Glimpses of the Colorado River

Urban watercyle

Colorado River, AZ, NV in 1871 | Timothy O’Sullivan/Library of Congress

It is said that each journey begins with one step and that a flood begins with a trickle of water. Over the past couple of weeks the Colorado River may have taken two small, but not insignificant steps, towards becoming something like the mighty Colorado explored by John Wesley Powell over 100 years ago. A new agreement between the US and Mexico could rejoin the Colorado River all the way to its Delta at the Sea of Cortez in Mexico.

To serve the needs of human populations of the Southwestern United States and Mexico, for the last decade the Colorado River has been completely drained dry by the time it reaches the Sea of Cortez.

On Nov. 20, the U.S. and Mexico signed a 5-year pact, updating the 1944 U.S. – Mexico Water Treaty. The new agreement tasks Mexico with drawing less water from Lake Mead in times of shortage, gives it rights to extra water in wet years, and allows it to store up to 1.5 million acre-feet in the reservoir.

At a cost of $10 million, regional agencies in the states of Southern California, Arizona, and Nevada will get almost 100,000 acre-feet of water from Mexico, according to the 5-year deal. (An acre-foot is roughly enough to supply two homes a year; one acre of alfalfa typically uses between 2.5 and 7 acre-feet of water per year).

The pact is an important part of addressing the challenges facing water users of the Colorado River (estimated at more more than 33 million people and growing) if the future demand for water outstrips the available supply, said Michael Connor, Bureau of Reclamation Commissioner. According to Connor, by the year 2060, the deficit between how much water the river can supply and how much states demand could be as much as 3.2 million acre-feet per year.

The U.S. and Mexico also agreed to release about 100,000 acre-feet of water in a one-time pulse, to help raise water levels in the beleaguered Colorado River Delta, parts of which have been practically dry since about 1998. While this is not enough water to simulate historical flows, it will help re-establish crucial habitat for migratory birds and wildlife at least for the near future.

Also, on November 19th The Department of Interior ordered a controlled flood event, released from the Glen Canyon Dam starting Nov. 19, to help create beaches and back eddies in the Grand Canyon. Since the dam was built in 1966, the only sediment sources for the Grand Canyon are the naturally flowing Little Colorado and Paria rivers, which feed into the Colorado River below the dam leaving the Grand Canyon looking more like a piece of scoured bedrock plumbing. USGS scientists observed the initial formation of beaches 100 miles below Glen Canyon. These beaches are a recreational and ecological resource for campers, rafters and native fish.

What does it all mean? These two events show what is possible when parties come together to look for solutions. All stakeholders will need to come to the table in the coming years if we are to divert the water train wreck in the Colorado Basin and ensure that the Colorado continues to be a river.

Climate change shows no sign of abating: The mean of all the models used in the forthcoming Bureau of Reclamation study indicates higher precipitation variability from year to year and a decline in average natural flows at Lees Ferry of 9% by 2060. Currently scheduled water deliveries from the Colorado system are not sustainable in the future if climate change reduces water runoff even by as little as 10%.

Leadership and a willingness of stakeholders to collaborate on making the hard decisions now regarding water management in the Basin will be critical to ensuring the Colorado continues to flow in the future.