When discussing the current drought in California, there is often talk of desalination and its potential to increase our freshwater supply. Desalination, the process of removing salt and minerals from saline water, seems like an obvious solution to the drought and ongoing water scarcity concerns because it is a reliable, drought-proof water source. Indeed, many new desalination plants have been proposed along the California coast and a number of them are already in operation, such as in Monterey and Carlsbad. While desalination may be a reliable option, the answer is much more complicated.
One of the greatest issues with desalination is the cost associated with these projects. A new plant may cost upwards of hundreds of millions of dollars to build (a billion in the case of the Carlsbad facility).
Beyond the costs to build these facilities, operational costs are substantial and raise concerns over the energy requirements and their impacts. Energy costs make up around a third of total operating costs for a typical desalination plant. These costs are often overlooked and not always factored into the total project cost. Long term, energy prices are not static and may increase due to the rising costs of developing renewable alternatives and building and maintaining new and existing infrastructure. Aside from the costs, there are other potential impacts associated with desalination facilities, including environmental impacts. Seawater intake systems that draw ocean water in through screened pipes trap marine organisms on the intakes. Smaller organisms able to pass through, such as eggs, larvae, and plankton, are entrained into the plant and killed during the desalination process. The byproduct of desalination is brine, the disposal of which can also have a substantial threat to marine life. Brine is usually pumped back out to sea for disposal. This increases salinity levels and may affect local sea life, depending on the plant’s location and sea currents.
The idea of building seawater desalination plants during a drought is not a new one. In 1991, a desalination plant in Santa Barbara was constructed in response to the 1987-1992 drought. Once the plant was completed, abundant rainfall rendered the plant cost-inefficient, and it shut down in 1992. Currently, costs to restart the plant are being assessed as the technology and infrastructure are dated and would incur new capital investment. Likewise, six seawater desalination plants were built in Australia in response to the Millennium Drought. Today, four out of the six plants are left idle due to the availability of cheaper alternatives. These examples should serve as cautionary tales.
The good news is that we still have cost-effective options readily available. A new study by the Pacific Institute and NRDC shows how California’s drought can be managed with better allocation and management of water resources. By implementing water-saving practices, water reuse, and storm water capture, California can save 5.2 to 7.1 million acre-feet of water each year in our urban areas – equivalent to the output of 125 large desalination plants!
Sustainable water management is best served by creating a comprehensive water management strategy in California, one that captures the most cost-effective options first. California has the ability to bridge the gap between water demand and supply by taking advantage of the existing resources and practices that have yet to be fully and efficiently harnessed.
The original article was written by Amanda Pegler, communications intern at Pacific Institute. The full report can be found at: www.californiadrought.org/what-about-desalination-during-the-drought/
— Brought to you by the City of Turlock Municipal Services Department
WATER CONSERVATION TIP #29
Redirect downspouts to capture water: Simply redirect downspouts outside your home to capture any rainwater and direct it to garden or plant areas.