Implementing California Flood Legislation into Local Land Use Planning: A Handbook for Local Communities

California Department of Water Resources (DWR) | October 1st, 2010

The potential for flooding is a significant risk for many localities in California. Flood events can cause substantial economic, social, and environmental damage. In addi

The potential for flooding is a significant risk for many localities in California. Flood events can cause substantial economic, social, and environmental damage. In addition, many flood management practices can be costly and have considerable effects on the environment. One of the most effective ways to reduce the vulnerability to potential flooding is through careful land use planning that is fully informed by and reflective of applicable flood information and flood management practices. This Handbook supports the Department of Water Resources (DWR) FloodSAFE California initiative, which is a statewide initiative to improve public safety through an integrated approach to flood management. Several bills were signed by Governor Schwarzenegger in 2007 adding to and amending State flood and land use management laws. These new laws are intended to improve local land use and other planning decisions by strengthening the link between land use and flood management. The laws contain requirements and considerations that outline a comprehensive approach to improving flood management at the State and local levels. This Handbook includes the 2007 California flood risk management legislation affecting cities’ and counties’ responsibilities related to local planning requirements such as general plans, zoning ordinances, development agreements, tentative maps, and other actions. It does not address all flood management related legislation passed in 2007. For a complete summary of California flood legislation passed in 2007, refer to the 2007 California Flood Legislation Summary and Companion Reference issued by DWR at http://www.water.ca.gov/legislation/2007-summary. pdf and http://www.water.ca.gov/legislation/2007-reference.pdf.

Implementing California’s Sustainable Groundwater Management Act (SGMA): Implementing California’s Sustainable Groundwater Management Act (SGMA)

Ostrom Workshop Colloquium Presentation | February 29th, 2016

This research effort is guided by the following overarching research question: What can be learned from existing groundwater management arrangements in Californ

This research effort is guided by the following overarching research question: What can be learned from existing groundwater management arrangements in California — adjudications, special act districts, and select AB 3030 planning processes and county ordi nances — to inform the creation of durable, sustainable groundwater management plans under California’s new Sustainable Groundwater Management Act? The current and planned research described in this presentation is being conducted with a team of researche rs at Stanford University’s Woods Institute on the Environment, Water in the West Program, and Gould Center on Dispute Resolution. Preliminary work is being supported by a grant from Stanford’s Environmental Ventures Program (Janet Martinez, PI).

Implementing Climate-Smart Conservation

Public Policy Institute of California (PPIC) | March 4th, 2025

In our first report, Climate-Smart Tools to Protect California’s Freshwater Biodiversity (Sommer et al. 2024), we reviewed a broad suite of tools available to a

In our first report, Climate-Smart Tools to Protect California’s Freshwater Biodiversity (Sommer et al. 2024), we reviewed a broad suite of tools available to address the urgent problem of safeguarding California’s freshwater biodiversity in the changing climate. This toolbox includes some familiar approaches—such as various ways to improve freshwater habitat—as well as approaches that may be less familiar, more experimental, and more controversial. We also recommended the adoption of a climate-smart conservation planning process, involving a broad range of stakeholders, to prioritize the selection of tools within watersheds and to adaptively implement those tools. In this follow-up report, we explore the feasibility of implementing these tools and climate-smart planning in light of legal, policy, and institutional factors.2 Our analysis draws on an extensive review of the legal literature on ecosystem and protected species management, as well as interviews and small workshops with a wide-ranging set of 45 experts from all over the state. These experts are working on the frontlines of ecosystem policy and management; they include state and federal regulators, members of the environmental conservation community, legal professionals, and representatives of many entities involved in water and land management.

Implementing Ecosystem Based Management

Duke Environmental Law & Policy Forum | June 7th, 2021

Implementing Environmental Justice: The New Agenda for California State Agencies

Golden Gate University (GSU) | January 1st, 2001

On October 6, 1999, Governor Gray Davis signed SB 115, the first bill explicitly enacting an environmental justice policy into California's statutes.  The bill defines "

On October 6, 1999, Governor Gray Davis signed SB 115, the first bill explicitly enacting an environmental justice policy into California's statutes.  The bill defines "environmental justice" as: "the fair treatment of people of all races, cultures, and incomes with respect to the development, adoption, implementation, and enforcement of environmental laws, regulations, and policies." The environmental justice bills signed into law by Governor Davis generally refer to the term "environmental justice" as "fair treatment," but the application of this definition is not spelled out. Rather, the execution of the environmental justice definition is assigned to California's administrative agencies under a procedural scheme coordinated by OPR and  implemented, in part, by Cal EPA.9 As always, the devil is in the details, and state agencies have begun to wrestle with the statutory mandate to achieve environmental justice. The purpose of this article is to give an account of the commencement of this process and to highlight some of the issues presented to the Davis administration. Preliminarily, some background is required for context. The achievement of environmental justice does not start on a fresh slate. Federal statutes and federal executive initiatives impose separate legal requirements. These federal mandates both require actions by California state agencies and provide guidance on how to interpret the new California statutes. Thus, this article begins with an account of the legal and historical development of the concept of environmental justice.

