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Statistics of plans for Colorado River development
Conditions with full upstream development and Total storcomplete upstream storage control
Average and equat-
installed evaporation ing stream power
horse- loss in flow in available
power second-feet acre-feet
1, 353 1, 283 1, 338 1, 338 1, 352 1, 282 1, 337 1, 337
3,080,000 $339,000,000 3, 155, 000 359,000,000 2,665, 000 331,000,000 2, 350,000 303,000,000 3, 280, 000 388,000,000 3, 317,000 398, 000, 000 2,967, 000 370,000,000 2, 770,000 356,000,000
$110 113 122 128 116 119 126 126
2, 810, 000 $316,000,000 2, 620,000 312,000,000 2, 810, 000 336, 000, 000 2, 825, 000 331,000,000 2, 900,000 341,000,000 2,715, 000 335, 000, 000 2, 905, 000 354, 000, 000 2, 920,000 356,000,000
$111 118 119 116 117 123 121 121
32,700,000 38, 900, 000 20, 700,000 14, 900,000 41, 600,000 47,800,000 29, 600,000 23, 800,000
Comparison of plans for Colorado River development
Conditions with present-day water supply
Conditions with present-day water supply
Conditions with full upstream development and complete upstream storage control
2, 920, 000 B.
1 Based on estimate for installations using convenient power units with total power approximating available power.
Now, plan A, in my opinion, presents the best scheme of development for the lower river as a whole. Its outstanding advantage is that it supplies the needed storage capacity with a minimum of evaporation loss. It provides for flood control by regulating the Williams River, and it entails a minimum destruction of irrigable areas. The cost of construction is the lowest of all plans, both under present and future conditions. Plan A contemplates a dam at Boulder Canyon which will back the water up to Bridge Canyon foundations. Conditions are suitable at Black Canyon, and yet it could be carried back to Diamond Creek, then another could be built at Bullshead. These several dams will utilize the entire head in the river between the west boundary of the national park and Parker, so no resources would be lost if all these dams were ultimately built, and the reason I worked this scheme out was because it has been argued by some that if a dam were built at Boulder Canyon it would not permit of the best development of the reservoir. We worked out many different schemes, and these are the most important and the best ones that we have illustrated in these tables.
With only partial control, such as will actually exist, the power output for these plans with small storage capacity would suffer far more severely than plan A. The cost of the Darker Dam is included in the total cost of this plan. It would provide a much-needed diversion for Parker Valley and for contemplated irrigation for the higher lands below. Of all the dams proposed under plan A, Boulder Canyon should be built first, at a cost of about $41,500,000. This dam would impound about 28,000,000 acre-feet of water.
A power plant and transmission line could be added for $70,500,000 more, or a total expenditure of $111,000,000. This power could be sold at four-tenths cent per kilowatt-hour at the end of the transmission line that is, at the substations and repay the entire cost in 42 years. This would be an installation of 1,000,000 horsepower. Next the Parker site should be improved to serve as a diversion dam for irrigation. With the complete regulation of Boulder Canyon it would be a fairly good power site. A dam at Bulls Head will back the water to the base of Boulder Dam, and with the regulation of that dam will constitute a good power site. Should a complete engineering investigation at Bridge Canyon show that that site is not suitable, the dam at Boulder Canyon can be increased sufficiently to back the water up to Diamond Creek; then no loss of head would obtain. In that case Boulder Canyon would have a total capacity of about 48,000,000 acre-feet. Åny dam built at Devils Slide would be a serious economic blunder, as it would destroy the best reservoir site in the basin and seriously limit the usefulness of the river.
The alternative reservoir advocated for construction at Mohave should not, in my opinion, be seriously considered. The site is extremely wasteful of water by evaporation, requiring the removal of about 22 miles of double track on the main line of the Santa Fe Railroad, increase its length about 3 miles, destroy the great bridge at Topock, submerge the large railroad hotel, roundhouse, machine shops, icing plant, 24 miles of yard tracks, and the entire city of Needles. It would also require the reconstruction of part of the Santa Fe Trail Highway. This reservoir would also submerge the whole Mohave Valley, containing about 34,000 acres of rich, irrigable bottom lands which can be economically irrigated. This dam site was examined 20 years ago and at intervals since by various engineers, including William Mulholland and J. B. Lippincott, and on account of the destruction of land, water, and other property was unanimously regarded as infeasible, and for this reason its foundations were not explored. Any money spent investigating the foundation of this dam would be wasted.
