SCIENCE SPOTLIGHT: “Prototyping Structured Decision Making for Water Resource Management in the San Francisco Bay-Delta ~ MAVEN’S NOTEBOOK

At the June meeting of the Delta Stewardship Council, Deputy Executive Officer for Science Henry DeBey filled in for Delta Lead Scientist Dr. Lisamarie Windham-Myers. This month’s spotlighted article, “Prototyping Structured Decision Making for Water Resource Management in the San Francisco Bay-Delta,” was published in the Environmental Science and Policy journal and authored by USGS scientist Dr. Jim Peterson and others. The article highlights structured decision-making, an approach that is increasingly being used in the Delta.

Structured decision-making, or SDM, is a framework for making informed and transparent choices in complex decision situations. SDM can help to break down management decisions and actions into digestible components, bring different points of view together, and foster collaboration and transparency. It can also incorporate models and data and help bridge the scientist-manager gap.

Mr. Debey gave the example of planning a family vacation as analogous to structured decision-making. “First, as a group, you may need to design on a vacation type, say, a beach or a mountain trip. Then you set your goals: do you want to relax or have some adventure or combination thereof? You identify possible destinations to meet those vacation goals and evaluate and compare each destination in terms of costs and other considerations. Then, you choose the best option, and you go. That same stepwise approach is helpful for informing and supporting decision-making in the Delta where the system is complex, and there are many different management objectives and possible management actions.”

The authors of the study used a prototype SDM to evaluate the effects of alternative management actions on multiple fish and water objectives. Since structured decision-making takes a long time, a prototype approach can be quicker and determine if it’s the right approach for the problem being addressed.

The slide outlines the standard steps for the structured decision-making process.

  • Step one: They identified the problem statement, which essentially boils down to how water supply and fish recovery can be simultaneously prioritized, objectives that often seem to be at odds.
  • Step two: With that problem statement in mind, the group settled on four management objectives: maximize Delta smelt populations, maximize Chinook salmon populations, minimize losses to water availability and reliability, and minimize losses of agricultural income.
  • Step three: The group then brainstormed 14 management actions that could meet those four goals. These actions included everything from reservoir releases to adding fish, from hatcheries to adding sediment for Delta smelt habitat.
  • Step four: They modeled all of these actions using fish community dynamics and hydrology models and created a consequence table or influence diagram to show the net positive, negative, or neutral effects on the different objectives.
  • Step five: Using the consequence table or influence diagram, the group could then see the trade-offs of the different actions. Some of the results were not surprising, like adding fish eggs or fish food helped the fish populations, but others were and showed somewhat unexpected co-benefits. In particular, two actions did not negatively affect water objectives yet boosted both smelt and salmon populations with food. These actions included the Fremont Weir notch, which allows fish migration through the Yolo bypass, and the second was a targeted pulse of water through the Yolo bypass to augment fish food.
  • Step six: Recognizing that all of these data and models have different parameters and levels of uncertainty, they performed a sensitivity analysis to identify the most significant areas of uncertainty. In this case, they determined that uncertainty stems from Chinook salmon reproduction and the limited availability of data on contaminants.
  • Step seven: This would be the implementation, but because this was a prototype SDM, they didn’t actually implement a decision, but they did determine that resource managers in the Delta would benefit from pursuing an SDM to assess the effectiveness of water management, restoration, and other natural resource management activities.

So, in conclusion, the authors describe that despite multiple decades of research and monitoring in the Bay Delta, the information collected in the system is often inconsistently linked to decision-making and that SDM could help with that. The authors also point out the usefulness of SDM, not just for the final decisions themselves but also for getting partners to agree on the problem statement and to identify key data and models needed to support that decision-making.

The written report notes, “Structured Decision Making has become a well-reviewed approach to optimizing resources by integrating research into the weak points in decision-making protocols. For example, the Department of Water Resources (DWR) uses SDMs for evaluating trade-offs and benefits of habitat actions and water management, such as Delta Smelt habitat in Suisun Marsh. DSP completed the independent peer review for DWR’s Summer-Fall Habitat Action and Structured Decision-Making Approach in May 2024, and the charge and independent review letters can be found at .”


  • Last month, the Delta Science Program hosted a career workshop with the 2022 class of Delta Science fellows. These eight fellows are in early careers at the master’s, PhD, and postdoctoral levels and were competitively awarded funds to pursue research projects for two years. They have been researching everything from pesticide management to studying learning and cooperation in the Delta’s governance system. This workshop aimed to equip fellows with key training and skills in everything from interviewing to science, communication, and more.
  • The Delta Science Program is gearing up for the next cohort of 2025 Delta Science fellows. We recently received 37 notices of intent across disciplines and for different projects, roughly double the number of applications they usually receive. It shows a high level of interest, but unfortunately, only six can be chosen, so it will be competitive this time.
  • In May, the Delta Science Program also convened a quarterly meeting of the Suisun Adaptive Management Advisory Team or Suisun AMAT. The team is comprised of local, state, and federal agencies that support adaptive management requirements under the Suisun Marsh Plan and Delta Plan, including habitat restoration projects and site scientific monitoring in Suisun Marsh. The meeting included touring projects across the Suisun Marsh that are restoring tidal wetlands, monitoring carbon fluxes, reversing subsidence, and restoring wetlands by reusing dredged sediment from the bay.
  • Earlier this month, the Delta science program senior engineer Ben Gaskey traveled to Annapolis, Maryland, to be a panelist at the Chesapeake community research symposium. He shared the work promoting a modeling collaborative in the Delta. The Chesapeake Bay Program is much further along in its integrated modeling efforts, so they can provide case studies to learn from. Also, their estuary shares a lot of the same challenges as the Bay Delta, everything from HABs to invasive species, so the symposium was a good opportunity to strengthen those connections with that group.

Back To Top