Design Life Level: Quantifying risk in a changing climate

American Geophysical Union (AGU) | September 23rd, 2013

In the past, the concepts of return levels and return periods have been standard and important tools for engineering design. However, these concepts are based on theassu

In the past, the concepts of return levels and return periods have been standard and important tools for engineering design. However, these concepts are based on theassumption of a stationary climate and do not apply to a changing climate, whether local orglobal. In this paper, we propose a refined concept, Design Life Level, which quantifies risk in a nonstationary climate and can serve as the basis for communication. In current practice, typical hydrologic risk management focuses on a standard (e.g., in terms of a high quantile corresponding to the specified probability of failure for a single year). Nevertheless, the basic information needed for engineering design should consist of (i) the design life period (e.g., the next 50 years, say 2015–2064); and (ii) the probability (e.g., 5% chance) of a hazardous event (typically, in the form of the hydrologic variable exceeding a high level) occurring during the design life period. Capturing both of these design characteristics, the Design Life Level is defined as an upper quantile (e.g., 5%) of the distribution of the maximum value of the hydrologic variable (e.g., water level) over the design life period. We relate this concept and variants of it to existing literature and illustrate how they, and some useful complementary plots, may be computed and used. One practically important consideration concerns quantifying the statistical uncertainty in estimating a high quantile under nonstationarity.

Designing Effective Groundwater Sustainability Agencies: Criteria for Evaluation of Local Governance Options

Center for Law, Energy, and the Environment (CLEE) | ?

With the passage of the Sustainable Groundwater Management Act (SGMA)1 in 2014, California took a historic step towards managing the state’s groundwater resources. SGMA

With the passage of the Sustainable Groundwater Management Act (SGMA)1 in 2014, California took a historic step towards managing the state’s groundwater resources. SGMA adopts a state policy of managing groundwater resources “sustainably for long-term reliability and multiple economic, social, and environmental benefits for current and future beneficial uses.”2 Although these ambitious goals are critical to California’s future water security and sustainablility, major questions remain about how to achieve them. Designing institutions for sustainable groundwater management is one of the most pressing challenges for SGMA implementation. Local entities in mediumand high-priority basins must establish Groundwater Sustainability Agencies (GSAs) by June 2017. GSA design and structure will play a critical role in meeting the sustainability goals required by SGMA. Because designing new institutions for good governance is not easy, the need for information and guidance is acute. SGMA leaves great latitude for local decision making. Primary responsibility for groundwater governance lies with GSAs, to be established by local entities in groundwater basins or sub-basins. SGMA does not specify the details for institutional design of GSAs, nor what specific governance actions must be taken to achieve sustainable groundwater management. Instead, the legislation provides an array of regulatory and non-regulatory tools—mostly optional—from which GSAs can choose. Those tools, in addition to existing authorities already available to local agencies, will provide the basis for groundwater governance in each basin. The relatively short timeline for GSA formation requires local governments and other stakeholders to analyze available options and decide, quickly, how to form novel agencies. These agencies should be armed with the tools necessary to meet current and future groundwater challenges. While no governance solution is ever perfect, GSAs will have a greater chance of governing fairly and effectively if their design anticipates some common challenges of shared resource governance. The primary purpose of this document is to assist stakeholders and decision makers in evaluating the design of GSAs. It aims to empower them to think critically about whether proposed GSAs will meet their needs now and in the future, and—if not—which tools may help to achieve these goals. The framework presented here draws on experience in other natural resource management contexts and on research on governance and institutional design to provide lessons learned and illustrative examples.

Developing Adaptation Strategies for San Luis Obispo: Preliminary Climate Change Vulnerability Assessment for Social Systems

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

San Luis Obispo faces a variety of risks from climate change, including extreme heat, a generally drier climate, increases in extreme weather events, and sea-level rise.

