Physical Sciences and Mathematics Commons^™

Increasing Water Efficiency In California’S Commercial, Industrial, And Institutional (Cii) Sector, Ronnie Cohen, Kristina Ortez, Crossley Pinkstaff

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Reliable and adequate access to water is critical for businesses and their surrounding communities. Across the nation, water shortages are triggering growing concern and an acceleration of efforts to increase water use efficiency. Adopting water-efficient technologies and practices that reduce consumption holds great potential for commercial, industrial, and institutional (CII) water users. Such measures can help stretch limited water supplies, save businesses money, reduce energy consumption, improve water quality, and protect local, regional, and statewide ecosystems.

In February of 2008, California’s governor called for a reduction in per capita urban water use of 20 percent by 2020, and the CII …

Land Cover Types Of The Las Vegas Wash, Nevada, Seth A. Shanahan, Dave Silverman, Art Ehrenberg

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Vegetation type, extent, continuity, and structure are some of the most important factors that determine wildlife diversity and distribution. Other contributing factors that shape wildlife communities include disturbance, competition, climate, and water availability. Because vegetation communities in the southwestern U.S. gradate sharply along zones of soil moisture, wildlife are often restricted to specific vegetation types. Along the Las Vegas Wash (Wash), Nevada, more than 250 wildlife species have been documented to occur in distinct wetland, riparian, and upland vegetation types. Recent studies have investigated the diversity and distribution of amphibians, birds, fishes, mammals, and reptiles (Shanahan 2005, 2005a, Van Dooremolen …

Durango Hills Water Resource Center, City Of Las Vegas, Nevada

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No abstract provided.

Arizona Source Water Assessment Plan Final Draft, Arizona Department Of Environmental Quality

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The safe drinking water amendments of 1996 placed a strong emphasis on the goal to establish a nationwide effort to protect drinking water sources. As part of that goal, the legislation provided for a preliminary assessment of drinking water sources and an inventory of surrounding adjacent land use (ALUs). This nationwide effort will result in the first comprehensive look at the nation's drinking water sources from an assessment perspective. One of the outcomes of this nationwide assessment will be information that public water systems (PWSs) can use to help determine appropriate monitoring frequencies and to protect their sources of drinking …

Interagency Lake Mead And Las Vegas Wash Monitoring Program: Standard Operating Procedures Manual, Bureau Of Reclamation, City Of Henderson Water Reclamation Facility, City Of Las Vegas Water Pollution Control Facility, Clark County Sanitation District, Nevada, Southern Nevada Water Authority

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A number of agencies sample Lake Mead and the Las Vegas Wash on a routine basis at several locations. In order to share and properly interpret the data, the Bureau of Reclamation, Southern Nevada Water Authority and the three Wastewater Treatment Facilities (City of Las Vegas, Clark County Sanitation District and City of Henderson) formed a committee to examine sampling and analytical protocols and to share information with the goal of maximizing the data quality. The group first met in April 1997.

It was agreed that an effort should be made to discuss and compare specific sampling and analytical techniques …

Artificial Recharge In The Las Vegas Valley: An Operational History, Michael Johnson, Erin Cole, Kay Brothers, Las Vegas Valley Water District

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Artificially recharging the Las Vegas Valley (Valley) ground-water system with treated Colorado River water is one water resource management option employed by the Las Vegas Valley Water District (District) to help meet future long-term and short-term peak water demands. The District began operation of an artificial ground-water recharge program in 1988 in order to bank water for future use and to slow declining water levels. Artificial recharge occurs in the winter months, typically from October to May, when there is excess capacity in the Southern Nevada Water System (SNWS), currently a 400 Million Gallon per Day (MGD) treatment and transmission …

The Influence Of The Wastewater Drainage From The Las Vegas Valley On The Limnology Of Boulder Basin, Lake Mead, Nevada-Arizona, James F. Labounty, Michael J. Horn, Bureau Of Reclamation

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Lake Mead, Colorado River, Arizona-Nevada, is one of the most heavily used reservoirs in the western United States, providing abundant recreational opportunities as well as downstream domestic and agricultural water for over 22 million users. Based on average nutrient levels and productivity, Lake Mead is classified as mildly mesotrophic. The interflow of the Colorado River dominates the limnology of much of the 106 km-long reservoir, and may still be identified at Hoover Dam under certain conditions. The lower basin of Lake Mead ending at Hoover Dam is known as Boulder Basin and is near the Las Vegas metropolitan area. Las …

Synthetic Organic Compounds: Las Vegas Wash And Lake Mead, National Water Quality Assessment Program (Nawqa): Nevada Basin And Range

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The Nevada Basin and Range (NVBR) study unit of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is investigating the status of, trends in, and factors affecting water quality in the Las Vegas area. A principal objective of the investigation is to assess the effects of urbanization on the quality of area water resources.