It has been suggested that a flood-control dam should first be built at Boulder Canyon and that this dam could later on be raised to sufficient height to provide for ultimate storage for irrigation and development of a large amount of power. There is less difference in the cost of a flood-control dam and a high dam than one would at first think. The cost of a flood-control dam at Boulder Canyon for 10,000,000 acre-feet capacity would be about $28,000,000; the cost of a high dam at the same point to store about 26,000,000 acre-feet would be $41,500,000, or a difference of $13,500,000 for the additional storage of 16,000,000 acre-feet. The reason for this is because of the fact that much of the expense connected with construction of a dam anywhere in the lower Colorado River would be the same whether a high or a low dam is built. That is, for any dam constructed a branch railroad will be required from the main line to the dam site. The most difficult feature in connection with construction of a dam on the river will be the diversion of the river and putting in the foundation.
This will be almost the same for a low dam as for a high dam for the reason that the largest crew that will be required at any period for construction will be while the river is being diverted and at that time the largest construction camp and construction plant will be needed. After diverting the river the first step should be to put in the upstream toe of the dam and build it up to a short distance above the low water of the river, and the next step will be to put in the downstream toe of the dam and bring that up to a short distance above the low water flow of the river. After that the real difficulties would be passed, and the only difference in the cost of a high dam over a low dam would be the small additional excavation required and the additional amount of concrete.
That is the fixed charges, as you might term them, for a dam on the Colorado River. For a high dam or a low dam you would have to have a railroad in connection with the construction of the plant and the diversion, and this, we estimate, will cost roughly $16,000,000 whether you are building a dam just for flood-control or a high dam.
Senator KENDRICK. Would you abandon the railway after the dam was completed ?
Mr. WEYMOUTH. I would not think so because the railroad would also be utilized for bringing in equipment for the power plant. The first unit of the power plant would be built when the dam was being built. Afterwards, however, other units would be installed and the power plant would require the railroad.
Senator KENDRICK. It occurred to me that perhaps there would not be much settlement in that neighborhood.
Mr. WEYMOUTH. No; that is a very arid region.
Senator KENDRICK. How far is it from the railroad?
Mr. WEYMOUTH. About 40 miles. There are three different possible locations for a railroad to go into Boulder Canyon. One would be from the end of one of the branches of the Santa Fe up to the dam. That would be about 55 miles but it is a much easier location than the railroad running out from Las Vegas to the dam on the Union Pacific. There are two possible locations from Las Vegas to the dam site.
Senator KENDRICK. You do not mean the Union Pacific?
Mr. WEYMOUTH. Well, it is now the Union Pacific line running from Salt Lake to Los Angeles.
Senator JOHNSON of California. Supposing you wanted to start out with a small dam, but built it upon a foundation that would be sufficient ultimately to increase it to a 550 or 605 foot dam. Would there be very much difference in cost?
Mr. WEYMOUTH. No.
Senator JOHNSON of California. You gave your figures in one instance as $28,000,000 and in the other as $41,000,000, you will recall?
Mr. WEYMOUTH. That was for both dams completed.
Senator JOHNSON of California. Now, assume that you built in the first instance the $28,000,000 dam upon a foundation sufficient upon which subsequently to build your 600-foot dam-would it make a difference in your cost?
Mr. WEYMOUTH. Yes.
Senator JOHNSON of California. And that would add to your cost of $28,000,000 about how much?
Mr. WEYMOUTH. Well, I do not know. It would be somewhere betwen the $28,000,000 and the $41,000,000—about halfway between.
Senator JOHNSON of California. So that there would be little saving in building a dam of that sort with a sufficient foundation to increase the height subsequently?
Mr. WEYMOUTH. Yes; and then there would be another cost added that would be difficult to properly estimate, and that is if you complete the foundation for the large dam and then build the small dam on top of it at a later date it would require building up of another organization.
Senator JOHNSON of California. So that you would have pretty nearly the same cost in the first instance in building this smaller dam with the foundation sufficient for the high dam?
Mr. WEYMOUTH. Yes. It would be a great waste, I think. The construction camp in that climate would deteriorate very rapidly, and it would cost a large amount of money to organize a construction crew and get it going again.
The CHAIRMAN. Does that conclude your statement?
Senator ASHURST. I draw the inference—I do not know whether it is justifiable or not-that you do not look more favorably upon Topock as a site for a dam than you have on Spencer Canyon and Glen Canyon. You think it is about as non feasible as the others?
Mr. WEYMOUTH. Yes; but for different reasons.
Senator ASHURST. Then I am correct in my assumption that you do not recommend a dam at Topock any more than you do at Glen or Spencer?