Indiana's Great Lakes Water Quality Agreement (GLWQA) Domestic Action Plan (DAP) for the Western Lake Erie Basin (WLEB)

The Great Lakes Nutrients Annex (Annex 4) is charged with coordinating actions to manage phosphorus loadings and concentrations within the Great Lakes. Indiana has been an active member of the Nutrients Annex since its establishment in 2013. Indiana’s commitment under the Nutrients Annex includes the development of a Domestic Action Plan (DAP) to assist in meeting nearshore and open water phosphorus objectives and loading targets for Lake Erie.

The focus of Indiana’s DAP is the 40% reduction goal for the Maumee River, which drives hazardous algal blooms (HABs) in the WLEB and contributes to central basin hypoxia.  The Maumee River is formed near Fort Wayne at the confluence of the St. Joseph River and the St. Mary’s River both of which enter Indiana from Ohio.  The Maumee River flows approximately 29 miles eastward into and through Ohio for another 108 miles to its mouth at Maumee Bay in Lake Erie near Toledo.

Indiana’s goal is to meet the spring-time flow weighted mean concentration (FWMC) targets of 0.23 mg/L and 0.05 mg/L for total phosphorus (TP) and dissolved reactive phosphorus (DRP) respectively in the Maumee River as it flows across the border into Ohio.  Indiana affirms that the reduction planned for the Maumee River will address Indiana’s obligation for the 40% phosphorus load reductions entering the WLEB to reduce both HABs therein and hypoxia in the central basin.