OCR Text |
Show ect. Based on a 1944 survey, Alamogordo Reser- voir, constructed in 1937 to replace McMillan, is losing about 2.3 percent of its original capacity an- nually. Here the chief contributors of sediment are Gallinas River and Tecolote and Alamogordo Creeks. The Red Bluff Reservoir has lost about 10 percent of its useful storage. A small reservoir on the Penasco River near Hope was filled with sedi- ment in a single storm. The river in the Middle Rio Grande Valley built up its bed at an average of 1 foot in 10 years, resulting in a rise of about the same rate in the shallow water table under nearly 90,000 acres of irrigated land. Unless sedimenta- tion is soon checked, waterlogging will ruin a large part of this fertile valley land. Soil erosion is moderate or severe on many areas. The sediments from this erosion in many cases have not yet reached stream channels whence they would be carried downstream to foul irrigation works, raise river beds, or help fill reservoirs. Many of these sediment deposits, although now doing little harm, constitute a future threat to valley lands. If erosion and valley trenching continue at present rates, new channels will in time tap these deposits and greatly increase sediment loads in the streams (figures 5 and 6). The following programs which are being carried on are effecting some degree of watershed improve- ment. They are aimed in part at controlling sedi- ment at or near its source. The Forest Service of the Department of Agri- culture administers the national forests, which in- clude much of the high mountain area and furnish most of the water supply. These forests are not now high sediment producers, but numerous local areas are eroding because of fire or range misuse. These conditions are slowly being improved by ad- justing livestock use to forage production, better logging methods, and more efficient forest fire con- trol. Much greater progress is necessary in obtain- ing better watershed conditions and in preventing the production of sediments. Most national forests contain a high percentage of intermingled private lands. Although the Forest Service attempts to obtain as good practices on these lands as on the Federal lands, many owners follow methods which result in land damage. By a program of land purchase and of exchanging timber for land, the Service has been able to con- solidate some of its holdings. The Forest Service also cooperates with the States and other agencies in establishing and maintaining forest fire control measures. This work, however, covers adequately only a part of the forest area. No fire control is provided for the woodland or brushland areas even though serious damage is caused to watershed values by the repeated fires. The Soil Conservation Service, also in the De- partment of Agriculture, through cooperation with local soil conservation districts furnishes technical services to fanners and ranchers with the object of bringing about control of accelerated erosion as a basic phase of sound land use. Progress within the districts is slow because of the inadequate num- ber of personnel available. Technical assistance to farmers and ranchers under this program is de- signed to build up and maintain soil productivity and to encourage them to use their lands in such a way that erosion will be minimized. The Production and Marketing Administration provides assistance to land owners for the establish- ment and carrying out of certain desirable erosion control and soil improvement measures. This pro- gram is used annually on approximately 55 percent of the farm land in the basin. Assistance offered under this program has resulted in the application and use of many needed conservation measures on privately owned land. The following tabulation shows the amount and a comparison of the needs met through this program accumulatively from 1936 to 1948. Practice Terraces constructed... Contour strip farming.. Permanent cover...... Drainage............ Seeding pastures...... Eradication of competi- tive plants. Farm ponds.......... Wells................ Amount 152, 000 72, 000 8,000 84, 000 260, 000 7, 386, 000 51, 500 8,000 Unit Per- cent- age of needsl Acres. . ..do... ..do... ..do... ..do... ..do... Number ..do... 26 20 15 12 8 48 75 53 1 Needs used in this comparison are the figures compiled by State and county PMA committees, based on informa- tion supplied to them by various Federal, State, and local agencies and individual farmers. Farmers Home Administration and the Farm Credit Administration make certain loans and pro- vide other opportunities to owners and operators to carry out erosion control measures. Land-administering agencies, such as the Bureaus 911610-51- -21 299 |