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Results for “Sustainable Water Resources Management”

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At least 19 recordsLinked to original sources
USGS2011

Quantifying the hydrological responses to climate change in an intact forested small watershed in southern China

Responses of hydrological processes to climate change are key components in the Intergovernmental Panel for Climate Change (IPCC) assessment. Understanding these responses is critical for developing appropriate mitigation and adaptation strategies for sustainable water resources management and protection of public safety. However, these responses are not well understood and little long-term evidence exists. Herein, we show how climate change, specifically increased air temperature and storm intensity, can affect soil moisture dynamics and hydrological variables based on both long-term observation and model simulations using the Soil and Water Assessment Tool (SWAT) in an intact forested watershed (the Dinghushan Biosphere Reserve) in Southern China. Our results show that, although total annual precipitation changed little from 1950 to 2009, soil moisture decreased significantly. A significant decline was also found in the monthly 7-day low flow from 2000 to 2009. However, the maximum daily streamflow in the wet season and unconfined groundwater tables have significantly increased during the same 10-year period. The significant decreasing trends on soil moisture and low flow variables suggest that the study watershed is moving towards drought-like condition. Our analysis indicates that the intensification of rainfall storms and the increasing number of annual no-rain days were responsible for the increasing chance of both droughts and floods. We conclude that climate change has indeed induced more extreme hydrological events (e.g. droughts and floods) in this watershed and perhaps other areas of Southern China. This study also demonstrated usefulness of our research methodology and its possible applications on quantifying the impacts of climate change on hydrology in any other watersheds where long-term data are available and human disturbance is negligible.

Guangdong Province↗
USGS2020

Trends in recent historical and projected climate data for the Colorado River Basin and potential effects on groundwater availability

Understanding recent historical and projected trends in precipitation and temperature in the Colorado River Basin, and estimating what the projected changes in these climate parameters may mean for groundwater resources in the region, is important for water managers and policymakers to sustainably manage water resources in the basin. Historical (1896–2019) precipitation and temperature data for the upper and lower Colorado River Basins were analyzed to better understand recent trends in climate data that may affect groundwater resources in the area. Historical data indicate multidecadal-scale cyclical patterns in precipitation in both the upper and lower basins. Although upper basin precipitation had no statistical trend over the recent historical period, the lower basin had a weak negative trend over this period. Multidecadal-scale cyclical patterns in temperature also are observed in historical climate data in both the upper and lower basins, at least until the early 1970s. Beginning at that time, both the upper and lower basins experienced strong, monotonic positive trends in temperature. Basic principles of hydrology indicate that periods of decreasing precipitation as well as increasing temperature would have a negative effect, that is, reduction in groundwater infiltration and hence, reduced recharge of aquifer systems. Projected climate data from 97 Coupled Model Intercomparison Project phase 5 (CMIP5) ensemble members across the full range of Representative Concentration Pathway (RCPs) from water years 1951 through 2099 were evaluated to understand what current global climate models are projecting about future conditions in the Colorado River Basin, and what this might mean for groundwater systems in the region. Precipitation in the upper basin is projected to increase throughout the rest of the century, rising to 6 percent above the 1951–2015 historical period by mid-century and to 9 percent above the historical period by the end of the century. Temperature in the upper basin also is projected to be above the recent historical median throughout the rest of the century, with steady warming in decadal average temperatures expected until the last quarter of this century. In contrast to projected precipitation in the upper basin, precipitation in the lower basin is projected to be the same as, or slightly less than, the historical period throughout most of the rest of this century. Like projected temperature in the upper basin, temperature in the lower basin also is projected to be above the recent historical median throughout the rest of the century. Comparing median projections for all future decades with median results from all historical decades, future precipitation is expected to be greater than that of the past in the upper basin, though no significant difference is projected for precipitation in the lower basin. Significant increases (p-value<0.05) are expected in temperature in both the upper and lower basins. To estimate the effects of projected precipitation and temperature on groundwater systems in the region, results from the 97 member CMIP5 climate projection ensemble were used as input in a Soil-Water Balance (SWB) groundwater infiltration model for the Colorado River Basin. SWB simulation results indicate that the upper Colorado River Basin is expected to experience decades of above-historical-average groundwater infiltration through the end of the century. For the lower Colorado River Basin, simulated groundwater infiltration is projected to be consistently less than the recent (1951–2015) historical period for most of the remaining century. A comparison of the distribution of all median simulated groundwater infiltration results between recent historical and future periods indicates projected groundwater infiltration in the upper basin is significantly (p-value<0.05) greater over the combined 2020–2099 future period than the recent (1951–2015) historical period. Moreover, in 41 of 71 (58 percent) possible future decades in this century, groundwater infiltration is projected to be greater than the 75th percentile of historical simulated groundwater infiltration. Projected groundwater infiltration in the lower Colorado River Basin across all future decades is significantly less than in the historical period. Of the 71 future decades in the century, projected groundwater infiltration in the lower basin is expected to be less than the 25th percentile of historical infiltration in 55 (77 percent) of the 10-year periods. Important differences in projected precipitation between the upper (increasing precipitation) and lower (decreasing precipitation) basins largely drive the different responses of simulated groundwater infiltration in the upper (increasing infiltration) and lower (decreasing infiltration) basins. It will be useful to revisit projections in groundwater infiltration in the Colorado River Basin when more up-to-date projections of precipitation become available from the next Coupled Model Intercomparison Project phases or by using climate input developments through Regional Climate Modeling efforts and stochastic weather generators.

