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Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IV, page 4ground-water basins where managed ground-water storage is possible. This concept could be applied throughout the Pacific Southwest. Implementation of a basinwide plan of water redistribution could allay the fears of water shortages by individual water-using entities. Water could be provided upon demand by direct diversion or exchange within the confines of negotiated agreements and based on predetermined water schedules. Thus, no consumer would be forced to carry the entire burden of reduced supplies in a water-short situation.
Conservation of Available Water--Possibilities for conservation of water exist on all natural channels and within conveyance and distribution systems.
On main river channels, uncontrolled water spreading into adjacent alluvial deposits increases the loss of water to evaporation and to noneneficial vegetative growth. This condition exists on the main stream of the Colorado River, in many areas on the Gila River, and also along many other streams of the Pacific Southwest. By channelization and phreatophyte eradication, significant quantities of these nonbeneficial losses could be salvaged. Selected vegetative areas should be maintained for wildlife purposes; however, this factor should not be allowed to overshadow the urgent need for conserving the water supplies of an arid land for the benefit of all its inhabitants. Channelization of streams could permit passing higher floodflows without the erosion of developed flood-plain areas, and could ease present sedimentation problems.
Many irrigation facilities and practies, born during the early history of western irrigation, still continue to exist. Wherever highly erratic water supplies made canal washouts an ever-recurring loss, these primitive canal systems and irrigation practices were an economic necessity. Unlined, they lose precious developed water and for many smaller irrigated areas, especially with uncertain surface-water supplies, these losses further suppress an uncertain production. With almost full regulatory control of the Colorado River and full or partial regulation of tributaries, these conveyance and distribution systems should be lined. This condition is not confined to small and remote ditches but applies to major canal systems throughout the Pacific Southwest. Progress has and is being made toward lining these canals or installing closed-pipe systems; however, many hundreds of miles of canals remain to be improved.
In the Pacific Southwest, where some areas perennially suffer water shortages and economic losses, salvage of waters lost by irrigation inefficiencies and historic overdiversions could do much to bolster the water economy of the area. In addition, unauthorized users along the Colorado River between Davis Dam
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Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IV, illustration no paginationEpson Perfection 4870 Photo, 400 dpi, 8 bit, 1,287,153 byte
Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IV, page 11Sheet 1 of 2
Table 16
Pacific Southwest Water Plan
Estimated Water Supply
Unit: 1,000 a.f.
Development year Present Development year 1975 Development year 1990 Development year 2000
Scheduled release--Glen Canyon Dam 1Epson Perfection 4870 Photo, 400 dpi, 8 bit, 1,316,803 byte
Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IV, page 12Table 16
Sheet 2 of 2
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Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IX, page 2Research is continuing to improve conventional-type linings and develop new types such as plastic film, rubber sheeting, and the subsurface injection of sealants. This research is expected to result in a significant increase in effectiveness in controlling seepage and in lowering lining costs.
Many of the small canals and laterals on existing projects, such as Salt River, Coachella, Imperial, Gila, and others, have been lined for the purpose of reducing losses and prevention of drainage problems. Studies are being made of the feasibility of lining large canals such as the All-American, the Coachella, and the Gila Gravity. It is apparent that tremendous water savings can be achieved by use of canal sealants and linings in the area, and studies will be continued on this important problem.
Evaporation reduction--The annual water-surface evaporation in the Pacific Southwest area varies from about 52 to 86 inches, with total losses of water amounting to over a million acre-feet annually. The significance of these losses becomes apparent when it is realized that Lake Mead evaporates about 834,000 acre-feet of water each year.
During the past decade, many individuals and research organizations all over the world, including the Bureau of Reclamation, have conducted laboratory and field investigations in search of practical methods to reduce these water losses. Of the many mthods under consideration for reducing reservoir evaporation losses, the only promising method involves covering the water surface with monomolecular films; however, the effects of long-range use of these films on fish and bird life need to be investigated.
