Robert B. Sowby

Groundwater storage change in the Great Salt Lake Basin (GSLB) is difficult to quantify because monitoring data are uneven. We estimate groundwater storage anomalies over 2002–2024 with five methods: Gravity Recovery and Climate Experiment (GRACE) total water storage minus Global Land Data Assimilation System (GLDAS) land‐surface components (GRACE‐raw); the same with lake and reservoir storage removed (GRACE‐sw); a further correction for GRACE signal leakage, calibrated against in situ data (GRACE‐Lf); the GRACE‐assimilated GLDAS v2.2 product (GLDAS‐2.2); and an in situ reconstruction from groundwater‐level observations (GWDM). Four of the five methods show drawdowns in 2011–2016 and 2019–2022. Surface water, dominated by the Great Salt Lake, accounts for about 31% of the basin's storage signal. A leakage factor of 2.3 indicates that uncorrected GRACE captures less than half of the signal where pumping is concentrated along the Wasatch Front. Over 2011–2016, leakage‐corrected GRACE indicates a groundwater loss of 13.3 ± 7.8 km ³ and the in situ reconstruction 10.1 ± 1.8 km ³ , both consistent with an independent GPS‐based estimate of 10.9 ± 2.8 km ³ . With a calibrated leakage factor, GRACE and GLDAS data can update the basin's storage estimate as new data are released.

The Great Salt Lake in northern Utah, the USA, is at record-low levels, causing interest in factors that have reduced inflow. One potential factor is the expansion of coniferous forests, which intercept snow that sublimates to the atmosphere rather than reaching streams. We evaluated the increase in coniferous cover in the lake tributary basins and quantified the potential sublimation water loss. In Google Earth Engine we built annual summer–winter Landsat composites (14 features: six reflectance bands and NDVI for each season, 1986–2025) and classified coniferous forest using a 100-member Random Forest ensemble, giving an annual uncertainty envelope with a median run-to-run spread of 4.3%. We assessed trends with the Mann–Kendall test and Sen’s slope and estimated canopy sublimation as a fraction of snowfall. Coniferous cover in the Bear, Weber, and Jordan River tributary basins increased significantly over 1986–2025 (Sen’s slope +27 km² yr⁻¹, p = 0.00064; trend-based increase 1059 km², about 35% of the 1986 extent). Applying Utah canopy-sublimation fractions (5–11% of snowfall) and a mean snowfall water equivalent of 0.71 m, the additional forest sublimates an estimated 30,000–67,000 acre-feet per year. While this is roughly 1.4–3.2% of mean annual river inflow, only a portion of the snowfall contributes to river flow, so the actual impact is lower, although loss is linear with snowfall.

A reliable water supply is essential for balancing hydrologic, operational, and institutional constraints and is intensified by the water demands of emerging carbon-removal technologies. This study applies a reliable water-supply framework to Castle Valley, Utah, USA, a region with favorable geologic conditions for carbon storage. Existing municipal, agricultural, and industrial water demands and surface-water, groundwater, and water-rights-based supply were quantified using publicly available datasets. Scenarios were then evaluated to test how a proposed 1 Mt/yr direct air capture (DAC) facility would affect the regional water balance. Results indicate that the existing supply–demand balance in Castle Valley is approximately in equilibrium, and that a 1 Mt/yr DAC facility would require an estimated 7–18% of total municipal water demand, disrupting the balance under several supply scenarios, particularly where supply is based on water rights rather than actual conditions. Retrofitting existing coal-fired power plants with carbon capture and storage (CCS) could double their water consumption. Non-potable water sources, such as brine water, may be necessary to support DAC development without compromising existing water users. The findings suggest that regional water-balance frameworks can help identify where carbon-removal infrastructure is feasible without exacerbating water scarcity, and that similar assessments should precede DAC siting decisions in other water-limited regions.

