Climate Action Plan Phase 1 Greenhouse Gas Emissions Reduction Plan Update 2023

California Department of Water Resources (DWR) | March 22nd, 2024

DWR developed the Greenhouse Gas Emissions Reduction Plan Update 2023 (Update 2023) to review its GHG reductions since Update 2020 and to update strategies for further re

DWR developed the Greenhouse Gas Emissions Reduction Plan Update 2023 (Update 2023) to review its GHG reductions since Update 2020 and to update strategies for further reduction consistent with legislative changes, including the GHG emissions reduction targets established in SB 1020 (2022) and SB 1203 (2022). It also includes DWR’s new role in emergency energy generation. Since the 2012 Plan was adopted, California’s wholesale electricity market has also seen a significant increase in renewable resources. To reflect this change and to align with industry practice in emission reporting, Update 2023 incorporates updated emission factors to determine emissions from unspecified market resources.

Climate Change and Water Supply Security: Reconfiguring Groundwater Management to Reduce Drought Vulnerability

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

Periodic droughts, projected to become more frequent and severe with climate change, present a significant planning challenge for California’s water agencies. This r

Periodic droughts, projected to become more frequent and severe with climate change, present a significant planning challenge for California’s water agencies. This research examined approaches to reducing drought vulnerability, focusing on five water agencies on California’s north and central coast that rely on local and regional sources of water. Curtailing water use is the principal response to drought. In contrast, this project highlights an important but underutilized proactive adaptation to improve water supply security during drought: the development of locally based groundwater drought reserves. While this approach represents an obvious solution in principle, it is uncommon to find it in practice, and this research provides insight into (1) motivating factors, (2) legal barriers and opportunities, (3) tools, and (4) policy options to support increased drought resilience and the development of drought reserves.

Climate Change Effects on the High-Elevation Hydropower System with Consideration of Warming Impacts on Electricity Demand and Pricing

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

While only about 30 percent of California’s usable water storage capacity lies at higher elevations, high-elevation hydropower units generate, on average, 74 percent of

While only about 30 percent of California’s usable water storage capacity lies at higher elevations, high-elevation hydropower units generate, on average, 74 percent of California’s instate hydroelectricity. In general, high-elevation plants have small man-made reservoirs and rely mainly on snowpack. Their low built-in storage capacity is a concern with regard to climate warming. Snowmelt is expected to shift to earlier in the year, and the system may not be able to store sufficient water for release in high-demand periods. Previous studies have explored the climate warming effects on California’s high-elevation hydropower system by focusing on the supply side (exploring the effects of hydrological changes on generation and revenues) but they have ignored the warming effects on hydropower demand and pricing. This study extends the previous work by simultaneous consideration of climate change effects on high-elevation hydropower supply and demand in California. Artificial Neural Network models were developed as long-term price estimation tools, to investigate the impact of climate warming on energy prices. California’s Energy-Based Hydropower Optimization Model (EBHOM) was then applied, to estimate the adaptability of California’s high-elevation hydropower system to climate warming, considering the warming effects on hydropower supply and demand. The model was run for dry and wet warming scenarios, representing a range of hydrological changes under climate change. The model’s results relative to energy generation, energy spills, reservoir energy storage, and average shadow prices of energy generation and storage capacity expansion are examined and discussed. The modeling results are compared with previous studies to emphasize the need to consider climate change effects on hydroelectricity demand and pricing when exploring the effects of climate change on California’s hydropower system.

Climate change impacts on water resources and hydropower potential in the Upper Colorado River Basin

Journal of Hydrology (Elsevier) | April 23rd, 2015

Precipitation projections from climate models vary up to 16%; flow projections revealed greater differences, up to 50%. The climate models projected increase in t

Precipitation projections from climate models vary up to 16%; flow projections revealed greater differences, up to 50%. The climate models projected increase in temperature at low elevations with extreme seasonality at high elevations, although summer temperatures increased at all elevations. The models projected a 60% decline in precipitation at lower elevations and a 74% increase at high elevations, although precipitation declined during the summer months at all elevations. Using the A2 scenario an overall decrease in annual flow was predicted, attributed to a reduction in precipitation and increasing temperature trends; however, this was not consistent during the winter months, which showed an increase in precipitation at high elevations and a modest temperature increase during the winter and resulted in an increase in stream flow. The responses to climate change on reservoir levels varied basin-wide due to variability in precipitation, evapotranspiration, and stream flow. Simulations indicated that water levels in Blue Mesa Reservoir (the largest reservoir in the UCRB) would decline by more than 70% with increasing annual temperatures. Reservoirs with smaller surface areas to the volume ratio were not significantly impacted by evapotranspiration. Our results indicate that hydropower management strategies in the UCRB must adapt to potential climate change, but the required adaptations are dependent on several factors including reservoir size and location.