Las Vegas Wash is the surface-water outlet for the Las Vegas area. The wash transports stormwater runoff, shallow ground-water discharge, and tertiary-treated sewage effluent from the Las Vegas area to Las Vegas Bay of Lake Mead on the Colorado River. Most of the flow—about 96 …

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

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Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service

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This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service

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This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

The Impact Of A Water-Imposed Interruption Of Growth In The Las Vegas Region, William T. White, Thomas M. Carroll, R. Keith Schwer

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This study is prompted by the expectation that water supplies for the Las Vegas Valley, both those used currently and those additional quantities available from existing sources, cannot sustain significant further economic growth of the region beyond the year 2006.

There are five parts to this study. Part I uses a regional econometric (REMI) model to project the growth of the Las Vegas region to natural maturity, essentially unconstrained by an overriding water shortage.

Part II is a reinforcing cross-section analysis of metropolitan areas in the United States to learn the most common natural growth patterns and those that have …

Temporal And Spatial Variation In Pelagic Fish Abundance In Lake Mead Determined From Echograms, Gene R. Wilde, Larry J. Paulson

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Echograms have been used extensively to locate and estimate the relative abundance of marine fish stocks (Cushing 1973). In freshwater, echograms have been used to describe vertical (Netsch et al. 1971; Eggers 1978; O'Brien et al. 1984; Matthews et al. 1985), spatial (O'Brien et al. 1984; Wanjala et al. 1986) and temporal (Baker and Paulson 1983) patterns in fish abundance. Although most uses of echograms have been qualitative, Mullan and Applegate (1969) and Matthews et al. (1985) obtained relative estimates of fish abundance by counting targets (fish) on echograms. However, neither Mullan and Applegate (1969) nor Matthews et al. (1985) …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

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A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines.

Because …

Environmental Assessment Of Las Vegas Wash And Lake Mead Artificial Wetlands Demonstration Project, John R. Baker, R. M. Gersberg, U.S. Environmental Protection Agency

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The effective use of artificial wetlands for treatment of municipal wastewater is well documented; however, design and economic data for artificial wetlands development are limited (Gersberg et al., 1984a). This is due partly to regional differences in climate, soils, and vegetation and partly to the desired waste treatment. As a result, specific treatment levels and cost benefits relative to the use of an artificial wetlands for a particular site cannot be evaluated adequately without a pilot demonstration project. Las Vegas Wash receives sewage effluent from the Las Vegas metropolitan area and has been designated as a wetlands community park. Las …

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

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Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.

River Discharge Study, Laughlin, Nevada: Colorado River Model And Diffusion Study, B. Dennis Hugh, David L. Stringfield, Jill C. Bicknell, Robert A. Ryder, Clark County Sanitation District, Nevada

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A water quality modeling study of the Mohave Reach of the Lower Colorado River (from Davis Dam to the Nevada/California Stateline) was conducted to evaluate potential water quality impacts resulting from a proposed Laughlin, Nevada wastewater effluent discharge. The study included four major components: (1) review of the current regulatory framework; (2) a field data collection program to document existing water quality conditions in winter, summer, and fall; (3) development and verification of far-field and near-field (mixing zone) water quality models; and (4) application of the models to project future river quality conditions for several treatment-discharge alternatives as well as …

Changes In The Morphometry Of Las Vegas Wash And The Impact On Water Quality, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

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Las Vegas Wash, a natural wash east of Las Vegas, Nevada, carries stormwater, groundwater drainage, and sewage effluent from two sewage treatment plants to Lake Mead. Over 80 percent of the normal discharge of approximately 3.4 m³/s (120 ft³/s) consists of effluent from the City of Las Vegas and Clark County sewage treatment plants. Beginning in the 1950s, a large wetland area developed along the wash that supported waterfowl populations and contributed to some water quality transformations. Heavy rains and subsequent flooding in the area in 1983 and 1984 resulted in erosion and channelization that greatly …

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

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Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

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Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

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Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m³. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m³. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

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Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …

The Role Of Nannoplankton In The Phytoplankton Dynamics Of Four Colorado River Reservoirs (Lakes Powell, Mead, Mohave, And Havasu), Jeffrey John Janik

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Phytoplankton species composition and community size structure were studied in four warm-monomictic Colorado River reservoirs; lakes Powell, Mead, Mohave, and Havasu from March 1981 to February 1982. Sampling was done at approximately monthly intervals from several stations in each reservoir. The Utermohl technique was used to enumerate phytoplankton. The phytoplankton assemblage was divided into the following six size classes using microscopic techniques; netplankton (>64 um), and nannoplankton (>5, 5-11, 12-21, 22-44, and 45-64 um).

