Water Managers Research Articles

Connecting With Building Water System Operators and Managers

Public water systems have access to an abundance of professional expertise and technical resources. Sharing this information with customers who operate and manage building water systems provides numerous benefits.

Carbon fate and potential carbon metabolism effects during in-situ cyanobacterial inhibition by artemisinin sustained-release algaecides.

Carbon pools and microbial carbon metabolism can be significantly altered due to the diverse organic matter properties and low pH characteristics of artemisinin sustained-release algaecides (ASAs). These effects have still not been systematically studied, leading to uncertainty in the application of ASAs for cyanobacterial management in natural waters. This study assessed the effects of ASAs on carbon fate, carbon metabolism and potential ecological impacts during in-situ cyanobacterial inhibition. In the initial phase of ASAs-induced cyanobacterial inhibition (2-10 days), the carbon pool underwent significant changes due to the increased proportion of C4 plant-derived organic matter (97%), humification level (FI =0.9-1.5), and inorganic carbon concentration (TIC = 80-110mg/L). The cyanobacterial apoptosis triggered by ASAs produced particulate organic carbon, which provided a bioavailable carbon source for bacterial metabolism. ASAs enhanced the connection between bacteria and the carbon pool, as well as their carbon metabolism capabilities, by increasing the relative abundance of Proteobacteria (33.1%-37.3%), bacterial diversity, the proportion of Alphaproteobacteria and Betaproteobacteria (19.3%-29.5%) involved in carbon metabolism, and the complexity of the environment-bacteria co-occurrence network. These effects contributed to maintaining long-term ecosystem stability and resistance to cyanobacterial proliferation. Our findings elucidate the influence of bacterial carbon metabolism by ASAs as one of an important mechanism for achieving cyanobacterial inhibition in natural water, and emphasize the important role of bacteria in maintaining ecological stability during in situ cyanobacterial management.

Rainwater harvesting technologies in arid plains of Argentina: small local strategies vs. large centralized projects

Access to water has been and remains one of humanity’s greatest challenges. Especially in arid plains exposed to significant climatic fluctuations and future global change trends. In the past and present, local communities of the arid plains of central-western Argentina (i.e., Guanacache Lagoons, Cuyo region) have developed multiple strategies to manage water supply problems. The aims of this study are: i) to characterize the different water harvesting technologies (pre-Hispanic and modern) used, and ii) to compare the small local strategies of water harvesting (bottom-up solutions) with the large centralized projects (top-down solutions). On the one hand, we show the transformations of these technologies over time, and the challenges faced by inhabitants in the context of climate change trends. On the other hand, we analyze the role of the state through hydraulic policies and projects implemented by the provincial states over the last two centuries and how this impacted the study area. This review is based on a historical and archaeological bibliography, and recent publications about the region, including articles based on our ethnographic fieldwork. Our results demonstrate the valuable experience accumulated by local populations in water harvesting methods, particularly in areas where groundwater is deep and saline, and shows the adaptability of these technologies in contexts of increasing scarcity. We considered that local indigenous knowledge can largely contribute to the sustainable management of water resources. This study might be useful for decision-makers and water managers in drylands around the world to find and equitable approach that combines technical advances with local knowledge.

Estimation of soil loss and sediment yield by using the modified RUSLE model in the Indus River basin, including the quantification of error and uncertainty in remote-sensing images

Context Indus River is the cradle of Pakistani lifeline, and its lower reaches are prone to soil loss owing to bank erosion. Aims The aim was to investigate the sediment yield in the Lower Indus River Basin (LIRB), while addressing challenges related to error or uncertainty in remote-sensing data. Methods We employed a modified revised universal soil loss equation (RUSLE) model, integrating high-resolution digital elevation model (DEM) and calibrated Climate Hazards Group InfraRed Precipitation with station data (CHIRPS). Additional data layers, including land use, soil and cropping data, were also utilised. Key results The extent of actual soil erosion ranges from minimum to maximum erosion; 38.9% area lies in the range >50 Mg ha‒1 year‒1, whereas 23.2% area lies in the range of 0–10 Mg ha‒1 year‒1, and 18.1% area lies in the range of 10–20 Mg ha‒1 year‒1. Conclusions The study identifies critical erosion areas and tackles uncertainties in remote-sensing data. The spatial analysis showed that higher distribution sediment erosion along the channel flow direction from the northern part of LIRB to the Arabian Sea. Implications The findings have provided critical information for policymakers and water managers to implement effective measures to reduce erosion, maintain soil integrity and promote the sustainability of the Indus River system.

