Water efficiency is key in California
The USA's independent environmental think-tank, the Pacific Institute, has just released a report that claims that efficiency measures could reduce statewide water use in 2030 by 20%, despite economic and population growth. Research associate, Heather Cooley, and president of the Institute, Peter H Gleick, explain how efficiency, conservation and technology could create a sustainable future.
To meet this challenge, federal, state and local governments have built a vast infrastructure to store, move and treat water. While that infrastructure has brought enormous benefits to Californians, it has also wrought serious ecological damage.
The political and economic costs of adding to this infrastructure are now so high that the state can no longer rely on new dams and storage to solve its problems. In many ways, California is already taking more water out of the system than it can afford.
The good news is that Californians could use water far more effectively, reducing demands while satisfying needs. For instance, while all new and remodelled homes feature efficient toilets, showerheads, and kitchen fixtures, millions of residents still use old, inefficient water-wasting appliances.
Front-loading washing machines save water, energy, and detergent for consumers. New toilets use a quarter of the water used by old models.
Thirty percent of all vineyards do not use efficient drip systems and nearly 80% of all vegetables are still grown with inefficient flood or sprinkler irrigation. This waste is good news for water planners, because it means that California has a massive reserve of potential water savings to draw upon.
In a recent report, California Water 2030: An Efficient Future, the Pacific Institute examines the implications of the widespread adoption of water-efficiency technologies on California's water use. The report concludes that by 2030, statewide water use could be 20% below 2000 levels - while still satisfying a growing population, maintaining a healthy agricultural sector, and supporting a vibrant economy.
Some of these reductions could be used to increase agricultural production in some regions; expand urban and industrial activities; and restore California's stressed rivers, groundwater aquifers, and wetlands.
The Pacific Institute's conclusions contradict everything water planners tend to assume. Traditional water planners look into the future, see rising populations and a growing economy, and typically assume that tomorrow's water uses will look much like today's.
That traditional vision of the future includes political fights over water allocations, deteriorating ecosystems and water quality, and rising prices. Yet by improving the efficiency of water use and cutting water waste with existing technology, Californians can continue to do the things they want with significantly less water.
State water planning
Since 1957, the principal tool for water planning at the state level has been the California Water Plan, an analysis published every five years by the California Department of Water Resources (DWR). For the Water Plan, DWR routinely prepares water scenarios and projections as part of long-term water planning.
These projections are based on the assumption that population, the economy and water use are inextricably linked, such that water use will increase as the population and economy grow. As a result, these plans routinely project substantial increases in water use over time, often far in excess of the use that actually materialises.
In the 2005 update of the California Water Plan, DWR introduced a long-term effort to develop multiple scenarios of water supply and demand. To initiate this effort, the state, with input from interested parties, developed three scenarios of future water demand in California.
Close analysis reveals that these scenarios are not dramatic departures from past analyses. All three scenarios include only modest efficiency improvements achievable with current policies and programmes.
DWR intends to evaluate various response packages, including greater water-use efficiency efforts, in future water plans. The Pacific Institute supports that effort, but believes it is critical to begin evaluating, and implementing, stronger water-conservation and efficiency programs now: waiting another five to ten years will only make solving California's complex water challenges more difficult and expensive.
An alternative vision
In California Water 2030: An Efficient Future, the Pacific Institute provides an alternative vision of California's future. The Institute produced a High Efficiency scenario using the same model DWR used for their future demand scenarios. The Institute's High Efficiency scenario adopted the same demographic, economic, and agricultural forecasts as DWR.
In contrast to DWR's scenarios, however, the Institute modified the assumptions about the potential for improving efficiency of water use for the urban and agricultural sectors based on more comprehensive implementation of existing technologies and application of historical trends for water prices.
The Pacific Institute's High Efficiency scenario suggests that substantial reductions in 2030 urban and agricultural water use are possible even with a growing population and healthy economy. Under the High Efficiency scenario, urban water use falls 616 million m3 per year below actual 2000 levels and far below levels projected in the DWR scenarios (see Figure 1).
Agricultural water demand declines in all scenarios due to DWR's forecasted reduction in irrigated crop area and changes in cropping patterns but the biggest agricultural savings comes from improving irrigation efficiency. Agricultural water demands decline 9 billion m3 or 23% below 2000 levels (see Figure 2) in the Institute's High Efficiency scenario.
Overall statewide human water demand in the High Efficiency scenario declines by 10 billion m3, a reduction of about 20% from California's total human water use in 2000, due to significant improvements in both urban and agricultural water use.
The Pacific Institute's High Efficiency scenario does not exhaust California's opportunities for improving water efficiency. Additional savings are possible if farmers continue the trend of moving away from water-intensive crops like cotton, pasture, rice, and alfalfa in favor of more valuable low-water crops like vegetables, fruits, and nuts.
The report also does not factor in future advancements in residential, commercial, and industrial technologies that will save even more water in our cities, though recent trends suggest that California is already moving in this direction.
Scenarios are not predictions, rather, they are tools to show the choices and options available to us, and the paths we might pursue. While the High Efficiency scenario suggests that an efficient future is possible, California's future depends upon the water policies implemented over the coming years.
This requires choices on the part of legislators, water managers, water districts and agencies, farmers, corporations, and residents. In order to move along a water efficient path, water planners need to update their long-held conceptions of what is possible.
Government subsidies must be restructured to encourage conservation and efficiency. Utilities and policymakers need to encourage residents to replace old, inefficient appliances with new, efficient ones.
However, Californians do not have to sacrifice their health, economy, or environment to meet future water demands. While the Pacific Institute's analysis focused on California's future water use, the conclusions are relevant nationally and internationally.
Sensible levels of water-use efficiency can be enormously effective in moderating demand and reducing the need to identify and provide new supplies. Experience in California, the US and throughout the world, has shown that efforts to improve water-use efficiency are consistently successful and cost-effective.
If all the time, money, and thought that goes into developing new water supplies were instead put into designing water-conservation and efficiency technologies, rate designs, and implementation strategies, water use would look far more like the Institute's High Efficiency scenario. This future is likely to be better for all people and their environment.
California Water 2030: An Efficient Future is available from the Pacific Institute and downloadable free from the website.