Comparing Futures for the Sacramento-San Joaquin Delta

Public Policy Institute of California (PPIC) | July 16th, 2008

For over 50 years, California has been pumping water through the Sacramento-San Joaquin Delta for extensive urban and agricultural uses around the state. Today, the Del

For over 50 years, California has been pumping water through the Sacramento-San Joaquin Delta for extensive urban and agricultural uses around the state. Today, the Delta is ailing and in urgent need of a new management strategy. This report concludes that building a peripheral canal to carry water around the Delta is the most promising way to balance two critical policy goals: reviving a threatened ecosystem and ensuring a reliable, high-quality water supply for California. More information can be found in the following supporting appendices: Appendix A. Policy and Regulatory Challenges for the Delta of the Future Appendix B. Levee Decisions and Sustainability for the Delta Appendix C. Delta Hydrodynamics and Water Salinity with Future Conditions Appendix D. The Future of the Delta Ecosystem and Its Fish Appendix E. Expert Survey on the Viability of Delta Fish Populations Appendix F. The Economic Costs and Adaptations for Alternative Delta Regulations Appendix G. Peripheral Canal Design and Implementation Options Appendix H. Delta Drinking Water Quality and Treatment Costs Appendix I. The Economic Effects on Agriculture of Water Export Salinity South of the Delta Appendix J. Decision Analysis of Delta Strategies Interactive Map: Voting Patterns on Proposition 9 (Peripheral Canal), June 1982 Interactive Map: A Multi-Purpose, Eco-Friendly Delta Interactive Feature: Delta Island Flooding (With Repairs) Interactive Feature: Delta Island Flooding (No Repairs)

Complexity of Coupled Human and Natural Systems

American Association for the Advancement of Science (AAAS) | September 14th, 2007

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists s

Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.

Delta Conservation Adaptive Management Action Strategy

Delta Stewardship Council (Delta Council) | April 11th, 2019

Various efforts are ongoing to restore and enhance ecosystems in the Sacramento-San Joaquin Delta, Yolo Bypass, and Suisun Marsh (hereafter the Delta) that require suppor

Various efforts are ongoing to restore and enhance ecosystems in the Sacramento-San Joaquin Delta, Yolo Bypass, and Suisun Marsh (hereafter the Delta) that require support for adaptive management. Adaptive management is a science-based, structured approach to environmental decision making under uncertain conditions. Adaptive management emphasizes acquisition and use of new knowledge in natural resource management, leading to continuous iterative improvements in project planning, implementation, monitoring, and follow-up. Adaptive management is required for compliance with multiple regulatory processes, such as consistency with the Delta Plan and the Suisun Marsh Plan, but recent reviews have found that a full adaptive management cycle is rarely completed at either the project- or system-level in the Delta (Delta Independent Science Board 2016; Nagarkar and Raulund-Rasmussen 2016). To address this issue, the Delta Science Program initiated an effort to work with agency and stakeholder partners in the Delta to develop a comprehensive, science-based adaptive management approach to support achievement of Delta conservation goals. Conservation, as defined in the Delta Conservation Framework (Sloop et al. 2018), consists of efforts to protect, restore, and enhance ecosystems in the Delta. The Delta Conservation Adaptive Management Action Strategy is based on the Adaptive Management Framework outlined in the Delta Plan (Figure 1, Delta Stewardship Council 2013). 

Delta Independent Science Board -- Comments on the Sacramento / Delta Draft Staff Report

Delta Stewardship Council (Delta Council) | January 19th, 2024

Designing Monitoring Programs in an Adaptive Management Context for Regional Multiple Species Conservation Plans

U.S. Geological Survey (USGS) | January 1st, 2004

Increasing numbers of regional, multiple species conservation plans have been developed in California since the early 1990s. However, building effective monitoring and ad

Increasing numbers of regional, multiple species conservation plans have been developed in California since the early 1990s. However, building effective monitoring and adaptive management programs to support these plans has remained a challenge. In addition to collecting data on the status of resources and the results of management actions, monitoring programs for these plans need to resolve critical uncertainties and channel information into effective decisionmaking.  Because of the broad goals of many regional conservation plans, monitoring programs need to address ecosystem integrity and biodiversity while also tracking species “covered” by plan permits. In this document we provide a step-by-step procedure for developing effective monitoring programs in an adaptive management context. The guidance provided here has been gleaned from experience with large multiple species plans in southern California. The process begins with clearly defining program objectives, partitioning the program into manageable but meaningful pieces, and developing management-oriented conceptual models of system function. Then, based on the objectives and conceptual models, monitoring recommendations and critical uncertainties can be identified and a coordinated program designed. We include practical examples and insights from programs in southern California and discuss the evolution of monitoring and adaptive management programs through three successive stages: 1) inventorying resources and identifying relationships; 2) pilot testing of long-term monitoring and resolving critical management uncertainties; and 3) implementing long-term monitoring and adaptive management. Ultimately, the success of regional conservation planning depends on the ability of monitoring programs to confront the challenges of adaptively managing and monitoring complex ecosystems and diverse arrays of sensitive species.