Optimal allocation model of port emergency resources based on the improved multi-objective particle swarm algorithm and TOPSIS method

The busy maritime traffic and occurrence of ship accidents have led to a growing recognition of the necessity to maritime emergency resources allocation. The port emergency resource allocation is of significant importance for the maritime safety. This paper presents an optimized allocation model for port emergency resources based on the improved multi-objective particle swarm optimization (IMOPSO). The model introduces the crowding distance and improves the external archive update strategy. The particle inertia weight is adjusted and a dynamic mutation operator is incorporated. The entropy-weighted technique for order preference by similarity to an ideal solution method is also employed to identify the optimal solution. A comprehensive comparison with MOPSO has been presented and discussed. Three metrics of generational distance (GD), spacing (SP) and delta indicator (Δ) were employed for performance evaluation. The results demonstrated that the proposed IMOPSO algorithm exhibited superior performance and robustness, with average values of GD = 0.0386, SP = 0.0023 and Δ = 0.6468 for ZDT test functions. The model efficacy is further validated by a case study of oil spill dispersant configuration at Zhanjiang Port, China. Seven alternative schemes have been obtained, among which the optimal scheme is selected by the entropy-weighted TOPSIS method. The overall cost is potentially to be reduced by approximately 33.03 %. The present study would provide a reference for the water pollutant control and environmental management in port waters.

Practical drought risk assessment and management framework: A step toward sustainable modernization in agricultural water management

A proposed framework to assess and manage risks associated with Agricultural Water Off-farm Conveyance and Distribution Systems (AWOCDS), quantify potential failure due to drought-induced scenarios, and provide short to long-term recovery plans to mitigate drought impacts. It makes an intellectual contribution by creating a new proactive risk assessment focusing specifically on AWOCDS as a crucial part of agricultural water management. The risk assessment comprises two components − risk probability and consequence. The former is calculated by analyzing droughts via the streamflow drought index using the DrinC calculator. The latter is determined through AWOCDS’ performance evaluation using hydraulic simulation via HEC-RAS. Additionally, water distribution is assessed spatiotemporally using adequacy and equity indicators, and an integrated consequence is developed by applying the simple additive weighting method. AWOCDS’ rehabilitation and modernization projects worldwide include three practical practices in its risk management component. These practices involve modifying standard operating procedures (SOPs) by updating maintenance, upgrading manual-based operations, and developing a centralized Model Predictive Controller (MPC) for AWOCDS automatic operation. The proposed framework underwent testing in an arid region. Based on the risk assessment results, the AWOCDS operating system failure rate ranges from 70% to 96% during extreme-severe drought scenarios and 53% to 65% during moderate-mild drought scenarios. Risk management analysis shows that a short-term recovery plan reduces the drought risk by 4% monthly and 3% yearly. However, the risk of failure ranges from 50 to 94% in mild to extreme drought scenarios. Upgrading SOPs decreases impact by 4–11% in extreme, 4–7% in moderate-severe and 7–9% in mild-moderate drought. Automating the operating system with MPC reduces impact by 40–43% and 30–56% in mild-moderate and severe-extreme drought scenarios. This proactive-based strategy can help water managers plan for rehabilitation and improve surface water distribution reliability.

