It would also be advantageous to the Government to have the water return to the river near the upper end of the reservation. The board therefore recommends that water from the San Carlos project in excess of that required for the Indians, be confined as far as existing water rights, if any, will permit, to the area north of the Santa Cruz Wash; or, more specifically, to the area limited on the south by the south line of township 6 south, range 8 east, and the diagonal line extending from the southwest corner of the same township, northwest to the Sacaton Mountains; and that within this area it be applied to such lands seeking water as are best adapted to irrigation. The above area amounts to upward of 80,000 acres. 1 156. Quality of lands and waters. In relation to the quality of the land and waters in this district, the board invites attention to the letter of Prof. R. H. Forbes, director of the Agricultural Experiment Station, University of Arizona, dated July 29, 1913, copy of which will be found in Appendix K and from which is quoted the following: * * * * In general, the soils of the Casa Grande Valley are exceedingly well graded naturally, entailing minimum expense in leveling for irrigation. They range in physical character from gravelly loams, at higher elevations, to somewhat heavy clays, usually in the valley bottoms. In a general way, it may be stated that in physical disposition and character the soils of Casa Grande Valley resemble those of the Salt River Valley. * * * * * Summing up, therefore: The soils of the Casa Grande Valley are physically desirable, but, generally speaking, contain noticeable, and sometimes serious, amounts of black alkali which it would be well to consider in general measures affecting the welfare of the district. 2. The well waters vary greatly in character, those along the Gila River being for the most part white alkaline in character, while those at a distance from the Gila River are for the most part black alkaline in character. A number of instances are observed where either black or white alkalies are contained in injurious excess; in other cases they are not contained in any damaging quantity. In cases of a large general development of the ground waters of the district through single or harmonious agencies, these waters should be so combined in irrigating that sodium carbonate and calcium sulphate contained may react in a manner improving the quality of the water. 3. In the case of river waters, the black alkaline flood waters and the calcium sulphate low flow, more especially of the Gila River, will unquestionably benefit by mixture in a storage reservoir. 4. Aside from discussions more or less theoretical in character, the history of the district for the last 20 years shows that for the most part, wherever abundant irrigating water is available, large and profitable crops may be grown. 157. The board has received from owners of lands in the FlorenceCasa Grande district, offers to enter an aggregate of 41,000 acres under the San Carlos project, upon condition that the cost of the *The soils of the arid and semiarid regions are largely the results of disintegration of rock. Many of them have not been completely washed by copious rains during their formation and contain large quantities of soluble mineral salts. Some of these salts, especially in limited quantities, are beneficial and necessary for the growth of vegetation, while others are harmful, and in suflicient quantities will prohibit its growth. Sodium carbonate, commonly known as black alkali, is the most detrimental of all the alkali salts to plant growth. The exact action of alkali on a plant is not clearly understood, its effects, however, is to destroy the root tissues near the surface of the soil and leave the plant to die for lack of food and moisture. On account of the action of alkali being near the surface it is essential that any accumulation of salts in the top stratum of soil be avoided. * * In their natural state the alkali salts are distributed more or less uniformly through the soils, frequently extending to considerable depths. When water is applied to the land, the soluble salts are dissolved. As the process of evaporation goes on from the surface of the soil and waters charged with alkali are brought up by capillary action there is a gradual accumulation of salts on or near the surface until finally the soil is unfit for the growing of crops. If the soil becomes saturated, or in other words, if the water plane is brought up near the surface, the capillary action in drawing water to the surface and consequently the rate of evapo ration and deposit of alkali is increased. (Principles of Irrigation Engineering, Newell & Murphy, p. 138.) project does not exceed $75 per acre. The forms used in making these offers are as follows: OFFER TO PLEDGE LANDS FOR SAN CARLOS RESERVOIR PROJECT. I, the undersigned, being at present the owner of the following-described lands situated in Pinal County, State of Arizona, for the purpose of showing the feasibility of the San Carlos Reservoir and irrigation works therefrom, offer to cause my above lands to become subject to a lien of not to exceed $75 per acre for proportionate shares of the cost of construction of said irrigation works by the United States Government, and to so do under such terms and conditions as may be finally imposed by the United States as an incident to construction thereof to irrigate said lands. Signed and sealed this day of —, 1913. (Affidavit acknowledging execution.) PLEDGE OF LANDS FOR SAN CARLOS RESERVOIR PROJECT. [1. S. L. S. I, the undersigned, a member of the Casa Grande Valley Water Users' Association, being owner or entryman of the following-described lands, situated in Pinal County, State of Arizona, to wit: , hereby express my willingness to cause my abovedescribed lands to become subject to a lien of $75, or so much thereof as may be necessary, as and for the proportionate share of the cost of construction by the Government of the United States of the San Carlos Reservoir project, and a distributing system thereunder, it being understood that said lands are to receive water for irrigation purposes under such rules and regulations as the Government of the United States may impose. Signed and sealed this day of (Affidavit acknowledging execution.) 