soil groups include: Franciscan shales and basalts, Knoxville shales, upper Cretaceous and Tertiary sandstones and shales, Miocene siliceous shales, and Pliocene sandstones and semiconglomerates. Both topography and geology of the watershed have been strongly affected by fault action. The major streams have carved their channels along fault zones, while frequent earth movements have deeply shattered the rock formations. LAND COVER According to their effect on run-off, 12 major vegetation cover types have been delineated for flood-control purposes in the Santa Ynez River watershed. These include barren areas, semibarren areas, grassland, dry-farmed cropland, irrigated cropland, sagebrush, sagegrass, chamise chaparral, mixed chaparral, woodland-grass, oak woodland, and stands of miscellaneous conifers. Barren areas include rock outcrops, water surfaces, paved urban areas, and road surfaces. Although limited in extent they are significant because over 95 percent of the precipitation which reaches them escapes as run-off. Together with the semibarren areas, in which vegetation covers less than 30 percent of the ground surface, the total area is about 1 percent of the watershed. Grassland includes areas on which the principal cover consists of annual grasses or other herbaceous vegetation. Abandoned cultivated land is considered in this type because it customarily reverts to a grass and weed cover. Total area of the type is about 15 percent of the watershed. Cultivated land, including temporarily idle and fallow land, covers about 11 percent of the watershed. Irrigated land is located primarily in the broad valley about Lompoc, in a narrow strip along the Santa Ynez River to Solvang, and in a few scattered areas in the Santa Ynez Valley and along Zaca Creek. Nonirrigated land occupies small areas on the gentler side slopes along the tributaries to the river, the largest being in the vicinity of Santa Ynez and Santa Rita. There is practically no cultivated land in the upper half of the watershed. The sage type includes areas with a cover principally of Salvia species and occupies about 3 percent of the watershed. This type occurs at the lower elevations intermixed with grassland, and has a rather low infiltration capacity. Sage-sagebrush-grass includes species of Salvia and Artemisia as dominants, together with various grasses. The type covers some 14 percent of the watershed and is scattered throughout the entire area. Chamise chaparral, including those areas on which the principal dominant species is Adenostoma, occupies about 15 percent of the watershed. Infiltration rates for soils supporting chamise cover are very low; stand density is low, and litter production is poor. hus, Mixed chaparral is characterized by such dominants as Ceanoth Arctostaphylos, and Quercus, together with other species of similar growth form. Stands tend to be quite dense; litter production is good, and infiltration rates are relatively high. This type covers 29 percent of the watershed. The woodland-grass type is intermediate between grassland and oak woodland, being typically composed of oak and pine trees quite widely spaced with unbroken grass cover between. It occupies seven percent of the watershed, mainly in the upper and central portions. 97226-44- -3 Oak woodland, composed of dense stands of broad-leaved trees, is distributed quite widely over the entire watershed, covering some 4 percent of the area. The type is generally confined to northerly exposures and stream bottoms where the supply of scil moisture is sufficient for dense growth. The soils are deep, and infiltration rates are high. Stands of miscellaneous conifers, usually with an undergrowth of shrubby vegetation, occupy 1 percent of the watershed and are found on the uplands or on riparian sites. Principal components of the type are various species of pine and big-cone Douglas fir. FLOOD HISTORY Beginning with the first recorded flood in 1862, the history of the Santa Ynez River watershed records 6 major floods during the period of record, namely those of 1862, 1884, 1907, 1914, 1915, and 1938, and 11 floods of lesser magnitude. Other smaller floods have caused damage in exposed parts of the lower watershed. The flood of January 1907 is believed to have been the largest experienced, though the greatest damage was done by that of March 1938. Floods of magnitude sufficient to cause extensive damage throughout the watershed are estimated to have a frequency of 5 in 100 years, while the lesser floods are estimated to occur 15 times in 100 years. Detailed damage records, however, are available only for the flood of March 1938. Past flood occurrence has been confined to the 7 months from October to April, inclusive, with the great majority coming during the winter months December to March. Peak occurrence is in the months of January and February. ECONOMIC DEVELOPMENT EARLY SETTLEMENT AND DEVELOPMENT With the founding of Purisima Mission in 1787, settlement of the Lompoc area began. Shortly afterward, in 1804, establishment of the Santa Ynez Mission opened that area also to agricultural use. From this time through