Delta Science Program Independent Scientific Reviews and Advice: Frequently Asked Questions

What is an independent scientific review and advice?

Scientific peer review and advice by independent subject matter experts is widely recognized by the science community as an effective tool to ensure the quality and integrity of scientific information used to inform natural resource decision-making. Independent reviews build trust and ensure high-quality science by providing rigorous, transparent, and objective feedback from experts on a scientific foundation of a project, plan, or product.

Who uses independent scientific reviews and advice?

Federal, state, regional, and local governments, public and private nongovernment groups, and others use feedback from independent experts to ensure the quality and integrity of the scientific information used for a project, plan, or product related to natural resource decision-making, regulatory compliance, and more.

Does the Delta Science Program conduct independent scientific reviews and provide advice?

Yes. The Delta Science Program is a recognized leader in coordinating unbiased, independent scientific reviews and advice to inform water and environmental decision-making in the Delta. The Delta Science Program has organized more than 25 reviews since it was formalized by the California Legislature in 2009. High profile examples include Long-Term Operations Biological Opinions for the Central Valley Project and State Water Project and Advice on the State Water Resources Control Board Bay-Delta Plan Biological Goals.

What’s the difference between independent scientific reviews and advice?

Scientific reviews consider work that is complete or near-complete, while advice focuses on ongoing, early-stage work. The main differences are the types of materials considered and the review process.

Table 1: Differences between scientific reviews and advice.

Differences Scientific Review Advice
Materials considered Complete or near-complete documents or scientific products (e.g., plan, report, permit application, analyses, study design, model). Early-draft documents or science-based products (e.g., models, study designs, plans, analyses).
Processes and products A review process can follow one of two formats: 1) public meeting with a consensus panel report, 2) a “letter review” with either (a) a consensus panel report, or (b) individual reviewer reports. Advice is intended to be an iterative process, so there may be several meetings or correspondences among the panel, requesting party, and product authors; all facilitated by the DSP. A draft advisory report may be discussed at a public workshop.
Full process details Delta Science Plan Appendix H: Policy and Procedures for Independent Scientific Review Delta Science Plan Appendix I: Policy and Procedures for Independent Science Advisors

What products do Delta Science Program independent scientific reviews and advice generate?

The products provided by an entity requesting a Delta Science Program review include technical reports, monitoring strategies, environmental permitting documents, models, and more. Following its assessment of the scope of work associated with the review charge, the Delta Science Program organizes a panel of recognized technical subject matter experts.

Throughout the process, the Delta Science Program acts as the liaison between the requesting party and panel, to foster an open and transparent process. Upon completion of its review, the panel publishes a final report and associated materials (e.g., charge to the panel, background materials, presentations) on the Delta Stewardship Council’s website detailing its findings and recommendations. Additional details related to policies and procedures are outlined in the Delta Science Plan.

How long is the Delta Science Program’s independent scientific review or advice process?

The duration of reviews and advice vary with the complexity and scope of the charge, but generally require one year to complete. In the case of advice, the processes of iterative communication between the panel and the requesting party often takes longer.

How do I request independent scientific review or advice from the Delta Science Program?

Any agency or interested party can request scientific review or advice by the Delta Science Program by emailing The following factors are taken into consideration and the final decision rests with the Delta Lead Scientist:

  • Does the topic align with Delta Stewardship Council mission and objectives?
  • Does the review or advisory effort advance the Delta Science Program’s mission in support of the Delta Stewardship Council?
  • Are the document(s) complete and ready for review?
  • Is there sufficient lead time available for the review or advice process?
  • Is there sufficient staff capacity to coordinate a review or advice?
  • Is sufficient funding available?

How much do independent scientific reviews and advice cost?

Costs vary by review depending on the materials for review and the format. Typical review contracts contain a budget based on the time spent reviewing materials, developing a report, attending a public meeting, and associated travel costs. The requesting party should reimburse the Delta Science Program for costs associated with the review, including staff time spent coordinating the review. To request a cost estimate, please contact

Who else conducts independent scientific reviews and advice?

The Delta Independent Science Board and the National Research Council provide periodic, high-level reviews of programs or issues with broad implications for natural resource management, which often take a year or longer to execute. By statute, Delta Independent Science Board is required to review scientific research, monitoring, and assessment programs that support adaptive management of the Sacramento-San Joaquin Delta.

Other agencies, academic institutions, and organizations also perform independent scientific reviews. For example, the California Environmental Protection Agency requires independent scientific reviews per California’s Health and Safety Code section 57004. These reviews do not typically involve a panel or a public venue, have a shorter timeframe, use a broad and predetermined set of charge questions for reviewers, and yield multiple review products.

Delta Science Program-coordinated peer review and advice differs from the above efforts in that there is a specific charge for each review or advisory effort and its products and processes are conducted in a fully transparent manner.

For additional questions, please contact

“This review, and the other reviews [the Delta Science Program] facilitates for us, play a critical role in improving the quality and credibility of our decision-making. I appreciate the expertise you bring to this forum.” – David Mooney, Bay-Delta Office Area Manager, U.S. Bureau of Reclamation (2017)