Workshop Report

Tree-ring reconstructions of streamflow for the Rio Grande basin

Albuquerque, NM - November 2, 2007

This workshop was the first stage of a NOAA-funded project to expand and improve the usability of tree-ring reconstructions for drought planning and water management in the Rio Grande basin. Along with the three conveners (Lukas, Woodhouse, and Bathke), there were 23 workshop participants, representing a broad array of water management and stakeholder interests in the Rio Grande basin (see participant list).

Connie and Jeff presented a version of our main instructional presentation (PDF), including a section highlighting existing tree-ring streamflow reconstructions for the Rio Grande headwaters region in Colorado. This was followed by presentations by several participants on applications of the tree-ring data:

  • Karen MacClune, S.S. Papadopulos and Associates - Application of tree-ring data to water planning and management (PDF) - on the use of a PDSI reconstruction to generate hydrologic traces to run in the URGWOM model for the middle Rio Grande
  • Charlie Ester, Salt River Project - Application of tree-ring research results - Salt River Project (PDF) - on the use of drought sequences of streamflow reconstructions to test the robustness of operating rules)
  • Claudia Borchert, City of Santa Fe - on the management context for the application of soon-to-be-developed streamflow reconstructions for the Santa Fe River
  • Ben Harding, Hydrosphere Resource Consultants - Paleo is so old. Is it obsolete? (PDF) - on the limitations of GCM models in capturing interannual variability and the need for paleohydrologic data)

The workshop concluded with a discussion of the opportunities to reconstruct particular gages in the middle Rio Grande, a demonstration of online data analysis and presentation tools similar to ones that will be developed for this project, and a final period of open discussion. This discussion, and the questions and discussion throughout the presentations, reflected a high degree of interest in the tree-ring reconstructions among the participants, and a general appreciation that considering data beyond the observed flow record will be necessary for future management of the Rio Grande.

The next stages of the project will include the following:

  • Development of preliminary flow reconstructions for relevant gages in the basin (see below), and creation of online tools to allow user-selected data display and analysis of those reconstructions
  • A follow-up workshop in spring 2008 to present the results of the above
  • Final development of flow reconstructions and tools based on feedback from the workshop, and a web portal to provide easy access to the data and the analysis tools (now the Rio Grande Basin home page)

The workshop participants identified several gages that they wanted to see reconstructed, including the Rio Grande at Otowi Bridge, Rio Chama near La Puente, Rio Puerco (gage TBD), and Canadian River (gage TBD). One constraint is that the gage records need to be "naturalized" (corrected for depletions and diversions) and have at least 50 years of overlap with the tree-ring records. Staff from the NM Interstate Stream Commission have offered to assist us in locating or generating naturalized streamflow records.

We encourage the workshop participants, and other water managers and stakeholders in the basin, to contact us if they have additional gages to be reconstructed, or interest in additional products or resources.

(Update: see the report on the followup workshop in May 2008 for the results and products of the Rio Grande project.)

Jeff Lukas, University of Colorado & Western Water Assessment

The Rio Grande project team:

    Brad Udall, Western Water Assessment, University of Colorado
    Deborah Bathke, University of Nebraska