros Reservoirs. The Southern California storage is particularly appealing to water users because it can be filled with water from a variety of sources, including local stormwater and recycled water, as well as Colorado and Bay-Delta water.

Around the San Joaquin River, ag. water districts are planning more groundwater storage to capture water in rare wet years. On the other hand, it is not yet clear that more storage north or south of the Delta will be valuable or cost effective. DWR has been studying Sites Reservoir for a decade and has yet to release many meaningful results of that analysis.

Californians have made major storage investments in the past 15 years. It's just that this new storage looks different from the projects built in the heyday of the reclamation program. I expect that trend to continue.

And as to your last point, you're absolutely right. Don't tell anyone, but what has stopped most old-fashioned dams in California during the past decade or two is not environmental opposition. It's the simple fact that no one wants to pay for them.


PhilipMar 12 2010 08:13 PM

There was a very interesting proposal about ten (?) years ago for underground storage a little southwest of Madera. It got bogged down in a lot of infighting and disputes over groundwater ownership (since then, as now, there is no regulation other than the law of the jungle in non-adjudicated groundwater basins. The thirstiest beast wins.)
As you know, you can't just squirt water into the ground anywhere and expect to have decent water when you pump it out. Overdrafting has destroyed some of the most promising aquifers, and I don't really know if there are more potential Kern Water Banks out there. It is really sad to see how much potential storage has already been destroyed, and why.

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