Assimilation of Satellite Albedo to Improve Simulations of Glacier Hydrology

ABSTRACTWildfires and heatwaves have recently affected the hydrological system in unprecedented ways due to climate change. In cold regions, these extremes cause rapid reductions in snow and ice albedo due to soot deposition and unseasonal melt. Snow and ice albedo dynamics control net shortwave radiation and the available energy for melt and runoff generation. Many albedo algorithms in hydrological models cannot accurately simulate albedo dynamics because they were developed or parameterised based on historical observations. Remotely sensed albedo data assimilation (DA) can potentially improve model performance by updating modelled albedo with observations. This study seeks to diagnose the effects of remotely sensed snow and ice albedo DA on the prediction of streamflow from glacierized basins during wildfires and heatwaves. Sentinel‐2 20‐m albedo estimates were assimilated into a glacio‐hydrological model created using the Cold Regions Hydrological Modelling Platform (CRHM) in two Canadian Rockies glacierized basins, Athabasca Glacier Research Basin (AGRB) and Peyto Glacier Research Basin (PGRB). The study was conducted in 2018 (wildfires), 2019 (soot/algae), 2020 (normal) and 2021 (heatwaves). DA was employed to assimilate albedo into CRHM to simulate streamflow and was compared to a control run (CTRL) using off‐the‐shelf albedo parameters. Albedo DA benefited streamflow predictions during wildfires for both basins, with a KGE coefficient improvement of 0.18 and 0.20 in AGRB and PGRB, respectively. Four‐year DA streamflow predictions were superior to CTRL in PGRB, but DA was slightly better in AGRB. DA was not beneficial to streamflow predictions during heatwaves. DA improved streamflow predictions by decreasing positive bias, showing that albedo DA can reveal unknown albedo and snowpack dynamics in remote glacier zones that are poorly simulated in models. These findings corroborate the power of observational tools to incorporate near real‐time information into hydrological models to better inform water managers of the streamflow response to wildfires and heatwaves.

Using archive hydrogeological data to enhance the hydrodynamic knowledge of hardrock aquifers in Western Africa

In the Kara River Watershed (KRW, northern Togo), drinking water is mainly supplied by groundwater flowing through fissures in the metamorphic formations of the Dahomeyides belt. The study was based on the use and valorisation of hydrogeological archive dataset from 1970s to 2021. The database comprises 1,389 boreholes, but only 710 are considered after pre-treatment, and provides information mainly on total depth, weathering thickness, discharge at drilling, piezometric level, specific discharge, transmissivity, and the nature of the lithology tapped. The methodological approach involved statistical analysis of data, characterization of the fissured horizon, establishment of relationships between hydrodynamic parameters and satellite image processing. The results showed that the aquifers structure is close to those observed worldwide in hardrock context and they provide operational details on the hydrogeological functioning of these environments in the West African particular context. From the surface downwards, aquifers show a layer of saprolite (thickness between 0.2 and 37.3 m) acting as a storage level, a fissured layer whose permeability depends on the number and connectivity of the fissures, and then a level of very low permeability, unfissured bedrock. In the study area, the depth of the useful fissured medium is 52 m with an average useful discharge of 7.1 m3.h-1. The coefficients of variation for specific discharge and transmissivity are greater than 100%, reflecting the structural heterogeneity of the study area. Analysis of the discharges measured in the boreholes as a function of lithology shows that the metasediments are more productive than other geological formations. Finally, all the geological, hydrogeological, and hydrodynamical data have been used to propose a preliminary conceptual model of the watershed's hardrock aquifers. These results will serve as decision-making tools for water managers and will facilitate the policy of integrated management of groundwater resources at the scale of the KRW. The developed methodology also shows how archive data should be used to achieve optimized management of aquifers without major investments.

Identifying Subsurface Connectivity From Observations: Experimentation With Equifinality Defines Both Challenges and Pathways to Progress

ABSTRACTLinkages between landscapes and streams are increasingly described in terms of hydrological connectivity. The ability to effectively distinguish different patterns of water movement through catchments makes connectivity particularly interesting to both scientists and practical water managers. Hydrometric data (groundwater levels, soil moisture and streamflow) are often employed to infer the connection between the landscape and its drainage network. Such observational data, however, are insufficient to infer subsurface connectivity in humid settings with perennial stream flow, due to the risk of equifinality. To quantify how much subsurface flow patterns can differ and still be consistent (equifinal) with comprehensive observations of hillslope groundwater levels and stream runoff (the hydrometric data), this study used a modelling experiment based on a well‐characterised field site. Particle‐tracking simulations at different flow rates defined the water flow paths and transit times of two virtual hillslopes that differed profoundly in the vertical distribution of the saturated hydraulic conductivity. Even though the simulated weekly stream flows and groundwater levels were similar (i.e., the hillslopes were hydrometrically equifinal) particle velocities and water ages at specific locations along these hillslopes differed by orders of magnitude. Flow path lengths and catchment transit times varied up to several 100%. The hillslope‐ and stream‐based metrics used to describe connectivity also varied with stream flow rates. These results underline the need to recognise the risks for equifinality when inferring subsurface connectivity from hydrometric observations alone, even when those observations are comprehensive. The results also highlight the value of model simulations for quantifying the uncertainty in the inferred connectivity, targeting the best sampling locations/times to reduce this uncertainty with tracer data and better understanding the way connectivity influences stream chemistry.

