Workshop Report

Tree-ring reconstructions of streamflow and climate and their application to Colorado River Basin water management

Lower Colorado Regional Office, US Bureau of Reclamation

Boulder City, NV - November 13, 2008

Reclamation staff members from the Lower Colorado region had previously traveled to our workshops in Boulder and Tucson, so it seemed very appropriate for us to bring our workshop series to the regional office in Boulder City, and open it up to other river stakeholders in the Las Vegas area. We were surprised and pleased by the high level of interest in the workshop: including the presenters, there were about 50 participants, making this our largest workshop. Over half of the participants were from Reclamation (representing the regional, Boulder Canyon, Yuma, and Phoenix offices), plus contingents from the Southern Nevada Water Authority, Colorado River Commission of Nevada, and several other water entities in the Colorado River basin.

The first objective of the workshop was to provide participants with a general understanding of how tree-ring reconstructions of streamflow are generated, to facilitate useful interpretation and application of these data. Connie and I presented a version of our main instructional presentation ("Tree-Ring 101"--see link below) which covered the essentials of how we go from the tree in the field to a streamflow reconstructions, or paleohydrology. The second objective was to introduce participants to a range of analyses and applications of the reconstructions for the Colorado River basin, including recent and ongoing applications by Reclamation, which was accomplished via several excellent presentations by our invited presenters (see links below).

Thanks again to Paul Miller, Doug Blatchford, Steve Hvinden, Terry Fulp, and other Reclamation staff for making this workshop possible, to the other presenters, and to all of the workshop participants for their interest and engagement.

Jeff Lukas, University of Colorado & WWA
Connie Woodhouse, University of Arizona & WWA

Workshop Presentations (PDFs):

Tree-ring reconstructions of streamflow and climate and their application to Colorado River Basin water management ("Tree-Ring 101") - Jeff Lukas, University of Colorado, and Connie Woodhouse, University of Arizona

Context and background
How tree rings record hydroclimatic information
Building the tree-ring chronology
How reconstructions of climate and streamflow are generated
Uncertainty in the reconstructions
What reconstruction data are available for the CRB and the West
What the latest reconstructions for the CRB show

Drought analysis using reconstructed snowpack and streamflow in the Upper Colorado basin - Tom Piechota, University of Nevada, Las Vegas, and Glenn Tootle, University of Tennessee, Knoxville

Tree-ring extension of hydrological records for selected eastern Nevada valleys: building the dataset - Franco Biondi and Scotty Strachan, University of Nevada, Reno, and Joe Leising, Southern Nevada Water Authority

Applying tree-ring reconstructions in Reclamation water management models - Dave Meko and Kiyomi Morino, University of Arizona

Combining paleo-reconstructed variability with observed and projected future flows: the hydrologic sensitivity analyses in the recent Shortage FEIS and an ongoing study – Jim Prairie, US Bureau of Reclamation