Arizona, California, Colorado, Nevada, New Mexico,↗
USGS2026

Small creatures, big challenge: A review of current knowledge and assessment of research needs to inform water withdrawal management for the Duck River's freshwater mussel fauna

The Duck River is a remarkable national resource, boasting outstanding biodiversity (Ahlstedt et al. 2017). It contains 151 fish species, over 60 mussel species, and 22 snail species, many of which are federally listed (Etnier and Starnes 1993; Johnson et al. 2013; Ahlstedt et al. 2017; Womble and Rosenberger 2025a). The Duck River watershed is at a pivotal time in its management and ecological history due to significant growth in human population and economic activity. The consequent increase in surface water demand presents challenges for sustainable water resource management. The Tennessee Department of Environment and Conservation (TDEC) has permitted or proposed to permit eight water utilities to withdraw over 77 million gallons per day (mgd) from the Duck River, representing > 40% increase from previously permitted amounts (USFWS 2025). On November 20, 2024, Tennessee Governor Bill Lee signed Executive Order No 108 to ensure long-term stability of the Duck River watershed through balancing economic growth, water resource management, and environmental conservation. Some primary components of this plan are the creation of a Comprehensive Regional Drought Management Plan, the development of a Habitat Conservation Plan, and the establishment of the Duck River Watershed Planning Partnership (DRWPP). Although the planning partnership is not focused on a sole aspect of the Duck River, but the watershed as a whole, the mussel assemblages of the Duck River have been a particular focus due to their importance in providing ecosystem services, sensitivity to water quality, conservation status, and sensitivity to periodic drought conditions in this system. With multiple state and federal agencies involved in managing the Duck River’s unique water resources, a focused review on how future water management could affect the freshwater mussel communities in the Duck River will contribute to this process. Our objectives of this review are to: 1. Review the effects of changing flow regimes on mussels, with emphasis on the effect of droughts/low flows, highlighting key processes/factors affecting mussels. 2. Highlight critical data gaps that could allow future, evidence-based water management decisions in this system. 3. Propose research topics to address critical data gaps and enable evidence-based water management decisions that consider the needs of freshwater mussels. Freshwater mussels are a critical component of riverine ecosystems, providing ecosystem services including water filtration, nutrient cycling, and habitat provision (Vaughn et al. 2004; Haag 2012) that benefit human communities. Environmental flows, also referred to as ecological or e-flows, refer to the quantity, timing, and quality of water flows necessary to maintain the ecological health of rivers, wetlands, and other aquatic ecosystems (Acreman and Dunbar 2004; Acreman 2016). For freshwater mussels, environmental flows include maintaining a flow regime and associated water quality regimes that are favorable for both juveniles and adults while also seasonally supporting host fish and the survival of settling glochidia (i.e., larval mussels) in suitable environments (Gates et al. 2015). Freshwater mussels are adapted to the natural flow regime of their native streams, including seasonal variability in flows. As sedentary filter feeders, mussels require adequate water flow to provide oxygen and food (Allen and Vaughn 2009); however, they also require periods of low flow to increase access to fish hosts and to ensure juveniles are not displaced (Gates et al 2015). Mussels are sensitive to water quality conditions, including pollutants, sedimentation, and artificial alterations of temperature and pH (Strayer and Malcom 2012). Mussel community characteristics, including presence, abundance, and species richness, generally increase with stream size (e.g., stream order); however, responses to changes in flow conditions are often species-specific, and the magnitude and timing of extreme flow conditions have more predictive power for mussel community response than general changes in flow (Lopez and Vaughn 2021). Complex hydraulic variables, such as relative shear stress and Reynolds number, can be strong predictors of mussel community responses because they combine simple hydraulic variables (e.g., velocity, depth) with stream channel characteristics, such as substrate composition and dynamics. Droughts directly and indirectly affect mussels by influencing their physiology, behavior, reproduction, and ecosystem roles. Mass mussel die-offs during droughts and low water conditions are widely documented (Vaughn et al. 2015; Sousa et al. 2018; Dubose et al. 2019). Droughts can also lead to a shift in mussel community composition, with drought-tolerant species becoming more dominant while more sensitive species experience declines (Galbraith et al, 2010; Lopez et al. 2022; Vaughn and Atkinson 2025). Droughts affect mussels through direct mortality from stranding as well as physiological stress from altered water temperature and quality, reduced habitat and food availability and quality, increased predation and competition, disruption of reproductive cycles, and increased susceptibility to disease and pathogens. Although the effects of droughts, water withdrawals, and low flow conditions on mussels are an increasing area of study, there is a general paucity of data-driven consensus regarding optimal mitigation approaches and strategies (Cushway et al. 2024). Long-term management decisions regarding water withdrawals, particularly during extended or multi-year drought conditions, may consider factors beyond direct mortality such as the sublethal effects of drought and low flow conditions on freshwater mussels for a comprehensive understanding of the effects of prolonged low flows on freshwater mussels and aquatic communities.

