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File #: AI 13-3746    Version: 1 Name: UT Tree ring study 26-007-AMS
Type: Action Item Status: Agenda Ready
File created: 3/30/2026 In control: Board of Directors
On agenda: 4/14/2026 Final action:
Title: Consider recommendation from the Research & Technology Committee to approve an Interlocal Cooperation Contract with The University of Texas at Austin, in an amount not to exceed $165,299.43, for a historical climate variability study.
Attachments: 1. 26-007-AMS UT for_Long-Term Climate Variability and Influence_Through Tree Ring Streamflow_Reconstruction Exp 12-2027, 2. 48I1937-26-0XX-AMS Resolution and Order UT
Title
Consider recommendation from the Research & Technology Committee to approve an Interlocal Cooperation Contract with The University of Texas at Austin, in an amount not to exceed $165,299.43, for a historical climate variability study.

Body
RECOMMENDED MOTION:

Move the board adopt Resolution and Order No. 04-26-141 of the Edwards Aquifer Authority Board of Directors approving Contract No. 26-007-AMS between the EAA and the University of Texas at Austin, in an amount not to exceed $165,299.43, upon signature by both parties, through December 31, 2027.


SUMMARY:

The purpose of this agenda item is for the board to consider a Research & Technology Committee recommendation to approve a contract between the EAA and the University of Texas at Austin for a historical climate variability study. The project will develop multi-century tree-ring records using bald cypress trees to improve understanding of long-term climate variability and its influence on streamflow and recharge within the Edwards Aquifer region. The work focuses on filling critical geographic data gaps and establishing a west-east transect to better capture spatial differences in precipitation, drought patterns, and hydrologic response.

Key tasks include:

· Field Sampling: Collection of tree-ring cores from riparian sites across the eastern, central, and western Edwards Aquifer region, including permitting and site access.
· Chronology Development: Processing, measuring, and cross-dating samples to create and expand tree-ring chronologies, including development of new datasets in underrepresented western areas.
· Environmental Reconstruction: Application of statistical methods to reconstruct historical seasonal climate conditions and streamflow for major recharge rivers (e.g., Frio, Medina, Cibolo, and Blanco).
· Spatial Analysis: Evaluation of east-west differences in climate variability and aquifer recharge dynamics, including assessment of shifting aridity gradients.
· Reporting: Preparat...

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