This animation illustrates how a standard Polychem chain and flight scraper system is assembled and installed.
Western water-use officials meeting in Las Vegas are using their annual conference to decide how California will reduce its use of the Colorado River for years to come.
Many see the conference as the best chance for the state to resolve differences with a holdout rural water district that opposes a 75-year agreement on how to use the river, fought over for decades by seven Western states and Mexico.
Without an agreement before Dec. 31, the federal government plans to withhold from California enough river water to supply 1.6 million households. The river now supplies water to 25 million people from Denver to San Diego.
Imperial Irrigation District officials were among those huddling in hotel conference rooms this weekend in advance of the annual Colorado River Water Users Association meeting.
``Time is running out,'' said Jack Porrelli of the Coachella Valley Water District in California. ``This needs to get done.''
Interior Secretary Gale Norton is expected to use her keynote speech to remind all involved that the deadline is near. She vowed that if an agreement isn't reached, the water reduction would have ``immediate effect'' on flow to Southern California.
Imperial Valley officials last week rejected as too risky a long-term conservation plan transferring water from Imperial farmland to Los Angeles and fast-growing San Diego County. They said the deal was forced on them and would endanger the county's $1 billion a year farm economy.
Imperial Valley officials have raised concerns that the district could be blamed if water diversions damaged the environmentally sensitive Salton Sea. A reduction of agricultural runoff could change the salinity of the inland body of water, which supports some 400 species of birds.
County officials say it would take a state law to smooth over concerns, and Norton said the Interior Department was powerless on the issue. ``Congress needs to grapple with the future of the sea,'' Norton said. ``It's an expensive, long-term project. That's not something that we have laying around in our budget.''
She added that though Interior Department is serious about the year-end deadline, it ``would not throw out the entire framework just because the deadline has not been met.''
Amanda Cyphers, chair of the Southern Nevada Water Authority, said that aside from the water deal, this year's conference was critical because drought throughout the West has worried officials from areas that depend on the Colorado River.
In the Gulf of California, marine life has been threatened in recent dry years despite a 1944 treaty guaranteeing Mexico about 10 percent of the river's flow.
``The reserves are low,'' Cyphers said. ``And we're all in this boat together.''