Exploring the Spatially Compounding Multi‐Sectoral Drought Vulnerabilities in Colorado's West Slope River Basins

AbstractThe state of Colorado's West Slope Basins are critical headwaters of the Colorado River and play a vital role in supporting Colorado's local economy and natural environment. However, balancing the multi‐sectoral water demands in the West Slope Basins while maintaining crucial downstream deliveries to Lake Powell is an increasing challenge for water managers. Internal variability of the hydroclimatic system and climate change complicate future vulnerability assessments. This work contributes a detailed accounting of multi‐sectoral drought vulnerability in the West Slope Basins and the impacts of drought on downstream deliveries. We first introduce a novel multi‐site Hidden Markov Model (HMM)‐based synthetic streamflow generator to create an ensemble of streamflows for all West Slope basins that better characterizes the region's drought extremes. We capture the effects of climate change by perturbing the HMM to generate an ensemble of streamflows reflecting plausible changes in climate. We then route both ensembles through StateMod, Colorado's water allocation model, to evaluate spatially compounding drought impacts across the West Slope Basins. Our results illustrate how drought events emerging from the system's stationary internal variability in the absence of climate change can significantly impact local water uses and deliveries to Lake Powell, exceeding extreme conditions in the historical record. Further, we find that even modest climate change can cause a regime shift where historically low downstream delivery volumes and extreme drought impacts become routine. These results can inform future Colorado River planning efforts, and our methodology can be expanded to other snow‐dominated regions that face persistent droughts.

Longitudinal Investigation of Groundwater and Surface Water Interaction of Two Gravel Pit Lakes in Central Texas: Chemical and Flow Implications

Two gravel pit lakes in central Texas were examined over the course of two years with upgradient and downgradient piezometer installations. Groundwater and lake water were sampled bimonthly for nutrients, water levels, and groundwater chemistry, and in addition, rain and lake gauges and mini-piezometers were installed, depth surveys were conducted, and a simple 2D flow model was constructed. The project goal was evaluating and examining flow dynamics and chemical effects as groundwater flows to surface water and back to groundwater with the intent to understand the effects that gravel pit lake systems have on connected shallow groundwater. Both lake systems were shown to be flow-through systems that influence the water quality by decreasing the dissolved nutrients in the groundwater in their vicinity while oxygenating the water and altering the pH. However, the lakes are also prone to high levels of evaporation, meaning that minor improvements to water quality come at the cost of decreasing the quantity of water in storage within the aquifer. Similar groundwater and mine lake systems may show comparable tendencies, providing new information for water managers, regulators, and stake-holders about the potential roles that non-remediated gravel pit lakes may play in local ecosystems and aquifer dynamics.

