Simulated environmental effects of wetland restoration scenarios in a typical Canadian prairie watershed / Wanhong Yang, Xixi Wang, Yongbo Liu, Shane Gabor, Lyle Boychuk, and Pascal Badiou.

Includes bibliographical references (pages 278-279).

Wetland conservation and restoration
contribute to improved watershed functions through
providing both water quantity benefits in terms of
flood attenuation and water quality benefits such as
retention of sediment and nutrients. However, it is
important to quantify these environmental benefits for
informed decision making. This study uses a ‘‘hydrologic
equivalent wetland’’ concept in the Soil and
Water Assessment Tool to examine the effects of
various wetland restoration scenarios on stream flow
and sediment at a watershed scale. The modeling
system was applied to the 25,139 ha Broughton’s
Creek watershed in western Manitoba in Canada. As
a representative prairie watershed, the Broughton’s
Creek watershed experienced historic wetland losses
from 2,998 ha in 1968 to 2,379 ha in 2005. Modeling
results showed that if wetlands in the Broughton’s
Creek watershed can be restored to the 1968 level, the
peak discharge and average sediment loading can be
reduced by 23.4 and 16.9%, respectively at the
watershed outlet. Based on wetland and stream
drainage areas estimated by the model and empirical
nutrient export coefficients, the corresponding water
quality benefits in terms of reductions in total
phosphorus and nitrogen loadings were estimated at
23.4%. The modeling results are helpful for designing
effective watershed restoration strategies in the
Broughton’s Creek watershed. The developed methodology
can be also applied to other study areas for
examining the environmental effects of wetland
restoration scenarios.