Transcript International committee on large dams

Reclamation
Mission
The mission of the
Bureau of Reclamation
is to manage, develop,
and protect water and
related resources in an
environmentally and
economically sound
manner in the interest
of the American public.
Observed Hydrology &
Vegetation Changes
Less spring snowpack
TRENDS (1950-97) in
April 1 snow-water content at
western snow courses
Less snow/more rain
Mote, 2003
Earlier greenup
Figs. M. Dettinger (USGS)
Stewart et al., 2005
Cayan et al., 2001
Implications for water supplies, water
demands, operating constraints?

Supplies
 warming
○ less snowpack  less controllable water supply
○ more landscape evapotranspiration (ET)  less runoff
 precipitation change? could be + or - , help or worsen…

Demands
 warming
○ Irrigation: increased seasonal water demand (longer season, more ET)
○ Electricity: increased summer demand, decreased winter demand

Operating Constraints
 Environment – instream flow requirements?
○
Reduction in cold-water supplies
 Flood Protection – storage reservation requirement?
All other things equal, warming leads to greater area contributing runoff during
western winter storm events – greater winter reservoir drafts?
○ Storm intensification could be + or -, worsen or help…
○
Key Challenges for Reclamation

Understand how climate variability and change
can affect Western water supply and demand, and
Reclamation delivery of water given operational
constraints (e.g., environmental constraints, flood
constraints)

Bring science and technology to bear on the
needs of water resources managers

Address goals of internal programs and
authorizations where climate change is a factor
Notable Activities

Understanding Impacts & Uncertainties
 Scoping Guidance:
○ “Level of Analysis” Options Paper
 list options, pros, cons andgeneral recommendations for using climate
change information in long-term planning (e.g., NEPA, ESA, general studies)
(Art Coykendall, [email protected])
 Tool Development:
○ Regional Literature Syntheses
 Living document, annual updates, summarize CC implications for water
resources, Western 17 states (J. Mark Spears, [email protected])
 http://www.usbr.gov/research/docs/climatechangelitsynthesis.pdf
○ Downscaled Climate Projections web-archive
 Collaboration with SCU, LLNL, USGS/Scripps, Climate Central, USACE (T.
Pruitt, [email protected]), 112 CMIP3 projections, 1950-2099, contiguous
U.S. , monthly, 12km x 12km resolution)
 http://gdo-dcp.ucllnl.org/downscaled_cmip3_projections/
Notable Activities

Understanding Impacts & Uncertainties
 Putting Guidance and Tools to action:
○ Ideally: we’d have well-trained practitioners, familiar with climate
change concepts, how to apply it in planning, how to communicate results
○ Reality: We have few internal practitioners trained in using projections
of future climate – limits capacity of scoping and doing. We also lack
refereed “best practices” (e.g., which climate models? which projections?
how to relate projections to planning assumptions?). Literature offers
many methods, but little guidance.
○ Reaction:
 Learn by doing.
 Conduct exploratory studies, use literature methods, guiding thoughts
on method choice: Simple. Manageable. Defendable.
 Refine methods, on-ramp to actual planning (e.g., NEPA, ESA)
- E.g., MP 2008 ESA consultation
(http://www.usbr.gov/mp/cvo/OCAP/sep08_docs/Appendix_R.pdf)
Notable Activities

Coalition Building between Science & Management
 Objectives:
○ stay abreast of new science, usher mature methods into practice
○ inform researchers on management community needs
 Vehicles:
○ DOI Climate Science Centers & Landscape Conservation Coops.
 Information on Reclamation involvement:
- Landscape Conservation Cooperatives - Avra Morgan ([email protected])
- Climate Science Centers – Curt Brown ([email protected])
○ Climate Change and Water Working Group, or CCAWWG (
 Currently six federal members: NOAA, USGS, USACE, USEPA, FEMA, Reclamation
 Current activities
- Training Program development (goal: build trained practitioner capacity)
- User Needs documents (goal: motivate research to address needs)
- Approaches Workshop - Aug 2010 (goal: develop guidance on methodologies)
 Information: Curtis Brown ([email protected]) , Chuck Hennig ([email protected])
Notable Activities

Recent Science Efforts funded by Reclamation R&D
 Flood Frequency Estimation within projections of Future Climate
○
Framework described in Raff et al. 2010. Framework applications are being explored
by Reclamation Dam Safety Office (DSO) and TSC Flood Hydrology Group (John
England, [email protected]).
 Comparison of Hydrology Models for Climate Change applications
○
Focused on four surface water hydrologic models (VIC, PRMS, SacSMA/Snow17,
TMWB), calibrate/validate across contrasting historical climates. Publication in
development. Contact: Levi Brekke ([email protected])
 Application of new daily downscaling technique: Bias Correction
Constructed Analogs
Useful for describing projected changes in storm patterns (sub-monthly occurrence)
and diurnal variability (relevant to portraying watershed ET losses, ecosystem
conditions)
○ Collaboration with USGS/Scripps, SCU, Climate Central, LLNL, USACE.
○ Data in development, to be served at DCP Archive mentioned earlier. Contact: Tom
Pruitt ([email protected])
○
Notable Activities:
Basin Study Program

WaterSMART Basin Studies
 http://www.usbr.gov/WaterSMART/basin.html
○ Fed / non-Fed cost-shared studies on future supply & demand imbalances,
management strategies to address imbalances, stressors including climate change.
○ FY10 study grants: Colorado River Basin, St Marys / Milk River Basin (MT), and
Yakima River Basin (WA). FY11 study proposals under review.

West Wide Risk Assessments (PL 111-11 Secure Water Act)
 periodic reports to Congress (first report due 2011)
○ Focus: climate change vulnerabilities and adaptation options, various resources
○ Basins: Colorado, Columbia-Snake, Klamath, Missouri, Rio Grande, Sacramento, San
Joaquin, and Truckee
 program approach: “West Wide Risk Assessments”
○ Hydrology: consistent west-wide assessment approach
○ Demands, Operations, other Resources: promote basin-to-basin reporting
consistency, but expect assessment to proceed with basin-specific approaches…
○ Program Information: David Raff, [email protected]