Connecting the dots between water, energy, food, and ecosystems issues for Integrated Water Management in a changing climate

California Department of Water Resources (DWR) | March 7th, 2017

Global climate change creates critical challenges through increasing temperature, reducing snowpack, and changing precipitation for water, energy, and food, as well as fo

Global climate change creates critical challenges through increasing temperature, reducing snowpack, and changing precipitation for water, energy, and food, as well as for ecosystem processes at a regional scale. The water, energy, and food (WEF) nexus and related ecosystems have complex linkages with climate change implications. The overall objectives of this white paper are to provide background on this important subject, and help local water managers and the public better understand: *The ecosystem services for water, energy, and food in a changing climate. *The water-energy nexus and related climate change mitigation actions in California. *The energy used in California’s water sector and estimates of the energy intensity of regional water supplies. Particularly, this paper largely consolidates the water-energy content originally published in California Water Plan Update 2013 (Volumes I, II, and III), which included: *A framework for the energy intensity of California water systems. *An estimate of the regional energy intensity of water supplies. *Water-energy related climate change mitigation policies and actions. *Climate change mitigation benefits and tradeoffs associated with each of the 30 Resource Management Strategies found in Volume III. Furthermore, this paper will explore how water, energy, food, and climate change are interconnected with ecosystems, and why we need to understand these connections and identify the information gaps and related challenges and opportunities for ecosystem services in multiple sectors. Ecosystem services provide life support, goods, and natural resources in water, energy, and food, as well as environments. These are knowledge gaps for lack of conceptual framework and practices to interlink major climate change drivers of water resources with water-energy-food nexus and related ecosystem processes. This white paper provides information review and a conceptual framework to bridge these knowledge gaps. The case studies summarized in this paper indicate there is a large variation in energy intensities for groundwater and federal, state, and local water supplies, both within each hydrological region and among the 10 hydrological regions in California. Regional decisions were critically important in addressing water-energy conflicts and meeting local climate change challenges. These examples can be applicable for the United States and other countries with similar climate change challenges that use diversity of regional water resources for energy and food production. Future interdisciplinary research and support could bridge information and data gaps that are important for using best management practices to obtain efficiency of water, energy, and food systems related to climate change. The increased regional temperature, changes in snowpack and precipitation, and increased water stresses from drought can reduce ecosystem services and affect the water and energy nexus, agricultural food production, and fish and wildlife habitats in California. Regional decisions and practices in integrated management of water, energy, food, and related ecosystem processes are essential to adapting to and mitigating global climate change effects. Science and policy support for interdisciplinary research are critical in developing databases and tools for comprehensive analysis to fill knowledge gaps and address ecosystem service complexity, related natural resource investment, and integrated planning needs. There are significant challenges and opportunities in California to use integrated water management for water, energy, food, and the environment related to climate change. The California Water Action Plan and California Water Plan Update provide a road map and resource management strategies to use integrated water resource management for the multiple benefits of these sectors. The examples and case studies in this white paper have been used to identify information gaps and address related complexity and challenges. Questions posed in this paper regarding water and energy related to the food production cycle need further research and discussion. Overall, we should identify opportunities for innovation and technologies with multiple benefits, evaluate tradeoffs, and address integrated challenges in water, energy, food, and the environment to adapt and mitigate climate change.

Curbing the Colorado

Scientific American | April 1st, 1922

Already, the electrical engineer has shown how the snows of the high Sierras can be transformed into energizing current distributable for hundreds of miles through a S

Already, the electrical engineer has shown how the snows of the high Sierras can be transformed into energizing current distributable for hundreds of miles through a State which i s notably deficient in deposits of power-producing coal. Similarly, this same technicist is busy planning ways by which the widely diversified flow of the second largest of our rivers, the Colorado, may be stabilized and utilized to operate a number of immense, hydroelectric stations. The Colorado River drains a watershed covering fully 250,000 square miles, and in the course of a twelvemonth its run-off  amounts to 16,000,000 acre-feet of water. The States affected by the movement of the Colorado are Nevada, Utah, Wyoming, Colorado, New Mexico, and California. Normally, the Colorado runs to extremes : in dry seasons it is low and its speed of travel comparatively sluggish, but when the melting snows and rains of the wet months pour their fullness into the far-flung basin the river becomes a raging, torrential stream capable of doing an enormous amount of damage. Uncontrolled, this great waterway is a continual menace to the lives and the property of dwellers in the Imperial Valley and in the adjacent lands, lying below the level of the sea and situated both in the United States and in Mexico.

Death Valley lower carbonate aquifer monitoring program—Wells down gradient of the proposed Yucca Mountain nuclear waste repository: U.S. Department of Energy Cooperative Agreement DE-FCO8-02RW12162 Final Project Report

Inyo County | July 1st, 2005

Death Valley regional ground-water flow system, Nevada and California—Hydrogeologic framework and transient ground-water flow model

U.S. Geological Survey (USGS) | July 1st, 2010

A numerical three-dimensional (3D) transient groundwater flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Ener

