Water and Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Simulating the Regulated Rivers of California’s West Slope Sierra Nevada

California Energy Commission (CEC) | August 7th, 2012

Climate warming is expected to affect the beneficial uses of water in the Sierra Nevada, impacting nearly every resident of California. This paper describes the developme

Climate warming is expected to affect the beneficial uses of water in the Sierra Nevada, impacting nearly every resident of California. This paper describes the development and results from an integrated water resource management model encompassing water operations and hydropower generation for the west slope Sierra Nevada spanning the Feather River basin in the north to the Kern River basin in the south at the weekly time step. This model application includes management of reservoirs, run-of-river hydropower plants, water supply demand locations, conveyances, and instream flow requirement. Model validation indicates that most major hydropower turbine flows were simulated well, with wetter years modeled more effectively than drier years. The results of this work indicated that hydropower generation will be reduced by approximately 8 percent with 6°C (10.8°F) warming, consistent with other studies, with a conservative parameterization of no change in precipitation. Reservoir operations adapt to capture earlier and greater runoff volumes that result from earlier and greater runoff due to climate warming. Seasonal compensation in operations is insufficient to overcome warming mediated losses.

Water and Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Water Year Classification in Non?Stationary Climates

California Energy Commission (CEC) | July 31st, 2012

This paper explores the sensitivity of water indexing methods to climate change scenarios to better understand how water management decisions and allocations will be affe

This paper explores the sensitivity of water indexing methods to climate change scenarios to better understand how water management decisions and allocations will be affected by climate change. Many water management decisions, such as environmental flow requirements and water supply allocations, are based on numerical “water year type” designations. Water year type designations vary by region and index, but most are defined by some measure of runoff in the current water year compared to average historical runoff, with numerical thresholds categorizing year types. Climate change is anticipated to alter the timing and volume of runoff, and change the relative frequency of water year types as presently defined. California’s Sacramento Valley and San Joaquin Valley Indices are used as a case study to examine climatic changes. These indices provide a framework for allocating and transferring water among users. Streamflow estimates for 1951–2099 from the climate-forced Variable Infiltration Capacity hydrologic model are used to estimate potential changes in runoff and water year type frequency, using six global circulation models for the A2 and B1 emissions scenarios. Results vary by emissions scenario and global circulation model, but indicate that critically dry water years in the Sacramento Valley and San Joaquin Valley are expected to be about 8 percent and 32 percent more likely by the latter half of the twenty-first century, respectively, if water year type definitions remain unchanged. If current water year type thresholds are maintained, more years will be classified as dry and less water will be allocated for environmental outflows, perhaps failing to provide adequate hydrologic variability to support species, habitats, and ecosystems. If thresholds are redefined to reflect the historical distribution of year types, the burden of climate change falls to consumptive users and water exporters. This case study illustrates how water policy and allocation frameworks were designed assuming climatic stationarity, and that adapting water policy (or maintaining the status quo) affects which users bear the burden of climate change.

Water Power in California: The factors on which it depends, and the extent to which it might be utilized

Scientific American | April 26th, 1919

Water-Energy Synergies: Coordinating Efficiency Programs in California

Pacific Institute | September 4th, 2013

All forms of energy – from hydropower to solar panels – use water to extract and process the fuels, construct the processing facilities, or generate the electricity.

All forms of energy – from hydropower to solar panels – use water to extract and process the fuels, construct the processing facilities, or generate the electricity. Likewise, water supply, treatment, use, and disposal use considerable amounts of energy. Coordinating water-energy efficiency efforts provides a significant opportunity to achieve greater savings for both water and energy utilities and for their customers, according to a new study from the Pacific Institute: Water-Energy Synergies: Coordinating Efficiency Programs in California. Recent events have made the connections between water and energy very visible. The Rim Fire has burned large sections of the Tuolumne River watershed and along several miles of the Hetch Hetchy Reservoir, affecting the water and energy supply of San Francisco and other Bay Area communities. Similarly in Southern California, the recent closure of the San Onofre Nuclear Generating Station has raised concerns about meeting regional energy needs, particularly during the hot summer months, when electricity and water demand are especially high. But while these events demonstrate some of the challenges associated with the water-energy connection, they also highlight some of the opportunities: namely that saving water saves energy – and using less energy in turn saves even more water – reducing our vulnerability to both water and energy constraints. To better understand the barriers to coordinating water and energy efficiency programs, the Pacific Institute interviewed and surveyed California water and energy managers. The managers reported the most significant barriers were associated with funding, limited staff time, uncertainty about how to allocate costs and benefits among project partners, and water-related pricing policies, as well as an absence of established relationships between potential water and energy partners. “We examine the barriers to coordinated water and energy efficiency programs and discuss, through case studies, ways that several California utilities have been able to overcome these barriers,” said Heather Cooley, co-director of the Pacific Institute Water Program. “Coordinating programs can be an important tool to meet efficiency goals, allowing the state to meet critical policy objectives and saving Californians’ money.”

Water, energy and environment nexus: The California experience

International Journal of Water Resources Development (Taylor & Francis) | July 21st, 2010

The paper addresses the local and inter-state connections between water, energy and the environment. Using California and the western USA as a case study, the paper highl

The paper addresses the local and inter-state connections between water, energy and the environment. Using California and the western USA as a case study, the paper highlights the difficulties of balancing the needs of diverse stakeholders and protecting valuable resources while providing reliable and safe supplies of both water and energy to agricultural, industrial and residential customers. The investigation of these complex relationships is necessary to inform local and national policy decisions regarding the management of water, energy and the environment.

WESim – The Water-Energy Simulator – Helps Water and Energy Managers Plan for Change

Pacific Institute | July 5th, 2012

The Water–Energy Simulator (WESim) is an easy-to-use analytical tool that can be used to evaluate the energy and greenhouse gas implications of water management decisio

The Water–Energy Simulator (WESim) is an easy-to-use analytical tool that can be used to evaluate the energy and greenhouse gas implications of water management decisions. The Excel-based model allows the user to explore a range of possible scenarios, such as increased demand for water resources, the development of alternative water and energy sources, and needed water treatment improvements resulting from emerging contaminants and stricter water-quality guidelines. WESim can be applied by individual water and energy utilities, groups of utilities, and policymakers and decision makers. A WESim User Manual and report, Implications of Future Water Supply Sources for Energy Demands, are provided, as well. Water provision and use require energy in all phases, from source extraction to the discharge of wastewater. Multiple factors will influence the energy intensity of the water sector in the near future: climate change will affect water supply, quality, and demand, potentially creating a need for new energy-intensive supply and treatment options; population growth, water use patterns, technology, and price all will affect water demand; and emerging contaminants may require more energy-intensive treatment technologies. These trends highlight the need for a clear and consistent methodology for evaluating the energy and greenhouse gas implications of water management decisions. WESim addresses this need, as a tool that creates a common framework in which to explore alternative scenarios. The model is designed to allow you to input actual operating data on water and energy use, allowing for an analysis that better reflects operating conditions. To facilitate use of the model, defaults for the energy requirements of various components of the water and wastewater system are provided, as well. WESim was developed by The Pacific Institute and Dr. Bob Wilkinson, with support from the WateReuse Research Foundation, the California Energy Commission, and the Canadian Mortgage and Housing Corporation.