No description available.

No description available.

Conjunctive management of surface and ground -water resources on state and local levels is a relatively new political phenomenon. This type of management has evolved, in part, in response to growing populations with ever -increasing, and often conflicting, water demands. In addition, a more sophisticated technical understanding of the physical link between groundwater and surface waters has led water managers to reconsider historical strategies for solving water supply problems. In light of growing demand and improved technology, some western states have begun the transition from crisis- oriented water management to one of long -term planning for population growth and environmental protection. This planning process requires that the constituents of a region define their water use goals and objectives so that various approaches to conjunctive management may be evaluated for their suitability to that particular physical and socio- political environment.

No description available.

A clear understanding of interactions between the arid Southwestern environment and that area's prehistoric inhabitants has been a goal of Southwestern archaeology. This research has reconstructed annual corn and dry bean crop yields for southwestern Colorado from A.D. 650 to 1968, as well as the amounts of those foods available for each of those years. Colorado's five southwestern county dry farming corn and dry bean crop records were combined to create two regional crop series. Modern technology's increasing influence was recognized as being present in the two series. This influence was felt to parallel Colorado's statewide fertilizer consumption and was removed using a multiple regression procedure. Two modern technology free regional crop series resulted. These two series, along with the original two historic crop series were calibrated against five Four Corners tree-ring chronologies from four localities. Both Douglas-fir and pinyon were employed in the calibration. The calibration process used multiple regression so that each series' current annual crop yield could be predicted using one or more of 25 separate dendrochronological predictors. The regression equation deemed most suitable for predicting each of the four crop series was utilized to reconstruct annual crop yield estimates for the A.D. 652-1968 period. Normal verification was impossible since additional independent crop data were lacking. The reconstructed crop yield series were evaluated statistically. Portions of them were compared against historically recorded events. These two types of testing suggested that the retrodictions were probably valid. The crop yield reconstructions provided the basic data for four sets of storage simulations that attempted to determine corn and dry bean availability for each year from A.D. 652 to 1968, given certain assumptions about the levels of storage technology available to the Anasazi of southwestern Colorado. A. E. Douglass' A.D. 1276-1299 "Great Drought" appears to be confirmed. A number of additional famines or food crises have also been recognized. In addition, periods when food was super abundant have been identified. It now appears that much of the Four Corners large public construction projects were undertaken during and perhaps because of these periods of excess surplus.

Section 1: Watershed-based Plan, Section 2: Pollutant Risk Ranking, Section 3: Watershed Management and Improvements, Appendix A: Soil Classification, Appendix B: Water Quality Data and Assessments, Appendix C: AGWA Tool, Appendix D: Suggested Readings

Section 1: Watershed-based Plan, Section 2: Pollutant Risk Ranking, Section 3: Watershed Management and Improvements, Appendix A: Soil Classification, Appendix B: Water Quality Data and Assessments, Appendix C: AGWA Tool, Appendix D: Suggested Readings

Water management models have evolved through three basic stages. The earliest models dealt with the problem of getting water to where it was needed. Adequate supplies of sufficiently high cudlity were assumed to exist, and thus these models attempted to determine optimal distribution networks. In 1966 J.A. Dracup developed a model of this form to explore alternate sources of supply to meet industrial and municipal demands, agricultural demand, and demand for water to provide artificial recharge of groundwater aquifers. The next developments in water management were due to the emerging awareness of the environmental impacts of water use. These models were primarily concerned with maintaining certain quality levels within the natural water system (rivers, streams, estuaries). They tended to ignore the quantity of water within the system, being concerned with optimizing over the distribution system and quality control through the use of by-pass piping, on-site and regionalized treatment plants. The final category of models is one in which both quality and quantity considerations are allowed to enter as decision variables. The most general model of this type was developed by D.E. Pingry and T.L. Shaftel in 1979. This model allows for any configuration of sources, users, piping, disposal areas, and treatment plants. Thus the problem of distribution and quality control are both handled. This model also employs realistic nonlinear cost functions through economies of scale in treatment, and diseconomies of scale in treatment efficiency. The major limitation of their model, and others of the same type, is that they have been applied only to closed water systems which do not include rivers, streams, etc., and therefore ignore the environmental impacts of the water development on the complete natural water systems (e.g., a river basin). The Pingry-Shaftel model has been expanded to allow for the integration of a river system into an optimization model where the distribution system, quality control, source development, recycling of wastewater, and other management strategy alternatives are all allowed to enter as decision variables. At the same time the quantity requirements and quality standards are being monitored in order to analyze their impacts on cost. Decomposing the problem and making use of a large-scale transportation algorithm permit a solution to be obtained in an efficient manner. The model has sufficient flexibility to permit the comparison of impacts of various natural, technological, economic, and legal constraints. The model has been applied to the Colorado River Basin under varying assumptions in order to determine the economic and environmental implications of various water supply allocations and salinity treatment strategies.