Tennessee↗
USGS2023

A watershed moment for western U.S. dams

The summer of 2023 is a notable time for water-resource management in the western United States: Glen Canyon Dam, on the Colorado River, turns 60 years old while the largest dam-removal project in history is beginning on the Klamath River. This commentary discusses these events in the context of a changing paradigm for dam and reservoir management in this region. Since the era of large dam building began to wane six decades ago, new challenges have arisen for dam and reservoir management owing to climate change, population increase, reservoir sedimentation, declining safety of aging dams, and more environmentally focused management objectives. Today we also better understand dams' benefits, costs, and environmental impacts, including some that were unforeseen and took decades to become apparent. Where dams have become unsafe, obsolete (e.g., due to excessive reservoir sedimentation), and uneconomical beyond saving, dam removal has become common. The science and practice of dam removal are accelerating rapidly, and some long-term physical and biological response studies are now available. Removal of four hydroelectric dams on the Klamath River will be a larger and more complex project than any previous dam removal. The imminency of this project reflects a very different situation for dam and reservoir management than 60 years ago. Looking forward, dam and reservoir management in the western United States and worldwide will require continued collaboration and innovative thinking to meet a wide range of objectives and to manage water resources sustainably for future generations.

Water Resources Research↗
USGS2018

The Connecticut Streamflow and Sustainable Water Use Estimator—A decision-support tool to estimate water availability at ungaged stream locations in Connecticut

Freshwater streams in Connecticut are subject to many competing demands, including public water supply; agricultural, commercial, and industrial water use; and ecosystem and habitat needs. In recent years, drought has further stressed Connecticut’s water resources. To sustainably allocate and manage water resources among these competing uses, Federal, State, and local water-resource managers require data and modeling tools to estimate the water availability at a variety of temporal and spatial scales for planning purposes. The Connecticut Streamflow and Sustainable Water Use Estimator (CT SSWUE), developed by the U.S. Geological Survey in cooperation with the Connecticut Department of Energy and Environmental Protection, is a decision-support tool for estimating daily unaltered streamflow and sustainable water use at ungaged sites in Connecticut. The CT SSWUE estimates unaltered daily mean streamflow and water-use-adjusted streamflow for the period from October 1, 1960, to September 30, 2015, and the monthly sustainable net withdrawal at ungaged sites in Connecticut. Unaltered streamflow is the estimated daily mean streamflow in a drainage basin in the absence of any water withdrawals or wastewater discharges and with minimal human development. Sustainable net withdrawal is the maximum net withdrawal (withdrawal minus wastewater discharges) that can be drawn from a basin without critically depleting the water available through natural streamflow patterns. Sustainable net withdrawal is defined for this study as the difference between the unaltered daily mean streamflow and a user-defined target minimum streamflow. Weighted least squares and Tobit regression techniques were used to develop equations for estimating streamflow at ungaged sites at 19 streamflow quantiles with exceedance probabilities ranging from 0.005 to 99.995 percent. Regressions were based on streamflow quantiles and basin characteristics from 36 reference streamgages in and around Connecticut. Four basin characteristics—drainage area, mean of the soil permeability, mean of the average annual precipitation, and ratio of the length of streams that overlay sand and gravel deposits to the total length of streams in the basin—are used as explanatory variables in the equations. At an ungaged site, interpolation between the streamflow quantiles estimated from the regression equations produces a continuous flow-duration curve. A time series of daily mean streamflow at an ungaged site is then estimated by assuming that for each day, the streamflow quantile occurs on the same date at both a reference streamgage and the ungaged site. In a remove-one cross validation, estimated unaltered daily mean streamflow agreed well with observed values at reference streamgages, with a few exceptions. Nash Sutcliffe efficiency ranged from −0.43 to 0.97 with a median value of 0.88. The normalized root-mean-square error ranged from 16.6 to 120.4 percent with a median value of 34.5 percent. An empirical method for estimating 95-percent prediction intervals for unaltered daily and monthly mean streamflow was developed and tested by using the cross-validation data. Prediction intervals for unaltered daily mean streamflow at the cross-validation reference streamgages performed well in most cases. Gaged streamflow values from the cross-validation data fell within the prediction intervals a median 96.6 percent of the time for daily mean time series and 93.9 percent of the time for monthly mean time series. The CT SSWUE computes water-use-adjusted streamflow using spatially referenced water-use information provided by the Connecticut Department of Energy and Environmental Protection. Available water-use information included permitted and registered water withdrawals and permitted wastewater discharges during 1998 to 2015 for the Thames River Basin and central coastal drainage basins. Water-use information was incorporated into the U.S. Geological Survey StreamStats web application for Connecticut and can be used for computing water-use-adjusted streamflow and sustainable net withdrawal at selected points of interest. Altered daily streamflow is computed by applying average daily withdrawals and wastewater discharges to the water balance equation. Average daily surface water withdrawals and wastewater discharges are applied directly to the daily water balance equation. Time-lagged alterations on streamflow from groundwater withdrawals or wastewater discharges are estimated by using a response-coefficient method developed from results of previously published, calibrated groundwater models.

