The Transcontinental Aqueduct; Will it pay for itself?

The goal of the Transcontinental Aqueduct is to save Lake Mead, save the American Southwest from becoming a desert, provide Hydroelectric peak storage for Texas, New Mexico and Arizona, provide sweet Mississippi water for irrigation, provide water to the Colorado river so it again can reach the ocean, revitalize San Carlos lake, provide more and better drinking water to 30 million people, to name just a few benefits.

The cost is substantial. The biggest problem is that the aqueduct must be substantially completed at full capacity before any benefits from the water will materialize. The cost to bring the aqueduct to half capacity is 300.5 billion dollars in construction cost only. This includes the cost of half the pumps or generators needed for full capacity, but not the cost of the power plants. Add to this the cost of filling the aqueduct and the 11 dams. The aqueduct itself will contain 1 million acre-ft of water when filled, the 11 dams will contain about 800,000 acre-ft when half full. To pump 1.8 MAF an average of 5000 feet requires about 10 TWh, when losses are included. Th filling stage water will be pumped, using excess wind and solar power at bargain rates, about 4 c/kwh , the same as the LFTR will produce when fully installed. This is about 320 million dollars in “liquid investment” The electric cost of moving one acre-ft from the Mississippi to the Colorado River is 6 MWh. This power is initially bought from off-peak wind and solar power, but as the aqueduct is completed with true hydropower storage up more and more the power will be generated with 100 MW LFTR power plants, the hydropower storage will be filled with excess wind and solar power.

In short: assuming a 50 year amortization plan for the aqueduct, and money available at 2%, , it will cost 12.5 billion a year in capital cost to deliver 7.5 MAF water from the Mississippi River to the Colorado river or any point in between, or $1,670 per acre-ft. Add to that $240 for electricity and another $50 per acre-ft in overhead and maintenance, the cost will be $1960 per acre-ft

When the aqueduct is fully built up, it will cost $13.4 billion yearly in capital cost to deliver 14.5 MAF of water from the Mississippi River to the Colorado river or any point in between, or $ 925 per acre-ft. The other costs stay the same, so the total cost of water will be $ 1,215 per acre-ft.

I have not yet mentioned the other major benefit of the Transcontinental Aqueduct. If I wanted the lowest cost of water possible, I would have used the lower route, going through the Texas lowlands to El Paso before routing it through New Mexico and Arizona. I routed it through the high and dry parts of Texas and New Mexico, at extra altitude penalty. The intent is to provide Hydropower storage at select places. These places are ideal for wind and solar power, but they need to store the energy when the sun is not up or doesn’t shine, or the wind doesn’t blow. Right now that is provided by coal and natural gas. Conventional nuclear power is best for use as base power only, so this transcontinental aqueduct will provide up to 23 GW of pure hydropower storage for 5 hours a day, but the LFTR nuclear stations providing the energy pumping the water in the aqueduct will shut off the pumps for five hours a day, or when the need arises, and instead provide another 20 GW of virtual hydropower power.

These 43 GW of hydropower capacity will be as follows: Louisiana, 0.4 GW; Texas, 18,5 GW (right now, Texas has no hydropower storage, but plenty of wind power); New Mexico, 10.5 GW; Arizona 13.6 GW. In Addition, when the Transcontinental Aqueduct is fully built up, the Hoover dam can provide a true 2.2 GW hydrostorage poser by pumping water back from Lake Mojave, a 3 billion dollar existing proposal waiting to be realized once Lake Mead is saved.

The amount of installed hydroelectric power storage is:

U.S. operating hydroelectric pumped storage capacity

Most hydroelectric pumped storage was installed in the 70’s. Now natural gas plants provide most of the peak power. This aqueduct will double, triple the U.S. pumped peak storage if virtual peak storage is included. By being pumped from surplus wind and solar energy as well as nuclear energy it is true “Green power”. Some people like that.

Published by

lenbilen

Retired engineer, graduated from Chalmers Technical University a long time ago with a degree in Technical Physics. Career in Aerospace, Analytical Chemistry, computer chip manufacturing and finally adjunct faculty at Pennsylvania State University, taught just one course in Computer Engineering, the Capstone Course.

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