Strategi Pemasaran Air Minum dalam Kemasan di Pondok Pesantren Riyadhus Samawi

In general, some of the community's drinking water needs can be sourced from well water and water that has been treated by the Regional Drinking Water Company (PDAM). However, the increasing demand for drinking water sometimes cannot be met by well water sources or water that has been treated by PDAM. Along with technological advances, accompanied by increasingly busy community activities today tend to choose a more practical way at a relatively low cost in meeting drinking water needs. One of the alternative ways to fulfill drinking water needs is by using mineral water products. Marketing is a process of preparing integrated communication that aims to provide information about goods or services in relation to human needs. The marketing carried out at the Riayadus Samawi Islamic Boarding School is still very simple, namely from word of mouth to the congregation. So that Yarisa Drinking Water has not been sold widely like bottled drinking water in general because the majority of consumers are still worshipers and the neighborhood around the cottage. The purpose of this community service is to contribute thoughts and training, especially to the manager of Yarisa drinking water regarding the importance of analyzing marketing strategies for a company in an effort to market its products so that these products can be accepted by the public and distributed widely. The PKM process carried out at the Riyadus Samawi Ludoyo Blitar Islamic Boarding School consists of three stages, including: first, problem identification with a study carried out by the PKM team, Yarisa drinking water managers, cottage administrators, cottage caregivers, and cottage owners to find out the quality and development of Yarisa drinking water marketing strategies. The second stage is the implementation of PKM by holding a seminar with the theme “Marketing Strategy for Bottled Drinking Water at Riyadus Samawi Islamic Boarding School” and attended by Yarisa drinking water managers and students and board members. The third stage is monitoring and evaluation of whether the bottled drinking water marketing strategy delivered by the PKM team has been implemented in Yarisa drinking water. The results of this PKM are socialization and assistance regarding bottled drinking water marketing strategies and making several marketing and motivational programs so that in the future Yarisa drinking water owned by Riyadus Samawi Islamic Boarding School can be marketed widely.

MODIS Evapotranspiration Forecasting Using ARIMA and ANN Approach at a Water-Stressed Irrigation Scheme in South Africa

The forecasting of evapotranspiration (ET) in some water-stressed regions remains a major challenge due to the lack of reliable and sufficient historical datasets. For efficient water balance, ET remains the major component and its proper forecasting and quantifying is of the utmost importance. This study utilises the 18-year (2001 to 2018) MODIS ET obtained from a drought-affected irrigation scheme in the Eastern Cape Province of South Africa. This study conducts a teleconnection evaluation between the satellite-derived evapotranspiration (ET) time series and other related remotely sensed parameters such as the Normalised Difference Vegetation Index (NDVI), Normalised Difference Water Index (NDWI), Normalised Difference Drought Index (NDDI), and precipitation (P). This comparative analysis was performed by adopting the Mann–Kendall (MK) test, Sequential Mann–Kendall (SQ-MK) test, and Multiple Linear Regression methods. Additionally, the ET detailed time-series analysis with the Keiskamma River streamflow (SF) and monthly volumes of the Sandile Dam, which are water supply sources close to the study area, was performed using the Wavelet Analysis, Breaks for Additive Seasonal and Trend (BFAST), Theil–Sen statistic, and Correlation statistics. The MODIS-obtained ET was then forecasted using the Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Networks (ANNs) for a period of 5 years and four modelling performance evaluations such as the Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), Mean Absolute Error (MAE), and the Pearson Correlation Coefficient (R) were used to evaluate the model performances. The results of this study proved that ET could be forecasted using these two time-series modeling tools; however, the ARIMA modelling technique achieved lesser values according to the four statistical modelling techniques employed with the RMSE for the ARIMA = 37.58, over the ANN = 44.18; the MAE for the ARIMA = 32.37, over the ANN = 35.88; the MAPE for the ARIMA = 17.26, over the ANN = 24.26; and for the R ARIMA = 0.94 with the ANN = 0.86. These results are interesting as they give hope to water managers at the irrigation scheme and equally serve as a tool to effectively manage the irrigation scheme.

Uniting agricultural water management, economics, and policy for climate adaptation through a new assessment of water markets for arid regions

Flexible policies aimed at irrigated agriculture are essential to adapt to climate change. Despite the importance of this goal, little published work has conceptualized, formulated, developed, and applied an integrated optimization framework for irrigated agriculture to guide adaptation to climate-related water stress. This research addresses the question: how can water management plans for irrigated agriculture be designed to minimize economic losses caused by adapting to climate-induced water stress? The study answers this by developing an optimization approach that identifies water use patterns to minimize farm income losses during water shortages, considering three water shortage sharing programs. An optimization model, calibrated using positive mathematical programming, is applied to replicate historical land use while adapting to future water supplies that deviate from the historical pattern. The analysis focuses on two irrigated regions in North America’s Rio Grande Basin, illustrating land use, water use, and cropping patterns that minimize regional farm economic losses to shortages. These losses are assessed under three water-sharing strategies: intercrop and interdistrict trading (IIT), intercrop and intradistrict trading (IRT), and no trading (NT). The results demonstrate that IIT yields an average economic gain of $2.824 million per year, while IRT results in an average gain of $2.600 million per year compared to NT. These findings offer valuable insights for water managers, scientists, stakeholders, and policymakers tasked with developing irrigation management strategies in arid regions facing future water supply challenges. The methods developed and results shown here highlight a path forward, using scientific, economic, and policy innovations to strengthen agricultural livelihoods in regions facing uncertain water availability.