Connecticut↗
USGS2000

From safe yield to sustainable development of water resources - The Kansas experience

This paper presents a synthesis of water sustainability issues from the hydrologic perspective. It shows that safe yield is a flawed concept and that sustainability is an idea that is broadly used but perhaps not well understood. In general, the sustainable yield of an aquifer must be considerably less than recharge if adequate amounts of water are to be available to sustain both the quantity and quality of streams, springs, wetlands, and ground-water-dependent ecosystems. To ensure sustainability, it is imperative that water limits be established based on hydrologic principles of mass balance. To establish water-use policies and planning horizons, the transition curves of aquifer systems from ground-water storage depletion to induced recharge of surface water need to be developed. Present-day numerical models are capable of generating such transition curves. Several idealized examples of aquifer systems show how this could be done. Because of the complexity of natural systems and the uncertainties in characterizing them, the current philosophy underlying sustainable management of water resources is based on the interconnected systems approach and on adaptive management. Examples of water-resources management from Kansas illustrate some of these concepts in a real-world setting. Some of the hallmarks of Kansas water management are the formation of local ground-water management districts, the adoption of minimum streamflow standards, the use of modified safe-yield policies in some districts, the implementation of integrated resource planning by the City of Wichita, and the subbasin water-resources management program in potential problem areas. These are all appropriate steps toward sustainable development. The Kansas examples show that local decision-making is the best way to fully account for local variability in water management. However, it is imperative that public education and involvement be encouraged, so that system complexities and constraints are better understood and overly simplistic solutions avoided. (C) 2000 Elsevier Science B.V.This paper presents a synthesis of water sustainability issues from the hydrologic perspective. It shows that safe yield is a flawed concept and that sustainability is an idea that is broadly used but perhaps not well understood. In general, the sustainable yield of an aquifer must be considerably less than recharge if adequate amounts of water are to be available to sustain both the quantity and quality of streams, springs, wetlands, and ground-water-dependent ecosystems. To ensure sustainability, it is imperative that water limits be established based on hydrologic principles of mass balance. To establish water-use policies and planning horizons, the transition curves of aquifer systems from ground-water storage depletion to induced recharge of surface water need to be developed. Present-day numerical models are capable of generating such transition curves. Several idealized examples of aquifer systems show how this could be done. Because of the complexity of natural systems and the uncertainties in characterizing them, the current philosophy underlying sustainable management of water resources is based on the interconnected systems approach and on adaptive management. Examples of water-resources management from Kansas illustrate some of these concepts in a real-world setting. Some of the hallmarks of Kansas water management are the formation of local ground-water management districts, the adoption of minimum streamflow standards, the use of modified safe-yield policies in some districts, the implementation of integrated resource planning by the City of Wichita, and the subbasin water-resources management program in potential problem areas. These are all appropriate steps toward sustainable development. The Kansas examples show that local decision-making is the best way to fully account for local variability in water management. However, it is imperative that public education and involv

