Lake Mallalieu TMDL
TMDL Development
Approved TMDL
Implement TMDL
Evaluate for Delisting

Project Description

Lake Mallalieu is a man-made riverine lake located within the channel of the Willow River. Since 2004, Lake Mallalieu and an upstream reach of the Willow River have been included on the Environmental Protection Agency (EPA) 303(d) impaired waters list. The lake is designated as high priority for eutrophication and ph impairments due to excess phosphorus, while the upstream reach of the river is a low priority for dissolved oxygen impairments. The river designation is due to excess phosphorus and biological oxygen demand (BOD).

The Clean Water Act and USEPA (United States Environmental Protection Agency) require Total Maximum Daily Load (TMDL) goals be developed for 303(d) listed waters. In light of this, Wisconsin Department of Natural Resources (WDNR) is required to prepare a phosphorus TMDL for Lake Mallalieu and its associated drainage area. Development of the TMDL goals has required monitoring of annual phosphorus loading upstream of the lake and of in-lake water quality conditions. Monitoring of phosphorus loads occurred in years 1991, 1999, 2003, and 2006. After monitoring was complete, a land use model using the Soil and Water Assessment Tool (SWAT) was developed to evaluate the effect of land management changes on the quality of water entering Lake Mallalieu (Almendinger 2008). In-lake water quality was modeled using the BATHTUB model (Oldenburg 2008). Information gathered from both the SWAT and BATHTUB models has been used to develop in-lake load reduction goals for the Lake Mallalieu/Willow River TMDL.

Due to excessive phosphorus, Lake Mallalieu is not currently meeting water quality criterion as defined in NR 102..04 (1); Wisconsin Administrative Code. In short, Lake Mallalieu currently cannot support a warm water sport fishery nor does it serve as a high quality recreational resource for its user. Contract with St. Croix County Lake Mallalieu put on "on hold". Will now be incorporated into a Lake Mallalieu/Willow River TMDL

Project Goals

The Implementation Plan identifies 10 elements as priorities for implementing the Lake Mallalieu/Willow River TMDL plan.

An identification of th causes and sources that will need to be controlled to achieve load reduction goals. Key Participants: WI DNR, St. Croix River Research Station, St. Croix County Land and Water Conservation Department, and University of Wisconsin Extension Discovery Farms Program.

An estimate of load reductions for management measures described. Key Participants: WI DNR and St. Croix County Land and water Conservation.

Non Point Source (NPS) management measures need implemention to achieve load reductions. Key Participants: St. Croix County Land and Water Conservation staff, Stakeholder group members.

Estimates of technical and financial assistance? for effective Plan implementationKey Participants: St. Croix County Land and Water Conservation Department, Wisconsin Department of Ag, Trade, and Consumer Protection, and WI DNR.

An Information and Education strategy. Key Participants: St. Croix County Land and Water Conservation staff and University of Wisconsin W Extension.

A schedule for implementing NPS management measures identified in the plan.
Key Participants: St. Croix County Land and Water Conservation staff and stakeholder Group members.

A description omeasurable milestones for determining whether management measures are being implemented. Key Participants: WI DNR and St. Croix County Land and Water Conservation Department staff.

Establish set of criteria that can be used to determine whether load reductions are being achieved. Key Participants: WI DNR, US Geological Survey (USGS), UW Extension Discovery Farm Program, St. Croix County Land and Water **9** Conservation Department

Establish a monitoring component to evaluate effectiveness of plan. Key Participants: WI DNR, USGS, and St. Croix County Land and Water Conservation Department.

Develop an Institutional Framework for how the plan?s management strategies will be delivered throughout the Willow River Watershed. Key Participants: Stakeholder Group members, St. Croix county Land and Water Conservation Department staff, and UW Extension staff.

This Implementation Plan includes an extensive list of control measures to reduce the input of pollutants to the Willow River and Lake Mallalieu. These measures will also allow for an increased ability to assimilate and recycle nutrients. It ultimately discusses the roles of its stakeholders and government agencies, and addresses potential funding sources. Finally, this plan details a monitoring plan for the purpose of effectively evaluating the plans? successes and or failures.

What's New

Contract with St. Croix County - Lake Mallalieu put on "on hold". Will now be incorporated into a Lake Mallalieu/Willow River TMDL

Resource Conditions

Lake Mallalieu is highly eutrophic and exhibits high concentrations of phosphorus (P) and chlorophyll in its surface waters during the summer months. Sediment and phosphorus enter the lake via the Willow River and its tributaries. Phosphorus is bound to sediment particles and once in the system, sediment has the ability to transfer phosphorus to the bottom of the lake. The lake�s shallow depth and phosphorus laden sediments cause the lake to experience severe algal blooms throughout the summer months. As a result, these conditions have impaired recreational opportunity on the lake. Algal blooms associated with high levels of phosphorus often result in the exceedance of Wisconsin�s water quality criterion for ph. Elevated ph levels are due to the removal of carbon dioxide from the water during photosynthesis. A reduction in phosphorus delivery to the lake would decrease chlorophyll levels and also result in a reduction of maximum ph levels.

Lower Willow River (SC02)

Impaired waters

Interactive Viewer

Interactive Viewer
Restoration Viewer This interactive webmapping application displays mapping products specifically for TMDL implementation.
Surface Water Data Viewer The Surface Water Data Viewer is a generalized interactive mapping application that displays a wide variety of water related datasets.
Water Condition Viewer The Water Condition Viewer provides monitoring, assessments, and management datasets for water quality.

Shapefiles
We have recently migrated all of our geospatial data to ARCGIS Open Data platform.
WDNR ARCGIS Open Data Portal (search for Rock River)

Weblinks

�Since 1906, the Wisconsin Water Science Center has been collecting high-quality hydrologic data and conducting unbiased, scientifically sound research on Wisconsin's water resources.
https://www.usgs.gov/centers/wisconsin-water-science-center
�The Wisconsin Geological and Natural History Survey (WGNHS) has been working to serve Wisconsin for over 100 years. We provide objective scientific information about the geology, mineral resources, and water resources of Wisconsin.
http://wgnhs.uwex.edu/

Draft TMDL

Lake Mallalieu is a man made riverine lake located within the channel of the Willow River. Since 2004, Lake Mallalieu and an upstream reach of the Willow River have been included on the Environmental Protection Agency?s (EPA) 303(d) impaired waters list. The lake is designated as high priority for eutrophication and ph impairments due to excess phosphorus, while the upstream reach of the river is a low priority for dissolved oxygen impairments. The river?s designation is due to excess phosphorus and biological oxygen demand (BOD). The Clean Water Act and USEPA (United States Environmental Protection Agency) require Total Maximum Daily Load (TMDL) goals be developed for 303(d) listed waters. In light of this, Wisconsin?s Department of Natural Resources (WDNR) is required to prepare a phosphorus TMDL for Lake Mallalieu and its associated drainage area. Development of the TMDL goals has required monitoring of annual phosphorus loading upstream of the lake and of in-lake water quality conditions.