1913. Other owners equally desirous of obtaining water have refrained from making this tender in advance of the time when it would be possible to enter into contract with the United States, for fear of clouding their titles or embarrassing themselves in work they have under way or in prospect. About 24,000 acres of the lands tendered lie outside of the area to which, as above explained, the board believes water from the San Carlos project should be restricted. 158. There are irrigation wells in use near Florence and Casa Grande, and, as already pointed out, on the reservation lands on the north side of the river opposite Sacaton. Water from the well at the Sacaton Agency has been used for irrigation for a number of years. As the board has not proposed that well water shall be used exclusively anywhere in the project, there is no need to go very deeply into the question whether land so irrigated can continue to produce indefinitely. Well water would lack the fertilizing value of river water, and there would be a greater objection to its exclusive use than there would be to the continued use of water which by passing through the reservoir had deposited five-sixths of its silt content. The quality of the ground water varies with the location of the wells, but there is sufficient evidence to show that at least in some wells in the Gila Valley the water is less alkaline than is the river water at very low stages. The board inspected crops of vegetables, corn, grain, and cotton at the experiment farm, Sacaton, growing in ground on which no water except that from the agency well had been used for six years. There was some appearance of alkali, but the farmer stated that all crops had done well during the six years in question. It appears from the records that alfalfa, Indian corn, sorghum, Egyptian cotton, Bermuda onions, and other crops; and pears, apricots, figs, pomegranates, dates, and other fruits have been grown successfully there with well water alone. For cotton, 2.7 acre-feet of well water per acre was applied in 1910; 2.52 in 1911; and 2.06 in 1912. On Peruvian alfalfa 3.6 acre-feet was used. 159. Whatever might be the ultimate effect of using well water alone, no bad effects would follow the proper use of well water in conjunction with or supplementary to the river flow or stored river water. Some who have had experience with well water prefer to use it in conjunction with river water rather than to use river water alone. Apart from the question of alkalinity, the river water at times contains so much silt as to make it unsuitable for use on young alfalfa; and in midsummer it contains large quantities of seeds; while on the other hand, well water is warmer than river water during cold weather. This subject is discussed in the letter of Prof. Forbes above referred to, copy of which appears in Appendix K. 160. Canals. Considering the acreage irrigable and the distribution of the tracts of land which would naturally be taken into the project, a main canal should extend for a length of about 14 miles. from the heading to a point about 5 miles southwest of Florence, where it should divide into two branches, viz: The "Pima branch" which would run westerly along the ridge past the Casa Grande ruins to the Indian reservation; and the "Picacho branch" which would run in a southerly direction to the Picacho Reservoir. The Pima branch would be about 8 miles long; the Picacho branch about 7 miles. The Picacho Reservoir would be of value as providing some storage and as facilitating the operation of the system. The Pima branch would lie along the ridge referred to in order to serve private lands on either side, as well as to convey water to the reservation. 161. The board proposes that the Indians' share of the stored water shall be conveyed in a canal rather than in the bed of the river, in order to save a loss of water and to serve private lands. This advantage will outweigh the extra cost involved. At the same time, as explained in paragraph 171, there is need for the construction of a diversion dam on the reservation. 162. The cost of the main canal and the Pima branch should be shared between the reservation lands and the district lands (par. 153). The Picacho branch should be entirely at the expense of the private lands. 163. To line main canals and distributors will effect a considerable saving of water, and will thus enable the district to be larger than it otherwise could be. The reduction in the cost of the project per acre due to the increase in acreage will offset the increase in cost due to lining the canals. The lined canal has other advantages besides reducing loss from seepage. It prevents swamping of adjacent lands with the resulting increase of alkali; due to the greater velocity permissible and the consequent reduction in width, it reduces evaporation losses; it is less dependent upon topography; the need and cost of drops is reduced; it requires less excavation and occupies less land; and it reduces the cost of operation and maintenance by preventing plant growth and the deposit of silt. Aside from considerations of first cost to individual landowners is that of public policy demanding prevention of