Technical Guidance for Incorporating Climate Change Information into Water Resources Planning Studies

U.S. Bureau of Reclamation (USBR) | ?

The impacts of climate change are being felt across the Western United States. Warming is affecting water supplies by changing the overall annual volume of precipitation

The impacts of climate change are being felt across the Western United States. Warming is affecting water supplies by changing the overall annual volume of precipitation and altering the balance of rain versus snowfall. Communities are facing increasing problems with water availability and drought, flooding, and increased risk of forest fires. The requirements established by Secretarial Order 3289, Departmental Manual 523 DM 1, Executive Order 13653, and Reclamation’s Directives and Standards CMP 09-02 for feasibility studies reinforces the need for Reclamation's on-going programs to be more resilient to the impacts of climate change and for continued efforts to incorporate climate change information into aspects of our mission where it has not been fully considered in the past such as in decisions regarding ecosystem restoration, reservoir operations, infrastructure investments and planning capacity. This document is an important step to reinforcing Reclamation’s planning capacity by providing guidance to help study teams navigate the range of planning and technical methods available to account for climate change impacts in feasibility studies. The effects of climate change have altered and will continue to alter the basic assumptions underlying Reclamation’s water resources planning. Effective water management and planning rely on an understanding of climate change impacts on water supply, demand, and criteria that govern or guide water management. The guidance in this document may also be applied to environmental compliance studies since they are typically conducted concurrently with feasibility studies. The guidance is organized around the planning and technical framework for conducting a feasibility study as detailed in CMP 09-02, and which occurs in two phases: the scoping phase and the alternative formulation and evaluation phase.

Temescal Basin Groundwater Sustainability Plan

Temescal Basin Groundwater Sustainability Agency | January 27th, 2022

Wishing to provide a framework for cooperative groundwater management and SGMA compliance, the City of Corona (Corona), City of Norco (Norco), and the Home Gardens Coun

Wishing to provide a framework for cooperative groundwater management and SGMA compliance, the City of Corona (Corona), City of Norco (Norco), and the Home Gardens County Water District (HGCWD) executed a Memorandum of Understanding (MOU) in March 2017 establishing the Temescal Basin Groundwater Sustainability Agency (Temescal GSA). In August 2017, the Temescal GSA became the GSA for the Basin by submitting a formation notice to DWR. While Corona is leading this effort, the GSP will be developed jointly among the three agencies, with coordinated implementation toward sustainable management. Due to size, the file has been divided into four parts. Part 1, Part 2, Part 3, Part 4

Temporary Restraining Order in Kings County Farm Bureau et al v. California State Water Resources Control Board

Superior Court of California, County of Kings | July 11th, 2024

Tentative Ruling, Friant Water Authority vs. Eastern Tule Groundwater Sustainability Agency

Superior Court of California, County of Tulare | June 25th, 2024

The 1991 Drought Water Bank

California Department of Water Resources (DWR) | January 1st, 1991

This report, produced by the Department of Water Resources, provides a retrospective of the operations of the 1991 Drought Water Bank.

This report, produced by the Department of Water Resources, provides a retrospective of the operations of the 1991 Drought Water Bank.

The 2025-26 Budget: Proposition 4 Spending Plan

Legislative Analyst's Office (LAO) | February 12th, 2025

The Ahwahnee Water Principles

Local Government Commission | July 1st, 2006

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at the local level. The LGC invited respected water resource policy, management and planning professionals – with experience at the federal,state and local levels – to craft a set of land use principles which would provide guidance to local officials and communities concerned about sustaining future water supplies. The process of developing the Ahwahnee Water Principles mirrored the LGC’s earlier Ahwahnee Principles for Resource-Efficient Communities, which were released in 1991. The Ahwahnee Principles presented a blueprint for elected officials to create compact, mixed-use,walkable,transit-oriented developments in their local communities,and have since paved the way for growing acceptance and inclusion of “smart growth”and the “New Urbanism”in local and regional land-use policies and practices.