Journal of Hydrology↗
USGS2000

Desert basins of the Southwest

Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

Arizona;California;Nevada;New Mexico;Utah↗
USGS2007

Vision for a worldwide fluvial-sediment information network

The nations of the world suffer both from the deleterious effects of some natural and human-altered fluxes of fluvial sediment and a lack of consistent and reliable information on the temporal and spatial occurrence of fluvial sediments. Decades ago, this difficulty was unavoidable due to a lack of understanding of the magnitude and scope of environmental influences exerted by fluvial sediment coupled with a dearth of tools for monitoring and studying the data. Such is no longer the case. Fluvial sediment has a broad influence on the environment and humanity. Data needs that were once limited primarily to reservoir and channel maintenance now include issues associated with public water supply; contaminated sediment management; productivity of agricultural lands; stream restoration and watershed health; in-stream biotic stability; post-wildfire channel morphology; dam decommissioning, rehabilitation, or removal; and legal requirements for sediment management (Gray and Glysson, 2005). The adverse effects of poorly managed or unmanaged sediment movement related to these and other issues are well-known qualitatively, and in some cases quantitatively. For example, physical, chemical, and biological damages attributable to fluvial sediment in North America alone are now estimated to range between $20 billion and $50 billion annually (Pimental and others, 1995; Osterkamp and others, 1998; 2004). Capabilities for monitoring, analyzing, storing, and sharing fluvial-sediment data have been developed and, in many cases, are sufficiently mature for consideration for global utilization. Hence, there is not only a strong and expanding need for a global effort to gauge and understand fluvial-sediment characteristics and processes better, but the knowledge and tools to achieve these ends are largely available and ready for their applicability to be evaluated. Given the increasing importance of erosion and sediment processes for water-resources management, an International Sedimentation Initiative (ISI, 2007a), under the United Nations Educational, Scientific, and Cultural Organization&rsquo;s International Hydrologic Programme (IHP, 2007) was adopted in 2004. The ISI, the focus of which is on sustainable water-resources management on the global scale, features six major activities and projects, which are listed as part of the section entitled, &ldquo;Relation of the WoFSIN concept to the thrusts of the International Sedimentation Initiative,&rdquo; that precedes the &ldquo;Conclusions&rdquo; section of this paper. Based on the need for more, and more consistent and reliable fluvial-sediment information and on the existence of the ISI and other international and national sediment programs, we envision the need for a Worldwide Fluvial Sediment-Information Network (WoFSIN) with a focus on data acquisition, storage, and dissemination globally. Envisioned components of a WoFSIN, administered largely via the Internet and relying mostly on the benefits derived from existing resources and programs, follow that summary. The goal of the WoFSIN is to maximize the availability and usefulness of the world&rsquo;s historical and current fluvial-sediment and ancillary data through collaboration with existing programs so as to require few additional resources in the long-term. Thus, the WoFSIN concept was developed recognizing that informed resource management is predicated on the availability of adequate and reliable information. The WoFSIN is described in the ensuing sections in stand-alone fashion, followed by a section that describes the complementary aspects of the WoFSIN and the International Sediment Initiative. Thus, our first objective is to describe the fundamental components of a WoFSIN. Our second objective is to identify overlap or gaps between the WoFSIN and ISI concepts that might be useful in refining the ISI&rsquo;s ability to meet its global mission to develop decision support for sediment management at the global scale more fully, cost-effectively, and (or) with enhanced quality.

Conference Paper↗
USGS2021

Runoff response to directional land cover change across reference basins in the conterminous United States

Land cover change plays a critical role in influencing hydrological responses. Change in land cover has impacted runoff across basins with substantial human interference; however, the impacts in basins with minimal human interference have been studied less. In this study, we investigated the impacts of directional land cover changes (forest to/from combined grassland and shrubland) in runoff coefficient (RC; ratio of runoff to precipitation) and runoff volume across 603 low human interference reference basins in the conterminous United States (CONUS). The results indicate basins with significant ( p <0.05) increasing trends in runoff and RC were across the northeast and northwest regions of CONUS, and basins with decreasing trends were in the southern CONUS region. A unit percent increase in basin area from grassland and shrubland to forest was associated with a ∼4% decrease in RC across basins with decreasing RC trends. Similarly, a unit percent increase in basin area from forest to a combined grassland and shrubland was associated with a ∼1% increase in RC across increasing RC trend basins. Runoff volume was decreased (increased) by ∼25 × 10 6 m 3 yr −1 (∼9 × 10 6 m 3 yr −1 ) across basins with decreasing (increasing) trends in runoff and RC. When relating runoff volume with the area of directional land cover changes, each 1 km 2 increase in area from grassland and shrubland to forest resulted in a decrease of ∼530,000 m 3 runoff volume across basins with decreasing trends. In contrast, each 1 km 2 increase in area from forest to grassland and shrubland increased runoff volume by ∼200,000 m 3 across increasing trend basins. Basins in the southern region of CONUS were more impacted by runoff parameters (RC and runoff volume) from directional land cover changes than basins in the northern region. The findings of this study are useful for planning and managing water availability for sustainable and adaptive water resources management at regional scales.

