Golf course superintendents often say the only thing separating them from farmers is the crop each grows.
Superintendents can look to traditional farmers in one of the world's most fertile food-producing regions for a valuable lesson on water use.According to research conducted by NASA and Stanford University, underground aquifers in some parts of California's San Joaquin Valley have been so overtaxed that the ground's ability to hold water has been irreversibly damaged. Overpumping from 2007 to 2010, researchers say, has led to the ground subsiding by as much as 3 feet in some areas. Subsidence occurs when water is extracted from the earth, causing underground pockets that once held water to collapse.
If too much water is extracted from clay layers, the compaction becomes so great that the soil's ability to retain water is permanently diminished, according to Stanford researchers.
Thanks to an abundance of rain and snow in the the higher elevations that have helped recharge surface water reservoirs around the state, California Gov. Jerry Brown declared on April 7 that the state's most recent drought was over. Lakes that once were nearly dry now are full. Lake Oroville, the second-largest reservoir in California's complex matrix of surface water impoundments that move water around the state, was in the news daily when it came crashing through its spillway this winter.
That news has done little to alleviate concerns in areas where groundwater supplies remain sparse.
Thanks to overpumping of groundwater and ensuing subsidence, the San Joaquin Valley alone has permanently lost underground water-storage capacity of 336,000-600,000 acre feet, according to the study. For perspective, the Hetch Hetchy Reservoir, which delivers drinking water to San Francisco and is the 22nd largest water-storage impoundment in California, has a capacity of 360,000 acre feet.
Researchers say they expect at least that much underground water-storage space was lost again in California's most recent drought.
Folks in the Coachella Valley have taken notice. The Palm Springs area, which receives only about 5-6 inches of rain per year, gets its water from a variety of sources, including groundwater and the Colorado River.
According to the Coachella Valley Water District, more than 20 courses in the valley use recycled water or a mix that also includes Colorado River water. Twenty-nine courses take water directly from the Colorado and 73 others pump groundwater. The goal is to eventually get at least 50 courses in the valley on recycled water.
Recently, the CVWD announced its third "cash for grass" program for golf courses that pays water users to convert irrigated turf to non-irrigated land.
Just as it did in the previous cash for grass programs the CVWD will pay $15,000 for each acre of irrigated turf that is converted to desert xeriscape. The program is funded through a $5.24 million grant from California's Proposition 84 Implementation Grants program.
A total of 16 golf courses took part in one or both of the previous rebate programs, including and removed 129.5 acres of turf resulting in an estimated saves of 800 acre feet of water per year, or enough to provide water for 1,000 homes for one year, according to the district.
The cap for the third rebate program is a total of $1 million. At least six courses so far have signed up to take part in the latest cash for grass program, totaling $420,000 in rebates.