irrigable acres of dry lands in the Talent Division will receive this water. A semidetailed land classification and survey of arable lands has been accomplished. Topographic maps of dams and reservoirs, canal lines, and other features have been made. Data have been assembled and studies made of water resources, requirements, and utilization. Economic, engineering, geologic, and other studies have been completed for the division plan. Cooperative studies and reports have been made on the recreational and fish and wildlife aspects of the proposed development. A flood benefit study for the enlarged Emigrant Dam was made by the Corps of Engineers. Selection of the plan presented in this report is based on factors of power potential, wishes of local interests, acreage to be included, and water yield of reservoirs. ACKNOWLEDGMENTS The present investigation was sponsored by the Bureau of Reclamation, with full cooperation by other agencies. Flood problems and flood control benefits were reported on by the Corps of Engineers. The Fish and Wildlife Service, Region 1, has investigated benefits to fish and wildlife. Use of reservoirs for recreation was investigated by the National Park Service. The board of directors and managers of Talent, Medford, and Rogue River Valley Irrigation Districts furnished valuable information and cooperation throughout the course of investigations. The Rogue River Valley Irrigation Association has worked closely with the Bureau in the interest of early development for this division. Numerous other local and State agencies and individuals have provided invaluable help in these studies. CHAPTER II LANDS Talent Division of the Rogue River Basin project is located in southwestern Oregon in Jackson County. It occupies a long comparatively narrow valley and includes areas of bottom land, terrace land, and steep sloping foothill lands which surround the area. Talent Division lands investigated include 28,480 acres. The investigated area includes all lands that could be served under present laterals or from short extensions of present laterals. However, engineering, economic, and land-use considerations eliminated 3,370 acres of arable lands, leaving a total of 18,980 arable acres within the division boundaries. A further reduction of 1,090 acres was made to allow for present and additional rights-of-way necessary to construct the division. This left 17,890 irrigable acres upon which charges for water would be levied. The topography is generally well suited to irrigation by gravity methods; however, special methods of application and careful planning of distribution systems will be necessary to insure proper coverage and efficient use of water. Drainage, both surface and subsurface, except for a few small areas, will not be a problem. SOILS OF THE INVESTIGATED AREA Soils of the area are similar to those formed in a humid climate. They are nearly neutral in reaction, free from accumulations of salts or lime carbonate, and possess heavy-textured subsoils. On the basis of topographic position and formation, the soils are divided naturally into three groups: (1) recent alluvial soils, (2) old alluvial soils (valley-filling materials), and (3) terrace or benchland soils. A discussion of soil characteristics within these groups follows. RECENT ALLUVIAL SOILS Recent alluvial soils occupy 1,160 acres of arable land within the investigated area. These soils have developed from recent alluvial deposits and occur in rather long and narrow strips or in small scattered patches along the major streams. Most of these soils have a uniform profile texture which ranges from sandy loam to silt loam. They usually show stratification and are underlain by sand and/or gravel and cobble at depths ranging from 3 to 6 feet. Some gravel and cobble may be present throughout the profile, but never in sufficient quantities to hinder cultural practices. These soils are highly productive and well adapted to all general farm crops common to the area. A small proportion of these recent alluvial soils are gravelly, shallow to open sand, gravel or cobble, and are best suited to production of hay and pasture crops. OLD ALLUVIAL SOILS Soils developed on old valley-filling materials occupy 2,480 acres of arable land within the investigated area. These soils occur in fairly large-sized blocks in the southern part of the area, and east of Jacksonville. Smaller patches occur along Bear Creek. Surface soil textures range from fine sandy loam to silt loam. Subsoil textures range from silt loam to clay loam. The understrata which occur at a depth of from 4 to 6 feet below the surface are generally a light-clay loam containing some sand and gravel. These soils are highly productive and are well adapted to all crops common to the area. A portion of these lands with light-textured surface soils are especially adapted to the production of truck crops. TERRACE OR BENCHLAND SOILS Terrace and benchland soils occupy 18,710 acres of arable land within the investigated area. The soils occupying these higher lying positions vary considerably within relatively short distances, but may be divided into two general groups as to location and general characteristics. The soils east of Bear Creek are generally heavy-textured clay loams to clay adobes; whereas the soils to the west of Bear Creek are generally lighter textured coarse sandy loams to silt loams. Characteristics of these soils vary with the kind of material from which they have been derived and the