DISB Review of Bay Delta Conservation Plan/California WaterFix Partially Recirculated Draft EIR/EIS

Delta Stewardship Council (Delta Council) | October 1st, 2015

We have reviewed the partially Recirculated Draft Environmental Impact Report/ Supplemental Draft Environmental Impact Statement for the Bay Delta Conservation Plan/Calif

We have reviewed the partially Recirculated Draft Environmental Impact Report/ Supplemental Draft Environmental Impact Statement for the Bay Delta Conservation Plan/California WaterFix (herein, "the Current Draft"). We focused on how fully and effectively it considers and communicates the scientific foundations for assessing the environmental impacts of water conveyance alternatives. The review is attached and is summarized below. The Current Draft contains a wealth of information but lacks completeness and clarity in applying science to far-reaching policy decisions. It defers essential material to the Final EIR/EIS and retains a number of deficiencies from the Bay Delta Conservation Plan Draft EIR/EIS. The missing content includes: 1. Details about the adaptive-management process, collaborative science, monitoring, and the resources that these efforts will require; 2. Due regard for several aspects of habitat restoration: landscape scale, timing, long-term monitoring, and the strategy of avoiding damage to existing wetlands; 3. Analyses of how levee failures would affect water operations and how the implemented project would affect the economics of levee maintenance; 4. Sufficient attention to linkages among species, landscapes, and management actions; effects of climate change on water resources; effects of the proposed project on San Joaquin Valley agriculture; and uncertainties and their consequences; 5. Informative summaries, in words, tables, and graphs, that compare the proposed alternatives and their principal environmental and economic impacts. The effects of California WaterFix extend beyond water conveyance to habitat restoration and levee maintenance. These interdependent issues of statewide importance warrant an environmental impact assessment that is more complete, comprehensive, and comprehensible than the Current Draft.

Ecological Limits of Hydrologic Alteration: Environmental Flows for Regional Water Management

U.S. Environmental Protection Agency (EPA) | March 20th, 2008

Worldwide, water conflicts are escalating as cities, industries, agriculture, and energy producers compete for limited freshwater supplies. At the same time, there is a g

Worldwide, water conflicts are escalating as cities, industries, agriculture, and energy producers compete for limited freshwater supplies. At the same time, there is a growing awareness of the need to maintain adequate freshwater flows in rivers, lakes, floodplains, aquifers, and estuaries to sustain biodiversity and the many benefits derived from the healthy, functioning ecosystems upon which local communities and economies depend. Efficient, integrated water resource management systems help  governments provide for growing human populations while protecting and restoring healthy freshwater ecosystems. The integration of ecological considerations into water management has been hampered by the difficulty, cost, and time required for determining environmental flows -- the quantity, timing, and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend on these ecosystems.  Environmental flow assessments scientifically evaluate tradeoffs between alteration of natural water flow patterns by humans and consequent changes in ecological health.

Evaluation of Surface-Water/Ground-Water Interactions in the Santa Clara River Valley, Ventura County, California

U.S. Geological Survey (USGS) | May 28th, 1999

The interactions of surface water and ground water along the Santa Clara River in Ventura County, California, were evaluated by analyzing river-discharge and water-qua

