Desalination: Is the US Navy the Solution to the World’s Droughts?
By Dr. Stephen Schwalbe
Faculty Member, Public Administration at American Public University
Since 2000, California has suffered some of its worst droughts since state climate record keeping began in the late 1800s.
The 2001-2002 rainy season in Southern California was the driest on record. The drought of 2011-2014 was the worst in state history. As of May 2015, the drought has worsened and continued.
Current Water Conservation Efforts Are Not Sufficient
California implemented numerous water conservation efforts to counteract the lack of fresh water. Eventually, those efforts will not be enough if the drought continues. So what is Plan B in case of emergencies?
There are three general solutions to water shortages: water conservation, water transfer from places with abundant water and desalination. California has already put water conservation practices into effect statewide.
As for transferring water, this measure is already in place from Northern to Southern California. Water is also transferred from the Colorado River to Southern California, where the Colorado River provides 80% of necessary water to Southern California.
However, there are approximately 25 million people living in Southern California who need water. That leaves the water desalinization option.
Desalination of Sea Water Is a Viable, But Costly Option
Desalination is the process of removing dissolved salts from water to create potable water. Around 150 countries rely on 17,000 desalination plants to produce over 211 billion gallons of fresh water daily.
Seawater is the primary source of water for 50 percent of these plants. Because of its steep costs and environmental concerns such as residual brine, desalinization of seawater is the last option.
There are three primary desalinization plants in California today. One plant is in Santa Barbara and provides 30% of the city’s water needs.
In Carlsbad, a city along the California coast between Los Angeles and San Diego, the largest desalinization plant in the country is about to go online, at a cost of $1 billion. This plant will produce 7 percent of San Diego County’s daily fresh water.
The third plant is scheduled to be built by 2020 in Monterey County, south of San Francisco. It should meet the water needs for three cities in the county.
These plants still leave a large number of Californians vulnerable to a water shortage crisis. In addition, these desalinization plants are susceptible to disruption from an earthquake or tsunami, which happened at Japan’s Fukushima nuclear power plant disaster in March of 2011.
Use of Desalinization Plants on Navy Vessels in Port
One possible solution to California’s water supply problem is to use the desalinization plants on board all U.S. naval ships and submarines while they are docked in port. These Navy plants use a reverse osmosis (RO) process to desalinate ocean water while a vessel is at sea. Osmosis is a process by which a liquid passes through a thin, porous membrane that acts as both a filter and a salt barrier.
Introduced into the Navy during the late 1980s, RO desalination plants quickly replaced the conventional water distillers formerly used for the shipboard production of fresh water because they were more effective and cheaper. The new RO plants proved to be highly reliable, generally performing at levels exceeding 98 percent. The Navy’s desalination plants may be helpful in establishing a water supply should California face a water shortage due to a natural disaster.
San Diego Has Over 50 Navy Ships and Submarines
For example, the largest naval base on the West Coast is in San Diego. It is home to the Navy’s Southwest Region Command Headquarters and its 46 surface ships of various types, including two aircraft carriers, 16 destroyers, eight cruisers and seven nuclear-powered submarines. Each one of these vessels has RO desalinization capability.
Each aircraft carrier produces up to 200,000 gallons of drinkable water daily. The destroyers and cruisers each create 12,000 gallons of fresh water per day, while each submarine produces 5,000 gallons per day.
In short, all 53 ships and submarines based in San Diego could manufacture as much as 1,217,000 gallons of fresh water each day. That equals 3.7 acre-feet of water per day, or 1,350 acre-feet per year. For reference, San Diego County uses around 450,000 acre-feet of water per year.
While the total Navy RO desalinization production of potable water in San Diego is not close to replacing all of San Diego County’s fresh water needs, these Navy vessels are a reliable source of water in an emergency. It should be noted that all of the Navy ships are not in port at the same time, so the actual amount of fresh water produced would depend upon which ships were in port and available.
Potable Water from Navy Ships Should Be Made Available in Emergencies
The Navy is capable of providing a substantial amount of fresh water to Southern California in an emergency. As long as providing water does not conflict with any Navy missions, this potable water should be made available to the public. The sooner that local governments and the military work out the required permissions and infrastructure to make this option possible, the better off California’s emergency water supply will be.
Navy Water Supply Solution Could Be Adapted Beyond San Diego
Water supply shortages are not unique to Southern California. In the event that other U.S. states suffered from water shortages, government agencies could make contingency plans to supply affected regions with Navy-produced water.
Emergency supplies of fresh water could come from a variety of Navy bases where vessels are in port, including these locations:
- Pearl Harbor, Hawaii
- Kitsap and Everett, Washington
- New London, Connecticut
- Kings Bay, Georgia
- Norfolk, Virginia
As drought conditions appear to be getting more severe across the country, it would be wise to consider the fresh water option available from the U.S. Navy. The American taxpayer is already paying for this desalinization capability, so using Navy ships as a water source is a solution waiting to be exploited to solve a potential problem.
About the Author
Dr. Stephen Schwalbe is an associate professor at American Public University. He is also an adjunct professor at Columbia College and Embry-Riddle Aeronautical University. Stephen received a Ph.D. in Public Administration and Public Policy from Auburn University in 2006. His book about military base closures was published in 2009.