Hydrology/water management and electricity generation projections have been modeled separately, but there has been little effort in intentionally and explicitly linking the two sides of the water-energy nexus. This paper describes a platform for assessing power plant cooling water withdrawals and consumption under different electricity pathways at geographic and time scales appropriate for both electricity and hydrology/water management. This platform uses estimates of regional electricity generation by the Regional Energy Deployment System (ReEDS) as input to a hydrologic and water management model-the Water Evaluation and Planning (WEAP) system. In WEAP, this electricity use represents thermoelectric cooling water withdrawals and consumption within the broader, regional water resource context. Here we describe linking the electricity and water models, including translating electricity generation results from ReEDS-relevant geographies to the water-relevant geographies of WEAP. The result of this analysis is water use by the electric sector at the regional watershed level, which is used to examine the water resource implications of these electricity pathways.

Abstract:In the Peruvian Andes, water infiltration from tropical wetlands, called páramo, generates headwaters for downstream rivers. The hydrological processes of these wetlands are not well understood within the larger hydrological system, impeding efforts to mitigate the rapid environmental changes anticipated due to regional population growth and climate change. This study constructed and calibrated a Water Evaluation and Planning (WEAP) system model for ecosystems with sparse data in the Quiroz-Chipillico watershed in the Piura region of Peru. The model simulates the impacts of possible changes within the hydrological system to assist decision-makers in strategizing about sustainable development for the region, especially the páramo. Using scenarios designed with stakeholder participation, the WEAP model for the Quiroz-Chipillico watershed examines river headflow production, reservoir water levels, and demand coverage for downstream users when the upstream páramo and its environs are subjected to changes of temperature, precipitation, and land use. The model reveals that while temperature and precipitation changes can be expected to impact páramo water production, the anticipated land use changes will be a primary driver of hydrological responses in the páramo and subsequent changes downstream.

This letter documents the development and validation of a climate-driven, southwestern-US-wide water resources planning model that is being used to explore the implications of extended drought and climate warming on the allocation of water among competing uses. These model uses include a separate accounting for irrigated agriculture; municipal indoor use based on local population and per-capita consumption; climate-driven municipal outdoor turf and amenity watering; and thermoelectric cooling. The model simulates the natural and managed flows of rivers throughout the southwest, including the South Platte, the Arkansas, the Colorado, the Green, the Salt, the Sacramento, the San Joaquin, the Owens, and more than 50 others. Calibration was performed on parameters of land cover, snow accumulation and melt, and water capacity and hydraulic conductivity of soil horizons. Goodness of fit statistics and other measures of performance are shown for a select number of locations and are used to summarize the model's ability to represent monthly streamflow, reservoir storages, surface and ground water deliveries, etc, under 1980-2010 levels of sectoral water use.

Agriculture often is considered to be a contributor of soluble reactive phosphorus (SRP) and nitrate‐N (NO3−‐N) to surface waters. This research analyzed SRP and NO3−‐N concentrations in groundwater and in a creek fed by groundwater on a valley dairy farm in the Cannonsville basin of the New York City (NYC) watershed. A total of 37 groundwater piezometers were installed to depths of 0.3 to 1.5 m. Water‐table depth and concentrations of SRP, NO3−‐N, dissolved organic carbon (DOC), and dissolved oxygen were measured at regular intervals over a three‐year period. A multivariate mixed model analysis of variance indicated that the SRP and NO3−‐N concentrations were controlled primarily by three classes of variables: environmental variables, including precipitation and water table depth; source variables, including manure applied and crop type; and chemical variables, including DOC and dissolved oxygen concentrations in groundwater. The highest groundwater concentrations of NO3−‐N and SRP were found at the shallowest water‐table depths, which has implications for agricultural nutrient management in areas with shallow groundwater.

Near-stream best management practices (BMPs), such as exclusionary fencing or cattle crossings, are often recommended to improve water quality, but quantification of their impacts is limited. Surface and subsurface processes in these near-stream areas impact the contribution of nitrogen and phosphorus to watercourses and the effectiveness of near-stream BMPs. To test the impact of the near-stream BMPs, groundwater samples from 30 piezometers and streamwater samples along two adjacent creeks (one control and one with BMP treatment) were collected over a three-year period before and after installation of exclusionary fencing with a cattle crossing in the Catskill Mountains of New York State. Samples were analyzed for nitrate nitrogen (NO 3 --N), soluble reactive phosphorus (SRP), dissolved oxygen, and dissolved organic carbon. Analysis results and other ancillary variables (rainfall and groundwater table depth) were incorporated into a multivariate statistical model to evaluate the impact of the BMPs on the concentrations of NO 3 --N and SRP in the treatment creek. Results of the analysis indicate that the installation of the near-stream BMPs resulted in a 27% yearly (34% during the growing season) reduction in treatment creek SRP concentrations, while there was little impact on NO 3 --N concentrations. Incorporating the SRP concentrations measured in a nearby control creek and controlling for the effects of groundwater SRP levels and groundwater hydrology (water table height) had a significant effect on the overall analytical model performance. These results indicate that protecting near-stream areas from potentially pollution-causing practices can be an important means of controlling phosphorus levels in water bodies.