Zipper et al. (2026) Lagged streamflow depletion due to pumping-induced stream drying: Incorporation into analytical streamflow depletion estimation methods

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Authors: Sam Zipper, Ian Gambill, Monty Schmitt, Claire Kouba, Leland Scantlebury, Thomas Harter, Nicholas P. Murphy
• DOI: 10.1016/j.jhydrol.2026.134909

Research Groups

• Kansas Geological Survey, University of Kansas, USA
• Department of Geology, University of Kansas, USA
• The Nature Conservancy, Sacramento, California, USA
• Yale University, School of the Environment, USA
• Hydrologic Sciences Graduate Group, University of California, Davis, USA
• Department of Land, Air and Water Resources, University of California, Davis, USA

Short Summary

This study develops a method to incorporate stream drying and network routing into Analytical Depletion Functions (ADFs), improving their ability to estimate streamflow depletion in non-perennial systems. The findings reveal that stream drying causes a temporal shift, lagging a significant portion of streamflow depletion until the stream network rewets in the fall and winter.

Objective

• To determine how the incorporation of stream drying and downstream routing affects the timing of streamflow depletion and the accuracy of ADFs in simulating spatiotemporal patterns of streamflow compared to numerical models and observational data.

Study Configuration

• Spatial Scale: Scott Valley, California, USA (aquifer area: ~200 km²; total watershed area: ~2100 km²).
• Temporal Scale: 33 years (October 1, 1990, to September 30, 2023) using 5-day simulation timesteps.

Methodology and Data

• Models used: Analytical Depletion Functions (ADFs) utilizing the Hunt (1999) and Glover & Balmer (1954) analytical solutions; Scott Valley Integrated Hydrologic Model (SVIHM), which is based on MODFLOW-NWT.
• Data sources: USGS streamflow gauge data (Fort Jones, gauge 11519500); California Natural Flows Database (CNFD) for monthly unimpaired flow estimates; SVIHM-derived hydrostratigraphic parameters (transmissivity and storativity) and pumping schedules.
• Novel Approach: A water budget-based "banking" algorithm was developed to redistribute potential depletion in time when streamflow is insufficient to meet depletion demand, propagating these effects downstream through a directed graph stream network.

Main Results

• Model Accuracy: ADFs incorporating stream drying showed high agreement with observed streamflow at the watershed outlet (KGE = 0.91, R² = 0.92, normalized RMSE = 5.9%), performing significantly better than ADFs without drying (KGE = 0.02).
• Lagged Depletion: The study identified a "double peak" in streamflow depletion. The first peak occurs during the summer pumping season; the second peak occurs during fall/winter rewetting, as streamflow is lost to refill groundwater storage depleted during the dry period.
• Management Thresholds: ADFs with drying accurately simulated the duration of streamflow below critical environmental thresholds (Mean Absolute Error = 7.3%), matching the performance of the locally calibrated numerical model (SVIHM).
• Regional Data Utility: Using CNFD data as an input for "water available" allowed ADFs to capture correct temporal dynamics but resulted in a high streamflow bias, suggesting a need for local bias correction in unmodeled basins.

Contributions

• Process Representation: First study to integrate a mechanistic stream-drying and routing framework into ADFs, addressing the "infinite water" assumption of traditional analytical models.
• Ecohydrological Insight: Quantified the magnitude and timing of lagged streamflow depletion, which is critical for managing salmonid habitats in Mediterranean climates.
• Scalability: Demonstrated a pathway for using regional statistical models (like CNFD) to implement low-cost streamflow depletion assessments in watersheds lacking complex numerical models.

Funding

• The Nature Conservancy (Grants #10192023-16680 and #06132024-17291).

Citation

@article{Zipper2026Lagged,
  author = {Zipper, Sam and Gambill, Ian and Schmitt, Monty and Kouba, Claire and Scantlebury, Leland and Harter, Thomas and Murphy, Nicholas P.},
  title = {Lagged streamflow depletion due to pumping-induced stream drying: Incorporation into analytical streamflow depletion estimation methods},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.134909},
  url = {https://doi.org/10.1016/j.jhydrol.2026.134909}
}

Generated by BiblioAssistant using gemini-3-flash-preview (Google API)