Hidden Oasis: Water Conservation and Efficiency in Las Vegas

Pacific Institute | November 20th, 2007

Two of the West’s preeminent water organizations report Las Vegas Valley is sitting on an oasis of water and money savings. In their new report, the Pacific Institute a

Two of the West’s preeminent water organizations report Las Vegas Valley is sitting on an oasis of water and money savings. In their new report, the Pacific Institute and Western Resource Advocates find up to 40% of water could be saved in some sectors through improvements to indoor and outdoor water efficiency. They also found that through improving indoor water efficiency in particular, Las Vegas residents and businesses can cut water-related energy use and greenhouse gases. These findings are contained in Hidden Oasis: Water Conservation and Efficiency in Las Vegas available for download below. “Ninety percent of Las Vegas’ water efficiency money is spent on one program—turf removal. This program is important, but participation has waned and it is far from the only tool at their disposal,” said Heather Cooley, report co-author and Pacific Institute Senior Associate. “Las Vegas should capitalize on strategies that other Western cities have proven to be effective.” Hidden Oasis reveals that the Southern Nevada Water Authority, which provides water to Las Vegas and surrounding communities, can tap a number of tested, cost-effective efficiency measures to cut current water waste by up to 86,000 acre-feet. Single-family homes in Las Vegas use 100 gallons of water outside, per person, per day—almost entirely for landscaping. This use is substantially higher than in Los Angeles, Tucson, or Albuquerque. Reducing Las Vegas’ outdoor water use to more reasonable levels could cut Nevada’s total Colorado River withdrawals by 10 percent. Researchers found that by improving and expanding existing programs, and adding programs proven elsewhere in the West, the SNWA can cut Las Vegas homeowners’ indoor water waste by 40% and hotel and casino water waste by 30%. These indoor efficiency gains come from upgrading fixtures and appliances, not changing behavior. Improving total water efficiency not only saves significant water and energy expenses, it also better insulates the region from drought. “Improving indoor and outdoor water efficiency makes Las Vegas less vulnerable to current and future droughts,” said Taryn Hutchins-Cabibi, report coauthor and Water Policy Analyst at WRA. “Given the scarcity of fresh water, rising energy prices, and the looming threat of climate change, Las Vegas’ water customers need the SNWA’s help to curb unnecessary water waste and save money.”

High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans

National Academy of Sciences (NAS) | January 6th, 2025

High Resolution Measurement of Levee Subsidence Related to Energy Infrastructure in the Sacramento-San Joaquin Delta

California Energy Commission (CEC) | August 31st, 2018

We assess flood overtopping potential (when flood water elevation exceeds levee elevation) to the levees surrounding the islands in the interior of California's S

We assess flood overtopping potential (when flood water elevation exceeds levee elevation) to the levees surrounding the islands in the interior of California's Sacramento-San Joaquin Delta. Because critical natural gas infrastructure is susceptible to overtopping-related disruption, we focus our analysis on regions that are crossed by the network of the state's natural gas pipelines. We use laser scanning data collected during 2015-2016 to estimate subsidence rates since 2007 when an earlier, Delta-wide, airborne laser-scanning topographic dataset was collected. For each levee studied, we combine: (1) the estimated subsidence rate, (2) a conservative range of sea-level rise projections and, (3) an estimate of the 100-year freshwater flood stage to project the time until exceedance of the federal levee height standard (PL84-99). We find that subsidence rates vary from 0-5 centimeters per year (cm/yr) with mean values of ~1-2 cm/year. Local gradients in subsidence can be on the order of cms/yr over a distance of 10s of meters parallel to the levee crests, and these types of gradients are present near some pipeline crossings. The Sherman Island region has subsidence rates close to a factor of 2 greater than other areas considered. Our projections indicate general ranges of exceedance date from about 2060 (fast sea-level rise scenario) to 2080 (slow sea-level rise scenario) with some places projected to exceed threshold by about 2050.

High resolution US water table depth estimates reveal quantity of accessible groundwater

Nature Portfolio (Springer Nature) | January 14th, 2026

Groundwater is the largest accessible freshwater on Earth, yet its quantity and distribution remain unknown. Here, we develop a high-resolution (approximately 30�

Groundwater is the largest accessible freshwater on Earth, yet its quantity and distribution remain unknown. Here, we develop a high-resolution (approximately 30 m) estimate of water table depth over the continental United States using machine learning that includes uncertainty. We estimate that there is 306,500 km³ (uncertainty range: 291,850–316,720 km³) of groundwater over North America. This represents our highest resolution estimate of accessible freshwater to date, supported by robust statistical performance. We calculate total and accessible groundwater storage, and results show that coarse resolution products are systematically biased in their estimates locally, where decisions are made, as well as at large scales. Our approaches are spatially extensive and locally relevant and thereby bridge a gap between remote sensing and point observations.

High-elevation snowpack loss during the 2021 Pacific Northwest heat dome amplified by successive spring heatwaves

Nature Portfolio (Springer Nature) | December 13th, 2023

High-resolution mapping of global surface water and its long-term changes

Nature Portfolio (Springer Nature) | December 7th, 2016

The location and persistence of surface water (inland and coastal) is both affected by climate and human activity and affects climate, biological diversity and hu

The location and persistence of surface water (inland and coastal) is both affected by climate and human activity and affects climate, biological diversity and human wellbeing. Global data sets documenting surface water location and seasonality have been produced from inventories and national descriptions, statistical extrapolation of regional data and satellite imagery, but measuring long-term changes at high resolution remains a challenge. Here, using three million Landsat satellite images, we quantify changes in global surface water over the past 32 years at 30-metre resolution. We record the months and years when water was present, where occurrence changed and what form changes took in terms of seasonality and persistence. Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere. All continental regions show a net increase in permanent water, except Oceania, which has a fractional (one per cent) net loss. Much of the increase is from reservoir filling, although climate change is also implicated. Loss is more geographically concentrated than gain. Over 70 per cent of global net permanent water loss occurred in the Middle East and Central Asia, linked to drought and human actions including river diversion or damming and unregulated withdrawal. Losses in Australia17 and the USA18 linked to long-term droughts are also evident. This globally consistent, validated data set shows that impacts of climate change and climate oscillations on surface water occurrence can be measured and that evidence can be gathered to show how surface water is altered by human activities. We anticipate that this freely available data will improve the modelling of surface forcing, provide evidence of state and change in wetland ecotones (the transition areas between biomes), and inform water-management decision-making.

