Geoscience Reference
In-Depth Information
turn has caused increases in turbidity and embeddedness of substrate within the
stream channels. Removal of streamside vegetation has contributed to the problem
of increased erosion, and also caused an increase in the temperature of waters and
reduced oxygen concentrations. Together, these changes have selected for species
of aquatic macroinvertebrates and fish that are more tolerant to these types of
environmental conditions.
7.2 Project Goals and Objectives
The objective of this study was to identify specific sites and develop conceptual
plans for wetland and riparian restoration within the watersheds that, once
implemented, would have measurable positive impacts on the following Beneficial
Use Impairments (BUIs) as identified within these two watersheds which are part of
the Great Lakes Area of Concern for the lower Maumee River basin: degradation of
fish and wildlife populations; degradation of benthos; and loss of fish and wildlife
habitats (MRAC
2006
). Ohio EPA has identified these BUIs as priorities to address
within Great Lakes Areas of Concern (including the Maumee AOC where these two
watersheds are located) and has provided guidance as to targeted goals to achieve
through restoration (OEPA
2005
).
As a secondary goal, this study is also intended to provide wetland and stream
restoration opportunities for permit applicants who are required to mitigate lost
wetlands and stream habitat and functions under Sections 404 and 401 of the Clean
Water Act and the State of Ohio's Isolated Wetlands Law. Past experiences have
shown that with no local mitigation opportunities readily available, wetland miti-
gation has oftentimes been accomplished outside of the watersheds where the
impacts have occurred, either by restoring wetland habitat on project specific
sites, or by purchasing wetland mitigation credits from a wetland mitigation bank
that has been approved to service an area that encompasses several watersheds.
While such mitigation projects meet the mitigation requirements under Sections
404 and 401 of the Clean Water Act, without the replacement of wetland and stream
functions within the watershed where the impacts occur, the identified BUIs may
continue to decline in the Swan Creek and Tenmile Creek/Ottawa River watersheds
as more wetland and stream impacts occur (MRAC
2006
).
7.3 Methods
In order to develop the necessary mapping to assist in the evaluation of existing
conditions and the development of conceptual wetland and/or stream restor-
ation plans, GIS shape files and other electronic data were gathered that were
available for the two watersheds (Table
7.1
). Using these data sources, the
