| Title | Numerical modeling of a regional groundwater flow system to assess groundwater storage loss, capture and sustainable exploitation of the transboundary Milk River Aquifer (Canada-USA) |
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| Author | Pétré, M -A; Rivera, A ; Lefebvre, R |
| Source | Journal of Hydrology vol. 575, 2019 p. 656-670, https://doi.org/10.1016/j.jhydrol.2019.05.057  Open Access |
| Image |  |
| Year | 2019 |
| Alt Series | Natural Resources Canada, Contribution Series 20190019 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html |
| Province | Alberta |
| NTS | 72E; 82H/01; 82H/08; 82H/09; 82H/16 |
| Area | Milk River; Aden; Taber; Bow Island; Skiff; Foremost; Warner; Manyberries; Montana; Sweetgrass Hills; Chester; Hill; Kevin; Cut Bank; Shelby; Canada; United States of America |
| Lat/Long WENS | -112.5000 -110.0000 50.0000 48.2500 |
| Subjects | hydrogeology; Science and Technology; Nature and Environment; groundwater resources; aquifers; groundwater flow; flow systems; modelling; buried valleys; water wells; artesian wells; hydraulic analyses;
hydraulic head; hydraulic conductivity; computer simulations; resource management; recharge rates; groundwater levels; pressure; Milk River Aquifer; Milk River Formation; Virgelle Member |
| Illustrations | location maps; geoscientific sketch maps; models; 3-D models; tables; plots; bar graphs |
| Program | Groundwater Geoscience National Aquifer Evaluation & Accounting |
| Released | 2019 05 22 |
| Abstract | Groundwater capture and storage loss play a major role in the sustainable exploitation of a regional aquifer. This study aimed to identify the impact of major and long-term groundwater exploitation on a
regional aquifer system to understand the processes controlling the sustainable exploitation of the transboundary Milk River Aquifer (MRA). The MRA extends over 26,300 km2, being a major water resource across southern Alberta (Canada) and northern
Montana (USA). Concerns about the sustainability of the MRA were raised as the century-old exploitation has led to important drawdowns and the local loss of historical artesian conditions. A steady-state numerical model of the regional flow system
was developed and calibrated against hydraulic heads, groundwater fluxes, and the area with flowing artesian wells. Four groundwater abstraction scenarios were simulated: 1) natural flow conditions without exploitation; 2) the mean abstraction rate
over the last 108 years; 3) the historical maximum global abstraction rate of the MRA; and 4) a theoretical high abstraction rate based on the maximum rate estimated for each MRA exploitation zone. The numerical model agrees with the previously
formulated conceptual model and supports its hydraulic plausibility. Results show that MRA exploitation has led to a major change in flow patterns to sustain groundwater abstraction. The MRA water balance under exploitation indicates that more
recharge and reduced seepage to bedrock valleys compensate groundwater withdrawals. Based on its impact on regional discharge and the reduction in MRA storage, the mean historical level of exploitation of the MRA appears sustainable. Larger
exploitation rates would significantly reduce groundwater discharge to surface seepage locations and lead to a larger reduction in groundwater storage in the MRA. Modeling also illustrates that the MRA is an internationally shared resource. This
situation would justify a joint management of the aquifer system between Canada and USA; especially in the area comprised between the recharge area in Montana and the Canadian reach of the Milk River. |
| Summary | (Plain Language Summary, not published)
The Milk River Aquifer (MRA) is a major resource across southern Alberta (Canada) and northern Montana (USA). There are concerns about the sustainability
of groundwater as its hundred-year exploitation led to important drawdowns and loss of artesian conditions. A numerical model of the groundwater flow system is use to assess the sustainability of the MRA and to support its transboundary management.
Four groundwater abstraction scenarios simulate natural flow conditions, actual mean abstraction rates, the historical maximum abstraction rate, and a theoretical high abstraction rate. Results show that the exploitation of the aquifer led to a major
change in flow patterns to support groundwater abstraction. Model results indicate that historical levels of aquifer exploitation appear sustainable. However, larger exploitation rates would significantly reduce groundwater discharge to surface
seepage locations leading to a larger reduction in groundwater storage in the MRA. This situation would justify implementing a joint management of the aquifer between Canada and the USA. |
| GEOSCAN ID | 314615 |
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