pumping rates, some areas within the glacial deposits
became dewatered. Model simulations using the Canadian
Population growth is expected, which will place
models showed dewatering of about 4.4 km2 within this
watershed. Even though there was an increase in recharge,
additional stress on the ground water supply and
an area of about 0.5 km2 was dewatered under the Hadley
will add to the effects on ground water from climate
model predictions (Lofgren et al. 2002b).
change, therefore a larger decline in ground water
Any reductions in stream base flow as a result of climate
levels and significant dewatered areas can be
change will have severe implications for ground water
dependant species, such as brook trout, some species of
lungless salamanders, and other plants and animals. Brook
trout require ground water upwellings to spawn and for fry
to grow and hatch, whereas the salamanders need cool, wet
ground water recharge and declining ground water levels.
ground water seepage areas to complete their life cycle.
The quality of ground water may be degraded by falling
Without these ground water discharges, the communities
levels and slow recharge. High intensity rainfall is more
in which brook trout and lungless salamanders live will see
likely to wash contaminants into surface water sources as
drastic alterations in community balance.
overland flow rather than allow gentle infiltration down to
the water table. However, if withdrawals increase, and
Areas that rely heavily on ground water for their water
recharge decreases, the amount of the ground water in an
supply may be significantly affected by climate change.
aquifer will decrease, possibly concentrating the contami-
Dewatered areas can no longer support wells for domestic
nants that may be within it. Because we are unsure as to
supply. Population growth is expected, which will place
how precipitation will change, it is still unclear whether
additional stress on the ground water supply and will add
climate change will have a significant effect on ground
to the effects on ground water from climate change,
water contamination (Adams and Gleick, 2000).
therefore a larger decline in ground water levels and
significant dewatered areas can be expected.
An evaluation of the effect of climate change on ground
water resources in the Lansing, Michigan area was made by
U.S. National Oceanic and Atmospheric Administration and
the Great Lakes Environmental Research Laboratory using
the Hadley Centre Model and the Canadian Model. A
The Council recommends the following to the IJC.
combination of a lake-evaporation model and a runoff
model was used to estimate stream flow, which was then
Recommend to the Parties that research funding
used to input into a ground water flow model. Results
be directed to the following areas related to the
from this process would amplify any mistakes, as results
impact of climate change on sources of ground
from each model were used as inputs for the next step.
water in the Great Lakes basin.
In terms of ground water, the Canadian model predicted a
Examine historical data to determine how climate
reduction in ground water levels in the Saginaw Aquifer
changes have affected ground water quality and
leading to a 19.7 percent decrease in base flow to streams
quantity, to identify linkages between ground
in 2030 (Lofgren et al. 2002b). Estimations using the
water and species/community distribution, to
Hadley model predicted an increase in ground water levels
understand temporal and spatial variability and to
and an increase in base flow of 4.1 percent. When 1995
assess how physical alterations of the land surface
pumping rates were applied to the scenario, ground water
affect ground water recharge.
levels declined by 2.7 meters for the Canadian model, and
increased by 0.1 meter under the Hadley predictions
Improve Regional Climate Models and make them
(Lofgren et al. 2002b).
accurate for smaller scales so as to understand
linkages to ground water and runoff at scales of
When applying these changes to the hydrological process,
overall ground water contribution to stream flow fell by 32
percent under the Canadian model and increased 6 percent
Maintain or increase regional and national moni-
under the Hadley model predictions, using the 1995
toring of hydrologic information, assess aquifer
pumping rate (Lofgren et al. 2002b). The changes in base
extent, ground water availability and the impact of
flow contribution from ground water were even greater
climate change on recharge and evapotranspira-
when using projected 2030 pumping rates. Using the 2030