the period of secularization of mission holdings and the Mexican land grants, cattle grazing constituted the main enterprise of the watershed. The great drought of 1862-63 brought this early period to a close. With almost complete destruction of the cattle industry, many of the grants were subdivided and sold to American settlers. With this event clearing of the Lompoc Valley began, and soon afterward the hill and tributary valleys were put to the plow. As a consequence the reviving cattle and sheep industry was pushed back into areas unsuited for crop agriculture. With the laying of the Southern Pacific Railroad tracks to Santa Barbara in 1887, the general pattern of modern agricultural use was well on its way to being established. Introduction of widespread irrigation during the years from 1910 to 1930 changed the pattern of agriculture to its present form. See appendix 3. Not printed. POPULATION AND URBAN DEVELOPMENT The total population of the Santa Ynez River watershed was given as 7,230 people at the 1940 census. Of this total number about 4,500 lived in urban communities, even though the greater part of the population is dependent upon agricultural pursuits. Since the construction and occupation of Camp Cooke in 1941, the number of people, especially in and around Lompoc, has increased greatly. Lompoc is the only incorporated town in the watershed. It was founded in 1874, and at the time of the last census had a population of 3,379 people. Other communities in the watershed are Solvang, Santa Ynez, Ballard, and Los Olivos, all situated in the lower Santa Ynez Valley, and Buellton. Solvang, with about 400 people, is the largest of these communities. With the exception of Buellton, ncne of the towns is located on a trunk highway and only a spur of the Southern Pacific Railroad connects Lompoc with the main line. None of the urban developments is threatened by floods from the Santa Ynez River. LAND OWNERSHIP AND USE The Santa Ynez River watershed embraces 576,000 acres, of which 347,318 acres are in private ownership and 223,317 acres are federally owned. Federal lands are in Los Padres National Forest except for 1,650 acres of unappropriated public domain and 87 acres of Indian reservation. State-owned land representing parks amounts to 648 acres, county land to 75 acres, and school land to 42 acres. In addition, 4,600 acres are municipal property, comprising the areas surrounding mountain reservoirs belonging to the cities of Santa Barbara and Montecito. The mountain land, mostly within the national forest, is reserved for watershed purposes and to a limited degree for recreation and grazing. Of the privately owned land, 89,165 acres are wild land. and a small acreage urban properties and roads. The greater portion of private holdings, embracing some 258,153 acres, is used for agricultural pursuits. Irrigation farming occupies 13,311 acres, dryland farming 52,342 acres, and grazing 192,500 acres. Approximately 17,500 acres of national forest range land are grazed under permit from the Federal Government. The irrigated land is restricted at the present time to areas with available water from underground basins and perennial streams. These areas extend throughout the Lompoc Valley, along the Santa Ynez River to the east of Solvang and scattered places in the Santa Ynez Valley. Vegetables, sugar beets, flowers, and alfalfa are the major irrigated croos. Wherever growing conditions are avorable for alfalfa, dairying is well established. Dry-land farming occupies the gentle slopes and tributary valleys on both sides of the river and most of the Santa Ynez Valley. Beans, mustard, grain, and hay are extensively grown. The steeper hills and other rough land in the lower portion are utilized for cattle grazing, which is still one of the major income producing industries of the watershed. Mining in the Santa Ynez River watershed is restricted to a few quicksilver mines near Gibraltar Reservoir and the Cachuma Gap. Diatomaceous earth deposits are located in the hills south of Lompoc, and large amounts are removed each year. A minor oil field north of Lompoc also adds somewhat to the total income produced within the watershed. LAND UTILIZATION AND FLOOD PROBLEMS RUN-OFF AND EROSION PROBLEMS IN RELATION TO LAND USE Farm land. The farm land is located almost entirely in the lower half of the watershed adjacent to the communities of Lompoc, Buellton, Santa Ynez, and Solvang, centering in the Lompoc and Santa Ynez Valleys. Although about 65,000 acres or 11 percent of the watershed area is cultivated, only the cropland in subwatersheds B and C, aggregating approximately 45,000 acres or 8 percent of the total watershed area, is so located that it contributes significantly to flood damage. Of the contributing 45,000 acres, approximately 41,000 acres are dry-farmed and 4,000 acres irrigated. The dry-farmed area is most significant to the flood-control problem because of its greater extent and location on more steeply sloping land. Existing problems on agricultural land grow out of a long history of exploitive cropping practices and cultivation without regard to