San Luis Obispo faces a variety of risks from climate change, including extreme heat, a generally drier climate, increases in extreme weather events, and sea-level rise. Important vulnerabilities are apparent for water supplies, in agriculture (especially for wine and cattle ranchers) and related tourism, for fishing, coastal tourism, coastal development and infrastructure, and for community services. Certain county populations may face disproportionate risks including the elderly, those already affected by diseases, and outdoor and migrant workers from extreme heat, people living in coastal and inland floodplains, those living at the wildland-urban interface, the student population, institutionalized individuals (especially the state hospital), and those members of the community that tend to be somewhat disenfranchised from public decision-making, such as non-English speaking individuals and those who can’t afford to take off from work to attend public meetings. The county is wise to begin planning and building its adaptive capacity at this time before climate change impacts become more severe, and before there may be greater competition for state and federal financial support for adaptation planning and implementation.

Development and Calibration of a Two-Dimensional Digital Model for the Analysis of the Ground-Water Flow System in the San Antonio Creek Valley, Santa Barbara County, California

U.S. Geological Survey (USGS) | August 1st, 1985

Development of Flow Criteria for the Sacramento-San Joaquin Delta Ecosystem

California State Water Resources Control Board (SWRCB) | August 4th, 2010

Water Code section 85086 (See Appendix B), contained in the Delta Reform Act, was enacted as part of the comprehensive package of water legislation adopted in November 20

Water Code section 85086 (See Appendix B), contained in the Delta Reform Act, was enacted as part of the comprehensive package of water legislation adopted in November 2009. Water Code section 85086 requires the State Water Resources Control Board (State Water Board) to use the best available scientific information gathered as part of a public process conducted as an informational proceeding to develop new flow criteria for the Delta ecosystem to protect public trust resources. The purpose of the flow criteria is to inform planning decisions for the Delta Plan and the BDCP. The Legislature intended to establish an accelerated process to determine the instream flow needs of the Delta in order to facilitate the planning decisions required to meet the objectives of the Delta Plan. Accordingly, Water Code section 85086 requires the State Water Board to develop the flow criteria within nine months of enactment of the statute and to submit its flow criteria determinations to the Council within 30 days of their development. This report, required by Water Code section 85086(c) (2009 Delta Reform Act) in 2010, suggests the flows that would be needed in the Delta ecosystem if fishery protection was the sole purpose for which its waters were put to beneficial use. In keeping with the narrow focus of the legislation, this report only presents a technical assessment of flow and operational requirements to provide fishery protection under existing conditions.  

Dispute Resolution Processes - Thinking Through SGMA Implementation: A Water in the West Series

Stanford University | October 9th, 2019

Groundwater serves as the primary water supply for more than two billion people worldwide (Famiglietti 2014) and supplies approximately 40% of irrigation water supply gl

