The Bureau of Land Management, Military, and National Monument lands of the desert areas receive small quantities of precipitation, and have generally well drained soils resulting in low to very low yields and poor water yield characteristics. Lands administered by the Bureau of Land Management in the northeastern California area also produce low water yields. The water yield characteristics of Bureau of Land Management, Military, National Wildlife Refuges and other public lands scattered throughout the remainder of the state are generally fair to poor. Colorado The mountainous National Forest and National Park lands, located at high elevations, receive most of the precipitation, have generally poorly drained soils, and yield most of the runoff in Colorado. Yields are moderately high to high and the water yield characteristics are good. The Bureau of Land Management lands scattered throughout most of central and western Colorado occur at various elevations and occupy diverse topography, from steep high mountains to flat low river valleys. Thus, the water yield and yield characteristics vary considerably. Generally, the bulk of such lands are well drained, receive small quantities of precipitation, and occupy areas of low topographic relief. The resulting water yields are low and water yield characteristics poor.. There are a few scattered areas of Bureau of Land Management lands in Colorado which have high water yields and good water yield characteristics. Idaho The high, rugged, mountainous National Forest lands of northern Idaho exhibit good water yield characteristics and high water yields. The lower elevations in this area and the National Forest lands in central Idaho yield moderately high runoff. The National Forest lands of east central and southeastern Idaho and the mountainous Bureau of Land Management lands of southeastern Idaho produce moderately low to moderate yields and exhibit fair to good water yield characteristics. The Bureau of Land Management lands in Idaho have, for the most part, poor water yield characteristics and receive limited precipitation, resulting in very low to low water yields. The exceptions occur from the scattered lands of western and northern Idaho and those occupying the higher elevations in the southwest and southeast. In these cases the water yields are Montana The greatest portion of the water yield in Montana is from the high mountainous National Forest areas of the western portion of the state, Here the precipitation is high and the soils are moderately well to poorly drained with abundant rock outcrop. These lands can for the most part be classed as high water yield areas with good water yield characteristics. Glacier National Park in northwestern Montana is also a high water yield area, one of the highest in the state. National Forest lands of southwestern and central Montana receive less precipitation and yield less water than the northwestern forest areas. The National Forest and Park lands of south central Montana have moderately high yields. The National Forest lands in southeastern Montana have low water yields and poor water yield characteristics. The Bureau of Land Management lands throughout Montana yield very little water. They generally include the flatter topography, are at lower elevations and are mantled by soils that are moderately well to well drained. Water yields from these lands are low to very low. Exceptions may occur in the western part of the state where scattered holdings include the fuothills and are adjacent to the National Forest land. Locally, these lands may yield slightly moderate to moderate quantities of water. Nevada For the most part, the water yield characteristics of Nevada can be grouped into two general categories: those of the mountainous lands and those of the basins and intermountain valleys. The water yields from the mountainous lands are low to moderately low with, at best, fair water yield characteristics. The National Forest lands of Nevada are located almost exclusively in mountainous areas. The basin and valley lands exhibit poor water yield characteristics and very low yields. The Bureau of Land Management, Atomic Energy Commission, Military, and Fish and Wildlife lands occupy both mountainous and lowland areas, ་་་,,, New Mexico The water yield characteristics of the National Forest lands in the Southern Rockies of New Mexico could be described as fair to good considering that they receive very little precipitation compared to similar mountains in the other states. The soil conditions on the steep slopes are favorable for high yields as they are only moderately well to poorly drained, including significant areas of rockland. However, the yield from these lands is moderately low. The National Forest lands in southern and western New Mexico have generally fair water yield characteristics and low to moderately low yields. Bureau of Land Management lands, present throughout most of western and southern New Mexico and along the northern portion of the Rio Grande Valley, have limited topographic relief. Precipitation is low in these areas and the soils well drained, resulting in poor water yield characteristics and very low yields. The White Sands Missile Range and National Monument is an area of very poor water yield characteristics and very low yields. Oregon The National Forest lands of Oregon in the Coast Range, and along the western slope and ridge areas of the Cascade Range, including Crater Lake National Park, have well to imperfectly well drained soils, receive large