Reclamation Climate Variabilaity Activities March 28 2014 Tucson

Reclamation Climate Variabilaity Activities March 28, 2014 Tucson, AZ

Colorado River Basin Water Supply and Demand Study • Study Objective – Assess future water supply and demand imbalances over next 50 years – Develop and evaluate opportunities for resolving imbalances • Study conducted by Reclamation and the Basin States in collaboration with stakeholders throughout the Basin • A 3 year study that began in January 2010 and completed December 2012 • A planning study – did not result in any decisions, but provides the technical foundation for future activities

Water Supply Assessment Scenarios *: • Observed Resampled • Paleo Resampled • Paleo Conditioned • Downscaled GCM Projected * Multiple realizations for each scenario

Quantification of Water Supply Scenarios Projections of 2011 -2060 Average Natural Flow at Lees Ferry 1991 – 2010 average = 13. 7 MAF Box represents 25 th – 75 th percentile, whiskers represent min and max, and triangle represents mean of all traces

Moving Forward Next Steps after the Study

Basin Study Next Steps Workgroups

Next Steps Workgroups “…all that rely on the Colorado are taking initial steps — working together — to identify positive solutions that can be implemented to meet the challenges ahead. ” • Brings wider stakeholder group with expertise to address topics identified in the Basin Study • More detailed analysis and discussion than was considered in the Basin Study

Data and Tool Development

River. Ware. TM River. SMART • Manage input and output for many scenarios • Automate simulation process

Climate Science Research

Water. SMART • West Wide Climate Risk Assessments (WWCRA) – Reconnaissance level baseline risk and impact assessments related to supply and demand • Basin Studies – Study of basins where imbalances in water supply and demand exist or are projected, including options to mitigate associated risks • Landscape Conservation Cooperatives – Bring together science and resource management to inform climate adaptation strategies to address climate change • Climate Science Centers – Provide natural and cultural resource managers with the tools and information they need to address the impacts of climate change

Reclamation Climate Change and Variability Research • Climate Change and Water Working Group – Federal collaborators: Army Corps of Engineers, NOAA, USGS, EPA, NASA, and FEMA • Downscaled CMIP 3 and CMIP 5 Climate and Hydrology Projections – Recent studies have relied on CMIP 3 base hydrologies – Had only applied the BCSD and BCCA downscaling techniques • Other research collaborators – NCAR, RISAs, Universities

Long-term and Short-term needs Addressing Climate Change in Long-Term Water Resources Planning and Short-Term Water Management: User Needs for Improving Decisions: User Needs for Improved Tools and Information Climate, Weather, and Hydrologic Information 13

Recently release CMIP 5 data

Improved techniques for climate projection downscaling and hydrologic impacts assessment Gap(s) Addressed 2. 03 Information on the strengths and weaknesses of downscaled data… 3. 03 4. 01 Basis for culling or weighting climate projections … Guidance on strengths and weaknesses of watershed hydrologic models/methods … Understanding how climate change should impact potential evapotranspiration and how it is represented in watershed hydrologic models. Uncertainty information on regional climate projections … …uncertainty information on system science and associated ways of portraying this science in a system model and the observations used to customize a model for a specific system. 4. 02 7. 04 Research Question(s) 1. 2. 3. How can we make greater use of projected changes in climate dynamics to downscale output from multiple GCMs? Graphic Precipitation from WRF & Simple Weather Model (SWM) Collaborators/Schedule/Source of Support • • Ø Ø How can we improve continental-scale hydrology simulations and better characterize hydrologic model uncertainty? What is the relative importance of different sources of uncertainty in the portrayal of climate change impacts on hydrology Reclamation, US Army Corps of Engineers Schedule: Ø • Fall 2013 – Baseline simulations and development of modeling infrastructure Summer 2014 – Prototypes for intermediatecomplexity downscaling and multi-model hydrology simulations Summer 2015 – Information for the SECURE report Funding: Reclamation, US Army Corps of Engineers; complemented by NSF

Colorado River Headwaters Project NCAR/MMM, University of Vienna, George Mason University, and the University of Texas A team of scientist from a variety of disciplines such as atmospheric science, hydrometeorology, climate and regional modeling, land–surface modeling, and social science will collaborate to investigate following questions: • How high should model resolution be for the regional climate model to accurately simulate seasonal snowfall and snowpack in the Colorado Headwaters regions? • Will the predicted increase in snowfall (caused by a warmer, moister climate) be enough to offset the accelerated melting and sublimation due to warmer temperatures? • If so, will the increase in snowfall be sufficient to maintain river flow at current levels?

Colorado River Hydrology Workgroup • Brings together Reclamation and Reclamation funded Colorado River Basin researchers • University of Arizona, University of Colorado, and UNLV • Topics being studied – – – Climate Teleconnections Inter-Decadal Streamflow Projections Hydroclimate analysis Economic Analysis Knowledge Exchange Dynamical downscaling

Summary • Reclamation has been and continues to be committed to a variety of ongoing efforts that address long-term risks and drought • Basin Study Next Steps workgroups aim to further explore areas identified in the Study to identify positive solutions to challenges ahead • There is a strong emphasis on collaboration with stakeholders, other departments or agencies, as well as the research community

Questions?