Implementing SGMA: Results from a Stakeholder Survey

University of California, Davis (UC Davis) | August 26th, 2019

The Sustainable Groundwater Management Act (SGMA) of 2014 represents a historic transition to collective groundwater resource management and has the potential to signif

The Sustainable Groundwater Management Act (SGMA) of 2014 represents a historic transition to collective groundwater resource management and has the potential to significantly reduce groundwater overdraft in California. A total of 260 groundwater sustainability agencies (GSAs) recently formed to collectively manage groundwater resources in the 127 high and medium priority groundwater basins of the state. The simultaneous formation of hundreds of new governing agencies is an unprecedented institutional effort with very few examples to learn from. As GSAs move towards the design and deliberation of their groundwater sustainability plans (GSPs), assessments on the process up until now can directly inform development processes that are still taking place. This report summarizes the results from a state-wide survey that targeted SGMA participants.

Implications of projected climate change for groundwater recharge in the western United States

Journal of Hydrology (Elsevier) | March 1st, 2016

Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform

Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100 longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10–20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed, process-based numerical models; (2) a generally poor understanding of hydrologic flowpaths and processes in mountain systems; (3) difficulty predicting the response of focused recharge to potential changes in the frequency and intensity of extreme precipitation events; and (4) unconstrained feedbacks between climate, irrigation practices, and recharge in highly developed aquifer systems.

Implicit and Explicit Biases for Recycled Water and Tap Water

American Geophysical Union (AGU) | May 31st, 2022

Increasing use of recycled water to irrigate agricultural products and decreasing consumption of bottled water are important components of sustainable water management pr

Increasing use of recycled water to irrigate agricultural products and decreasing consumption of bottled water are important components of sustainable water management practices and consumer-driven efforts to improve water security and quality. However, consumers frequently discount agricultural products irrigated with recycled water relative to products irrigated with conventional water and place a premium on bottled water relative to tap water. This study measures consumer attitudes regarding recycled water and bottled water to understand more fully the reasons behind these preferences. We conduct two studies involving 2,616 adult consumers in the United States designed to measure consumer attitudes and preferences: the use of recycled water versus conventional water to irrigate food products and tap water versus bottled water for drinking. In each study, implicit attitudes are measured using an Implicit Association Test as well as explicit attitudes. We find that respondents have negative implicit attitudes regarding recycled water compared to conventional water and tap water compared to bottled water, and a negative explicit attitude toward recycled water. Tap water and food grown with recycled water were believed to be less healthy to consume and less tasty, although these are believed to be more sustainable options. Beliefs about water attributes (i.e., healthfulness, taste, and sustainability) are associated with attitudes, and both beliefs about attributes and attitudes are associated with preferences for products. Further, we find that respondents' stated preferences are consistent with their implicit and explicit attitudes.

Importance of subsurface water for hydrological response during storms in a post-wildfire bedrock landscape

Nature Portfolio (Springer Nature) | June 29th, 2023

Improved Bias Correction Techniques for Hydrological Simulations of Climate Change

American Meteorological Society (AMS) | December 13th, 2015

Global climate model (GCM) output typically needs to be bias corrected before it can be used for climate change impact studies. Three existing bias correction met

Global climate model (GCM) output typically needs to be bias corrected before it can be used for climate change impact studies. Three existing bias correction methods, and a new one developed here, are applied to daily maximum temperature and precipitation from 21 GCMs to investigate how different methods alter the climate change signal of the GCM. The quantile mapping (QM) and cumulative distribution function transform (CDF-t) bias correction methods can significantly alter the GCM’s mean climate change signal, with differences of up to 28C and 30% points for monthly mean temperature and precipitation, respectively. Equidistant quantile matching (EDCDFm) bias correction preserves GCM changes in mean daily maximum temperature but not precipitation. An extension to EDCDFm termed PresRat is introduced, which generally preserves the GCM changes in mean precipitation. Another problem is that GCMs can have difficulty simulating variance as a function of frequency. To address this, a frequency-dependent bias correction method is introduced that is twice as effective as standard bias correction in reducing errors in the models’ simulation of variance as a function of frequency, and it does so without making any locations worse, unlike standard bias correction. Last, a preconditioning technique is introduced that improves the simulation of the annual cycle while still allowing the bias correction to take account of an entire season’s values at once.