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Show 4. Land Treatment Programs in Plans for Water Resources Development The Problem Erosion control measures, forestry activities, and related land treatment measures essential to com- plete water resources development of the valley. The Situation Land treatment is lagging far behind other types of water resources development in the Central Val- ley. Land treatment programs are proceeding at a slower pace in the Central Valley than in most other parts of the country. For example, while soil conservation districts have been organized to in- clude over three-fourths of the farms and ranches of the Nation as a whole, only about 10 percent of the farms and ranches of the Central Valley are included in soil conservation districts. This is true even though soil productivity is deteriorating on over half of the 7 million acres of cultivated land. Improvements in the manner of distributing and applying water are needed in many irrigated areas. These would provide protection against soil deteri- oration and would contribute to more efficient use of water. Of almost equal concern is the situation on the 8 million acres of brush and open range lands. Pub- lic domain lands and many private range lands have been so overgrazed in the San Joaquin that dust storms in dry years have stopped traffic on some major highways, and sand deposits have blocked some side roads. The lower slopes and foothill valleys of the west side of both the Sacramento and San Joaquin have been destructively grazed. In the Paskenta district gullies have added greatly to the sediments which farmers must remove from ditches. At flood times the sediment is flushed into the Sacramento. Recently, fire is being used an- nually on about 80,000 acres of grazing land scat- tered throughout the basin in an effort to convert the cover to grass. Soils, particularly the thin ones, will suffer severely from this effort. In many high mountain meadows, overgrazing has caused serious gully erosion. This destroys the value of th_ese excellent grazing areas, since worth- less brush often replaces the lush grasses as the water table is lowered. Great quantities of eroded material from these meadows are poured into the stream channels. The Central Valley area has a deer herd now numbering about 600,000 animals. In certain 134 areas, these animals are in direct competition with livestock for available feed on the range. There are at present seven areasir where big-game grazing is creating watershed problems. Although steps have been taken toward better game management, the number of areas affected may increase until direct measures for reducing herds are adopted. Logging practices on the 4 million acres of com- mercial timber stands in the national forests are generally better than on the 3 million acres of nonpublic land, but on both too little attention is currently paid to methods that would reduce ero- sion. Skidways and roads are a primary source of damaging erosion, and practically no efforts are being made to prevent or heal the scars. Current practices on national forest timber sales require the logger to restore the cut-over land to as nearly normal condition as possible upon completion of the logging operation. Local control is not so effective on the private lands, of which only about 25 percent is considered adequate from a watershed protection standpoint. Forest fires have resulted in damage to the water resources and to water improvements. In one in- stance several years ago a 17,000-acre fire in the Upper San Joaquin disabled a powerhouse until the sediment and debris at the intake and in the tunnel could be sluiced downstream. Nearly 600,000 acres of forest land at present require planting, of which about a third should be reforested to restore good watershed conditions. About half of this total is on public lands. Some 250,000 acres of privately owned watershed lands are thought to be in a critical condition because they are destructively logged and badly burned. A smaller acreage of lands needing attention is that in old mine workings, especially those ruined by placer mining. These now virtually worthless lands are so located as to be a menace to good water condi- tions. One objective of watershed management in the water-producing areas of the basin is to provide protection to soils and channels so as to minimize surface runoff and erosion on slopes and flood peaks in the streams. Another objective is to manage the timber, chaparral, and grasslands in such way that they will yield the maximum amounts of usable and regulated water. Further research is needed to show how much safe water yield can be increased by watershed management practices. " E. g., adjacent to Yosemite, at the southern end of the Coast Range, and in the Yuba River and Modoc areas. |