Product Abstract

This report is a general guide to analytical techniques used to address water resource management as related to long-term sustainability planning, and short-term regulatory requirements, including total maximum daily loads, endangered species, and relicensing of hydropower facilities. The example applications presented in the report highlight the capability of the techniques, and help electric power company and government regulatory staffs identify the best approach for a specific need.

Background

Resource managers expect societal demands on water resources to continue to grow as a result of increasing population and development, and concomitant needs for electricity generation and agriculture. They also expect public demand for protecting aquatic ecosystems and human health to put more restrictive regulatory limits on water withdrawals and discharges. A consequence of these trends is the need for enhanced assessment and management of water resource constraints for all sectors of the economy, especially for the electric utility sector, which needs water for cooling for fossil, nuclear, and some renewable energy production facilities. In the medium term, i.e., 20-25 years, resource managers predict substantial new generation that will require water resources. In addition, existing power plants may be constrained with respect to water withdrawals. Over the past decade, EPRI-sponsored research has addressed a variety of assessment/management issues relating to sustainable water supplies for power plant (thermal and hydro) operations (EPRI Reports 1005181, 1005474, and 1010116). These studies have developed and applied a variety of analytic methodologies, and addressed surface and groundwater systems and water withdrawals by multiple sectors at different levels of detail (national, regional, and watershed). A large body of scientific literature on water resources and water quality management parallels these studies.

Objective

• To provide an overview of the wide variety of analytic tools and approaches for watershed assessment and management documented in the published literature, including several prior EPRI reports.
• To present water resource concerns relevant to the electric power industry, and relate them to appropriate types of analyses using illustrative scenarios and calculations.

Approach

The project team reviewed water resource regulatory drivers and planning needs and described relevant watershed processes at different spatial and temporal scales. The report includes examples of indicator analyses, including the application of national-scale water sustainability evaluation updated from prior EPRI work. It also presents examples of water budget analyses, including application to three regions in the U.S. (river basins in the South-Atlantic and the Southwest, and a groundwater basin in the Southwest). The project team performed dynamic modeling analyses on two of these watersheds, demonstrating additional data needs and outputs associated with this level of analysis. The report also includes a summary of the approaches used in long-range planning studies-as opposed to those required by current regulatory requirements-in several states that have published such plans. The project team also reviewed the strengths and weaknesses of the different analytical approaches.

Results

Sophisticated tools for hydrology and water quality assessment, management and regulatory compliance are commonly available. A key resource need with respect to their application relates to data collection and calibration. A recommended approach to analysis is to evaluate benefits and costs of progressing analytic levels of complexity. Examples provided in this report illustrate applications to specific regions and watersheds, and demonstrate how managers can gain additional insights by performing progressively more detailed analyses. However, an important finding is that increasing the complexity of the analysis does not necessarily improve its quality, and a user must always question whether the study objectives and available data justify additional complexity.

EPRI Perspective

There is a rapidly increasing concern about how society in the United States will manage growing constraints on its use of water resources. These constraints impact all societal and economic sectors, especially the electric power industry, which is the largest withdrawer of freshwater in the U.S. Since the turn of the century, EPRI has conducted research on assessment and management of constrained water resources and development of technologies to increase water use efficiency in electric generation. In addition to conducting this research (often in cooperation with government agencies), EPRI has actively transferred its results to EPRI members, government agencies and legislatures, professional societies, and various stakeholder groups. EPRI believes that through a vigorous research and outreach effort there is tremendous potential to increase the efficacy of water saving technologies and strategies while reducing energy and dollar costs.