Study paints grim picture of future of Colorado River

By Michael Clark - 09 Jun 2011 16:38:0 GMT
Study paints grim picture of future of Colorado River

An interim study released by the US Bureau of Reclamation indicates that flows in the Colorado River may decrease in the coming decades and that the frequency and duration of drought events may increase, threatening the water supply of the Southwest. The study is the first in a series of reports that will estimate the future gaps in water supply and demand in the basin and make recommendations for closing the gaps. The report may be critical to sustaining the river and the region's water supply.

Though the report indicates the need to implement long term solutions to mitigate for future climactic conditions, recent events suggest the need for immediate action. In 2003, the supply and demand curves crossed, largely the result of steadily increasing demand and a precipitous drop in supply related to drought. The drought, which started in 2000, persists today. In Ocotober 2009,  Lake Mead, which is the source of water for Las Vegas and Southern California, reached its lowest elevation ever. The drought prompted allocation restrictions and rationing. Perhaps the most telling harbinger of things to come is the construction of Intake 3 at Lake Mead. The intake, constructed by the Southern Nevada Water Authority, which supplies water to Las Vegas, at cost of $700 million, is the supplier's third 'straw' that draws water from Lake Mead. It was built to ensure water deliveries should the other, higher intakes become obsolete due to sinking lake levels.

The current supply and demand problems are tied to the insufficiency of the river flow data used as the basis for  the Colorado River Compact of 1922, the allocation agreement between seven states, including California, Arizona, New Mexico, Utah, Colorado, Nevada, and Wyoming, and Mexico. The agreement was based on flow data from 1906 to 1922, a time of unusually high flows. Flow data since then indicate much lower average annual flows. Recent allocation policies have been geared toward allocating water within the Upper and Lower Basins during drought to account for low flows.

The Colorado River Municipal Utilities, a coalition of major water suppliers in the basin, has issued a statement in response to the study highlighting it as a "critical step toward understanding potential imbalances in Colorado River supply and demand and toward identifying potential opportunities to address the Basin's long-term water needs." The statement emphasizes the need for solutions implemented across end user sectors, emphasizing the fact that municipal demand accounts for only 15% of withdrawals in the basin. In short, it means that agriculture and water utilities will need to work closely.

Utilities have been taking steps to reduce demand and develop alternative supplies. The San Diego County Water Authority is undertaking initial technical studies for what would be the largest desalination facility in the US. The Orange County Water District has built a groundwater replenishment system that injects treated wastewater into the local aquifer to augment potable water supplies. The Southern Nevada Water Authority developed a cash for grass program to pay customers to remove grass, in the hopes of reducing lawn irrigation demand.

Pressure on the river will likely increase as flows decrease and demands increase. Population will likely continue to increase, and rising temperatures could spur increased demand in the agricultural sector. The burgeoning renewable energy sector in the region could also place additional demands on the river. In fact, the Imperial Irrigation District, in Southern California, developed an interim allocation policy for renewable energy projects due to an increasing number of water supply requests.

Clearly, the river is crucial to the Southwest and the US in general. The river supports a massive economy. Should desperation strike, it may be possible that the region may start looking east for water. Though it doesn't have the environmental controls of the US, China is building a massive $62 billion system of canals, pipelines and treatment facilities to transport water from the water rich south to its water poor north.

The study is scheduled to be completed in summer 2012. The next phase will detail the findings of demand projections. The last phase will include recommendations for closing the supply and demand gap. Folks should be waiting with baited breath for the findings of this report. It could very well dictate the future of the region.

Top Image Credit: © Paul Moore