agents which have been active in their formation. The residual soils, those formed in place by decay of rock, are confined mainly to the hilly and mountainous areas. Only a small amount of the arable soils are of this type. The heavytextured soils north of Bear Creek have developed from a variety of materials including basaltic rock, shale, sandstone, and conglomerate. The lighter-textured terrace soils south of Bear Creek were derived primarily from granitic rock, sandstone, and shale. In general these soils are productive and will produce any of the crops common to the area. However, in some places crop production and choice of crops are limited because of shallow soil depths or undesirable topographic features. TOPOGRAPHY The topography of the land within the investigated area varies from steep slopes at the base of the mountains on each side of Bear Creek Valley to the gently sloping and gently rolling terrace and old alluvial deposits of the valley floor to the gently sloping, undulating, recent alluvial lands along the stream channels. The topography of this area is not ideal for irrigation by gravity methods. However, with reasonable care, some smoothing or light leveling and adaptation of proper methods of application, irrigation can be accomplished satisfactorily and efficiently. DRAINAGE Natural stream channels and general slope of the land provide good surface drainage in this area. Subsurface drainage is good with the exception of a few small areas along some of the small stream branches of Bear Creek which have a relatively low gradient as they cross the old alluvial deposits of the valley floor. It is anticipated that some intercepting drains will be needed at the toe of the steeper slopes to prevent seepage of lower lying leveler lands. No extensive drainage problems are expected to develop. These Heavy-textured soils predominate east of Bear Creek. soils are slowly permeable and internal drainage is slow. With reasonable care in application of irrigation water, difficult or costly drainage problems are not expected to develop. This assumption is substantiated by the lack of drainage problems in this area where irrigation has been practiced for years. SALINITY AND ALKALINITY Salinity and alkalinity are not a problem. Under the semihumid climatic conditions which exist in this area, most of the precipitation occurs in the fall, winter, and spring months in the form of rain. Deep percolation of this rainwater has carried the soluble salts originally present in the soil materials and those formed by the weathering of minerals downward into the ground water and through natural drainage channels out of the area. Drainage works may be necessary in some small areas to lower the water table or to prevent seepage of lower lying lands, but in no case will they be necessary for removal of harmful concentrations of salts. LAND CLASSIFICATION A semidetailed land classification of Talent division was made in 1942. In 1948 and 1949 a reexamination was made of the area and additional information was placed on the field sheets. This additional information was essential in determining irrigation water requirement; potential productive capacity, range of crop adaptability and need of land preparation for irrigation. The land classification involved separation of arable lands (22,350 acres) from nonarable lands (6,130 acres). Arable lands were further separated into land classes. The most favorable lands regarded as suitable for irrigation were designated as class 1; class 2 lands are next best; class 3 lands are of lesser suitability; and class 6 lands are nonarable. During the investigation about 3,370 acres of arable land were deleted and are described as follows: 1. Lands with private water rights total about 2,090 acres. These lands are irrigated by individuals who have water rights from small streams which cross the area. The most prominent are Neil Creek, Wagner Creek, and Ashland Creek. A small acreage is irrigated by pumping from Bear Creek. 2. Lands totaling 140 acres irrigated with water furnished by the city of Ashland. 3. The proposed Talent lateral extension was considered infeasible, which eliminated 390 acres. 4. Lands totaling 590 acres, which lie above west lateral and below upper west and Frederick laterals. These lands were eliminated from the division area because they will not receive any benefit from the proposed works and are presently irrigated from Wagner Creek. 5. Class 3 dry lands under Ashland lateral, totaling about 160 acres. ། CLASSIFICATION SPECIFICATIONS Lands of the investigated area were all classified as to arability according to the minimum specifications indicated in table 2. The specifications for classification define the minimum requirements for each characteristic by land class. Primary factors considered were soils, topography, and drainage. These field factors were used as a basis for judging crop adaptability and productivity, and for making a classification of the land. TABLE 2.-Minimum land classification specifications, Talent division, Rogue River Basin project, Oregon Class 5, nonarable, includes lands which are covered with trees or brush and will need to be cleared before they can be farmed. Class 6, nonarable, includes lands which do not meet the minimum requirements of the next higher class mapped. LAND CLASS CHARACTERISTICS Classification of lands under the minimum specifications noted, resulted in the following agronomic appraisal for the various land classes. |