Advances in Water Resources↗
USGS2023

Recharge estimation approach in a data-scarce semi-arid region, Northern Ethiopian Rift Valley

Sustainable management of groundwater resources highly relies on the accurate estimation of recharge. However, accurate recharge estimation is a challenge, especially in data-scarce regions, as the existing models are data-intensive and require extensive parameterization. This study developed a process-based hydrologic model combining local and remotely sensed data for characterizing recharge in data-limited regions using a Basin Characterization Model (BCM). This study was conducted in Raya and Kobo Valleys, a semi-arid region in Northern Ethiopia, considering both the structural basin and the surrounding mountainous recharge areas. Climatic Research Unit monthly datasets for 1991 to 2020 and WaPOR actual evapotranspiration data were used. The model results show that the average annual recharge and surface runoff from 1991 to 2020 were 73 mm and 167 mm, respectively, with a substantial portion contributed along the front of the mountainous parts of the study area. The mountainous recharge occurred along and above the valleys as mountain-block and mountain-front recharge. The long-term estimates of the monthly recharge time series indicated that the water balance components follow the temporal pattern of rainfall amount. However, the relation of recharge to precipitation was nonlinearly related, showing the episodic nature of recharge in semi-arid regions. This study informed the spatial and temporal distribution of recharge and runoff hydrologic variables at fine spatial scales for each grid cell, allowing results to be summarized for various planning units, including farmlands. One third of the precipitation in the drainage basin becomes recharge and runoff, while the remaining is lost through evapotranspiration. The current study’s findings are vital for developing plans for sustainable management of water resources in semi-arid regions. Also, monthly groundwater withdrawals for agriculture should be regulated in relation to spatial and temporal recharge patterns. We conclude that combining scarce local data with global datasets and tools is a useful approach for estimating recharge to manage groundwater resources in data-scarce regions.

Kobo Valley, Riya Valley↗
USGS2013

Sustainability of water-supply at military installations, Kabul Basin, Afghanistan

The Kabul Basin, including the city of Kabul, Afghanistan, is host to several military installations of Afghanistan, the United States, and other nations that depend on groundwater resources for water supply. These installations are within or close to the city of Kabul. Groundwater also is the potable supply for the approximately four million residents of Kabul. The sustainability of water resources in the Kabul Basin is a concern to military operations, and Afghan water-resource managers, owing to increased water demands from a growing population and potential mining activities. This study illustrates the use of chemical and isotopic analysis, groundwater flow modeling, and hydrogeologic investigations to assess the sustainability of groundwater resources in the Kabul Basin. Water supplies for military installations in the southern Kabul Basin were found to be subject to sustainability concerns, such as the potential drying of shallow-water supply wells as a result of declining water levels. Model simulations indicate that new withdrawals from deep aquifers may have less of an impact on surrounding community water supply wells than increased withdrawals from near- surface aquifers. Higher rates of recharge in the northern Kabul Basin indicate that military installations in that part of the basin may have fewer issues with long-term water sustainability. Simulations of groundwater withdrawals may be used to evaluate different withdrawal scenarios in an effort to manage water resources in a sustainable manner in the Kabul Basin.

Kabul↗
USGS2021

Effects of climate and irrigation on GRACE-based estimates of water storage changes in major US aquifers

Understanding climate and human impacts on water storage is critical for sustainable water-resources management. Here we assessed climate and human drivers of total water storage (TWS) variability from Gravity Recovery and Climate Experiment (GRACE) satellites compared with drought severity and irrigation water use in 14 major aquifers in the United States. Results show that long-term variability in TWS tracked by GRACE satellites is dominated by interannual variability in most of the 14 major US aquifers. Low TWS trends in the humid eastern U.S. are linked to low drought intensity. Although irrigation pumpage in the humid Mississippi Embayment aquifer exceeded that in the semi-arid California Central Valley, a surprising lack of TWS depletion in the Mississippi Embayment aquifer is attributed to extensive streamflow capture. Marked storage depletion in the semi-arid southwestern Central Valley and south-central High Plains totaled ∼90 km 3 , about three times greater than the capacity of Lake Mead, the largest U.S. reservoir. Depletion in the Central Valley was driven by long-term droughts (⩽5 yr) amplified by switching from mostly surface water to groundwater irrigation. Low or slightly rising TWS trends in the northwestern (Columbia and Snake Basins) US are attributed to dampening drought impacts by mostly surface water irrigation. GRACE satellite data highlight synergies between climate and irrigation, resulting in little impact on TWS in the humid east, amplified TWS depletion in the semi-arid southwest and southcentral US, and dampened TWS deletion in the northwest and north central US Sustainable groundwater management benefits from conjunctive use of surface water and groundwater, inefficient surface water irrigation promoting groundwater recharge, efficient groundwater irrigation minimizing depletion, and increasing managed aquifer recharge. This study has important implications for sustainable water development in many regions globally.