Groundwater serves as the primary water supply for more than two billion people worldwide (Famiglietti 2014) and supplies approximately 40% of irrigation water supply globally (Siebert et al. 2010). This heavy reliance on groundwater aquifers has led to the unsustainable depletion of groundwater resources at the regional and global scale resulting in an increasing number of conflicts over groundwater resources (Jarvis 2014). Similar to global trends, a long-term overreliance on groundwater in California has resulted in historically low groundwater levels in basins throughout the state. Groundwater level declines have had widespread impacts, including drying of domestic wells, land subsidence and the loss of supply wells. In 2014, California passed the Sustainable Groundwater Management Act (SGMA) to address the impacts resulting from chronic groundwater overdraft in the state. SGMA requires formation of local Groundwater Sustainability Agencies (GSAs). GSAs must develop and implement Groundwater Sustainability Plans (GSPs, Plan) to achieve sustainability within 20 years of Plan implementation. Achieving sustainability requires local agencies, stakeholders and water users to make many difficult and potentially contentious decisions such as regulating pumping, levying pumping fees and finding and purchasing alternative water supplies to meet legislated sustainability goals. These decisions are prone to conflict, particularly when pumping restrictions are viewed as infringing on property rights, or when fees are charged to support local management. Traditionally, many of these decisions have been resolved through court adjudications, many of which have been long and expensive processes in California (Szeptycki et al. 2018) and elsewhere (USDA 2018). In recent decades, the Alternative Dispute Resolution (ADR) movement has fostered use of alternative processes, including direct negotiation among the parties, facilitation, mediation and arbitration in lieu of, or supplemental to, adjudication to resolve environmental conflicts. The U.S. Department of Agriculture (USDA) mediation program has the explicit goal of helping “avoid expensive and time-consuming administrative appeals and/ or litigation” (USDA 2018). Other government departments like the Department of Energy and the U.S. Environmental Protection Agency also have mediation programs with similar goals. Many of the local GSAs established under SGMA are multi-entity GSAs formed through Joint Powers Authorities Agreements (JPAA) or through Memorandums of Understanding Agreements (MOUA) – we refer to these agreements collectively as “Agreements.” Additionally, the jurisdictional area of many GSAs does not span the entire groundwater basin. SGMA requires sustainability at the basin-scale, so many GSAs will need to collaborate internally (among member agencies within a GSA) and externally (with other GSAs in their basin) to develop and implement GSPs which are “together likely to achieve the groundwater sustainability goal for the basin,” (California Water Code (CWC) § 10733(b)). Newly formed GSAs have additional layers of potential conflict that may not be present in interpersonal or even other inter-organizational contexts with well-established processes and precedents, including questions of who has the authority, what process(es) should be followed when exercising that authority and what the constraints on the exercise of that authority are. These questions are particularly pertinent when agencies with similar or overlapping authorities are working together – as is common practice under SGMA. Questions regarding authority, tight legal and regulatory timelines, a lack of existing precedents and the need to represent agency and constituent interests have the potential to exacerbate conflicts under SGMA. In some cases, where authoritative interpretations of legal authority and limits have not been established yet, litigation may be necessary and warranted. When institutions have to coordinate and cooperate, as JPAs do, identifying processes and forums for resolving conflicts is crucial (Marta et al. 2014). However, developing effective mechanisms for resolving conflicts and using them can be challenging. Learning from the experiences of past water management agencies in California, as well as the natural resource conflict resolution literature more broadly, may help GSAs develop robust dispute resolution plans with processes to incentivize and streamline their resolution.

Diverse stakeholders create collaborative, multilevel basin governance for groundwater sustainability

California Agriculture (UCANR) | March 13th, 2018

The Sustainable Groundwater Management Act (SGMA) is introducing significant changes in the way groundwater is governed for agricultural use. It requires the format

The Sustainable Groundwater Management Act (SGMA) is introducing significant changes in the way groundwater is governed for agricultural use. It requires the formation of groundwater sustainability agencies (GSAs) to manage groundwater basins for sustainability with the engagement of all users. That presents opportunities for collaboration, as well as challenges, particularly in basins with large numbers of agricultural water users who have longstanding private pumping rights. The GSA formation process has resulted in the creation of multiple GSAs in many such basins, particularly in the Central Valley. In case studies of three basins, we examine agricultural stakeholders' concerns about SGMA, and how these are being addressed in collaborative approaches to groundwater basin governance. We find that many water districts and private pumpers share a strong interest in maintaining local autonomy, but they have distinct concerns and different options for forming and participating in GSAs. Multilevel collaborative governance structures may help meet SGMA's requirements for broad stakeholder engagement, our studies suggest, while also addressing concerns about autonomy and including agricultural water users in decision-making.

