This 2020 study, Comparing Streamflow Depletion Estimation Approaches in a Heavily Stressed, Conjunctively Managed Aquifer, offers a comparison of analytical depletion functions (ADFs) against a validated numerical model created for estimating streamflow depletion. This numerical model was developed as part of an interstate compact, and as such had substantially greater effort put into its development and calibration compared to models used for comparison studies elsewhere. Authors Samuel C. Zipper, Tom Gleeson, Qiang Li, and Ben Kerr conducted the study in the highly stressed aquifer of the Republican River (Colorado/Kansas, USA) with funding from NSERC, Kansas Geological Survey, the University of Victoria, and Foundry Spatial. Overall, the ADF produced comparable results to the validated numerical model at a fraction of the cost and time.

In this 2019 study, Cannabis and residential groundwater pumping impacts on streamflow and ecosystems in Northern California, authors Samuel C Zipper, Jennifer K Carah, Christopher Dillis, Tom Gleeson, Ben Kerr, Melissa M Rohde, Jeanette K Howard, and Julie K H Zimmerman demonstrate the application of analytical depletion functions for evaluating impacts of groundwater pumping from different water uses.

This study was made possible with funding from the Natural Sciences and Engineering Resources Council of Canada, SD Bechtel, Jr. Foundation, University of Victoria, The Nature Conservancy — California, and Foundry Spatial. With their help, authors quantified the impact of an emerging agricultural frontier, Cannabis cultivation, on water resources, using the Navarro River (Coastal Range) in Northern California as a case study.

Conducted in 2019 at the Navarro River (Coastal Range) in Northern California, the Rapid and Accurate Estimates of Streamflow Depletion Caused by Groundwater Pumping Using Analytical Depletion Functions study tested 50 combinations of analytical depletion functions against an ‘archetypal’ numerical model.

Overall, authors Samuel C. Zipper, Tom Gleeson, Ben Kerr, Jeanette K. Howard, Melissa M. Rohde, Jennifer Carah, and Julie Zimmerman found that the performance of analytical depletion functions was comparable to archetypal numerical models. With the help of funding from the Natural Sciences and Engineering Resources Council of Canada, S.D. Bechtel, Jr. Foundation, University of Victoria, The Nature Conservancy — California, and Foundry Spatial, researchers also identified that the new approach works best in flatter terrain, with wells close to streams.

Published in May 2018, this study, Groundwater Pumping Impacts on Real Stream Networks: Testing the Performance of Simple Management Tools, defined three components of the analytical model approach: analytical model, apportionment method, and area of influence. Funded by the Government of Canada (NSERC) and the University of Victoria, this study provides the first test against numerical models using the groundwater flow system around Nanaimo on Vancouver Island, B.C. as the exemplar.

Overall, authors Samuel C. Zipper, Tom Dallemange, Tom Gleeson, Thomas C. Boerman and Andreas Hartmann identified the significance of stream geometry and drainage network for calculating estimates.