conservation. The effects of extensive cultivation and heavy grazing of the hill land became evident in the form of accelerated run-off and erosion. Heavy rains in 1910 and 1914 cut large gullies in the valley bottoms, initiating a cycle of severe erosion that has destroyed some agricultural land, made other acreage inaccessible and carried erosion debris downstream to cause damage through sedimentation. The gullies so started have grown with the passing years until some 400 acres of land have now been destroyed. The process of destruction was lent impetus by the high farm prices that prevailed during World War I. During that period virtually all the land that could be plowed was brought under cultivation, including slopes of 40 percent gradient and steeper. Some of the land that was retired because of decreased yields and unprofitable operation resulting from site deterioration is again being cultivated because of current (1942) higher prices for the crops. Crops raised in the watershed at present are governed strongly by topography and availability of water. Grain and grain hay, beans, vegetables, sugar beets, mustard, alfalfa, corn and sorghum, and flower seed are the principal crops grown, listed in order of the 1937-40 acreage planted. Vegetables, sugar beets, alfalfa, and flower seed predominate under irrigation on the alluvial valley fills. Dairying is found wherever alfalfa culture is successful. On alluvial fills along the creeks where water is limited, and on the hill lands that must be dry-farmed, beans, grain, grain hay, and mustard predominate.* Yields on the valley land are generally excellent, but the hill land affords only a bare existence to the farmer. Destruction of the valley For details by individual areas within the watershed see appendix 4. land by erosion would make the whole area submarginal for present crops, and would force more areas into range and grazing use. If this should occur, the number of people finding support in the region would be considerably reduced. Among detrimental farming practices are the utilization of steep slopes, clean cultivation, cultivation parallel to the direction of runoff-that is, up and down the slope-and a general failure to return. nutrients to the soil in the form of crop residues or fertilizer. The existing practice of short-term crop-share leases has materially aggravated the conditions on dry-farmed land. Such leasing provisions foster exploitive use of the land because the tenant has little security in the continuance of the operations and little to gain from installing conservation methods of farming. Range land. Closely associated with the problems of farm land are those of the range land. The chief problems on range land are widespread soil compaction and local overuse. Both problems arise from the system of extensive management under which grazing is now practiced. Problems of less importance are erosion and the deterioration of range vegetation. Soil compaction is present to a significant degree on approximately 82,000 acres of the range land throughout the watershed. Of this area about 76,000 acres lie in subwatersheds B, C, and D, so located that they contribute excessive run-off to the major flood damage area around Lompoc. Over-use occurs on some 4,000 acres of range land in subwatershed C. Subwatershed A is excluded because of its position downstream from the area of significant flood damage, and no range problem exists in subwatershed E. (Map 1, facing p. 10.) Range use in the watershed dates back to 1787 when La Purisima Mission was founded near the present city of Lompoc. In the early days, heavy grazing and years of drought acted together to destroy the native perennial grass cover. The perennials were replaced, however, by annual grasses introduced largely through seed carried by the livestock that were shipped in, often from foreign lands. The result has been conversion to an annual grass type of range, the introduced species having become established and widely naturalized. Due to the hardiness and other characteristics of this annual cover, range lands of the watershed are still in comparatively good condition with regard to the erosion and gullying. The principal livestock enterprises carried on in the watershed include beef cattle feeding and breeding and the maintenance of dairy herds. Most of the beef cattle in the watershed are brought in as weaner calves or yearlings and sold after one or two grass seasons. Breeding of purebreds is confined to relatively few ranches, although most ranches maintain breeding herds. The present trend is toward increased interest in breeding cattle, although Santa Barbara County is known as a stocker type of range. Dairies in the watershed produce both market milk and manufacturing milk. Horses are relatively few in number and are kept mainly for riding and breeding purposes. Sheep, goats, and hogs are not significant to the range problem, since they are few in number and are grazed on pastures of small acreage. Of the 210,000 acres of usable range in the watershed, about 190,000 acres, or 90 percent are privately owned. In Los Padres |