Across the western US, growing populations and urbanization along with environmental demands and a changing climate have strained water allocation mechanisms originally designed to provide water to agriculture. This paper provides a methodology, using Utah as an example, for examining the options for new water supply via conservation, interpretable by policymakers, water agencies, and water users. Findings indicate that the largest potential water savings, at the lowest cost, are in agriculture and outdoor residential water use, where more efficient applications can maintain the acreage of crops and lawns at current levels while dramatically reducing use. Full article

Integrated water resource management (IWRM) is facing great challenges due to growing uncertainties caused by climate change (CC), rapid socio-economic and technological changes, and population growth. In the present study, we have developed different indices to assess the availability of water using an IWRM approach. These indices evaluate supply to demands, surface availability, groundwater availability, reservoirs, and environmental flow. Moreover, reliability, resilience, and vulnerability were determined. Sustainability index (SI) and sustainability index by groups (SG) were determined based on the five indices (all indices vary from 0 to 1). The impacts of climate change affect surface and groundwater availability, as do the agricultural, urban, and industrial requirements on the different supplies. We used the generalized AQUATOOL Decision Support System Shell (DSSS) to evaluate the IWRM in the Rio Grande Basin (Morelia, México). Various emission scenarios from representative concentration pathways (RCPs) were applied to the basin for the years 2015–2039 and 2075–2099. The results indicate increases in agricultural and urban demand, and decreases in surface runoff, as well as groundwater recharge. The proposed indices are useful for different approaches (decision-makers, water policy, and drought risks, among others). CC significantly affects the different proposed indices and indicates a decrease of the SI, SG1, and SG2 (i.e., less availability). For example, we found that SG2 decreased from 0.812 to 0.195 under the RCP 8.5 2075–2099 scenario, and SG2 equal to 0.252 and 0.326 for the RCP 6.0 2075–2099 and RCP 4.5 2070–2099 scenarios, respectively (values close to 0 indicate worst drought conditions). Full article

Assessing the drought resilience of snow‐fed river dependent communities in the arid Western United States has taken on critical importance in response to changing climatic conditions. The process of assessing drought resiliency involves understanding the extent to which snow‐fed dependent communities can absorb the effects of uncertain and variable water supplies while acknowledging and encouraging their capacity for adaptation. Participatory research approaches are particularly well suited to assess resiliency in this context because they rely upon local water managers’ knowledge and perspectives. The research presented here provides measured insight into local water managers’ perceptions of drought resiliency in the Truckee‐Carson River System in northwestern Nevada. These findings are reported in the context of the collaborative modeling research design developed for this case study. The objectives of this study are: (1) to define resiliency and present a rationale for a participatory approach to assess drought resiliency in snow‐fed arid river basins in the Western United States; (2) to outline collaborative modeling as a participatory research design developed for the Truckee‐Carson River System case study area; (3) to describe the development and implementation of a resiliency assessment undertaken to implement this research design; (4) to highlight selected results of the assessment, summarizing interviews with 66 water managers in the case study area; (5) to discuss the use of assessment findings to inform collaborative modeling toward adaptation strategies; and (6) to review lessons learned to date from the collaborative modeling case study and note opportunities for further exploration. According to water managers surveyed, climate change is very important and is mobilizing adaptation strategies that include improvements in communication and coordination with other water managers, monitoring and data collection,and planning. The majority of water managers indicate that future adaptation requires modifying institutionalized water management regimes to allow for temporary water leasing programs, water right stacking on the most productive agricultural lands while fallowing marginal lands,incentivizing water conservation, reducing or eliminating residential landscaping, and recruiting less water intensive industry to the region. Full article

Cimarron County, Oklahoma and Union County, New Mexico, neighboring counties in the Southern High Plains, are part of a vital agricultural region in the United States. This region experiences extended periods of cyclical drought threatening its ability to produce, creating an incentive for extensive center pivot irrigation (CPI). Center pivots draw from the rapidly depleting High Plains Aquifer System. As a result, the prospect of long-term sustainability for these agricultural communities is questionable. We use Remote Sensing and Geographic Information Systems to quantify growth in land irrigated by CPI between the 1950s and 2014, and key informant interviews to explore local perspectives on the causes and impact of such growth. In Cimarron County, OK, CPI increased by the mid-1980s, and has continually increased since. Results suggest adaptation to drought, a depleting aquifer, high corn prices, and less rigid groundwater regulations contribute to CPI growth. Conversely, CPI in Union County, NM, increased until 2010, and then declined. Results also suggest that drought-related agricultural changes and more aggressive well drilling regulations contribute to this decrease. Nevertheless, in both counties, there is a growing concern over the depleting aquifer, the long-term sustainability of CPI, and the region’s economic future. Full article

