When writing about the fight to keep dams out of the Grand Canyon, several authors make statements like this one, from eminent historian of the American West, Donald Worster, on pp 275-6 of his Rivers of Empire, 1985:
“Originally the (Central Arizona Project) plan had been to run the pumps on hydroelectricity generated by two more Colorado River dams, one at Marble and the other at Bridge Canyon, the latter creating a reservoir that would bury a portion of the Grand Canyon National Park. (f.n. 21; see below) Once more the environmentalists buckled to battle to save a last piece of the natural, and once more—for the second time in the century—they were victorious. Once more, however, they lost something as well, for the energy to make the CAP go would be derived instead (my emphasis) from coal strip-mined on Hopi sacred lands at Black Mesa in northern Arizona and burned in the Navajo Generating Station near Page, polluting the crystalline desert air with ash and poison gas.” (The fuller discussion, with footnotes and other examples, is at my blog post of 16 Nov 2016: Lies Float, under the tab DAMS.)
The errors in that paragraph arise in part from an ignorance of the CAP’s history, but more importantly, from a fundamental misunderstanding of how power would have been allocated to move CAP water from the Colorado River over mountains and down into the Phoenix area.
The Bureau of Reclamation’s concept of how to optimize power use and financial return had two main elements.
1. Electricity would be generated from the dams releasing water to match peak demand for power that could therefore be sold at the highest — peaking — rate.
2. Electricity needed to move the water could be bought at the lowest, base, rate for power generated by thermal plants that operate best if run steadily.
Think of it this, too simple, way. Run the dams to handle demand for, say, industrial use or air conditioning in Arizona’s hot times. Pump the water at night when other demands are lowest. And integrate all of this into the larger manipulation of power sources to meet the needs of a region through its power grid.
Conclusion, Reclamation would seek to buy CAP power for pumping at the lowest rate, and sell Grand Canyon dam power at the highest rate. This works best when there is the widest spread of power generator types, that is, while the dam power is saved for peaks, the steadily operating baseload thermal plants can push the water when other demands are lowest.
Secondary conclusion: The dams’s power would not be used to “run the pumps”. There must be baseload thermal plants for cheaper, optimal operation of this system.
Question: Were these thermal plants built because the advocates for an undammed Grand Canyon (Worster’s “environmentalists”) made them necessary “instead“ of the dams?
For an answer, I refer to an article from the Grand Junction Sentinel, 24 Mar 1968, from which I have winnowed the following information:
Power needed for CAP: 400-470 megawatts (MW); SRP (the Salt River Project, one of Arizona’s main utilities) will buy any of that that the CAP doesnt use. SRP will integrate its power with the output of Glen Canyon dam. The thermal baseload power will come from a plant near Page using Black Mesa coal mined by Peabody Coal. the Page plant will be built and run by Salt River Project and will be able to generate 750 MW in 1974. (The major Grand Canyon dam was designed for 1500 MW.) To gain the CAP’s share, the federal government would have pre-paid SRP for that 400-470 MW capacity.
(Other points: The power for the rest of the Page plant was not yet contracted for.
Secretary of the Interior Udall estimated 3.5 mills/kwh as the cost for power from the WEST plant near Page, based on the federal government pre-paying for its power share.
Another consideration: Page might be limited to 1500 MW, since it requires 40,000 af. of cooling water. Arizona has 50,000 af, but only 35-38,000 af of that is available.)
The article continued. There are other plants and companies whose operators in the area would like the CAP work. e.g., Utah Construction & Mining, Pittsburgh & Midway Coal Mining.
Currently, in New Mexico, coal deposits are held by, and supplying these powerplants:
Four Corners plant: 2 units of 755 MW, under construction; ready in 1969-70.
APS now using 3 plants totalling 675 MW. It wants 15% of new 1510 MW capacity.
The Mohave WEST plant — 1510 MW (2 units) at Bullhead City AZ, ready 1970-1— is being built by SoCalEd, LADWP, NevPower, SRP, and will use coal from Black Mesa sent by Peabody.
Other regional power utilities involved in regional planning: SRP, TGE, SoCalEd, PS of NM, ElPasoE.
There may be two more plants, totalling 1510, in the 1970’s
Overall, these plants will generate 6700 MW as follows:
675 4 Corners now
1510 4 Corners under construction
1510 4 Corners future
A reminder: the CAP needs 400-470 MW.
Even had the Grand Canyon dams been built, the power needs of the southwestern United States had led the utilities to build and plan for thousands of megawatts more than the CAP requirement, and indeed, more than the Grand Canyon dams could supply.
Without “buckling for battle” against the dams, we would all have lost both “the crystalline desert air” and the Grand Canyon.