St Croix Basin Runoff Sampling as a part of the overall Lake St Croix TMDL NOR_08_CMP12

Purpose

Currently the St. Croix InterAgency Basin Team has developed a detailed monitoring plan for the St. Croix River to facilitate nutrient loading calculations for the TMDL process. The Minnesota Pollution Control Agency, National Park Service, USGS, Metropolitan Council Environmental Services, and MN DNR are actively monitoring 8 priority tributaries and numerous main stem sites within each of their geographic areas. Currently they are collecting standard nutrient parameters (Flow, TP, DP, TN, Nitrate + Nitrite, Ammonia, Total Suspended Solids, and Turbidity) during baseflow and runoff events at the bottom of each sub watershed within their areas. Flow measurements and gauging stations are being used to calculate loads at the time of each sampling event. Additional biological monitoring (Ffsh and invertebrates) are being collected at each of their respective monitoring sites. Before an accurate TMDL can be calculated, the Wisconsin tributaries to the St. Croix need similar nutrient monitoring data linked with flows to accurately calculate loads for a fully integrated TMDL calculation. Currently there is no long term monitoring of the Wisconsin tributaries to the St. Croix River. This project seeks to gain funding and approval of a long term monitoring network for the Wisconsin tributaries including Clam River, Yellow River, and Wood River. WDNR does have 2 long term monitoring sites on the mainstem of the St. Croix River at Danbury and St. Croix Falls, which is not adequate for a fully integrated TMDL. Non long term nutrient and biological sampling on the Wisconsin tributaries has been collected; but the Interagency Monitoring Team has set a standard of using only long term data sets for modeling efforts.

Objective

This project seeks to collect tributary nutrient concentration samples linked with flow, to calculate current loading rates from Clam, Yellow, and Wood rivers, which provide critical tributary data necessary to calculate a functional and accurate TMDL for the St. Croix River Basin. Our long term monitoring data will also be used to identify any impairments that could lead to 303d listing or delisting on the Wood, Yellow, and Clam rivers. The Minnesota Pollution Control Agency, National Park Service, USGS, Metropolitan Council Environmental Services, and MN DNR are currently working on the Minnesota side of the St Croix to collect similar information to determine loading rates that will be used in the final TMDL process.

Outcome

Performance Measures: These are milestones that will be reported on in the Division Quarterly Report. Please estimate dates in a manner that encourages success. 1) Number of sample sites associated with the project. 2) Number of sampling events associated with project. 3) Estimated date when sample collection will be complete. 4) Estimated date when all data will be entered into appropriate database. 5) Estimated date when final report will be complete. This project seeks to collect flow data and nutrient concentration data during baseflow and targeted runoff events on the lowest access point available on the Yellow, Wood, and Clam rivers. 5 baseflow samples will be collected at each site per year. 10 runoff event samples will be collected at each site per year. Flow will also be collected with each sampling event. Baseflow sampling events with occur monthy, May -October, which follows the recommended 303d listing monitoring protocol which requires a minimum of 10 baseflow sampling events over a 2 year period. Data will be entered by the state lab of hygeine following sampling analysis. Data will be then integrated into the overall St. Croix Inter Agency modeling effort at the end of the field season. Data will be integrated annually into the St. Croix Basin TMDL. A summary report will be compiled linking sample concentrations with flow to calculate an event loading rate for each sample location. This data will also be shared and integrated into the states 303d listing process.

Related Reports

Run Project Summary Report
View Umbrella-Projects
View Related-Projects

Targeted Monitoring
Special Project
NOR_08_CMP12
2011
Active
 
Reports and Documents
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.
 
Activities & Recommendations
TMDL Actions in Wisconsin
Currently the St. Croix InterAgency Basin Team has developed a detailed monitoring plan for the St. Croix River to facilitate nutrient loading calculations for the TMDL process. The Minnesota Pollution Control Agency, National Park Service, USGS, Metropolitan Council Environmental Services, and MN DNR are actively monitoring 8 priority tributaries and numerous main stem sites within each of their geographic areas. Currently they are collecting standard nutrient parameters (Flow, TP, DP, TN, Nitrate + Nitrite, Ammonia, Total Suspended Solids, and Turbidity) during baseflow and runoff events at the bottom of each sub watershed within their areas. Flow measurements and gauging stations are being used to calculate loads at the time of each sampling event. Additional biological monitoring (Ffsh and invertebrates) are being collected at each of their respective monitoring sites. Before an accurate TMDL can be calculated, the Wisconsin tributaries to the St. Croix need similar nutrient monitoring data linked with flows to accurately calculate loads for a fully integrated TMDL calculation.