quantities of precipitation and yield large quantities of runoff. The water yield characteristics of these areas can be described as fairly good to good and the yields as high to very high. The National Forest lands of the eastern slope of the Cascade Range and the northeastern area of Oregon are well drained, with moderate yields and fair water yield characteristics. The Klamath Mountains, which include National Forest lands, produce high water yields and exhibit good to excellent water yield characteristics. The Bureau of Land Management lands of western Oregon are high water producers in comparison to most of its lands in the other 11 western states. Those lands occuring on the Coast Range and southern part of western Oregon produce moderately high to high water yields and have fairly good water yield characteristics. The Bureau of Land Management lands along the foothills of the Willamette Valley have moderately well to well drained soils and moderately high yields. The water yield characteristics could be described as fair to gocd. Such lands in eastern Oregon are generally located in an area of low Therefore, relief, limited precipitation and well drained soils, Utah The water yield characteristics of the relatively arid Colorado Plateau and Basin and Range areas of Utah are generally poor. The public lands in these areas are predominantly Bureau of Land Management, National Monument and military lands. Precip. itation is low, the soils are generally well drained, and water yields are low. Along the deeply dissected river areas of the Colorado Plateau, where rockland is exposed, the water yield characteristics may be fair and yields moderate. The National Forest lands in southeastern Utah have fair to good yield characteristics with moderate yields from the higher elevations. The higher elevations of the Uinta and Wasatch Mountains which include the National Forest lands have good water yield characteristics and yield moderately high to high quantities of run off. The topography is relatively steep and soils only moderately well to poorly drained. Bureau of Land Management, National Park, National Monument and National Forest lands at the lower elevations in these mountains and in the mountains and plateaus of southwestern Utah exhibit poor to fair water yield characteristics and yields are moderately low. Washington The water yielding characteristics of the National Forest and National Park lands in the Olympic mountains and the Cascade Range are good and water yields are very high, Precipi tation is high, topography steep, and the soils only moderately well to poorly, to very poorly drained, resulting in high runoff. The dense vegetative cover probably reduces the yield to some degree. The National Forest lands of eastern Washington have fair to good water yield characteristics and yield less water than National Forest lands in the western part of the state. Elevations are not as high in the east, topography not as steep. and precipitation is less, The Bureau of Land Management lands adjacent to the National Forest lands in northeastern and southwestern Washington have only poor to fair water yield characteristics with low to moderate water yields. Although the soils are weil drained, these lands receive mederate quantitios of precipitaion and have moderate topographic relief. The Bureau of Land Management lands adjacent to the Columbia River in the south central portion of the state receive very little precipitation, have well to imperfectly drained soils and flat topography. They yield very low quantities of runoff and exhibit very poor water yield characteristics. Wyoming The water yield characteristics of Wyoming are highly variable as is the case of the other western states. At the lower elevations the soils are generally sandy and well drained and topographic relief is low. As a result the basin areas of western and central Wyoming, where most of the Bureau of Land Management lands are located, have poor water yield characteristics and low to almost non-existent water yields. Those Bureau of Land Management lands in the foothill and low mountain areas have slightly better water yield characteristics and yields. In high mountain areas of the state, where soils are thin, impermeable rock is exposed, elevations are high, topography is steep and precipitation is greater, the water yield is high. These areas have fair to good water yield characteristics and include National Forest and National Park lands located predominantly in the northeastern portion of the state. The possible exception to the generally high yields from National Forest lands in Wyoming would be the Black Hills and Laramie Mountains in eastern Wyoming. The soils of the area are well to imperfectly drained to poorly drained. At best, the water yield characteristics could be described as fair to poor. Water Yield by State and Region Water yield, as used herein, is the reconstructed quantity of water yield unaltered by man's use of water through diversions, storage or importation of water from another watershed. The Nation's Water Resources 5/ utilizes the term "natural runoff" to express water yield. The terms "water yield" and "natural runoff" and their contractions "yield" and "runoff" are used herein synonymously. Table 3 presents the average annual water yield of the 11 western states. The data are presented by state and by water resource regions. The total average annual water yield of the 11 western states is estimated to be about 363.2 million acre-feet. 5/ Supra note 1. |
