Stone et al. (2026) Vegetation groundwater use drives streamflow declines in Colorado River headwaters

Identification

• Journal: Communications Earth & Environment
• Year: 2026
• Date: 2026-09-14
• Authors: Harry Stone, R. M. Maxwell
• DOI: 10.1038/s43247-026-04045-2

Research Groups

• Department of Civil and Environmental Engineering, Princeton University
• High Meadows Environmental Institute, Princeton University
• Integrated GroundWater Modeling Center, Princeton University

Short Summary

This study reveals that vegetation in the Colorado River headwaters draws on shallow stream-bound groundwater to sustain evapotranspiration during dry periods, leading to reduced summer streamflow. The research demonstrates that growing-season temperature, not just winter snowpack, regulates streamflow through groundwater-supported ET.

Objective

• Investigate the mechanisms linking rising temperatures and streamflow decline in the Colorado River headwaters

Study Configuration

• Spatial Scale: Local (81-ha) to basin-wide (18 headwater catchments)
• Temporal Scale: Daily to decadal (4 decades)

Methodology and Data

• Models used: Penman equation, eddy flux towers, sap flux sensors
• Data sources: Field measurements, satellite data, reanalysis

Main Results

• Vegetation sustains ET during dry periods by accessing shallow groundwater
• Summer temperature independently regulates streamflow through changes in vegetation water use
• Groundwater-supported ET operates at regional scales, rivaling snowpack effects in magnitude

Contributions

• Provides new insights into the mechanisms driving summer streamflow decline in the Colorado River headwaters
• Highlights the importance of considering groundwater-supported ET in hydrological models
• Has implications for water management and climate change adaptation strategies in snowmelt-dependent regions

Funding

• This research was supported by funding from [insert funding agencies or programs, e.g., NSF, DOE, etc.], with reference codes [insert reference codes].

Citation

@article{Stone2026Vegetation,
  author = {Stone, Harry and Maxwell, R. M.},
  title = {Vegetation groundwater use drives streamflow declines in Colorado River headwaters},
  journal = {Communications Earth & Environment},
  year = {2026},
  doi = {10.1038/s43247-026-04045-2},
  url = {https://doi.org/10.1038/s43247-026-04045-2}
}