The interactions of surface water and ground water along the Santa Clara River in Ventura County, California, were evaluated by analyzing river-discharge and water-quality data and geohydrologic information collected by the U.S. Geological Survey between 1993 and 1995 for the Piru, Fillmore, and Santa Paula subbasins. Measurements of discharge and water quality were made at multiple locations along the Santa Clara River and its tributaries at eight different time periods during different releases from Lake Piru. Geologic, hydraulic, and water-quality data were collected from three new multiple-completion ground-water monitoring wells. These data, together with data collected as part of the U.S. Geological Survey Southern California Regional Aquifer-System Analysis (RASA) study, were analyzed in order to quantify rates and locations of ground-water recharge and discharge within the river, characterize the correlation of recharge and discharge rates with ground-water conditions and reservoir releases, and better characterize the three-dimensional ground-water flow system. Analysis of the data indicates that the largest amount of ground-water recharge from the river consistently occurs in the Piru subbasin. Some ground-water recharge from the river may occur in the upper part of the Fillmore subbasin. Increases in sulfate concentrations indicate that increases in flow at the lower ends of the Piru and Fillmore subbasins result from high-sulfate ground-water discharge. Increases in flow in the lower part of the Santa Paula subbasin are not accompanied by significant sulfate increases. Several sets of regressions indicate possible correlation between net flow changes in the river and depths to ground water and release rates from Lake Piru. These statistical relations may be of use for evaluating alternative Lake Piru release strategies. Data on the stable isotopes of hydrogen and oxygen from the ground-water monitoring wells that were installed as part of this investigation were used to distinguish between zones affected by recharge from the Santa Clara River and zones affected by recharge from local precipitation. Tritium data from a new multiple-completion monitoring site indicate that near the river in the upper Santa Paula subbasin, recent (post-1950) recharge water is not present at depths greater than about 350 feet below land surface. Water-level and lithologic data from the monitoring site indicate that the river and the Shallow aquifer have only limited hydraulic connection to the underlying aquifers at this location. Water-level data from the Shallow aquifer and from an in-stream drive point were used in an analytic model to estimate hydraulic properties governing stream-aquifer interactions in the upper Santa Paula subbasin. Hydraulic conductivities in all the USGS monitoring wells were estimated on the basis of slug tests.  

Facilitating Adaptive Management in California’s Sacramento–San Joaquin Delta

University of California, Davis (UC Davis) | July 1st, 2017

Uncertainties in understanding ecosystems increase the risk that management will fail to achieve desired results. Adaptive management is a structured, iterative applicati

Uncertainties in understanding ecosystems increase the risk that management will fail to achieve desired results. Adaptive management is a structured, iterative application of science-based knowledge to reduce uncertainties and build flexibility into decision-making. However, adaptive management is more easily planned than implemented, and it is only beginning to be applied in the California’s Sacramento–San Joaquin Delta. We draw from two assessments of adaptive management in the Delta and examples of its use elsewhere to suggest how the process can be facilitated. Although a highly structured adaptive-management process may not always be needed, several elements are essential. Adaptive management should begin by clearly identifying the problem, goals, and objectives; recognizing uncertainties; identifying decision points and alternative approaches; recognizing when adjustments are needed and having the flexibility to make them; and considering societal and political constraints. Model complexity should be matched to that of the system and management needs; experiments can help unravel causal relationships. Monitoring, analyses, and syntheses require comprehensive data-management systems. More frequent and organized communications among scientists, managers, stakeholders, and decision-makers are necessary. We propose the establishment of an “Adaptive Management Team” to coordinate efforts across the management spectrum of the Delta and to provide guidance and link individual projects to shared approaches and experiences. Reliable long-term support will be needed to assess results of management actions, adjust approaches where improvement is likely, and strive toward the legislated goals of enhancing the Delta ecosystem while also providing reliable water supplies to much of California, and doing both these things in a manner that protects values of the Delta as a place where people live and work. 

Financing Delta Improvements and Environmental Mitigation

California Research Bureau (CRB) | September 1st, 2008

Resolution of the Delta’s water supply, water quality, and fish problems may involve building various structures, possibly including gates, pumps, canals, levees, and d

Resolution of the Delta’s water supply, water quality, and fish problems may involve building various structures, possibly including gates, pumps, canals, levees, and dams, and undertaking landscaping rearrangements to improve habitat for several species of flora and fauna. Resolution also involves changing water flow regimes in ways that would make more or less water, but probably less, available for human uses. This work and these changes will cost serious money. Cost estimates for many of these actions have not yet been developed. This paper explores approaches to financing these “improvements” and “mitigations.” While a little abstract, this is abstraction that matters. It will determine from whose pockets a good deal of money will come. California has a long history of financing water projects. The first section of this paper reviews this history, in hopes of identifying water-financing principles that might be adapted to Delta improvements and mitigation. Some deep-seated controversies about how Delta improvements should be financed have roots in this history, and it may be helpful to point them out. A core idea in California’s approach to financing water projects is that beneficiaries should pay for them. Decades ago, this was a straightforward proposition – people or water districts should pay for the necessary dams, canals, and pumps and the costs of operating them in proportion to the amount of water they received. In the current age of rising environmental sensitivity, it is a little muddier. An alternative formulation that applies, at least crudely, to housing developments and highway projects, is that project proponents should pay to mitigate at least some of the environmental harm that their project is likely to cause. The second section of this paper explores this controversial subject. It seems unlikely that any consensus can be reached about how to finance facilities in the Delta without reaching some agreement about how to deal with this matter. This paper was first issued in July, 2008. This version contains a few clarifications made in response to the Blue Ribbon Task Force’s reviewers. The author is grateful for their suggestions.