Pierre River Mine Project

WATER AENV SIRS 15 – 43
References
For lakes:
• head was based on the lake elevation
• the width was equal to the width of the model cell
• the lakebed thickness was 5 m
• the lakebed hydraulic conductivity was 1 x 10 -8 m/s
For drain boundaries at the ground surface (representing wetlands and
ephemeral streams):
• the drain stage (or head) was equal to topography
Section 12.1
• the width and length of the drain was equal to the width and length of the
model cell
• the thickness of the drainbed was 1 m
• the hydraulic conductivity of the drainbed was 1 x 10 -8 m/s
For drain boundaries in aquifer layers (representing dewatering and
depressurization):
• the drain stage (or head) was equal to the bottom elevation of the
Quaternary deposits (for overburden dewatering) or the top elevation of
the basal aquifer
• the width and length of the drain was equal to the width and length of the
model cell
• the thickness of the drainbed was 1 m
• the hydraulic conductivity of the drainbed was 1 x 10 -8 m/s
De Marsily, G. 1986. Quantitative Hydrogeology, Groundwater Hydrology for
Engineers. Academic Press Inc., London. 440 pp.
Environmental Simulations Inc. 2004. Guide to Using Groundwater Vistas,
Version 4.
ii. The calibration results were insensitive to the head-dependent flux boundary
input parameters because the flows represented by these boundaries are
generally small in comparison to the regional inflows and outflows.
The calibration results were most sensitive to values of recharge and
hydraulic conductivity, so these parameters were investigated with prediction
confidence simulations (see EIA, Volume 4B, Appendix 4-1, Sections
1.2.2.7, 1.2.3.7 and 1.2.4.7).
April 2010 Shell Canada Limited 12-17
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