Workshop Report

Using tree-ring reconstructions of streamflow for water management in the Pacific Northwest

Spokane, WA - May 22, 2008

Sponsored by the University of Washington JISAO CSES Climate Impacts Group and NOAA Climate Program Office, Sector Applications Research Program (SARP)

Workshop presenters:

Jeremy Littell, Climate Impacts Group

Alan Hamlet, Climate Impacts Group

Connie Woodhouse, University of Arizona

As part of a NOAA-funded project to develop tree-ring reconstructions of streamflow in the Pacific Northwest, the Climate Impacts Group convened a one-day workshop to:

    • provide information on how reconstructions are developed from tree-ring data
    • describe the potential for tree-ring reconstructions in municipal and agricultural basins of the Pacific Northwest
    • solicit feedback from water managers and professionals on needs that could be addressed with tree-ring reconstructions
    • initiate collaborations to develop reconstructions and products useful for water management

The objectives of this first tree-ring workshop in the Pacific Northwest were to get a better sense of the information needs of water managers in the region, and compile a list of target gages in the Columbia Basin and the west slope of the Cascades for which paleoclimatic information could be helpful in decision making. The workshop participants included staff from the Idaho Department of Water Resources, Seattle Public Utilities, Portland Water Bureau, and the US Bureau of Reclamation. Participant comments indicated that hydrologic model experiments that incorporated the variability evident in the tree-ring record would potentially be useful for scenario building exercises. The Idaho participants also thought the development of tree ring chronologies and reconstructions for Idaho basins would be very useful, and this led to a focus on work in Idaho the summer of 2008, with three updated chronologies and further analysis on 24 existing chronologies in northern Idaho.

The Spokane River was near all-time record high flows during the meeting, and several participants who had indicated they would participate had to cancel the week prior to the workshop, ironically, to stay home and manage the high water.

Links to workshop presentations (all PDF):