The Colorado River is tapped out. So the Bureau of Reclamation and the people who live in the Colorado Basin are eyeing the Mississippi to relieve some of the demands we have put on the Colorado.
The Bureau of Reclamation?: Think the Corps of Engineers for the western states. While the job of the Corps of Engineers is to control flooding on the Mississippi and its tributaries, the job of the Bureau of Reclamation is get water for drinking and irrigation to the parched states west of the Great Plains. It also provides hydroelectric power to those states. Where the Corps of Engineers manages the Mississippi, the Bureau of Reclamation manages the Colorado and the Columbia.
To get water to all those farmers and electricity to all those cities it has dredged canals and constructed dams and power plants. It has also allowed the sparsely settled west of the early 20th century grow into the densely populated cities of the 21st. All those people and all those farmers need water to irrigate their lawns and their vegetable crops and to light their cities. Actually, the farmers are competing with the city dwellers for water and when push comes to shove the farmers lose.
It took 19 years to fill Lake Mead, upstream of the Hoover Dam, to 24 million acre-feet. Between 1998 and 2007, Lake Mead, which serves Las Vegas and its surrounds, lost 54% of its water.
One solution is to tap the Mississippi River just below its confluence with the Ohio and send the water to the Navajo River in southwest Colorado through a 775 mile=long pipe 144 inches in diameter. From their it would flow to the San Juan River, a tributary of the Colorado. Agricultural users in Colorado, Arizona, and New Mexico would cease their demands on the Colorado, leaving it free to serve the cities. The history of the Corps of Engineers’ interventions on the Mississippi River is the story of the law of unintended consequences.
To repeat what I have written before in The Mississippi:
“Artificial levees, extending clear to the Gulf of Mexico, may have made human habitation of the delta south of Cape Girardeau possible, but prevented the Mississippi from refreshing its marshes with its sediment when it did flood. Revetments built of concrete mats may have stabilized the navigation channel, but reduced erosion of the banks, a source of sediment in the marshes. James Eads’ jetties at the mouth of the river may have allowed the river to cut a thirty-foot navigation channel through the sandbar blocking the South Pass of the modern delta, but delivered sediment carried by the river to very deep water at the continental shelf, where it washed away, never to be used for marsh building. Closure of the old distributaries of the river may have prevented flooding in the bayou country of Louisiana, but cut the flow of Mississippi sediment to the coastal marshes. Channel dams may have made navigation on the Upper Mississippi profitable, but they retained its sediment north of Alton, Illinois. Dams on the Missouri, from which the Mississippi drew sixty percent of its sediment, did the same. In short at the beginning of the twenty-first century, the coastal marshes south of New Orleans received eighty percent less sediment than they had at the beginning of the twentieth and eroded away.”
According to Amy Joi O’Donoghue, who had written an excellent series of articles in Deseret News, which is published in Salt Lake City, folks in Utah and other states served by the Bureau of Reclamation look at the Flood of 2011 and say the Mississippi has more water than is needed in the Midwestern and Southern states that border it.
But the Louisiana coastal marshes, particularly those in the Barataria Basin and Breton Sound, need the fresh water and mud that the Mississippi delivered to the Gulf of Mexico during floods like that of 2011 to rebuild its wetlands and protect its cities, including New Orleans. The cities along the Mississippi Gulf Coast, which were wiped out during Katrina, could also use some solid wetlands out front in the Gulf of Mexico. During the BP Flood of Oil in 2010, freshwater flowing out of the Mississippi helped push some of that oil away from the wetlands.
So yes, we in the Mississippi River Basin occasionally have way too much water, but tapping the Mississippi year after year, flood or drought, could have the kind of unintended consequences that building the levees had and that constructing the dams on the Missouri had on the Louisiana Coast.
The time is fast approaching when we Americans are going to have to sort out how we manage freshwater, be it in the Mississippi Basin or in the Colorado Basin and other western river basins.