WASHINGTON—With snowfall diminishing at "statistically significant" rates, spring runoff coming earlier and a dead zone the size of Rhode Island in the ocean off the Oregon coast, senators were told Wednesday that global climate change is already being felt in the West.
Dam operators, water district managers, farmers, conservationists and scientists all predicted mounting problems as scarce water supplies dwindle further in an area stretching from the Pacific Northwest to the desert Southwest.
"The warming in the West can now confidently be attributed to rising greenhouse gases and are not explained by any combination of natural factors," said Philip Mote, head of the Climate Impacts Group at the University of Washington.
Mote said some models show temperatures in the West could rise by 6 degrees Fahrenheit in the coming years. Signs of climate change, such as lilacs blooming earlier in the spring, are just a "harbinger of changes to come," he said.
Among other things, the Senate Energy and Natural Resources water and power subcommittee learned:
_Spring snow pack already has declined at nearly 75 percent of all weather recording stations in Washington, Oregon and California, and the spring runoff is coming two weeks earlier than in the past.
_Southern California is experiencing its driest year on record, and Lake Mead, which supplies water to large parts of the fast-growing Southwest, could be empty in 10 years.
_By some estimates, populations of Pacific salmon in the Northwest could drop between 20 percent and 40 percent by 2050, with even greater losses in California and Idaho. Western trout populations eventually could fall by more than 60 percent.
_A dead zone of "very low dissolved oxygen" has appeared every year in the Pacific Ocean off the Oregon coast since 2001, and unlike other ocean dead zones, pollution or other human activity isn't believed to be the cause. Instead, some scientists say there may be a "fundamental change" occurring in the ocean off the West Coast, changes that may involve wind patterns "modified" by climate change.
_ Tens of thousands of irrigated acres will fall out of production as water supplies tighten, and tensions over water supplies will only be exacerbated as the effects of climate change deepen.
"These changes will force us to adapt how we manage irrigation and agriculture, our hydropower system, salmon recovery, municipal water supplies and flood control," said Sen. Maria Cantwell, D-Wash., who chaired the hearing. "We need a real strategy to keep our region strong and to respond to any impacts we observe."
While all of the witnesses said more scientific modeling was needed to provide a more focused picture of climate change effects on specific regions in the West, Cantwell seemed impatient that federal, state and local agencies might not be doing sufficient planning.
Terry Fulp, who manages operations at Hoover Dam and Lake Mead for the Bureau of Reclamation, said he has the flexibility he needs to manage water supplies. But under questioning from Cantwell, Fulp said the bureau probably needs to be developing longer-range plans to deal with the effects of climate change on its operations.
In Washington state, Tim Culbertson, general manager of the Grant County Public Utility District, said interim storage reservoirs are being considered at Black Rock in the Yakima Valley and at Crab Creek in the Columbia Basin Project.
Cantwell said Congress and the federal government may have to rethink its skepticism over building more reservoirs, which can be filled when flows are high and drained during summer months.
"We have turned away from reservoirs, right or wrong," Cantwell said. "Maybe we should rethink that."
Culbertson also testified that the Grant County PUD, which operates two major dams on the Columbia River, is considering adding turbines at water storage facilities and has been tracking the development of "microturbines," which could be placed in irrigation canals to generate electricity.
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