A numerical three-dimensional (3D) transient groundwater flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the groundwater flow system and previous less extensive groundwater flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect groundwater flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley regional groundwater flow system (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the groundwater flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural groundwater discharge occurring through evapotranspiration (ET) and spring flow; the history of groundwater pumping from 1913 through 1998; groundwater recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were provided by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional groundwater flow system. Groundwater flow in the Death Valley region is composed of several interconnected, complex groundwater flow systems. Groundwater flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional groundwater flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and ET are the dominant natural groundwater discharge processes. Groundwater also is withdrawn for agricultural, commercial, and domestic uses. Groundwater flow in the DVRFS was simulated using MODFLOW-2000, the U.S. Geological Survey 3D finitedifference modular groundwater flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 meters (m) on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins simulated by constant-head boundaries. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient model generally fit observed heads reasonably well (residuals with absolute values less than 10 meters) with two exceptions: in most areas of nearly flat hydraulic gradient the fit is considered moderate (residuals with absolute values of 10 to 20 meters), and in areas of steep hydraulic gradient along the Eleana Range and western part of Yucca Flat, southern part of the Owlshead Mountains, southern part of the Bullfrog Hills, and the north-northwestern part of the model domain (residuals with absolute values greater than 20 meters). Groundwater discharge residuals are fairly random, with as many areas where simulated flows are less than observed flows as areas where simulated flows are greater. The highest unweighted groundwater discharge residuals occur at Death Valley, Sarcobatus Flat (northeastern area), Tecopa, and early observations at Manse Spring in Pahrump Valley. High weighted-discharge residuals were computed in Indian Springs Valley and parts of Death Valley. Most of these inaccuracies in head and discharge can be attributed to insufficient representation of the hydrogeology in the HFM and(or) discharge estimates, misrepresentation of water levels, and(or) model error associated with grid-cell size. The model represents the large and complex groundwater flow system of the Death Valley region at a greater degree of refinement and accuracy than has been possible previously. The representation of detail provided by the 3D digital hydrogeologic framework model and the numerical groundwater flow model enabled greater spatial accuracy in every model parameter. The lithostratigraphy and structural effects of the hydrogeologic framework; recharge estimates from simulated net infiltration; discharge estimates from ET, spring flow, and pumping; and boundary inflow and outflow estimates all were reevaluated, some additional data were collected, and accuracy was improved. Uncertainty in the results of the flow model simulations can be reduced by improving on the quality, interpretation, and representation of the water-level and discharge observations used to calibrate the model and improving on the representation of the HGU geometries, the spatial variability of HGU material properties, the flow model physical framework, and the hydrologic conditions.

Desalination Plant Entrainment Impacts and Mitigation

California State Water Resources Control Board (SWRCB) | October 9th, 2013

Raw seawater is used for a variety of purposes, including as source water for desalination plants and to cool coastal power plants. Raw seawater is, however, not just col

Raw seawater is used for a variety of purposes, including as source water for desalination plants and to cool coastal power plants. Raw seawater is, however, not just cold and salty but an ecosystem that contains diverse and abundant organisms including the young stages of numerous invertebrates and fishes. Whether impinged (large individuals stuck on screens prior to entering the plant or killed during other plant processes such as heat treatment) or entrained (small individuals carried into the plant with the water) the organisms are killed, essentially eliminating the living production in the water used (review in York and Foster 2005). Considerable research has have been done in California to better estimate losses to this ecosystem by coastal power plant intakes (York and Foster 2005, Steinbeck et al. 2007), and to determine how these losses can be mitigated (Strange et al. 2004). The information from this research has contributed to State of California policy regulating water used by power plants.

Energizing Water Efficiency: California Energy Sector Experiences Can Advance State’s Water Conservation and Efficiency

Pacific Institute | December 29th, 2013

As a dry December accentuates the stress on California’s limited water supplies, the success of the state’s energy sector in implementing efficiency programs offers v

As a dry December accentuates the stress on California’s limited water supplies, the success of the state’s energy sector in implementing efficiency programs offers valuable lessons to the water sector. A new report from the Pacific Institute examines the rules, regulations, and policies that promote energy efficiency and finds models for water management in drivers like the energy sector’s appliance standards, building codes, pricing policies, and utility-sponsored efficiency programs. California has made remarkable improvements in energy efficiency over the last several decades and is recognized as a national leader. The state’s per capita electricity and natural gas consumption is about 45% and 30% less, respectively, than other Americans. Indeed, California’s per capita electricity consumption has remained largely unchanged since the mid-1970s – while increasing by more than 50% across the U.S.  Efficiency policies, including incentive and education programs, have been a major factor in reducing per capita energy use in California. In water conservation and efficiency, California has also made major advances. Many urban areas across the state, including Los Angeles and San Francisco, are serving a larger population with the same or even less water than 20 years ago. But with increasing pressure on water supply from population and economic growth, the need to restore freshwater ecosystems, and climate change, greater water conservation and efficiency are essential. “Reductions in per-capita water demand have been driven first by a shift to a less water-intensive service-oriented economy, and second by federal, state, and local policies as well as utility programs facilitating water-efficiency improvements,” said Heather Cooley, co-director of the Pacific Institute Water Program. “We must examine new approaches for achieving even greater savings to address the water challenges we now face.” The Pacific Institute report identifies programs that have worked for the energy sector and offers recommendations for how they could be adapted to the water sector. First among them are to continuously update standards and codes for fixtures and buildings to capture new technologies and practices.