Results of field tests of these chemicals on lakes and reservoirs of small surface areas have indicated savings in evaporation ranging from 10 to 35 percent. In most areas a large portion of the annual evaporation would occur during a relatively few months. Application of the monolayers would probably be made during these peak evaporation months. Tests conducted to date would indicate that routine applications of monolayers to certain reservoirs, during the peak evaporation periods, could result in savings of 10 percent of the annual losses.
Rather extensive investigations are currently being sponsored by the Bureau of Reclamation, as well as by other organizations, to find more efficient evaporation retardants and methods of application to large water surfaces. Should these investigations prove successful, such applications could result in economically acceptable costs per acre-foot of saved water. Since the Pacific Southwest area is subjected to the highest reservoir evaporation rates in the United States, it would be the area in which evaporation savings could be accomplished at the lowest cost per acre-foot.
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Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IX, page 6arrowweed, saltbush, willows, and other plants occupy over 0.5 million acres of land along the flood plains of the rivers. Investigations show that it would be feasible to salvage some of this water by the eradication of the phreatophytes. These plants, in some cases, annually use 50 to 100 percent more water than most irrigated crops. Estimates of water use and salvage are only approximate. Continuing studies are necessary to determine practical methods for elimination and control of this high water-using plant.
At the present time there is a great deal of research being conducted at various universities, and cooperative studies are underway by several governmental agencies to determine actual bare-ground evaporation and the transpiration rate of river-bottom vegetation.
Evaporation losses from the wet channels of ephemeral streams following floodflows are known to be great. This is attested by the observed decrease in unit runoff as drainage area increases. The practicability of increasing recharge to ground water by ephemeral streams depends to a great extent upon the hydrologic regimen of the stream channels.
Research in general hydrology--Long-range research in general hydrology has two distinct functions--to improve the design of proposed irrigation works and to encourage more efficient use of water for specific purposes and the salvage of waters now used nonbeneficially. Studies of this nature have been carried on for several years. Long-range programs have been developed for continued study and research in these fields.
In the field of improvement of design, there are scheduled studies on hydrometeorological investigations, research in sediment transport, and stream hydrograph analysis. The hydrometeorological investigations deal mainly in the improvement of techniques used in the determination of maximum probable precipitation to be expected above potential damsites in the Lower Colorado Basin. This maximum probable precipitation is used in developing the design storms which are in turn used to develop the design flood for determination of the spillway capacity to insure safety of the structure. In many instances the spillway is one of the more expensive features of the dam, and it is necessary that as much be known about the flood potential as possible.
Sediment transport studies are necessary in designing a storage system, as a significant proportion of the storage space provided in reservoirs and streams, such as the tributaries of the Lower Colorado River, is needed for the storage and control of sediment. It is necessary that we have a reliable estimate of sediment transport on the streams to properly determine this space requirement. There is
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Pacific Southwest Water Plan - Report January 1964
No full textReport:United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, "Pacific Southwest Water Plan", Report of August 1963 as modified January 1964, Chapter IX, page 8more nearly ideal irrigation water requirements if the greatest use is to be made of the water available. Continued study of the ideal demand is planned so that requirements can be established for different crops, soils, climate, etc.
It is impractical to design and operate irrigation projects without taking some irrigation water shortage in the extremely dry years. New projects are generally designed to accept a tolerable water shortage in such years. Studies of this tolerable shortage are being conducted to aid in ascertaining the acreage that can be irrigated with water supplies that will be available in extremely dry years.
Sediment transport studies are also necessary in the field of water salvage as they are in the field of design. The aggradation of the stream above a control structure causes an area on which phreatophytes thrive, which in turn presents a major water loss problem. Studies of this aggradation problem are necessary to combat the water losses associated with this aggradation. Details of the phenomenon of sediment transport are also essential in making studies of channel rectification in areas of high water loss where it is desired to lower the water table by means of changing the channel alignment and slope. This has been an important study on the Lower Colorado River Basin in connection with the salvage of water in the Mohave and Cibola Valleys.
