power. With the low dam the power plant would develop under the maximum head about 765,000 horsepower, and under the minimum head it would be down to 400,000 horsepower, but we can elevate that as much as we choose by increasing the silt storage and carrying the water to a higher level.

The question was asked yesterday or the day before as to how long it would take to fill the reservoir. The reservoir as planned by Mr. Davis would under favorable conditions fill in one year, and under the most unfavorable conditions prior to depletion it would require three years to fill.

Mr. LEATHERWOOD. What reservoir are you talking about?

Mr. CLARK. I am talking about a reservoir of approximately the height discussed by Mr. Davis.

Mr. LEATHERWOOD. At Boulder Dam?

Mr. CLARK. At Boulder Dam; yes.

Mr. LEATHERWOOD. With a dam approximately how high?

Mr. CLARK. Mr. Davis's figure was 550 feet. I have used the 565foot figure with 1,400,000 acre-feet more capacity.

Mr. LEATHERWOOD. Do you mean that would be filled in a year with silt?

Mr. CLARK. No; with water. The silt capacity, taking into consideration an extreme drought after depletion in the upper basin and locating the outlet low enough to provide water storage to carry over that period, would provide 50 years storage for silt.

The question of the adequacy of the water supply for the entire area has come up and is referred to quite frequently. The records show that the quantity available is ample for all feasible irrigation projects, but if the people in the upper basin undertook to pump water 200 feet they could irrigate a much greater area and use a much greater quantity of water than the amount allotted to them. Under what are regarded as feasible projects in either basin no such pumping head as that proposed by Mr. La Rue was ever considered. In Mr. Davis's report, Senate Document No. 142, they have not regarded as feasible any pumping lifts above 80 feet.

I want to say that I have had considerable experience along that line. Years ago when Miller and Lux were installing irrigation projects in the San Joaquin Valley this problem came up and I was employed as an engineer on the question of pumping and distributing water. We found after careful investigation that an 80-foot lift was the maximum feasible height with current at three-quarters of a cent per kilowat.

In the Snake River and the Columbia River projects, with which I was associated, we found that from 60 to 75 feet was the maximum to which water could be economically lifted for irrigation.

In South Africa on a large development near Johannesburg, with which I was associated, there was a big rush for power for pumping. The English people thought that they could irrigate the high land by pumping water from the subterranean sources. We went into the matter very carefully, and with power at 1 cent, or an English halfpenny, per kilowatt we found we could not economically pump the water more than 60 feet. That was the extreme economical limit.

Reference has been made to pumping in the Hawaiian Islands. I installed pumping plants there operating on heads of from 200 to 400 feet, but it was only the high price of sugar under a protective

tariff that permitted those plants to go in; a portion of that extra profit was used for the purchase of coal and oil, but the pumping head was way beyond the limit of economical pumping if the sugar produced had been in competition with other parts of the world.

Mr. RAKEE. What is the highest pumping you have in the Philippine Islands?

Mr. CLARK. I think at one of the plants the Hawaiian Sugar Co. pump up to 450 feet. I am not sure that this is the head, but that is my understanding.

Mr. LEATHERWOOD. I think that is corroborated in a recent issue of the Geographic Magazine; something like 400 feet.

Mr. CLARK. Another point I wanted to touch on was the decrease in the demand for water after the land had been under cultivation for a time. I find from the surveys of the Salton Sea that over 700,000 acre-feet of water is now evaporated annually. I believe Mr. Leatherwood said 750,000 acre-feet of evaporation. That is supplied by the stepage from the area irrigated, for the land does not now require as much water as it did when first brought under cultivation. I have been interested for quite a number of years in a tract of land in Virgin Valley in southern Utah. When we started to grow alfalfa it needed 14 acre-feet per year, but now since the coverage is complete the evaporation is less and we are getting along very well with three-fourths of an acre-foot per year. That is now all the water that is actually needed for the alfalfa.

Mr. RAKER. About one-half?

Mr. CLARK. About one-half.

Any observations in Colorado and Utah-I was born in Utahconvinces me that others have found that as the coverage is increased the amount of water required becomes less.

Mr. RAKER. Did you live anywhere near where the very distinguished gentleman from Utah lives?

Mr. CLARK. I was born in Salt Lake City.

One other point is the question of maximum demand for power and irrigation. The maximum irrigation demand for the lower basin comes in the months of June, July, and August, and the maximum demand for power for lighting and commercial service comes in the winter-December, January, and February. But if we are going to utilize the head to the best advantage for the development of power after full depletion in the upper basin, we should provide a balancing reservoir to balance the maximum demand for power in the winter against the maximum demand for irrigation in the

summer.