Surface water quality assessment and probable health threats of metal exposure in the Tano South Municipality, Ahafo, Ghana

The prime goal of this study was to assess the surface water quality and the associated health risks for residents in the Tano South Municipality, Ghana. The WHO drinking water criteria were compared with the findings of an analysis of eight surface waters for parameters such as physiochemical parameters, nutrient levels, and concentrations of selected metals. An evaluation was performed regarding the potential non-carcinogenic and carcinogenic risks associated with metal exposure by oral and dermal absorption. The estimated water quality index indicated that seven water samples were deemed unsuitable for human consumption, while one sample indicated very low water quality. The fluoride levels in all water samples were below the limit of detection, although it guards against dental caries. All of the water samples had mean concentrations of Cd and Fe above WHO guideline values, while one water sample had a Pb concentration that was higher than recommended. Principal component analysis showed that aside from the natural source, human-induced sources such as runoff of excess chemicals and soil erosion from adjacent farm soils were responsible for the substantial levels of contaminants in surface water samples. There was a possibility of non-carcinogenic consequences for children in seven out of eight water samples. However, cancer risk for Cd and Pb was not likely for adults and children in the study area. Findings serve as a representative case study for other districts and call on water managers to treat surface waters to guard against harmful health consequences and safeguard the designated buffer zones.

A parsimonious model for springs discharge reconstruction and forecast for drought management: Lessons from a case study in Central Italy

Study regionKarst springs located in Central Apennine ridge (Central Italy), in the Tiber River basin. Study focusThe assessment of water availability is a key issue in a water supply system because of increasing drought and water scarcity events. Analysing and predicting the dynamic behaviour of groundwater resources is challenging to conceptualize and model, especially in poorly-monitored systems. A parsimonious model based on linear regression between the monthly spring discharge time series and Standardized Precipitation Index is proposed. The model is conceived for management purposes and suitable for users with a limited background in modelling techniques, who can take advantage from an initial knowledge of the aquifers hydrological regime. New hydrological insights for the regionThe model developed for long-term monitored springs is used to reconstruct the historical groundwater hydrographs and to make predictions for poorly-monitored springs with similar properties, exploiting the “similarity principle”. Results highlight the notable performance of this approach, which represents a useful tool for overcoming the limitations in spring discharge monitoring networks. Moreover, the tool is used to test forecast performance enabling water managers to develop a monthly early-warning system fostering a sustainable water resource exploitation and limiting the critical issues of the water supply system, especially during drought periods. Results are discussed from the perspective of the water utilities entrusted to manage their resources in the study region.

Non‐Native Invasive Fish Species (NIFS) in Inland Waters of India: Management Issues, Strategies and Suggestions

ABSTRACTIn India, there are 626 non‐native invasive fish species (NIFS), with 16 becoming invasive in inland waters, adversely impacting native biodiversity, and fisheries by altering the abundance of NIFS in commercial catches. Scientific findings highlight that the movement of NIFS interacts with agricultural activities and the evolving environment, facilitating their spread and establishment. The scenario of NIFS invasion disrupts biological communities, ecosystem services and fisherfolk livelihoods. Despite the implementation of existed guidelines, issues related to NIFS have persisted and escalated over time scale putting increased pressure on indigenous aquatic biological resources in inland waters. This paper suggests the need of framing a new management plans, guidelines and regulatory policies to control NIFS invasions, protecting riverine fish biodiversity and ecosystem services. Proposed management strategies include functional response (FR) and adaptive response (AR)‐based approaches, which are discussed to address NIFS management in inland waters.

