Alteration of the flow regimes of rivers greatly impacts their ecological integrity.  Through direct physical change, including dams, culverts, dredging and channelization, the flow of rivers has been dramatically altered. No less importantly, changing land use, particularly the transformation of forested to agricultural and urban lands, with increases in impermeability and runoff, has indirectly altered river flow by affecting the hydrologic pathways that generate runoff.  This project addresses the need for a synoptic and basin-wide assessment of the extent of flow regulation of Great Lakes tributaries, impacts on the physical habitat and the biota, and the opportunities for innovative and effective restoration.  Through a coordinated program that includes new research, analysis and synthesis of existing data, outreach, and web-based information transfer, this project will provide a basin-wide assessment of the ecological benefits of flow restoration.  This science-based synthesis of restoration potential will inform agency personnel, environmental organizations and private grant makers of need, opportunity, and potential targets for flow restoration, hopefully energizing the Great Lakes community to restore the basin's ecological integrity.

The Natural Flow Regime paradigm provides a guiding concept and analytic foundation for environmental restoration planning, implementation, and evaluation.  The central proposition of the Natural Flow Regime Paradigm (Poff et al. 1997) is that the ecological integrity of flowing water systems depends on their natural dynamic character.  Deviations from a natural flow regime should then act as indicators of stream degradation.  Altered streamflows are well known to be associated with poor channel habitats, accelerated erosion, bank instability, and diminished base flow.  Restoration of stream habitats and water quality therefore depends on restoring, to the extent possible, the natural pattern of streamflow.

 
Project Goal:

Complete an analysis of flow regimes and their degree of alteration for Great Lakes Basin rivers, accessible over the web using maps and icons, and suitable for use by managers and community groups in targeting restoration activities.

Specific Objectives:

1. Describe hydrologic regimes of (US) Great Lakes Basin rivers
Spatial and temporal variability in hydrologic regimes will be quantified for representative USGS streamflow gaging sites.  Using flow exceedence curves and indicators of hydrologic variability, comparisons over the temporal record and among locations will reveal patterns in flow regime and extent of flow alteration from river segments across the US portion of the Great Lakes Basin.

2.  Assess influence of dams and land use on variation in flow regimes
The influence of dams vs land use on flow regimes will be analyzed across space and through time by developing multiple regression models of flow parameters, testing the explanatory power of independent variables including land use, dams, climate, and physiography.

3.  Determine how flow alteration affects the fish assemblage
Using existing fish assemblage data for sites that we can categorize hydrologically, we will determine changes in the composition and relative abundance of species and in functional attributes, in order to determine the extent to which fish assemblages have changed in response to flow regime.

4.  Map flow regime, flow alteration, and relevant databases for restoration activities
Clickable maps will be provided over the internet, displaying Great Lakes Basin rivers and their flow regimes, dams, fish assemblages, and narrative information, making the outcomes of our investigations readily accessible to potential users.  Meetings with managers and community groups early and near completion of this project will maximize relevance of the disseminated outcomes.
 
 

Longnose Sucker	Gibson Dam	White Sucker