The worldwide data center boom is driving water and energy demand with uncertain impacts. Information on direct water demands (e.g., for cooling) and indirect water demands (e.g., through energy use) is not well known or the information is restricted. Policies on data centers’ water accountability are swiftly emerging, but consistent analysis of the policy motivations, instruments, and statuses is lagging. To this end we review state-level policies in the United States that apply to or govern data centers’ water use. We tabulate legislative activity from the states’ 2025 and 2026 general legislative sessions. We find that 36 states have attempted such statutes, with seven passing. The policy instruments vary. Six states passed information-based policies, requiring pre-construction water use projections, operational water use reports, or other studies. Seven states (some overlapping the earlier six) passed regulatory policy, enforcing limitations on types of cooling technology, water use, or economic criteria. No single policy instrument dominates, but we identify three cross-cutting themes. First, transparency is the primary objective driving policy activity. Second, enforcement policies are inconsistent; although a few policies propose civil penalties for noncompliance, such provisions are generally weak. Third, technology mandates are emerging (e.g., closed-loop cooling), typically when local water stress or public opposition is acute. Although policy is still forming, this review establishes a baseline that can inform future analysis and early policymaking.

The water levels of Great Salt Lake continue to decline despite growing public awareness. Farmers, because of their large water consumption, are often portrayed as the villains in the story of lake recovery. We argue, however, that farmers are in the best position to save the lake: They are experienced in water management, long-term stewardship, and knowledge of the land. Indeed, they are the only group that controls enough water to make a difference. Unlike municipal water use, agricultural water use is largely consumptive, so its reduction directly increases inflow to the lake. Lake recovery therefore depends on agricultural participation; no other sector has comparable capacity to deliver water at scale and in time. Promising tools to decrease consumptive water use include voluntary, compensated reductions in irrigation; rotational or partial-season fallowing; and water leasing or banking programs explicitly tied to Great Salt Lake inflows. Predictable, fair, and durable policies will be the most appealing. We recommend that additional policies deliberately target agriculture-not as punishment, but as partnership-positioning farmers as the heroes of Great Salt Lake.

Water utilities must assess the condition of buried pipelines without excavation or interruption of service. We review 20 pipeline risk models – specifically for the likelihood of failure – and 10 leak detection methods. We find that common risk factors include physical attributes (e.g., pipe age, material, diameter), operational attributes (e.g., pressure, flow, repair history), and environmental attributes (e.g., soil type, bury depth, fault proximity). The models contain 4–27 risk factors, differing in inclusion and weight. For an industry perspective, we interview water utilities in Utah, USA, on their condition assessment and leak detection practices. Physical attributes are most available, and environmental attributes are least available. Many models are unworkable because the water utilities lack the required data. Instead, they use acoustic methods, if any, for reactive leak detection. We recommend developing data-light risk models (using a few common attributes) to inform the best leak detection method for a given water system.

The strength of a nation's civil infrastructure is a vital component in its ability to achieve global leadership. At city, state, and national levels, infrastructure development is not merely a technical or economic pursuit but also a training ground for governance. This viewpoint explores how domestic infrastructure initiatives shape governance capabilities in cooperation, innovation, resilience, and foresight, enabling nations to extend their influence globally.

Agricultural irrigation is the largest consumer of water in the United States. Many changes have occurred over the years, but we question the recent attention on efficiency. Comparing 2015 and 1985, we find that more land is being irrigated with less water: irrigation withdrawals fell by 14%, irrigated area expanded by 11%, and flood irrigation was substantially displaced by sprinkler and microirrigation systems. However, consumptive water use fell by only 1%, and return flows—an important part of the water balance that supports many downstream needs—declined by 39%. This gain in efficiency and loss in return flow, without any apparent saving of water, is the conflicting legacy of U.S. irrigation. We propose the links among irrigation efficiency, return flows, and consumptive water use as a central theme around which to organize future irrigation research, policy, and management. We call on state and federal agencies that fund research and adoption of improved irrigation practices to require accounting of all aspects of the water balance-including return flow-and promote sustainable, basin-scale water conservation.