Total phytoplankton biomass and community size structure were different among these four reservoirs with considerable spatial and temporal variation present. Average reservoir-wide areal weighted …

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

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At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982.

A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …

Water Quality Trends In The Las Vegas Wash Wetlands, F. A. Morris, L. J. Paulson

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The Las Vegas Wash is a wetlands ecosystem that acts to buffer the effects of wastewater discharges on the receiving waters of Lake Mead. The wash is the terminus for the 4,144 km2 Las Vegas Valley drainage basin, emptying into Las Vegas Bay of Lake Mead (Colorado River). It is in the northern Mojave desert, which receives an average of only 10 cm of rainfall annually. The Las Vegas Wash is technically an artificial wetland supported almost entirely by the perennial flows from sewage treatment plants. These flows contribute an average of 3-7 t of nutrients (nitrogen and phosphorus) and …

Use Of Hydroelectric Dams To Control Evaporation And Salinity In The Colorado River System, Larry J. Paulson

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The main stem reservoirs on the Colorado River comprise one of the largest and most heavily used freshwater bodies in the nation. These reservoirs (Lake Powell, Lake Mead, Lake Mohave and Lake Havasu) can store up to 53,590,400 acre-feet of water at their maximum capacities. Nonetheless, local water shortages still exist in some areas of the Colorado River Basin. There is also concern that salt concentrations are approaching levels that could severely affect municipal and agricultural uses. Water shortages will become even more acute as demands for water increase with continued urban and agricultural development in the basin.

Water conservation …

The Effects Of Impoundments On Salinity In The Colorado River, Larry J. Paulson, John R. Baker

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The increase in salinity of our western rivers has been identified as one of the most serious water quality problems in the nation. This is of special concern in the Colorado River where salinity has increased from pristine levels estimated at 380 mg/1 to present-day levels of 825 mg/1 at Imperial Dam. Flow depletions, associated with decreased runoff and increased evaporation and diversions, coupled with high salt loading from natural and man-created sources are considered the primary causes for rising salinity in the river. The urban and agricultural development projected to occur in the basin through this century could deplete …

The Influence Of Lake Powell On The Suspended Sediment-Phosphorus Dynamics Of The Colorado River Inflow To Lake Mead, T. D. Evans, Larry J. Paulson

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The Colorado River has been successively modified by the construction of several reservoirs, beginning in 1935 with the formation of Lake Mead by Hoover Dam. These reservoirs are located in a chain, and each one has an influence on the nutrient dynamics and productivity of the river and downstream reservoir. Lake Mead derives 98% of its annual inflow from the Colorado River. Historically, the Colorado River inflow was unregulated into Lake Mead. Regulation occurred in 1963, when Lake Powell was impounded by the construction of Glen Canyon Dam, approximately 450 km upstream. The formation of Lake Powell drastically altered the …

Effects Of Wastewater Discharges On Periphyton Growth In Lake Mead, Nevada-Arizona, Marsha Korb Morris

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A study of the effects of secondary-treated wastewater on periphyton growth in Lake Mead, Nevada-Arizona was conducted from September 1979 to December 1980. Periphyton ash-free dry weight, chlorophyll-a, dominant species composition, and alkaline phosphatase activity were measured on fiberglass substrates. Substrates were incubated for two to four weeks in littoral and limnetic habitats. Physical and chemical variables and phytoplankton chlorophyll-a were measured concurrently.

Transparency increased with increasing distance from the discharge. Secchi depth ranged from 0.75 m at the discharge confluence (station 2) in August, to greater than 20 m at the most distant stations (stations 9 and 10) in …

Lake Mead And Lake Powell Salinity Reports, Cathy Lee, Steve Gazafy

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The enclosed reports were compiled for the Colorado River Water Quality Office based on salinity data for Lake Mead and Lake Powell. According to the regional director of the office, the reports are not considered "polished" documents for public distribution. However, he considers them to be "interesting, rough appraisals of general trends that may be very important In our understanding the hydro-salinity system in the Colorado River."