After a careful investigation I arrived at the conclusion that the Parker reservoir site was the proper location for a balancing reservoir. Two million acre-feet of storage can be secured there with a dam less than 100 feet high without interfering with the Santa Fe Railroad or the town of Needles, or submerging valuable agricultural land. I would not attempt to develop any power there, but would simply use it as a balancing reservoir to store water in the winter to be released when and as demanded for irrigation in the

summer.

Mr. LEATHERWOOD. That is at Topock?

Mr. CLARK. No; that is below Topock, just above Parker. It would conserve 2.000,000 acre-feet of water and would be drawn dry by the end of the irrigation season, but it would not be necessary to build that dam and reservoir until the flow from the upper basin was fully depleted-probably 40 to 50 years from now.

On the question of a dam in the upper river above Boulder. If a dam were put in at Diamond Creek or Glen Canyon to develop power it would discharge its maximum water in the winter during the maximum demand for power and would discharge less water in the late summer during the maximum demand for irrigation; so if a dam was constructed on the upper river for power it would still be necessary to have a balancing reservoir below.

It would mean that eventually the Boulder Canyon dam would have to be constructed to conserve enough water to carry over from the winter to the summer, and to safeguard the lower valley against a drouth of long duration which we may expect at intervals of from 20 to 50 years.

Mr. RAKER. That would hold the water when you do not need it for irrigation for the time when you have to discharge the extra amount for electric power, and then you can take it all out in the summer time when you need it for irrigation?

Mr. CLARK. Yes. The Parker reservoir would do that after final depletion in the upper basin without reducing the firm power available from a power plant at Boulder.

Mr. RAKER. I meant the Parker reservoir would do that.

Mr. LEATHERWOOD. What advantage is there over this Parker Canyon dam and the one at Topock?

Mr. CLARK. At Topock the reservoir would submerge about 30 miles of the Santa Fe Railroad and the town of Needles. It would also submerge the area above Needles to a point above the Bulls Head development, an excellent agricultural area in the river bottom amounting to several thousand acres would be lost. It would destroy the Parker reservoir site, and the Bulls Head reservoir site, for the dam would be located in the upper end of the Parker reservoir site. and it would submerge the dam location at Bulls Head and leave about 100 feet of fall in the river undeveloped.

Mr. LEATHERWOOD. May I ask whether you have any interests between the proposed Topock site and the proposed Boulder Canyon dam site?

Mr. CLARK. No; I have no interest whatever except as an engineer. I have investigated all three, and so far as power is concerned the lower two are not very valuable. Bulls Head is the first location on the river available for the economic development of any considerable amount of power.

Mr. LEATHERWOOD. You apparently misunderstood my question. I asked if you have any interest in any property between the proposed Topock site and the proposed Boulder dam?

Mr. CLARK. No; I have no interest there.

Mr. LEATHERWOOD. Have you any interest between the so-called Parker site and the Topock site?

Mr. CLARK. No; I am not interested except from an engineering point of view.

Mr. RAKER. That is all.

The CHAIRMAN. If there is no objection, these maps may be inserted in the hearings. And, also, Mr. Davis and Mr. Clark, when you correct the record will you have those maps that are on the wall inserted so that they will fit into your testimony in their proper places?

Colorado River-Possible dam-site locations Boulder Canyon to Parker compared on a percentage basis-The same basis of comparison under each classification has been applied to all locations

1 100 per cent when flood storage capacity before depletion in the upper basin permits discharge to be limited to maximum of 40,000 second-feet. Zero per cent when no flood storage capacity is availble.

2 100 per cent when after maximum depletion in the upper basis all flood waters can be stored for future use. Stored waters divided by annual flow equal per cent conserved.

3100 per cent when all silt arriving at the dam site during a period of 500 years can be stored without reducing flood and irrigation storage capacity of reservoir. Zero per cent when silt can not be stored without reducing flood and irrigation capacity of the reservoir.

100 per cent flow can be limited to that actually required for domestic purposes and agriculture. The total demand divided by amount actually discharged when in excess of demand, or amount actually discharged divided by demand when discharge is below actual demand, equals per cent of control.

100 per cent when after final depletion in upper basin (4,000,000 acres irrigated) stored water will provide for total requirements of lower basin (2,020,000 acres irrigated) over 3-year period of maximum drought as calculated on available drought records. Zero per cent when it is necessary to empty reservoir to provide flood storage for succeeding year.

100 per cent when required water can be delivered to destination by gravity on a gradient of 10 feet or more to the mile. Zero per cent when gradient is zero feet per mile.

7100 per cent when all water released for agricultural purposes is available for the production of power under a head of 725 feet or more. Zero per cent when water is released for agricultural purposes under a head too low to justify the installation of power equipment.