Environmental Research Letters↗
USGS2014

Estimates of groundwater recharge rates and sources in the East Mountain area, Eastern Bernalillo County, New Mexico, 2005-12

The U.S. Geological Survey, in cooperation with the Bernalillo County Public Works Division, has conducted a monitoring program in the East Mountain area of eastern Bernalillo County, New Mexico, since 2000 to better define the hydrogeologic characteristics of the East Mountain area and to provide scientific information that will assist in the sustainable management of water resources. This report presents estimates of groundwater recharge to the aquifers that supply water to a network of springs that discharged within the East Mountain area of eastern Bernalillo County during 2005&ndash;12. Chloride concentration, the mass ratio of chloride to bromide, and the stable isotope ratios of hydrogen and oxygen were used to estimate annual groundwater recharge rates and to identify the sources and timing of recharge to the aquifers in the East Mountain area. Groundwater recharge rates were estimated by using a chloride mass-balance (CMB) method applied to data from selected springs located in the study area. Eleven springs and four downgradient monitoring wells were sampled for this study. On the basis of chloride concentrations and the mass ratio of chloride to bromide, eight of the eleven sampled springs are considered representative of dilute groundwater recharged by meteoric water in the Sandia Mountains. Eight of the eleven springs sampled as part of this investigation are considered representative of dilute groundwater not influenced by nonmeteoric chloride sources on the basis of analysis of chloride concentrations and the mass ratio of chloride to bromide. Chloride concentrations at three of the sampled springs were likely affected by nonmeteoric chloride sources. Results of CMB calculations for the eight springs with Cl:Br ratios and chloride concentrations within the range of dilute groundwater (not influenced by nonmeteoric chloride sources) indicated that between about 5.5 and 23 percent of annual precipitation recharges the groundwater system. The variation in estimated recharge rates indicated that the mechanisms for recharge and groundwater movement in the East Mountain area are complex and that factors such as climate variability, the extent and interconnection of structural features such as faults and fractures, and potential solution enhancement of the aquifers all play important roles in the rates and timing of recharge. Stable isotope data from springs and snowpacks sampled in the East Mountain area were compared with local, regional, and global meteoric water lines and were analyzed along with values representing the stable isotope composition of winter precipitation and summer monsoonal rains. Results of the stable isotope analysis from springs in this study suggested that winter precipitation is the primary source of groundwater recharge to the aquifers supplying the springs, but there is a component of more isotopically enriched precipitation being recharged as well, likely from summer monsoonal rains. Specific conductance, groundwater-level hydrographs, snowpack chemistry, and snow-water equivalent data were used to inform the analyses and corroborate the findings of the CMB and stable isotope results.

New Mexico↗
USGS2018

Water budget of the upper Chehalis River Basin, southwestern Washington

Groundwater and surface water collectively supply the domestic, agricultural, and industrial needs of the 895-square mile upper Chehalis River Basin upstream of Grand Mound, Washington, while providing streamflow for fish and other aquatic species in the Chehalis River and its tributaries. To support sustainable water management decision-making, a water budget (including precipitation, interception, groundwater recharge, surface runoff, and groundwater pumping) was developed for the upper Chehalis River Basin during October 2001–September 2015. Water-budget components were estimated from the U.S. Geological Survey Soil-Water-Balance (SWB) model except for groundwater pumping, which was estimated from public water purveyor records, annual system data from the Washington State Department of Health, census population data, and water-use estimates. Groundwater recharge estimated from the SWB model was compared to base flow, a proxy for groundwater recharge, independently estimated from separation of the hydrograph recorded by the U.S. Geological Survey streamgage at the outlet of the basin. Mean annual precipitation for the basin was estimated at 72.6 inches, of which 35 percent was lost to evapotranspiration, 30 percent was recharged to groundwater, 30 percent was surface runoff, and 5 percent was lost to interception. SWB model estimates of groundwater recharge were 17 percent less than estimates of base flow from hydrograph separation. Groundwater pumpage in the basin was estimated at 1 percent of groundwater recharge estimated by SWB and 0.8 percent of base flow estimated by hydrograph separation. These estimates form a baseline for understanding future changes to components of water use and may be used to inform numerical groundwater models to support sustainable management of water resources in the upper Chehalis River Basin.

