The St. Croix River, its tributary streams and rivers, and Lake St. Croix are highly valued resources that provide exceptional recreational opportunities and support diverse wildlife in and out of the water. However, over the years eutrophication, or nutrient enrichment, has occurred in Lake St. Croix due to increasing amounts of phosphorus entering the lake from the watershed. The elevated level of phosphorus in Lake St. Croix results in algae blooms which diminish the enjoyment and use of the lake and impact the ecologic integrity. Elevated phosphorus levels not only impact Lake St. Croix, but also impact tributary streams, rivers, and lakes throughout the watershed. While progress has been made in recent years to understand and reduce the amount of phosphorus finding its way into streams and lakes, much work remains. The Implementation Plan has been developed to meet the Lake St. Croix Nutrient Total Maximum Daily Load (TMDL). Section 303(d) of the federal Clean Water Act and EPA's Water Quality Planning and Management Regulations (40 CFR Part 130) require states to develop TMDLs for water bodies that are not meeting water quality standards. The TMDL process establishes the allowable loading of pollutants for a water body based on the relationship between pollution sources and conditions in the water body. By following the TMDL process, states can establish water quality-based controls to reduce pollution and restore and maintain the quality of their water resources. Once a TMDL is established, an Implementation Plan must be developed. The Implementation Plan is designed to ensure that the required reductions in pollutant loadings identified by the TMDL will be achieved. The Implementation Plan provides information on management measures and regulatory controls; timelines for implementation of management measures and attainment of water quality standards; a monitoring plan designed to determine the effectiveness of implementation actions; and a description of adaptive management procedures. In order to meet the goals for Lake St. Croix and improve water quality throughout the watershed, communities and landowners in the St. Croix Basin will need to reduce phosphorus in wastewater treatment facility discharges and storm water runoff from urban, residential, agricultural, and forestry land. Restoration of water quality depends upon local support as many phosphorus reduction activities will require voluntary efforts on privately owned land areas. Effective watershed management involves citizens, landowners, state and local government agencies, and non-profit agencies all working together to sustainably manage local water resources. This Implementation Plan presents the essential components of a watershed based plan to restore and protect Lake St. Croix and its tributary streams from the impacts of excessive phosphorus loadings.

Addendum to Lake St. Croix TMDL implementation plan

Lake St. Croix Nutrient Total Maximum Daily Load Nine Key Element Plan - The St. Croix River, its tributary streams and rivers, and Lake St. Croix are highly valued resources that provide exceptional recreational opportunities and support diverse wildlife in and out of the water. However, over the years eutrophication, or nutrient enrichment, has occurred in Lake St. Croix due to increasing amounts of phosphorus entering the lake from the watershed. The elevated level of phosphorus in Lake St. Croix results in algae blooms which diminish the enjoyment and use of the lake and impact the ecologic integrity. Elevated phosphorus levels not only impact Lake St. Croix, but also impact tributary streams, rivers, and lakes throughout the watershed. While progress has been made in recent years to understand and reduce the amount of phosphorus finding its way into streams and lakes, much work remains.

Lake St. Croix Nutrient Total Maximum Daily Load Nine Key Element Plan - The St. Croix River, its tributary streams and rivers, and Lake St. Croix are highly valued resources that provide exceptional recreational opportunities and support diverse wildlife in and out of the water. However, over the years eutrophication, or nutrient enrichment, has occurred in Lake St. Croix due to increasing amounts of phosphorus entering the lake from the watershed. The elevated level of phosphorus in Lake St. Croix results in algae blooms which diminish the enjoyment and use of the lake and impact the ecologic integrity. Elevated phosphorus levels not only impact Lake St. Croix, but also impact tributary streams, rivers, and lakes throughout the watershed. While progress has been made in recent years to understand and reduce the amount of phosphorus finding its way into streams and lakes, much work remains.