To assist water resource managers with future land use planning efforts, the eco-hydrological model Soil and Water Assessment Tool (SWAT) was applied to three catchments in South Australia that experience extreme low flow conditions. Particular land uses and management issues of interest included forest covers, known to affect water yields, and farm dams, known to intercept and change the hydrological dynamics in a catchment. The study achieved a satisfactory daily calibration when irrigation farm dams were incorporated in the model. For the catchment dominated by extreme low flows, a better daily simulation across a range of qualitative and quantitative metrics was gained using the base-flow static threshold optimization technique. Scenario analysis on effects of forest cover indicated an increase of surface flow and a reduction of base-flow when native eucalyptus lands were replaced by pastures and vice versa. A decreasing trend was observed for the overall water yield of catchments with more forest plantation due to the higher evapotranspiration (ET) rate and the decline in surface flow. With regards to effects of irrigation farm dams, assessment on a daily time step suggested that a significant volume of water is stored in these systems with the water loss rate highest in June and July. On an annual basis, the model indicated that approximately 13.1% to 22.0% of water has been captured by farm dams for irrigation. However, the scenario analysis revealed that the purposes of use of farm dams rather than their volumetric capacities in the catchment determined the magnitude of effects on streamflows. Water extracted from farm dams for irrigation of orchards and vineyards are more likely to diminish streamflows than other land uses. Outputs from this study suggest that the water use restrictions from farm dams during recent drought periods were an effective tool to minimize impacts on streamflows. Full article

Irrigated row-crop agriculture is contributing to declining groundwater in areas such as the Mississippi Delta region of eastern Arkansas. There is a need to move toward sustainable levels of groundwater withdrawal. Recent improvements in remote monitoring technologies such as wireless soil moisture sensors and unmanned aerial vehicles offer the potential for farmers to effectively practice site-specific variable-rate irrigation management for the purpose of applying water more efficiently, reducing pumping costs, and retaining groundwater. Soil moisture sensors and unmanned aerial vehicles are compared here in terms of their net returns per acre-foot and cost-effectiveness of aquifer retention. Soil moisture sensors ($9.09 per acre-foot) offer slightly more net returns to producers than unmanned aerial vehicles ($7.69 per acre-foot), though costs associated with unmanned aerial vehicles continue to drop as more manufacturers enter the market and regulations become clear. Full article

Forests play an important role with respect to water resources, and can be managed to increase surface- and groundwater recharge. With the creation of a forest water yield payment system, privately-owned forests, which comprise the majority of forest area in the Southeastern US, could become an important potential source of additional water supply. The economic tradeoffs between timber revenues and water yield are not well understood. To address this, we use the example case of slash pine production in Florida, and employ a forest stand-level optimal rotation model that incorporates forest management, and assessed a range of feasible water yield prices on forest profitability. Our analysis was limited to a range of water yield prices ($0.03, $0.07, and $0.30 kL⁻¹) that would make water yield from slash pine economically competitive with water supply alternatives (e.g., reservoir construction). Even at relatively low water prices, we found that managing slash pine forests for both timber and water yield was preferred to managing just for timber when assuming an initial tree density less than 2200 trees·ha⁻¹. However, with higher levels of initial tree planting density and low water prices, managing slash pine for timber production alone was more profitable unless stands are heavily-thinned, suggesting that even mid-rotation stands could be included in a forest water yield payments program. Compared to low-tree planting density and lightly thinned slash pine forests, an intensive approach of planting a lot of trees and then heavily thinning them generated 8% to 33% higher profits, and 11% more ($192 ha⁻¹) on average. We conclude that payments for water yield are economically feasible for slash pine stands in Florida, and would benefit forest landowners, particularly with higher prices for water yield. Full article

Based on the national precipitation dataset in the Huang-Huai-Hai River Basin of China for the 1961–2011 period, the China-Z growing season index was calculated to analyze the characteristics of the evolution of meteorological droughts. Data from statistical droughts (the droughts which are defined and classified by the actual statistic data) were compared with those of meteorological droughts during the 2000–2011 period. Nine indexes were selected to evaluate the drought coping ability of water conservancy projects based on the fuzzy comprehensive assessment model. The results showed that the China-Z growing season index was a downward trend with a rate of −0.063 per decade from 1961 to 2011, which indicates an increasing trend in drought intensity. Droughts were more frequent than average during the 1961–1979 period and returned to normal frequency during the 1980–2011 period. Both the ratio of drought affected area (RDAA) and the ratio of drought suffering area (RDSA) of statistical droughts decreased more quickly than those of meteorological droughts (2000–2011). The indexes of water conservancy projects were lower than the average all-China indexes. Half of the 59 three-level water resources districts exhibited a relatively poor drought coping ability, which means that enhancing the drought coping ability of the water conservancy project was quite important. Full article

This work develops a rule curve-based conjunctive use management model for optimizing the operating rules for a lake–groundwater system with off-stream storage lakes. The proposed procedure is a simulation-optimization approach that embeds an Artificial Neural Network (ANN) instead of a groundwater numerical model into a genetic algorithm (GA). The direct physical exchange between lake water with groundwater is simulated using the ANN model, which is a reduced version of a full numerical model, MODFLOW with an LAK3 module. By applying the ANN model, the proposed procedure can reduce the computational burden that is induced by the nonlinear exchange. An operating rule-based optimal conjunctive use management model for the Gaopin Artificial lakes system in Taiwan was thus developed using the proposed framework. A set of optimal solutions involves rule curves and a discount ratio. Simulation results demonstrate that the embedded ANN model can accurately simulate the nonlinear exchange of a lake with groundwater. The embedded ANN model is less computationally complex than the numerical model. This work demonstrates a methodology for reducing the computational burden of the optimal conjunctive use management model that is associated with an internal nonlinear system by using the ANN reduced model. Specifically, the concept of, and results obtained using the developed operating rule-based model incorporating five artificial lakes and considering the nonlinear exchange of those lakes with the groundwater system provides a valuable practical reference for solving related conjunctive use problems. Full article