Water quality analyses in Grand Canyon examined Colorado River and tributary baseline water quality status in relation to recreational float trip use of the river corridor. Float trip use of Grand Canyon has increased over recent years (since 1966) to levels which have caused concern for water quality-river running associations. River runners have traditionally used the Colorado River and tributaries as sources of drinking and cooking water, for swimming and bathing, and, at times, as a disposal for some refuse, e.g., dishwater and leftover food. Associated with float trip use of the river corridor water resources has been potential water quality hazards. During the 1972 and 1979 float trip seasons (May through September) outbreaks of gastroenteritis occurred among river runners in Grand Canyon, prompting investigation by the Center for Disease Control, Atlanta, Georgia; an enteric pathogen Shigella sonnei was isolated from some river-trip participants. Potentially, the Colorado River or a tributary served as a source or carrier of the pathogen, though this has not been confirmed. Enteric disease organisms excreted in feces by humans, wildlife or domestic animals can become potential sources of infection; water contaminated with fecal organisms can distribute diseases. Water quality analyses of the Colorado River corridor occurred during the 1978 and 1979 river running seasons. Examination of the extensive river corridor necessitated analyses in the field. Travel through the Grand Canyon was via research rafts in a series of six float trips, April through September, in 1978, and two float trips, July and August, in 1979; 82 field days in 1978 and 22 field days in 1979. A total of 497 water quality samples were collected over two seasons from the Colorado River along the 225-mile stretch from Lees Ferry to Diamond Creek, the launch and take-out points of the research trips. The confluent reaches (within approximately 200 yards of the Colorado River) of 26 side creeks in the river corridor were also sampled in 1978; nine tributaries were sampled in 1979. Additional samples collected from upstream locations on some side creeks increased the tributary sample site total to 33 in 1978 and to 13 in 1979 for a two season total of 165 individual tributary samples. Selected microbial, physical, and chemical parameters were measured to determine baseline water quality status in the Colorado River corridor of Grand Canyon. Research emphasis was on microbial water quality; physical and chemical parameters were measured to facilitate evaluation of the microbial profiles. Microbial parameters included fecal coliform bacteria and fecal streptococcus bacteria densities; physical parameters included turbidity and water and air temperature; chemical determinations included alkalinity, hardness, phosphate, nitrate, chloride, total dissolved solids, and pH. Data from 1978 and 1979 show that the Colorado River and tributaries have similar bacterial water quality profiles. Surface waters show predominantly low FC densities, indicating high quality waters for recreational activities, based on established federal and state water quality standards. Treatment of river and tributary surface water is necessary to assure drinking water quality standards. Bottom sediment analyses modify considerably the water quality status represented by surface water analyses alone. Significant densities of enteric organisms are present in the river and tributary environments, representing an important water quality hazard. Associated with resuspension of bottom sediments is the probability of surface water contamination by enteric organisms. Recreational activities, particularly water play in confined tributary pools, can bring river runners in direct contact with concentrated sediment suspension in surface waters.

No description available.