High-Salinity Sensitivity Study: Short-and Long-Term Exposure Assessments

California State Water Resources Control Board (SWRCB) | April 12th, 2013

The West Basin Municipal Water District (WBMWD) High Salinity Sensitivity Study (HSS Study) comprehensively evaluated the potential short-term and long-term exposure effe

The West Basin Municipal Water District (WBMWD) High Salinity Sensitivity Study (HSS Study) comprehensively evaluated the potential short-term and long-term exposure effects of high salinity discharges from the WBMWD ocean water desalination demonstration facility (OWDDF) on aquatic organisms representative of communities indigenous to various near shore environments in Southern California. Short-term effects were evaluated using Whole Effluent Toxicity (WET) bioassays developed by the U.S. Environmental Protection Agency (USEPA) to quantify the magnitude and threshold of potential biological effects of discharges (e.g. treated wastewater). Both acute toxicity (mortality effects) and chronic toxicity (mortality + sublethal effects) bioassays were performed by a state accredited bioassay laboratory. Long-term effects were evaluated using mesocosm procedures performed at the OWDDF by exposing multiple organisms for eight weeks to ambient seawater and diluted brine flows from the OWDDF in large aquaria constructed to simulate the OWDDF discharge environment.

High‐resolution surface water dynamics in Earth’s small and medium‐sized reservoirs

Nature Portfolio (Springer Nature) | August 12th, 2022

Small and medium‐sized reservoirs play an important role in water systems that need to cope with climate variability and various other man‐made and natural challenges

Small and medium‐sized reservoirs play an important role in water systems that need to cope with climate variability and various other man‐made and natural challenges. Although reservoirs and dams are criticized for their negative social and environmental impacts by reducing natural flow variability and obstructing river connections, they are also recognized as important for social and economic development and climate change adaptation. Multiple studies map large dams and analyze the dynamics of water stored in the reservoirs behind these dams, but very few studies focus on small and medium‐sized reservoirs on a global scale. In this research, we use multi‐annual multi‐sensor satellite data, combined with cloud analytics, to monitor the state of small (10–100 ha) to medium‐ sized (> 100 ha, excluding 479 large ones) artificial water reservoirs globally for the first time. These reservoirs are of crucial importance to the well‐being of many societies, but regular monitoring records of their water dynamics are mostly missing. We combine the results of multiple studies to identify 71,208 small to medium‐sized reservoirs, followed by reconstructing surface water area changes from satellite data using a novel method introduced in this study. The dataset is validated using 768 daily in‐situ water level and storage measurements (r2 > 0.7 for 67% of the reservoirs used for the validation) demonstrating that the surface water area dynamics can be used as a proxy for water storage dynamics in many cases. Our analysis shows that for small reservoirs, the inter‐annual and intra‐annual variability is much higher than for medium‐sized reservoirs worldwide. This implies that the communities reliant on small reservoirs are more vulnerable to climate extremes, both short‐term (within seasons) and longer‐term (across seasons). Our findings show that the long‐term inter‐annual and intra‐annual changes in these reservoirs are not equally distributed geographically. Through several cases, we demonstrate that this technology can help monitor water scarcity conditions and emerging food insecurity, and facilitate transboundary cooperation. It has the potential to provide operational information on conditions in ungauged or upstream riparian countries that do not share such data with neighboring countries. This may help to create a more level playing field in water resource information globally.

Highlights Central Valley Flood Protection Plan 2022 Update

California Department of Water Resources (DWR) | January 23rd, 2023

The 2022 Central Valley Flood Protection Plan Update was adopted by the Central Valley Flood Protection Board on December 16th, 2022. Just days later, beginning on Decemb

The 2022 Central Valley Flood Protection Plan Update was adopted by the Central Valley Flood Protection Board on December 16th, 2022. Just days later, beginning on December 27th, 2022, a series of atmospheric rivers began to impact California. This succession of atmospheric rivers resulted in 34 trillion gallons of water falling across California in 24 days, and 21 forecast points in the Central Valley reaching flood or monitor stage. Governor Gavin Newsom declared a state of emergency on January 4th, 2023; federal emergency and disaster declarations followed soon thereafter. These events underscore the importance of the CVFPP as the State’s strategic blueprint for investment in flood risk reduction in the Central Valley, especially in an era of whiplash weather—from drought to flooding— driven by the impacts of climate change.

Hillslope Stability and Land Use

American Geophysical Union (AGU) | January 1st, 1985

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 11. This monograph compiles research findings on soil mass movement

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 11. This monograph compiles research findings on soil mass movement into a format usable by practitioners and students. Applications are stressed in the areas of extensive and management practices rather than engineering earthworks. Examples are included to illustrate various prediction, avoidance, and control measures used in managing unstable terrain. We use the term soil (i.e., soil mass movement) to mean the mantle of unconsolidated or poorly consolidated material of either residual or transported origin, that overlies bedrock and forms the surface of the land. This usage is consistent with the conventional civil engineering use of the word and is synonymous with the geological term regolith and with soil mantle.