From AZCentral.com (Brandon Loomis):
The Southwest needs a new vision and technologies to shore up its diminishing water supplies instead of relying on old “security blankets” like a drought-busting winter that refills America’s two biggest reservoirs, water experts and users argued Monday.
That’s what’s been happening with water use in the Colorado River basin.
No matter how big the reservoir, “if you’re taking more out than you put in, you’ve got a problem,” former U.S. Interior Department water and science chief Anne Castle said.
Castle and other experts, including a Colorado city water director, a California water recycler and a Pinal County farmer, discussed a range of likely responses and challenges at the University of Arizona Water Resources Research Center conference…
In recent years the Colorado has given Lake Mead about 9 million acre-feet a year, while demands from downstream have averaged 9.6 million acre-feet and evaporation has claimed about 600,000 acre-feet each year…
Water recycling will increasingly be a part of the solution, and not just for watering golf courses or cooling power plants, said Fernando Paludi, associate general manager of Southern California’s West Basin Municipal Water District.
His district has invested $600 million in treatment plants allowing reuse for industrial uses, irrigation and groundwater replenishment. Since 1995 it has saved 165 billion gallons that Los Angeles otherwise would have dumped in the sea.
“We all share a water system, the mighty Colorado River,” Paludi said. “Heretofore the paradigm has been to get the water from where it is and bring it to Southern California.”
The future is about diversification and sustainability, he said…
One approach that many hope will free up water in the region is drip irrigation, a technology that delivers what a plant needs directly to its roots by pipe instead of flooding a field and watching water run off or sink into the ground. The potential for savings is huge, given that agriculture uses the majority of the Colorado River’s flows.
Drip irrigation is expensive — about $1,500 more per acre than a flood system — Pinal County farmer Dan Thelander said. Yet “the stars were in alignment” for his farm, Tempe Farming Co. near Maricopa, to install it on 1,000 of its 5,000 acres…
“We need to conserve water, which you can with drip,” Thelander said, “but the long-term outlook for water in Pinal County with the (Central Arizona Project) district is very concerning.”
CAP is the canal system delivering central Arizona’s share from the Colorado downstream of Lake Mead.
Israeli company Netafim invented drip irrigation 51 years ago, Netafim U.S. marketing director Ze’ev Barylka said, and it radically increases yields while decreasing fertilizer costs.
Yet only 4 percent of the world’s farmland uses it.
“It’s really in its infancy,” Barylka said…
Besides technological shifts, Castle said the region needs legal reform of water rights to make its management more nimble.
For instance, she said, Colorado has a water bank that would allow rights holders who don’t need to use all of their water allocation in any given year to deposit some water for sale to other users without risking loss of their full allocation in future years.
Such arrangements throughout the river basin are complicated by the legal requirement to research and prove that new water uses won’t harm other users. It’s a costly and time-consuming process that deters all but large “buy and dry” farm fallowing programs that many communities hope to avoid, Castle said.
The Southwest must adapt to climate change instead of hoping for a snowy winter in the Rockies or El Niño rains to reverse the drying, Castle said.
“We need to be prepared for a range of conditions,” she said, “and not pray for a wet year.”