Navigating a Flood of Information

The report argues that incorporating climate change projections into groundwater planning is essential for California's water and food security, particularly as groundwater provides over half of the state's water supply during dry years. It provides a technical guide for water managers to understand Global Climate Models (GCMs), spatial resolution, downscaling, and emissions scenarios (specifically RCP 4.5 and 8.5). The authors identify inconsistencies between state (State Water Project) and federal (Central Valley Project) water delivery projections and recommend that local agencies use 'rule of thumb' methodologies and stress-testing to address these gaps. A proposed four-step process for GSPs includes determining management objectives, evaluating existing data, selecting appropriate information, and stress-testing actions. An analysis of 24 submitted Alternative Plans revealed that only about half included quantitative climate analysis, and many lacked a clear link between climate modeling and management objectives.

• Groundwater is a critical resource for California, contributing more than 50% of the state's water supply during dry years, making the integration of climate science into planning vital for long-term food and water security.
• There are significant inconsistencies in how state and federal agencies project water deliveries; the State Water Project's Delivery Capability Report and the Central Valley Project's Integrated Resource Plan use different methodologies, which can create uncertainty for local agencies.
• The authors recommend a four-step process for incorporating climate projections into Groundwater Sustainability Plans: 1) Determine management objectives, 2) Evaluate existing climate change information, 3) Select appropriate information for management actions, and 4) Stress-test potential management actions.
• An analysis of 24 Alternative Plans submitted under SGMA found that only approximately 50% included quantitative climate change analysis, and those that did often failed to link the analysis to their stated management objectives.
• To address incomplete or inconsistent state data, local agencies are encouraged to use 'rule of thumb' estimates by combining historical drought frequency data with climate change projections of future drought frequency.
• GSAs should employ stress-testing by using worst-case scenario projections (such as the driest and hottest ensemble members) to identify vulnerabilities and develop contingency plans in advance.
• The report emphasizes that uncertainty regarding the probability of an event should not be confused with risk, which relates to the negative consequences of that event; high-risk events like severe multi-year droughts require more rigorous analysis regardless of uncertainty.

APA

Christian-Smith, J., Moran, T., Persad, G., Smith, G., & Szeptycki, L. (2017). Navigating a Flood of Information. Union of Concerned Scientists. https://www.ucs.org/sites/default/files/attach/2017/11/gw-ws-whitepaper-groundwater-climate-science.pdf

Chicago

Christian-Smith, Juliet, Tara Moran, Geeta Persad, Gemma Smith, and Leon Szeptycki. Navigating a Flood of Information. Union of Concerned Scientists, 2017. https://www.ucs.org/sites/default/files/attach/2017/11/gw-ws-whitepaper-groundwater-climate-science.pdf.

Wikipedia

{{cite report |last1=Christian-Smith |first1=Juliet |last2=Moran |first2=Tara |last3=Persad |first3=Geeta |last4=Smith |first4=Gemma |last5=Szeptycki |first5=Leon |title=Navigating a Flood of Information |publisher=Union of Concerned Scientists |date=November 2017 |url=https://www.ucs.org/sites/default/files/attach/2017/11/gw-ws-whitepaper-groundwater-climate-science.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{christiansmith2017navigating, author = {Christian-Smith, Juliet and Moran, Tara and Persad, Geeta and Smith, Gemma and Szeptycki, Leon}, title = {{Navigating a Flood of Information}}, institution = {Union of Concerned Scientists}, year = {2017}, month = nov, url = {https://www.ucs.org/sites/default/files/attach/2017/11/gw-ws-whitepaper-groundwater-climate-science.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }