I've always had a fondness for the Colorado River of the Southwestern USA (as opposed to the one in Texas). As a nascent hydrologist who emigrated to Arizona from New York in 1970, I was introduced to the vagaries of such things as Western water law, over-appropriated rivers, irrigation projects, and the Bureau of Reclamation, all via the Colorado River. Marc Reisner gave it the moniker 'An American Nile' in his book Cadillac Desert. Two of the world's great dams, Hoover and Glen Canyon, grace (some may object to that word, preferring 'obstruct') its channel. Along its 1450-mile (2330 km) length you'll see some of the most spectacular landscapes in the world. Although its drainage basin area is about the size of the Columbia River's - approximately 250,000 square miles (650,000 square km) - its average annual flow is but a fraction of the Columbia's, about 15 million acre-feet (MAF) (590 cubic meters per second or cms) to around 200 MAF (7800 cms) for the Columbia. The aridity of the Colorado Basin becomes even more obvious when you compare the Colorado River to the Willamette River of Oregon, whose drainage basin of about 12,000 square miles (31,000 square km), 5% of the Colorado's, produces an average annual discharge of about 24 MAF (940 cms), 60% greater than the Colorado's.
So my connection to the Colorado explains why I am especially intrigued by the controversy surrounding leakage from the All-American Canal, which extracts irrigation water from the Colorado and then hugs the USA-Mexico border on its 82-mile (132 km) journey westward. The canal is unlined and about 70,000 acre-feet per year (3 cms) of its annual flow of almost 3 MAF (120 cms) are lost to seepage. Wasted water, right? Hold your horses, pardner! It all depends on which side of the border you live.
View this photo - map of the All-American Canal region.
A recent article, 'The Efficiency Paradox', by Matt Jenkins in the 5 February 2007 issue of the High Country News (www.hcn.org) discussed the 'wasted water'. It's not really wasted at all. It recharges the ground-water system and flows in the subsurface to Mexico where it is harvested by Mexican irrigators. USA interests - mainly the San Diego County Water Authority and the Imperial Irrigation District - want to harvest this seepage by replacing 23 miles (37 km) of the the old canal with a lined (non-leaky) one and delivering the 'saved' water to thirsty SoCal denizens. The USA claims that it can do this, since this 'wasted' water is part of its allocation under the 1944 treaty with Mexico. The Mexicans say, no, they are entitled to this water because they have been using it almost continuously. Ah, good ol' Western prior appropriation water law: "If you don't use it, you lose it." The Mexicans claim that the gringos have not been using it. Might the gringos be hoisted upon their own petard?
A lawsuit has been filed, and last August a federal court prohibited any further work on the $250M project. But in December 2006 Congress passed an omnibus bill reaffirming its support for the project and expressing a desire for the matter to be resolved by existing treaties and not the courts.
But now the plot thickens. The Colorado Delta ecosystem, which was virtually destroyed by the development of the Colorado River, has been showing signs of life recently. Why? Well, the irrigation return flow from the Mexicali Valley, dumped into the Colorado south of the USA-Mexico border, has been serving to rejuvenate the system. So where does this flow come from? Leakage from the All-American Canal, that 'wasted' water. This ecosystem-sustaining flow will diminish once the canal is lined. Environmental groups are now encouraging farmers in the Mexicali Valley to invest in efficiency to save water for the Delta ecosystem.
So here's the paradox: some environmental groups have found themselves in the awkward position of defending 'water waste' - leakage from the All-American Canal - to protect the Delta ecosystem. So, as Jenkins said, you have the absurd situation where efficiency is being deployed "...to fight the environmental impacts of efficiency itself."
So is there really such a thing as 'wasted water'? Doesn't it depend upon your point of view? Let me assure you I have heard this mantra before - that leakage from irrigation canals is not wasted, as it recharges aquifers (but what is the quality of the recharge?) and also creates a nice riparian habitat.
It's no wonder that dealing with Western USA water issues continues to be a growth industry.
"The meek shall inherit the earth but not its water rights." - apologies to J. Paul Getty.
Hello.
I have just read your article, I would like to read more about this topic and I was wondering If you could give me more information about laws and things related to the All American Canal.
Thank you. I hope to hearing soon from you.
Daniela D.
Posted by: Daniela | Friday, 11 July 2008 at 05:24 PM