If past patterns of California land-use change continue, projected water needs by the year 2062 will increase beyond current supply.
If past patterns of California land-use change continue, projected water needs by the year 2062 will increase beyond current supply. If historical trends of land use changes to or from urban, agricultural or other uses continue, the result will be increased water-use demand beyond what existing supplies can provide. Large uncertainties associated with weather and climate variability have the potential to exacerbate the problem.
Scientists with the U.S. Geological Survey and the Nature Conservancy calculated historical trends of land-use change, urbanization, agriculture expansion and contraction from 1992 to 2012, and then used those trends to project future land-use patterns and water demand from 2012 to 2062 in California’s Central Valley and foothills, Central Coast and South Coast. These new projections are detailed in the paper, “Future land-use related water demand in California” published this week in the journal Environmental Research Letters.
Assuming no new storage, efficiency or technology is created to improve California’s water supply, the study results indicate that the current 25 percent urban water-use restrictions called for in Governor Edmund G. Brown’s Executive Orders B-29-15 and B-37-16 would need to be maintained through 2062 for future water demand to remain at or below 2012 demand, unless restrictions were put in place on other water uses. Water use in 2012 was already proven unsustainable given the ongoing multi-year drought, which led to mandated statewide urban-use restrictions in 2015.
Source: US Geological Survey, May 18, 2016