MODFLOW 6 Datasets for a Groundwater-flow Model in the Saco River Basin, New Hampshire and Maine

A MODFLOW 6 groundwater model for the Wards Brook aquifer in New Hampshire and Maine was developed to understand the effects of groundwater withdrawals for historical and potential future conditions. The model assesses how groundwater withdrawals, including for bottled water, affect base flows from Wards Brook, groundwater levels, and pond levels under different scenarios.

Model runs included a calibrated transient groundwater-flow model for calendar years 2016 to 2021 used to simulate scenarios which included water withdrawals (‘1_original’), no pumping (‘2_no_pumping’), and pumping only for municipal water use (‘3_no_bottled_water_pumping’). The final transient scenario (‘3_no_bottled_water_pumping’) was developed to help identify the effects of groundwater withdrawals for bottled water as compared to municipal water supply. A dynamic-equilibrium transient model with monthly stress periods was created as a base case (‘4_base_climate’) for comparison with future recharge scenarios (‘5_climate_scenarios’) that were created using meteorological data from five downscaled General Circulation Models (GCM) and Representative Concentration Pathways (RCP) 4.5, and 8.5 Bias-Corrected Constructed Analogs V2 Daily Future Coupled Model Intercomparison Project Phase 5(CMIP5) climate projections. The simulations based on recharge derived from GCM data used the mean recharge for calendar years 2016 to 2021, 2046 to 2065, and 2080 to 2099.  Additional hypothetical drought scenarios were created for each GCM / RCP based on a three-year drought with the lowest annual recharge for each time period.

This data release includes MODFLOW 6 input files for the simulated scenarios, as well as associated ancillary and supporting files. Considering the repetitive nature and computer storage requirements of each MODFLOW 6 output file, a representative example of output from one scenario run among the many in ‘5_climate_scenarios’ was included in this data release. 

Development of the MODFLOW 6 model input files and associated output files included in this data release are documented in the associated Scientific Investigations Report. A soil-water-balance (SWB) model was used to estimate groundwater recharge. The development of that model is documented in the same report and the input and output files for the SWB model are in a U.S. Geological Survey data release (Holland and Barclay, 2026).

Interpretive Report:
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Mullaney, J., Barclay, J., Stanton, J., Carlson, C., and Holland, M., 2026, 
Effects of Groundwater Withdrawals for Water Bottling and Municipal Use, 
Wards Brook Valley, Maine and New Hampshire. Environmental Sciences Preprint
(eartharxiv), https://doi.org/10.31223/X5KN1M.y


Other Associated Data Releases:
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Holland, M.J., and Barclay, J.R., 2026, Soil-Water-Balance (SWB) model archive used to simulate potential recharge with projections for future climate scenarios, Saco River Basin, Maine and New Hampshire: U.S. Geological Survey data release, https://doi.org/10.5066/P90QS3H2oi.org/10.5066/P90QS3H2.