First, Do No Harm: A Water Conservation Expert Describes Alternatives to New California Dams

Monday, September 15, 2008

Governor Arnold Schwarzenegger has proposed controversial new dams for water supply in California. Heather Cooley, a senior researcher with the Pacific Institute's Water and Sustainability Program, argues that dams should be our last resort, not first.

WRR: What are some of the viable alternatives to more water storage?
HC: There are a number of good alternatives we should pursue before new surface storage dams. We've made a fair amount of progress in the past 10-20 years on residential water conservation - with new plumbing codes, appliance rebates, and technical advances, for example - but there is plenty more we could do. Our 2003 report "Waste Not, Want Not" showed that existing policies and technologies could reduce urban water use by up to one-third s. Most of the savings would be cheaper than new sources of supply, and with fewer social and environmental impacts. In particular, there is still a lot of room for water efficiency improvements in outdoor residential use, and the business and industrial sectors.

In addition to reducing demand, there is tremendous potential for augmenting local supplies, including recycled wastewater. We're beginning to see real leadership from some communities and agencies on this - for example, the mayor of Los Angeles has come out in support of water recycling, and Orange County is now recharging groundwater aquifers with recycled wastewater. In addition, capturing storm water provides another potential new source of water. In the past, storm water was viewed as a liability. Communities are now beginning to understand that it is an asset and are designing systems to capture this water so that it can recharge local groundwater aquifers. In addition to providing a new supply, storm water capture provides a number of other benefits: it cuts costs for handling storm water flows, and reduces impacts from pollution associated with urban runoff. In many places in the state this can be accomplished with low-tech methods - just allow the water to spread out on the ground where it can sink into an aquifer - but in some places it requires pumps to get it into wells.

Many of these methods would provide water or reduce demand at lower cost than building new water supplies. Desalting seawater, for example, costs $1,200 - $2,000 per acre-foot. In comparison, many water conservation and efficiency improvements can save water at a cost of less than $600 per acre-foot. In addition, dams and other supply projects are prone to cost overruns as well as associated social and environmental damage that are often not reflected in a typical cost comparison.  

WRR: If the dams did go through, how would that affect water-conservation efforts?
HC: It would remove the political pressure to conserve. When a new large supply system comes online, you tend to forget that water is a scarce resource. In addition, both of the proposed dams will be energy consumers, because of the need for pumping. One or two new dams will not solve our water problems, they will simply prolong the inevitable.  We must use our existing resources efficiently to ensure that water is available for existing social, economic, and environmental needs and those of future generations.

WRR: Climate change could reduce the state's snowpack by up to 40%. Is it possible to conserve our way out of that?  
HC: Reductions in the snowpack will have major repercussions for water management in the state, and we may need more storage at some point. In the meantime, we have other "no regrets" options available, such as recycled wastewater and water conservation and efficiency.  These options make sense regardless of the impacts of climate change. Large, irreversible, and expensive infrastructure can actually increase our vulnerability to climate change. If the hydrological regime changes significantly, we may find that the current dam proposals are inappropriate - we may find that those particular sites, on those particular rivers, aren't the best places to build dams. Furthermore, our depleted groundwater aquifers may provide sufficient storage. These aquifers can store water during wet years that can be used during dry years.  

WRR: What energy savings might we see from increased water conservation in the state?
HC: Energy is used throughout the water cycle. We use energy to capture, convey, treat, and distribute water. We then use additional energy to pressurize and heat water for use in our homes and businesses. A 2005 report by the state Energy Commission found that 19% of the state's electricity use and 33% of our natural gas use are water-related. So, saving water saves energy. For example, front-loading clothes washers use about 40% less water than top-loading models. And with front-loaders you are saving not just water, but hot water and thus energy.

WRR: If you were Water Queen for a Day, what smart water practices would you make the law of the land?
HC: I would begin by limiting the use of lawns, and promote the planting of more drought-tolerant native-plant landscapes, which have the added benefit of increasing wildlife habitat and reducing pesticide use. Then I would urge communities to rely less on long-distance imported water supply and begin to develop local water resources (and conserve them). Finally, I'd make sure that water was appropriately valued, so that those who waste it would have to pay more.

WRR: The damming of the US west is still often put forth as a model for some developing countries. What advice would you give to governments looking at this model for replication in their own countries?

HC: A reliable water supply is certainly critical to development, and our dams have brought tremendous benefits. But you need to look at the costs, too, which have also been very high: salmon fisheries along the West coast are collapsing. We're also taking down dams, and I believe this trend will continue. I would encourage governments to develop other alternatives first, emphasizing conservation and efficiency. I would also advocate for transparent and inclusive decision-making processes. Dams should be compared against other options first, and if a dam is the chosen option, it should be through a decision-making process that involves local communities.

 Major water conservation potential on farms

The Pacific Institute has just released a report showing that California farmers could save billions of gallons of water each year - the equivalent of 3-20 dams - by growing less-thirsty crops and using more efficient irrigation systems, and other improvements. The report recommends ways to overcome some of the financial, legal, and institutional barriers that can hinder farmers from implementing water-saving adaptations and investments.

The report, titled "More with Less: Agricultural Water Conservation and Efficiency in California," suggests that more dams may be necessary, but first, the state must create a better system for tracking water use.  Peter Gleick, president of the Pacific Institute, told the San Francisco Chronicle: "Wouldn't it be best to know exactly how much water we need to deliver so we don't overbuild (dams) or spend more money than we need to spend?"

More information: 

For more information on water conservation plans, see

For more on the proposed dams see WRR, February 2007 issue.