PurposeA TMDL has been developed for Lake St. Croix by the St. Croix Inter-agency Basin Team. Team partners include the MNPCA, MNDNR, NPS, USGS, WIDNR, and Metropolitan Council Environmental Services. Multiple tributaries are being monitored by team partners to provide nutrient loading estimates and basic water quality information. The WIDNR monitored the Clam, Yellow, and Wood Rivers for nutrient concentrations and flows during late 2011 and early 2012 to contribute to the TMDL effort by providing nutrient loading estimates from these three tributaries. Monitoring would continue in 2013 to provide an adequate base of data to produce reliable loading estimates for these three streams. This data is needed for TMDL implementation.
ObjectiveReliable nutrient loading estimates are needed for St. Croix River tributaries to allow implementation of the Lake St. Croix TMDL. Sites near the mouths of the 3 rivers will be monitored. Clam R. WBIC is 2654200. Yellow R. WBIC is 2670300. Wood R. WBIC is 2642900. Samples will be tested for total phosphorus, total nitrogen, and suspended solids. Field measurements will be temp., D.O., conductivity, pH, and transparency. Flow data will be obtained from the dams near the mouths of the Yellow and Clam Rivers. Flow data from the Clam River will be extrapolated to the Wood River. Occasional in stream flow measurements will also be made. Samples will be collected on 20 dates during March through December, 2013. 75% of samples will be targeted to high flow periods. This monitoring strategy is recommended by MPCA and is also being used for Minnesota tributaries. Nutrient loads will be esimated with the FLUX32 model, which is also being used by MPCA.
OutcomeData collected will be compiled into a report that will also provide nutrient loading estimates for the streams.
Study Designsee above.
QA MeasuresRun Project Summary Report
Lake Mallalieu TMDL Implementation