| OCR Text |
Show Rehabilitation of existing irrigated lands.-The present irrigated lands of the basin are in need of considerable rehabilitation. Water for 4,450,000 acres out of approximately 5 million acres now irri- gated was provided by private and State initiative. Only about 10 percent, or 500,000 acres, are sup- plied with water from Federal reclamation projects. Investigation of many of these projects revealed the existence of almost every possible engineering, agronomic, financial, and management difficulty. Rehabilitation and improvement of these irrigation enterprises, the improvement of individual farm irrigation systems, and the preparation of land for better use of water, provide an immediate and prac- tical way to increase efficiency in using soil and water. The Department of Agriculture estimates that a 30 percent increase in production is possible by rehabilitation and effective use of present re- sources. Engineering problems range from the inadequacy of storage reservoirs to the need for installing water- measuring devices on individual farms. Between these extremes are problems relating to diversions, headgates, canal relocation, canal lining, and struc- tures such as siphons, flumes, drops, checks, and crossings. About 45 percent of land now irrigated needs some leveling. In some instances two or more separate enterprises should be consolidated to achieve economical use of water and land. An estimated 2.5 million acres of irrigated land needs some rehabilitation. Drainage is one of the most serious problems in irrigation. Large amounts of water are lost through inadequately designed and maintained canals and ditches. Transit losses reduce the amount available at the farm and at the same time jeopardize adjacent lands by seepage. Drainage problems also result from ignorance of crop require- ments for water, careless application, poorly de- signed farm irrigation systems, and improper land preparation. The practice of delaying drainage until the need is acute has ruined some lands. Re- turn flow from these lands often causes considerable erosion and a decline in productivity. In some sections alkali in the topsoil is a serious result. A major part of the 5 million acres now being irrigated needs drainage. Rehabilitation of these systems is often neces- sitated by improper and inadequate maintenance. Poor maintenance sometimes results from lack of knowledge or suitable organization among the farm- ers. Many of the smaller irrigation units cannot afford the technical personnel necessary for mainte- nance. Inadequate finances often result in patch- work maintenance and rehabilitation. Rehabilitation will require large investments which are often difficult to obtain. The enterprise may be located in an area, generally considered questionable by credit agencies; lending institutions may find the security inadequate, and outstanding mortgages often limit borrowing power; Federal credit agencies do not have the funds to meet all needs. Rehabilitation of irrigation works involves three principal types of installations: the irrigation dis- trict organized under State law to distribute water among many farms, the small incorporated or un- incorporated enterprise serving 10 or more farms, and the individual enterprise serving a single farm. Those proposing to construct private irrigation works may need specialized help in preparing land for effective use. Planning requires competent ad- vice and assistance as to the availability and depend- ability of water supplies, the capacity of the land to respond satisfactorily under irrigation, and the estimated cost of installing and maintaining the proposed facilities. Construction also requires supervisory technical assistance. Involved in bringing such land under irrigation are problems of land development, de- sirable methods of water application, and farm organization or reorganization. These and other problems require competent technical advice and assistance to avoid loss of time and income. More than 800 small irrigation enterprises are believed to need assistance. Conclusions New land.-In those areas where irrigation can help stabilize the grazing industry, single-purpose or other irrigation projects should be built as soon as possible to alleviate suffering and hardship in drought years, to protect and preserve established service communities and public services, and to pjovide insurance against heavy relief loads. For the basin as a whole the rate of irrigation construction probably will not be rapid enough to make it a national problem for several reasons. The acreage involved in many of the units, even as a total, is small compared to the amount of agricul- tural land in the Nation. Most products of these lands are not "surplus" crops. Many instead are in short supply. Large competing financial de- 222 |