unnecessary waste of water in the arid regions. It is estimated that with lined main canals and distributors the loss between the diversion dam and the land irrigated will not exceed 20 per cent. 164. The maximum capacity of the main canal, to carry the "peak of the load," would need to be 1,000 second-feet at the head, diminishing as tapped by laterals. A smooth cement-lined canal on a grade of 1 in 2,000, 18 feet wide on the bottom and with side slopes of 1 on 1, with water 6 feet deep, would have a velocity of about 7 feet per second and a capacity of about 1,000 second-feet. Its cost, including concrete lining 4 inches thick on bottom and sides, together with the necessary gates and bridges, is estimated at about $36,000 per mile. 165. The Pima branch canal, about 8 miles long, would need to have a maximum capacity of about 500 second-feet at the head. A steep grade can be given it, producing high velocities, and permitting the cross section to be small, averaging about 5 feet on the bottom, side slopes 45°, and water 5 feet deep. It is estimated that its cost, with concrete lining 3 inches thick, together with the necessary structures, would be about $15,000 per mile. 166. Beyond the above canals, the elements of the distributing system can not be determined in advance of knowledge of the exact territory to be irrigated, which latter will depend on the will of landowners, and possibly on adjudication of water rights or claims. It may be said, however, that the topography is particularly favorable to cheap construction. This, and the existence of some canals which would doubtless be useful in the new system, is expected to make the cost of an unlined distributing system, aside from the main canal and its Pima branch, not more than $7 per acre, including structures. An additional $10 per acre would provide a sufficient concrete lining for these subsidiary canals and ditches. ESTIMATE OF COST OF PROJECT. 167. The reclamation law (act of June 17, 1902) requires that the cost of construction of any given project shall be returned to the reclamation fund by the owners of land thereunder in not to exceed 10 annual installments, the number of payments and the time when such payments shall commence to be determined by the Secretary of the Interior. It seems to the board that to require that payment for the San Carlos project should be made in 10 years is to place an undue burden upon the first irrigators on whom will fall greater outside expenses than on their successors, and the board has therefore assumed that payment for the project is to be made in 20 equal annual installments. Under the reclamation law interest is not charged, but the board sees no reason for recommending that interest be not charged on money advanced by the United States for that part of the San Carlos project which is for the irrigation of private lands. In the following estimate, interest at 3 per cent compounded annually is included. 168. For the items of the project that relate both to Indian and to private lands, the estimated cost is as follows: Impounding dam, 263,000 cubic yards, at $8 (par. 79).. Moving Arizona Eastern Railroad. Main Canal, lined, 14 miles, at $36,000.. Pima Branch Canal, lined, 8 miles, at $15.000 1. Engineering and contingencies, 15 per cent.... Interest during construction, at 3 per cent for two years.... Total to be prorated between Indian and private lands.... $2, 104, 000. 00 200,000.00 680, 191.00 150,000.00 504,000.00 120,000.00 3,758, 191. 00 563, 729.00 4,321, 920. 00 259, 315. 00 4, 581, 235.00 50.90 169. The partial total, $4,581,235, is to be divided between Indian and private lands in the proportion of 35/90 and 55/90, making— Indian share............... Private land share.... $1,781, 591 170. Additional and total cost to Uated States for Indian lands.In addition to the sum of $1,781,591, above, will be the cost of some means of carrying flood water to the lands under the new Santan ditch, and the cost of constructing a certain part of the distribution system on the reservation lands on the south side of the river and of lining certain of the distributors and main laterals on the south and possibly also on the north side. 171. Stored water might be gotten to the new Santan ditch by building a canal about 31 miles long on the north side of the river from the diversion dam; by building a diversion dam at the reservation, either at the Santan ditch or at the Little Gila heading, with a canal in the latter case, about 11 miles long on the north side; or by an aqueduct or siphon at the reservation. A diversion dam on the reservation would also intercept a portion of the return flow from the private-land district. (Par. 153.) Again there will be at times water running over the diversion dam above Florence; and finally, a lower diversion dam would be available for the diversion of water to the Indian lands on either side of the river, in case of a breach in the main canal or in the Pima branch. An aqueduct might be considered in case it were in contemplation to construct a permanent bridge across the river near Sacaton. A means of getting stored water to the north side will not become a necessity until the storage dam has been constructed and water begins to be impounded. The estimated cost of any satisfactory means of accomplishing the purpose under discussion will be taken as the same as the estimated cost of the upper diversion dam, viz, $150,000. 172. The board adopts $12 per acre on 35,000 acres, in all, $420,000, as a rough estimate of the cost of the work referred to on the distribution system. The Pima Branch Canal is included here and the Picacho Branch omitted, as private lands will be served under the former, while no Indian lands will be served under the latter. |