OCR Text |
Show control program of structural and nonstructural measures would prevent a large portion of the damages, so that remaining damages of only $68 million annually are estimated by the year 2020. For these remaining damages, there appear to be no feasible solutions. Irrigation and Drainage Irrigated land is expected to increase from the 1965 level of l,315fOOO l/ to 1,613,000 acres. Urbanization is expected to remove 204,000 acres from production. The total new irrigation development would be 502,000 acres. The program includes completion of the reha- bilitation of existing water conveyance systems for 429,000 acres of presently irrigated lands and new distribution systems to serve l,O755OOO acres, a portion of which is presently irrigated exclu- sively from ground water. Onfarm water management measures such as land leveling and water control structures are recommended for about 2.2 million acres during the study period. The 2.2 million acres include retreatment of some land because of the expected improved technology and limited life of the structures and measures. These measures would provide better control and more efficient use of irri- gation water and/or would reduce costs of irrigation. New drainage facilities are included to serve 188,000 acres. Municipal and Industrial Water The rapidly increasing population will require that water for municipal and industrial uses be increased from a 1965 level of 450,000 acre-feet to 2.8 million acre-feet in year 2020. Presently authorized projects will supply 446,000 acre-feet of additional water by 2000. Major urban centers would satisfy their additional water requirements through the importation program and through treatment and recycling of waste water. Smaller communities would fulfill their increasing needs by a variety of means, including additional surface- and ground-water development, desalting of brackish ground water, and by importation. Mineral Resources Adequate mineral resources are available to meet the expected increased production, $511 million in 1965 to $1.93 billion in year 2020 (1958 dollars). Water withdrawal requirements would increase from 105,100 to 357>200 acre-feet in this period, while land require- ments would increase from 76,000 acres to 223,000 acres. Environ- mental impacts of the mining and processing of ores will need to be l/ Includes only those acres actually irrigated in 1965 plus the acreage double cropped. xi |