An improved understanding of the factors governing the movement of ground water, with the complications of varying permeability and hydrostatic pressures, is needed for effective management of ground-water storage. More knowledge on the factors influencing infiltration and on the flow of water through unsaturated media, may lead to means for increasing recharge.
Other problems include the influence of land-use practices and of vegetation modification on the hydrologic regimen; the drought tolerance of various species of phreatophytes; the relation between depth of water table and consumptive use by vegetation; and the processes involved in natural ground-water recharge from ephemeral stream channels.
Better procedures are needed for predicting the occurrence of irrigation return flows and changes in water quality. More information is needed on evaporation from soils, reuse of sewage effluent, and saline water conversion.
These are but a few of the many problems which make continued research in hydrology essential to extend water uses of an arid land.
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Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project
No full textDocument: "Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project" December 1963, filler, no paginationCHAPTER II
PLAN
OF
DEVELOPMENTEpson Perfection 4870 Photo, 400 dpi, 24 bit, 1,947,648 byte
Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project
No full textDocument: "Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project" December 1963, page 20annual depletions of streamflow made in 1957 for the "Financial and Economic Analysis" of the Colorado River Storage Project, which were published in 1958 as Senate Document No. 101, 85th Congress, 2d Session, and upon the February 1960 Colorado River Storage Project operation studies.
Glen Canyon Reservoir, the principal storage feature of the Colorado River Storage Project, will provide cyclic regulation of the flows of the Colorado River and assure delivery of water to the Lower Basin in compliance with the Colorado River Compact, which apportions the waters of the Colorado River system between the Upper and Lower Basins.
Based upon the recurrence of Colorado River flow corresponding to the 1906-1959 period after making appropriate deductions for future water uses within the Upper Colorado River Basin, it is estimated that power releases from the Bridge Canyon Powerplant would produce an average of 5,706,000,000 kilowatt-hours of energy each year. After supply transmission losses, 1,350,000 kilowatts of capacity and 5,250,000,000 kilowatt-hours of energy would be available for supplying commercial loads and pumping requirements of the Pacific Southwest Water Plan. Under normal operation, the reservoir would fluctuate between elevations 1866 and 1862.
Operation of the powerplant would be fully integrated with both Glen Canyon and Marble Canyon hydraulically and electrically to provide optimum daily and seasonal operation.
Access--The potential damsite access highway from its junction with U.S. Highway 66, at a point 3.6 miles west of Peach Springs, to the damsite, would be a two-lane surfaced road with a total
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Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project
No full textDocument: "Pacific Southwest Water Plan Supplemental Information on Bridge Canyon Project" December 1963, page 24for the benefit of all members of the tribe, and these lands constitute, to all intents and purpose, the only source of their livelihood.
The Hualapai Indians are increasing in number and consequently the available resources per individual are shrinking. The acquisition of the lands for the Bridge Canyon Project further reduces these resources.
As an alternate to cash payment, consideration has been given to an exchange of lands in lieu of cash settlement. Lands adjacent to the westerly boundary of the Hualapai Indian Reservation are equal to or above the carrying capacity of the mesa land required for the Bridge Canyon rights-of-way.
Coconino Dam and Reservoir
This development is proposed to protect storage of Bridge Canyon Reservoir from serious depletion by sediment from the Little Colorado River. The dam would be located on the Little Colorado River about 9 miles downstream from the town of Cameron, Arizona.
Dam--The dam as presently planned would be a concrete gravity-type composite structure 480 feet long between abutments at the top elevation 4300. Its total height above streambed would be about 250 feet. The dam would be composite in that it would consist of barriers for the inner and outer gorges of the canyon.
Reservoir--The reservoir would be operated for the single purpose of sediment retention by the use of stoplog placement to maintain a 40,000 to 80,000 acre-foot detention pool. At spillway crest elevation 4260, the total capacity of the reservoir would be approximately 2,100,000 acre-feet.
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