Simulating the effects of Glen Canyon Dam releases on Grand Canyon river trips

The Shechter-Lucas wilderness use simulation model (WUSM) has been modified to quantify the effects of fluctuating Glen Canyon Dam releases on Grand Canyon river trips. The model now simulates changes in flow as predicted by the Streamflow Synthesis and Reservoir Regulation computer model for the Colorado River. This revised WUSM provides data on several flow-related effects, including delays at rapids, encounters with other parties, and the time available for visiting attraction sites. Nine flow alternatives are evaluated and compared. Analysis of these outputs provides useful information to the Bureau of Reclamation on how the operation of Glen Canyon Dam effects river trips through Grand Canyon National Park.     

BRUSHLAND MANAGEMENT FOR INCREASED WATER YIELD IN TEXAS1

ABSTRACT: Policies to encourage brush management are under consideration as a means to address the water scarcity issue in Texas. Additional water can be generated by treating some of the 100-million-plus acres of brush-infested rangelands in Texas. Evidence of water yield benefits are, however, tentative at this time. Economic investigations based on available data show the potential desirability of brush management but also show benefits to be critically dependent on added water yield, value, and cost-sharing policy. Wildlife, water rights, and environmental issues are also important considerations. The lack of research information on likely impacts makes it difficult to choose among alternative policies for encouraging brush management. More research on this potential opportunity is needed.     

COST SHARING AND IMPLEMENTATION OF NATIONAL WATER RESOURCES POLICY1

ABSTRACT: In this article a managerial approach to developing and implementing National Water Resources policy is suggested. Proper consideration can be given to national economic development (NED), environmental quality (EQ) and conservation and still result in an implementable policy at the operational level if proper incentives are built into the process with proper attention to alternate non-Federal cost sharing rates. Not only can these multiple objectives be entertained but the Administration and Congress will have a management tool that should ensure a certain probability of success.     

ELEMENTS OF A WATER QUALITY INFORMATION SYSTEM FOR THE STATE OF ILLINOIS1

ABSTRACT: A great deal of information can be derived from study of standard stream monitoring data, if these are properly ordered and organized. This information may then be used to make decisions about water quality management. Among critical information items are evaluation of performance to standards, determination of seasonality and time-trends of water quality conditions, and estimation of the effects on water quality to be expected from load reductions or standards modifications. Additional information on the magnitude of individual pollution sources is also critical to water quality management. Each of these items can be derived within the water quality information system which is currently under development for the State of Illinois.     

ACUTE RESIDUAL TOXICITY OF SEVERAL WASTEWATER DISINFECTANTS TO AQUATIC LIFE1

ABSTRACT: This study was conducted to determine the comparative acute toxicity of chlorine, bromine chloride and ozone in wastewater, and to determine any acute toxicity associated with chlorinated wastewater which had been dechlorinated with sulfur dioxide. Toxicity tests were conducted with several species of cyprinids, salmonids and centrarchids, and the freshwater macroinvertebrate, Daphnia magna. Chlorinated effluent exhibited the greatest potential for residual toxicity of any disinfected stream tested. The reduced residual toxicity of chlorobrominated or ozonated effluent was largely the result of the more rapid dissipation of these disinfectants in wastewater. The acute residual toxicity of chlorinated effluent was eliminated by dechlorination with sulfur dioxide.     

A DIGITAL OVERLAY TECHNIQUE FOR EVALUATION OF POTENTIAL INFILTRATION AND RECHARGE1

ABSTRACT: A common problem encountered during regional planning and development of ground water dependent communities is the difficulty in deciding which areas should be preserved for aquifer recharge purposes. This paper describes the development and application of a digital overlay technique for objective evaluation and ranking of potential infiltration and potential recharge areas. Equations are developed which relate the hydrologic parameters pertaining to infiltration and recharge in a surface aquifer-confined aquifer system. These equations make use of discrete data, yet by application in a digital overlay technique results are obtained in the form of spatial distributions in order for regional trends and conditions to be examined. An application of this procedure to the 551,000 acre region of central Florida, known as the Green Swamp, is discussed. The results are presented in the form of computer generated maps which identify and rank areas of potential recharge to the aquifer system.     

FRICTION SLOPE MODELS FOR M2 PROFILES1

ABSTRACT: Results of studies which have considered the relative merit of various friction slope averaging equations previously used in water surface profile computations are described. Limitations of the most accurate equation known for the M2 profile have indicated that a new equation which gives more emphasis to the upstream energy gradient is desirable. Based upon friction slope curves developed for M2 water surface profiles two new equations, one a parabolic and the other an elliptical approximation, are presented. The behavior of the new equations and of the previously most recommended equation is described by test calculations. The elliptical equation performed more satisfactorily than the harmonic method commonly recommended for M2 profile computations. Insertion of an additional cross-section about 50 feet upstream from a critical depth section was found to reduce computational errors for any energy gradient averaging method.     

Two granular-activated carbons for adsorbing army explosives

Explosives-contaminated groundwater percolating from storage ponds at the Milan Army Ammunition Plant (MAAP) in Milan, Tennessee, into the Claiborne aquifer threatens to contaminate more groundwater—and possibly surface water—in the area. The research described in this article sought to determine whether granular-activated carbon (GAC) could help remove the explosives from the water and to identify which carbons can adsorb the most TNT, RDX, HMX, Tetryl, and others. Two carbons—Atochem, Inc. GAC 830 and Calgon Filtrasorb 300—were found to be promising candidates. As for what to do with the explosives that would be adsorbed, as well as the contaminated carbon, stay tuned.