Draft Final Groundwater Sustainability Plan for the Borrego Springs Groundwater Subbasin

Borrego Water District (BWD) | August 30th, 2019

The Borrego Valley Groundwater Sustainability Agency (GSA, Agency), which comprises the Borrego Water District (BWD) and the County of San Diego (County), developed a Gro

The Borrego Valley Groundwater Sustainability Agency (GSA, Agency), which comprises the Borrego Water District (BWD) and the County of San Diego (County), developed a Groundwater Sustainability Plan (GSP, Plan) to provide a structure to enable local government, groundwater users and the local community to work together to achieve sustainable use of groundwater resources in the Borrego Springs Groundwater Subbasin (Subbasin) (California Department of Water Resources (DWR) Basin No. 7.024.01) of the Borrego Valley Groundwater Basin. The GSP was subsequently repurposed as a Groundwater Management Plan (GMP), an integral part of a Physical Solution in a groundwater rights adjudication consistent with the requirements of the Sustainable Groundwater Management Act (SGMA). The purpose of this GMP is to refine and expedite implementation of the Physical Solution and to avoid litigation over the GSP and its associated Project and Management Actions (PMAs). The GSP and this resulting GMP was developed through a process of stakeholder negotiation among major water users, landowners and government agencies. Specifically, this GMP is adopted as part of the Physical Solution by means of a Judgment. The Judgment was agreed to by Stipulating Parties accounting for more than 75% of groundwater production and more than 50% of non-minimal producer well owners as an alternative to the GSA/GSP process for the Borrego Springs Subbasin under SGMA (California Water Code Sections 10733.6 and 10737.4). This GMP includes and is to be interpreted and implemented consistent with and subject to the provisions of the Judgment. The provisions of the Judgment control over and supersede any contrary provisions contained in this GMP. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

DRAFT Staff Report/Substitute Environmental Document in Support of Potential Updates to the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary for the Sacramento River and its Tributaries, Delta Eastside Tributaries, and Delta

California State Water Resources Control Board (SWRCB) | September 28th, 2023

DRERIP Ecosystem Conceptual Model: Mercury

California Department of Fish and Wildlife (CDFW) | January 24th, 2008

Mercury has been identified as an important contaminant in the Delta, based on elevated concentrations of methylmercury (a toxic, organic form that readily bioaccumulates

Mercury has been identified as an important contaminant in the Delta, based on elevated concentrations of methylmercury (a toxic, organic form that readily bioaccumulates) in fish and wildlife. There are health risks associated with human exposure to methylmercury by consumption of sport fish, particularly top predators such as bass species. Original mercury sources were upstream tributaries where historical mining of mercury in the Coast Ranges and gold in the Sierra Nevada and Klamath-Trinity Mountains caused contamination of water and sediment on a regional scale. Remediation of abandoned mine sites may reduce local sources in these watersheds, but much of the mercury contamination occurs in sediments stored in the riverbeds, floodplains, and the Bay-Delta, where scouring of Gold-Rush-era sediment represents an ongoing source. Conversion of inorganic mercury to toxic methylmercury occurs in anaerobic environments including some wetlands. Wetland restoration managers must be cognizant of potential effects on mercury cycling so that the problem is not exacerbated. Recent research suggests that wetting-drying cycles can contribute to mercury methylation. For example, high marshes (inundated only during the highest tides for several days per month) tend to have higher methylmercury concentrations in water, sediment, and biota compared with low marshes, which do not dry out completely during the tidal cycle. Seasonally inundated flood plains are another environment experiencing wetting and drying where methylmercury concentrations are typically elevated. Stream restoration efforts using gravel injection or other reworking of coarse sediment in most watersheds of the Central Valley involve tailings from historical gold mining that are likely to contain elevated mercury in associated fines. Habitat restoration projects, particularly those involving wetlands, may cause increases in methylmercury exposure in the watershed. This possibility should be evaluated. The DRERIP mercury conceptual model and its four submodels (1. Methylation, 2. Bioaccumulation, 3. Human Health Effects, and 4. Wildlife Heath Effects) can be used to understand the general relationships among drivers and outcomes associated with mercury cycling in the Delta. Several linkages between important drivers and outcomes have been identified as important but highly uncertain (i.e. poorly understood). For example, there may be significant wildlife health effect of mercury on mammals and reptiles in the Delta, but there is currently very little or no information about it. The characteristics of such linkages are important when prioritizing and funding restoration projects and associated monitoring in the Delta and its tributaries.