The Application of Ground-Water Flow Models as Predictive Tools—A Review of Two Ground-Water Models of Eastern Honey Lake Valley, California-Nevada

Geological Society of America (GSA) | January 9th, 1992

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of the arid Honey Lake Valley to the rapidly growing Reno-Sparks area. The proposed project is known as the Truckee Meadows Project (TMP). Honey Lake Valley is 35 mi north of Reno, Nevada; but is located predominantly in California. Computer groundwater models of the valley were prepared by the USGS and the TMP proponents and presented to the Nevada State Engineer to evaluate the impacts of the proposed exportation of 15,000 ac-ft annually from eastern Honey Lake Valley. By using assumptions, numbers, and data which are not justified by the scientific data, both models place unreasonable and, in some instances, artificial constraints on the geology and hydrogeology of the groundwater system rather than allowing the geology and hydrogeology to constrain the models. Neither model is useful as a predictive tool. However, the major problems with the two models fall into two fundamentally different classes. The USGS model exceeded the technical limitations of the model code and made large, inappropriate adjustments to the water budget to compensate for these undetected errors. The TMP model used a water budget that was not technically justified or explained and placed the spatial distribution of ground-water recharge and discharge beyond the realm of hydrogeologic reality.  

The Basin Characterization Model—A Regional Water Balance Software Package

U.S. Geological Survey (USGS) | March 22nd, 2021

This report documents the computer software package, Basin Characterization Model, version 8 (BCMv8)—a monthly, gridded, regional water-balance model—and provides det

This report documents the computer software package, Basin Characterization Model, version 8 (BCMv8)—a monthly, gridded, regional water-balance model—and provides detailed operational instructions and example applications. After several years of many applications and uses of a previous version, CA-BCM, published in 2014, the BCMv8 was refined to improve the accuracy of the water-balance components, particularly the recharge estimate, which is the most difficult to accurately assess. The improvement of the various water-balance components targeted the actual evapotranspiration component, which, in turn, reduced the uncertainty of the recharge estimate. The improvement of this component was enabled by the availability of a national, gridded actual-evapotranspiration product from the U.S. Geological Survey that was unique in its scope to combine remotely sensed spatial variability and ground-based long-term water-balance constraints. This dataset provided the ability to assess monthly actual evapotranspiration for 62 vegetation types and to perform regional calibration in watersheds throughout California with the objective of closing the water balance using improved estimates for each component. The refinements, including vegetation-specific evapotranspiration, enabled the development of applications that could explore various aspects of landscape disturbance, such as wildfire, forest management, or urbanization. The improvements to BCMv8 also provided the ability to assess long-term sustainability of water resources under a variety of management applications or future climate projections.

The Benefits of Headwater Forest Management

Public Policy Institute of California (PPIC) | April 1st, 2020

Forests in California are increasingly vulnerable to major wildfires and droughts that threaten the benefits they provide. Improving the health of headwater forests in th

Forests in California are increasingly vulnerable to major wildfires and droughts that threaten the benefits they provide. Improving the health of headwater forests in the Sierra, in particular—where most of the state’s surface water supplies originate—will provide an array of social, economic, and environmental benefits across multiple sectors and geographies. Research by forest ecologists and wildfire behavior experts finds that the best way to realize these benefits is to reestablish and maintain lower densities of trees, which will help make these forests more resilient to fire, drought, and pests.  Healthier forests can support rural communities, reduce air quality impacts from wildfires, securely store carbon and reduce greenhouse gas emissions, protect water quality from post-fire erosion, and increase water supply. The broad base of beneficiaries of headwater forest management includes rural communities in the headwater region, regions that are vulnerable to smoke impacts from major wildfires, and major urban areas and agricultural regions that receive water and hydropower from headwater forests.  Improving forest health will require a substantial lift from an array of private and public entities—along with new policies and sources of funding to facilitate complex, collaborative management. Clarifying the benefits and beneficiaries of forest management is a critical step in motivating long-term stewardship, and will inform efforts to craft financial tools, policies, and other governance solutions needed to make this heavy lift. By assessing what is known about the benefits of forest management, this report provides crucial information for ongoing policy discussions on long-term stewardship of California’s headwater forests.