Watershed Assessment of Detroit River Nutrient Loads to Lake Erie

Kelly Island
Detroit River WatershedsProject study area. Click for a detailed map. (PDF)

The rivers flowing into Lake Erie carry nutrients such as phosphorus that can lead to nuisance and harmful algal blooms in its western basin, and hypoxic (low oxygen levels) conditions in its central basin. Despite nutrient management efforts, algal blooms and hypoxia that impact fishing, swimming, tourism and drinking water systems have become more extensive in recent years. The sources contributing to Detroit River’s nutrient loads are somewhat uncertain due to limited data and lack of attention to its watersheds, and this uncertainty has complicated efforts to develop a regional strategy for reducing nutrient inputs.

Through the 2012 Great Lakes Water Quality Agreement, the U.S. and Canadian governments are developing strategies and domestic action plans to reach specific water quality goals. Phosphorus inputs (loads) have been identified as a central driver for Lake Erie, but it is not clear which management techniques and locations should be targeted to most efficiently and effectively reduce inputs. For example, what level of emphasis should be placed on combined sewer overflow releases, run-off from agricultural lands, or point sources of nutrients?

Modeling Approach

This study will model the nutrient dynamics in the watersheds that drain into the St. Clair and Detroit Rivers.  This bi-national watershed includes the Clinton, Rouge, Sydenham and Thames Rivers, as well as Lake St Clair and inputs from the cities of Detroit, London and Windsor.

The research team is developing three unique models that can simulate the dynamics of this complex watershed that includes extensive urban and agricultural environments on both sides of the border as well as a large lake (Lake St. Clair) that receives and processes much of the loads upstream of the Detroit River. The three models being developed are:

  • An urban model to characterize loads from the greater Detroit area;
  • A regional watershed model for the entire study area using the Soil and Water Assessment Tool (SWAT); and
  • A Lake St. Clair model to explore nutrient transport and retention in the lake.

The planned modeling approach is designed to characterize nutrient loads to the Detroit River and then compare the efficacy of different management options. The University of Michigan team conducting this effort has modeled other river systems connected to Lake Erie, including the Maumee, Huron, and Raisin river watersheds.

Input from Policy and Management Advisors

A project advisory group will provide feedback on the policy context, planned research approach, and resulting products. The advisory group includes representatives from federal, state, and provincial governments; non-profits; universities; and local organizations actively involved in watershed management, policy development or applied research. Through bi-annual meetings and ongoing communication, the advisory group will help ensure the research is scientifically credible and the results are relevant and usable for the Great Lakes policy and management community. Follow the link below to review slides and notes from prior meetings.

Additional Information

Funding: This project is supported by the Fred A. and Barbara M. Erb Family Foundation

Project Period : January 2016 – December 2018

Project References

Project fact sheet
Participant list
How SWAT models P - project handout
Draft summary of data and assumptions for SWAT
Compiled list of scenario ideas

Background Resources

Maumee River modeling project
Related journal articles, visit: Scavia lab group and Kerkez lab group
Phosphorus reduction targets announced
Great Lakes Water Quality Agreement Annex 4
Domestic Action Plans for Lake Erie

Project Contacts

Jennifer Read, Water Center Director; 734-763-2642; jenread@umich.edu
Don Scavia, Graham Sustainability Institute
Branko Kerkez, Civil and Environmental Engineering