$100 per cent when no water is evaporated. Zero per cent when all water is evaporated. Evaporation, divided by capacity, subtracted from 100, equals per cent.

2 100 per cent when 100 per cent flood protection; 100 per cent silt storage; 100 per cent reserve against drought can be secured for 50 cents per acre-foot or less. Zero per cent when cost is $5 or more per acrefoot.

10 100 per cent when transportation investment and camp construction cost does not exceed 1 per cent of cost of dam and spillway. Zero per cent when the cost is 10 per cent of the cost of dam and spillway. 11 100 per cent when there is no charge for lands and improvements flooded. Zero per cent when the cost of lands and improvements flooded is $1 or more per acre available acre-feet of storage.

12 The probable net value of gold to be recovered between Black Canyon and Boulder Canyon ($32,000,000.00) is here charged against the location.

1s 100 per cent when the material at dam location is granite or diorite, or their equal. Zero per cent when material is shale, soft sandstone, or similar material.

14 100 per cent when bedrock is exposed. Zero per cent when bedrock is 200 feet or more below the water surface.

15 100 per cent when no investment is required for spillway of necessary capacity. Zero per cent when spillway cost is one-quarter the cost of the dam.

16 100 per cent when cost does not exceed 2 per cent of the cost of the dam. Zero per cent when cost is 25 per cent of the cost of the dam.

1100 per cent when the market for power to the ultimate capacity of the water supply at the location of the dam is within 5 miles of the generating plant. Zero per cent when the distance to the market for power exceeds 500 miles.

18 100 per cent when the firm power available at the dam site is 1,000,000 horsepower. Power available at location, divided by 1,000,000, equals per cent rating for location.

The foregoing tabulation has been prepared from data available April 5, 1924. Sources of information: Topographic maps of the United States Geological Survey, published reports of the United States Geological Survey and the Department of the Interior, and surveys conducted under the supervision of Walter G. Clark, consulting engineer, No. 8 West Fortieth Street, New York. WALTER G. CLARKE,

Sworn to and subscribed before me this 8th day of April, 1924.

My commission expires March 30, 1925.

ETHEL C. MUDDELL, Notary Public, Kings County.

Mr. SWING. Senator Evans will wait, and Mr. Maxwell would like to make a statement.

Mr. RAKER. All right, Mr. Maxwell.

STATEMENT OF GEORGE H. MAXWELL-Resumed

Mr. MAXWELL. Mr. Chairman and gentlemen, in reference to the irrigable area below the line in Mexico, in Lower California, and in Sonora, I was rather surprised when I learned that the fact was questioned at all that there is approximately 2,000,000 acres of land which can be reclaimed in that territory. In looking up some of the data which I had on the subject I ran across an exceedingly interesting document, which is an application to the Mexican Government with reference to the reclamation of 600,000 acres of land in Sonora, and the entire policy of the project and the American owners' is very fully set forth in this document. I hesitate to ask permission to read it, because there are seven closely typewritten pages. The CHAIRMAN. Who is it from and who is it addressed to?

Mr. MAXWELL. I received it from Mr. William B. Raymond, of 1512 South Los Angeles Street, Los Angeles. It is a carbon copy of a letter that was addressed on March 18, 1912, to Señor Don Manuel Calero, minister de relaciones, Mexico, and I think this ought to go into the record.

Mr. RAKER. It covers the situation down there, does it, Mr. Maxwell?

Mr. MAXWELL. It does; the entire situation at that time, particularly with reference to the irrigable area in Sonora.

Mr. RAKER. I ask that it go in the record without its being read. The CHAIRMAN. If there is no objection, it will go in the record. Mr. MAXWELL. I will furnish an exact copy.

Senor DON MANUAL CALERO,

Minister do Relaciones, Mexico, D. F.

MARCH 18, 1912.

DEAR SIR: We received your request through Mr. Pizarro Suarez for memorandum concerning our company.

As the value of the Del Rio grant which our company proposes to take over is entirely contingent upon whether or not it receives an appropriation of water from the Colorado River, as the lands are entirely an absolute desert, having a rainfall not to exceed 2 inches per annum, it becomes very evident that we are vitally interested in the position taken by the Mexican Government in its coming negotiations with the United States, with the object in view of settling the rights of the respective countries to the waters of the Colorado River for irrigation purposes, it having been practically acknowledged, at least by the Government of the United States in throwing a dam across the river at Laguna, 12 miles above Yuma, that this stream is more important for irrigation than for navigation, and the rights of the respective countries to navigation should be abandoned in the interest of irrigation. We do not feel that we can do justice