Posted 06 June 2011, by Mike Lee, Sign On San Diego, signonsandiego.com
The U.S. Bureau of Reclamation, which manages water flows on the river, issued the first installment of a long-range study about bridging the gap between supply and demand for river water. The next update will deal with water-use projections and ways to address shortages. The final report, with recommendations, is expected in July 2012.
The Colorado River is one of the San Diego region’s two main water sources, along with the Sacramento-San Joaquin River Delta. Local officials are trying to develop local sources such as groundwater, reclaimed wastewater and desalinated ocean water.
After a long line of dreary forecasts for the Colorado River Basin, no one expected the bureau’s projections to be rosy — and they weren’t. The study anticipates roughly a 9 percent decrease in flows on the river over the next 50 years, along with increased drought periods. Projections are based on climate models that show decreased precipitation across the Southwest in years to come.
“This is the most comprehensive look at the water supply and water demand picture in the Colorado River Basin,” said Halla Razak, Colorado River program director for the San Diego County Water Authority. “Everybody really believes that this study will give us a pretty good road map to move forward.”
That’s no easy task given that there’s more demand for Colorado River water than it can provide today, let alone with lower flows and higher demands.
Monday’s study said the period from 2000 through 2010 represents the lowest 11-year average natural flow at a given point on the Colorado River in recorded history, approximately 20 percent below the 103-year average. Although an 11-year drought of that magnitude is unprecedented in over 100 years, reconstructions of prehistoric stream flows show that equal or greater droughts have occurred.
On the demand side, the study said that from 1971-1999 water use in the Colorado River Basin increased by about 23 percent.
San Diego County and the rest of the state emerged from a three-year drought and related water-use restrictions after heavy snowfall last winter. Many water experts expect the reprieve to be temporary.
About 15 percent of Colorado River withdrawals are used by the basin’s urban water utilities use that serve more than 30 million people and support hundreds of billions of dollars in economic activity annually. In addition, the Colorado River is a major source of water for agriculture, irrigating nearly 4 million acres of land. The river also is a major source of hydroelectric power.
“While there is no ‘silver bullet’ for managing future supply challenges, there are opportunities for urban, agricultural, and other water users in the basin to collaborate on a balanced, sensible approach for managing future Colorado River supplies and managing potential future shortages while avoiding significant economic and quality of life impacts to the region,” said a statement issued Monday by urban water agencies across the West, including the county water authority.
The conservation group Environmental Defense Fund said it’s pushing the Bureau of Reclamation and state officials to ensure that the federal study identifies solutions to the imbalance between water supply and demand while sustaining healthy river flows.
“Active outdoor recreation in the Colorado River Basin contributes more than $75 billion annually to the region’s economy and supports more than 780,000 jobs,” said Dan Grossman, the group’s director in the Rocky Mountain region. “That’s why we must capitalize on this study by crafting a path forward that protects the health of the Colorado River–and the ecosystems and economies it supports–or we’ll miss a critical opportunity with potentially tragic consequences for the region.
He added: “While the Bureau of Reclamation and Colorado River Basin states have made some progress, they have a lot of work left to do.”
Mike Lee: (619)293-2034; firstname.lastname@example.org. Follow on Twitter @sdutlee.