Hydrologic Responses to Climate Change and Implications for Reservoirs in the Source Region of the Yangtze River

ABSTRACTUnderstanding the hydrological impacts of climate change is essential for robust and sustainable water management. This study assessed the hydrologic conditions under changing climate in the Jinshajiang River basin, the source region of the Yangtze River, using the hydrological model SWAT with the historical observations and the future climate simulations under two Shared Socioeconomic Pathways (SSP2‐4.5 and SSP5‐8.5). For the historical period, with an increasing trend of precipitation, evapotranspiration, and snowmelt, streamflow increases in upstream region but keeps decreasing in the downstream catchment. For future scenarios, a warmer and wetter climate is projected for the basin throughout the 21st century, leading to an overall increase in mean and extreme streamflow. The streamflow magnitude increases more significantly in the far future than in the near future, and more significant under SSP5‐8.5 than SSP2‐4.5. The projected remarkable increase in precipitation causes the transition in changing trend of streamflow compared with the historical period. The projected warming leads to a continuing decline in snowfall and snow water equivalent, followed by an earlier snowmelt and higher peak streamflow, especially at the upstream catchment. Ultimately, reservoirs in the basin are expected to gain more inflows, however, with greater variability including higher likelihoods of flood and drought events, which impose potential challenges on reservoir operations. These outcomes indicate the importance of adaptive water resources management in the melting water contributed basin to sustain and enhance its services under global warming.

Groundwater Recharge Response to Reduced Irrigation Pumping: Checkbook Irrigation and the Water Savings Payment Plan

Ongoing investments in irrigation technologies highlight the need to accurately estimate the longevity and magnitude of water savings at the watershed level to avoid the paradox of irrigation efficiency. This paradox arises when irrigation pumping exceeds crop water demand, leading to excess water that is not recovered by the watershed. Comprehensive water accounting from farm to watershed scales is challenging due to spatial variability and inadequate socio-hydrological data. We hypothesize that water savings are short term, as prior studies show rapid recharge responses to surface changes. Precise estimation of these time scales and water savings can aid water managers making decisions. In this study, we examined water savings at three 65-hectare sites in Nebraska with diverse soil textures, management practices, and groundwater depths. Surface geophysics effectively identified in-field variability in soil water content and water flux. A one-dimensional model showed an average 80% agreement with chloride mass balance estimates of deep drainage. Our findings indicate that groundwater response times are short and water savings are modest (1–3 years; 50–900 mm over 10 years) following a 120 mm/year reduction in pumping. However, sandy soils with shallow groundwater show minimal potential for water savings, suggesting limited effectiveness of irrigation efficiency programs in such regions.

Addressing Challenges to Ensuring Justice and Sustainability in Policy and Infrastructure for Texas Water Resources in the 21st Century

Environmental justice and sustainability have both become major concerns for water resource management, particularly with recent federal emphasis on environmental justice under the Biden administration in the United States. Texas, like many U.S. states, lags behind the federal government in this emphasis. While many localities have made progress in some respects—for example, some major Texas municipalities have included equity and sustainability metrics in their recent climate action plans—others have not. This has left a patchwork of persistent water management and availability issues that are exacerbated by extreme weather and worsening impacts of climate change. We provide a review of many of Texas’s water equity and sustainability challenges, both now and in a more extreme climate future. These include water access, affordability, contamination, flooding, drought, and aging infrastructure. For example, many Texas counties rank highest in the nation for flood risk, including coastal counties with high populations of disadvantaged communities and counties containing populations that live in persistent poverty in the Lower Rio Grande Valley. Additionally, approximately 44,000 Texans, or about 0.4% of the state population, lack access to complete plumbing facilities in their homes. The costs of water infrastructure leaks (estimated at about 51 gallons of water per day statewide) are shared across customers of all income levels, though they place a disproportionate burden on low-income customers. We then assess existing statewide and local policy and planning efforts and gaps in addressing these concerns in Texas. We focus particularly on the role of efforts to incorporate community voice—the ideas, concerns, needs, and expertise of impacted community members, dismantle causes of injustice, and improve equity in spending. If communities are not intentional with future development, new water infrastructure could continue to perpetuate existing harms. Thus, we provide a research agenda and recommendations for addressing some of the policy and planning gaps and persistent environmental justice issues. We aim to help water managers and policy makers identify and dismantle sources of inequity, particularly through including community voice.