Washington↗
USGS2015

Sustainable water management under future uncertainty with eco-engineering decision scaling

Managing freshwater resources sustainably under future climatic and hydrological uncertainty poses novel challenges. Rehabilitation of ageing infrastructure and construction of new dams are widely viewed as solutions to diminish climate risk, but attaining the broad goal of freshwater sustainability will require expansion of the prevailing water resources management paradigm beyond narrow economic criteria to include socially valued ecosystem functions and services. We introduce a new decision framework, eco-engineering decision scaling (EEDS), that explicitly and quantitatively explores trade-offs in stakeholder-defined engineering and ecological performance metrics across a range of possible management actions under unknown future hydrological and climate states. We illustrate its potential application through a hypothetical case study of the Iowa River, USA. EEDS holds promise as a powerful framework for operationalizing freshwater sustainability under future hydrological uncertainty by fostering collaboration across historically conflicting perspectives of water resource engineering and river conservation ecology to design and operate water infrastructure for social and environmental benefits.

Nature Climate Change↗
USGS2017

Satellite-based water use dynamics using historical Landsat data (1984–2014) in the southwestern United States

Remote sensing-based field-scale evapotranspiration (ET) maps are useful for characterizing water use patterns and assessing crop performance. The relative impact of climate variability and water management decisions are better studied and quantified using historical data that are derived using a set of consistent datasets and methodology. Historical (1984–2014) Landsat-based ET maps were generated for major irrigation districts in California, i.e., Palo Verde and eight other sub-basins in parts of the middle and lower Central Valley. A total of 3396 Landsat images were processed using the Operational Simplified Surface Energy Balance (SSEBop) model that integrates weather and remotely sensed images to estimate monthly and annual ET within the study sites over the 31 years. Model output evaluation and validation using gridded-flux data and water balance ET approaches indicated relatively good correspondence (R 2 up to 0.88, root mean square error as low as 14 mm/month) between SSEBop ET and validation datasets. In a pairwise comparison, annual variability of agro-hydrologic parameters of actual evapotranspiration ( ET a ), land surface temperature ( T s ), and runoff ( Q ) were found to be more variable than their corresponding climatic counterparts of atmospheric water demand ( ET o ), air temperature ( T a ), and precipitation ( P ), revealing process differences between regional climatic drivers and localized agro-hydrologic responses. However, only T a showed a consistent increase (up to 1.2 K) over study sites during the 31 years, whereas other climate variables such as ET o and P showed a generally neutral trend. This study demonstrates a useful application of “Big Data” science where large volumes of historical Landsat and weather datasets were used to quantify and understand the relative importance of water management and climate variability in crop water use dynamics in regards to the linkages among water management decisions, hydrologic processes and economic transactions. Irrigation district-wide ET a estimates were used to compute historical crop water use volumes and monetary equivalents of water savings for the Palo Verde Irrigation District (PVID). During the peak crop fallowing year in PVID, the water saved reached a maximum of ~ 107,200 acre-feet in 2011 with an estimated monetary payout value of $20.5 million. A significant decreasing trend in actual ET despite an increasing atmospheric demand in PVID highlights the role of management decisions in affecting local hydrologic processes. This study has importance for planning water resource allocation, managing water rights, sustaining agricultural production, and quantifying impacts of climate and land use/land cover changes on water resources. With increased computational efficiency, similar studies can be conducted in other parts of the world to help policy and decision makers understand and quantify various aspects of water resources management.

Arizona, California↗
USGS2020

Isotopic and geochemical assessment of the sensitivity of groundwater resources of Guam, Mariana Islands, to intra- and inter-annual variations in hydroclimate

Assessing the sensitivity of groundwater systems to hydroclimate variability is critical to sustainable management of the water resources of Guam, US territory. We assess spatial and temporal variability of isotopic and geochemical compositions of vadose and phreatic groundwater sampled from cave drip sites and production wells, respectively, to better understand the vulnerability of the freshwater lens on Guam to variability in hydroclimate. We independently evaluate the existing conceptual model of the Northern Guam Lens Aquifer that is largely based on physical, as opposed to geochemical, observations. Sampling was conducted from 2008 to 2015, over which rainfall gradually increased. Major ion geochemistry and Sr isotope values of groundwater show varying influence from soil, limestone bedrock, and seawater. Geochemical modeling that can explain spatial variability in groundwater Na+ and Mg2+ concentrations and Sr/Ca and 87Sr/86 Sr values indicates that groundwater compositions are dominantly controlled by mixing of freshwater with seawater and water-rock interaction. Differences between amount-weighted annual average precipitation δ18 O values and groundwater δ18 O values indicate a recharge bias toward the wet season, consistent with other tropical carbonate island aquifer settings. Intra- and inter-annual variations in Na+ concentrations and δ18 O values in groundwater reflect sensitivity of recharge to seasonal variations in rainfall amount and changes in annual rainfall amounts. Our results indicate the influence of multiple modes of recharge on groundwater compositions and spatial variability in the sensitivity of groundwater to seawater mixing. This sensitivity of the freshwater lens points to the vulnerability of groundwater resources to changes in recharge associated with climate, land-use change, and increases in population.

Journal of Hydrology↗