Pierre River Mine Project

WATER AENV SIRS 15 – 43
References
conductivity (Laitinen et al. 2008). Deeper peat layers are more
compacted and likely have less influence on the water table.
Section 12.1
• peak flows in boreal wetlands typically occur in late spring and early
summer (Devito and Mendoza 2006). In general, the water balance in
boreal wetlands is influenced by spring snow melt, but the numerous
small precipitation events in spring through to fall that add water directly
to wetlands are believed to have the most influence on boreal wetlands
(Devito and Mendoza 2006). Surface runoff from surrounding terrestrial
uplands is considered to be limited during these events relative to direct
input from precipitation.
• groundwater influences are uncertain and site specific primarily because
glacial deposits are highly variable (Price and Waddington 2000; Devito
and Mendoza 2006)
• depth of water table in unaltered peatlands can fluctuate seasonally and
annually. Thormann et al. (1998) have shown that annual water levels in
fens range between approximately 7 cm below the moss surface to 20 cm
above the moss surface. Patterned fens are typically subject to lower
seasonal fluctuations in water depth (approximately 5 cm) (Laitinen et al.
2008). Annual fluctuations in bogs are more consistent over time (Halsey
et al. 2003).
• drops in water table of 70 cm or more can drastically alter nutrient
regime and vegetation composition in peatlands (Jeglum 1971). Water
table declines (an estimated 20 cm for poor fens and 14 cm for
moderate-rich fens) may lead to moderate changes in peatland function
(Gignac et al. 1991).
• high and stable water levels are important to rich fen communities, as
these communities are generally dominated by sedges and moss
(Kotowski et al. 2001; Whitehouse and Bayley 2005)
Devito, K., and C. Mendoza. 2006. Maintenance and Dynamics of Natural
Wetlands in Western Boreal Forests: Synthesis of Current Understanding
from the Utikuma Research Study Area. In Guidelines for Wetland
Establishment on Reclaimed Oil Sands Leases Revised (2007) Edition,
Appendix C. Cumulative Environmental Management Association.
Wood Buffalo Region, Alberta.
Gignac, L.D., D.H. Vitt, and S.E. Bayley. 1991. Bryophyte Response Surfaces
Along Ecological and Climatic Gradients. Vegetation 93:29-45.
Halsey, L.A., D.H. Vitt, D. Beilman, S. Crow, S. Mehelcic, and R. Wells. 2003.
Alberta Wetland Inventory Standards Version 2.0. Resource Data
Division, Alberta Sustainable Resource Development. Edmonton,
Alberta.
12-34 Shell Canada Limited April 2010
CR029