Baseline Water Quality Monitoring, Milwaukee River Watershed

The 2018-2019 baseline water quality monitoring project was initiated in 2017 by the Milwaukee Metropolitan Sewerage District (MMSD) to collect information where monitoring data were scarce in parts of the Milwaukee River Watershed. Surface water quality data (Total Suspended Solids, Total Phosphorus, fecal coliform, E. coli, dissolved oxygen, pH, specific conductance, water temperature and turbidity) and continuous stage and discharge (flow) measurements were collected at 25 sites representative of portions of the Milwaukee River Watershed located in Ozaukee and Washington Counties. This 2018-2019 baseline water quality data will be used to help determine the present state of surface water quality in these relatively uncharacterized portions of the watershed and measure changes in trends over time. Ultimately, the goal is to make information available to better track progress toward reducing water quality impairments and delisting streams from the Wisconsin Department of Natural Resources’ (WDNR) 303(d) list of impaired streams. 

Streams within the Milwaukee River Watershed have been identified as impaired. These water quality impairments include: degraded biological communities, degraded aquatic habitat, elevated water temperatures, low concentrations of dissolved oxygen, recreational use restrictions, and water quality use restrictions. The impairments are all related to one or more of the following pollutants: Total Suspended Solids (TSS), Total Phosphorus (TP), and fecal indicator bacteria (fecal coliform, or FC and Escherichia coli, or E. coli). 

In 2017 the Southeastern Wisconsin Regional Planning Commission provided a guidance memo outlining a) recommended monitoring site locations based on accessibility, efficiency and historical data, and b) recommended sampling methodologies and standards for sampling and data collection to serve as baseline data gathering. 

MMSD hired Great Lakes Environmental Center, Inc., in the fall of 2017 to confirm monitoring site locations, collect stream flow information, collect water samples, develop site-specific rating curves, estimate daily stream flow rates, and calculate pollutant loads. Monthly water samples were collected at the 25 sites September through November 2017, and March through November 2018 and 2019, as flow conditions allowed. Water samples were collected at four of the 25 sites seven times during targeted high flow events.

• In 2018, the September-November daily Milwaukee River discharge exceeded the maximum recorded daily flow on 15 days (data going back to 1981).

• 2019 was the wettest year ever across Wisconsin and the Midwest since record keeping began in 1895. In 2019 flow rates were high and exceeded the maximum recorded daily flow on 24 days. 

• The U.S. Geological Survey (USGS) also reported exceptionally high stream flow at the Cedar Creek gauge in the fall of 2018 and especially 2019.

• Pollutant loadings increased substantially during wet weather. Pollutant loading increases during wet weather were often greater than the increase in flow rate.

• Extra high flow sampling was conducted in addition to routine monthly sampling at: CDC03, CDC05, MLR06b and LCC01, where the highest high flow maximum concentrations were observed.

• Four sites, CDC08c, LEC01, PGC01c, and MLR06b met three out of four water quality criteria. 

• Numerous sites only met one out of four criteria: CBC01, EVC01, NCC01b, CDC04b, CDC05, ULC01, ULC02, KRB01b, RDC01.

• One site, LCC01, did not meet any of its criteria.

• The watersheds close to, or meeting water quality criteria, are Cedar Creek-East and Cedar Lake-Cedar Creek. Two sites within these areas met water quality criteria for all four parameters: MDC01 and CDC01b.

• Pigeon Creek-Milwaukee River has two sites close to meeting all their criteria (PGC01c, MLR06b); while two of the sites are not meeting most of their criteria (ULC01, ULC02).

Total Suspended Solids (TSS)

• The median value for TSS at all sites was at or below the TMDL criterion for TSS (12 mg/L), except for site LCC01.

• In general, the TSS and TP loadings on the Milwaukee River are much higher compared to all other sites.

• On the Milwaukee River: the measured TSS and TP loadings exhibit seasonal trends, with highest loading in spring and fall. TSS and TP concentrations were lower in 2017 than in 2018 or 2019, except at ULC02 where the TSS yields were consistent over time.

• On Cedar Creek: the measured TSS loadings increased from the upper reaches (CDC01b and CDC03) to the middle reach (CDC04b and CDC05) commensurate with increased stream flow. In the lower river reaches (CDC07b and CDC08c), TSS loadings generally fell in between the upper and middle reach values.

• TSS pollutant yields were an order of magnitude higher at site CDC03 and were lower at CDC01b and MDC01.

Total Phosphorus (TP)

• Measured TP loadings on Cedar Creek increased from the sites on the upper reaches to the middle reach.

• TP loadings in the middle and lower reaches were generally comparable.

• TP pollutant yields were order-of-magnitude higher at site CDC03 and RDC01 (in 2018 and 2019).

• TP pollutant yields were lower at CDC01b and MDC01.

Fecal Coliform (FC) & E. coli

• High flow is a strong determinant of elevated FC and E. coli at all sites.

• Four sites are meeting the criterion for E. coli with their median value: CDC01b, CDC08c, MDC01, MLR03d.

• Pollutant yields for E. coli were an order-of-magnitude higher at site CDC03 and NCC01b.

• For both FC and E. coli the measured loadings in the upper reaches increased from CDC01b to CDC03, and also increased from the upper reaches to middle and lower reaches. In the middle and lower reaches the spatial trends loading were less consistent for FC and E. coli.

• The Milwaukee River also showed a seasonal trend for measured loadings of FC and E. coli. Highest loadings were in spring and fall.

• For FC and E. coli, there were no consistent trends in pollutant yields from one year to another.

The water quality in flowing streams is quite literally a moving target. Nevertheless, we cannot manage what we do not measure. The baseline information provides a reference and indication in time of what water quality trends are and where site conditions can be maintained or improved upon through land and water management. The information is intended to foster collaboration among landowners, managers and organizations to work together and identify strategic investments and management strategies. With cooperation and action, we can sustain healthier watersheds in the Milwaukee River Basin. For access to the project final report please visit:  https://www.mmsd.com/what-we-do/water-quality/research-reports.  Search for Report title:  Baseline Water Quality Monitoring Upper Milwaukee River Watershed Phase 1 Report 2018-2019 . The report outlines the project purpose, sampling criteria, calculation methods for pollutant loading and discharge rating curves.

To request data from the study, please submit a request by email to:  Recordsrequest@mmsd.com 

This project’s scope was limited to data collection during the fall 2017 through fall 2019, a two-year period. If you would like to assist area organizations in their ongoing water quality data collection, please check out the Wisconsin  Water Action Volunteer Network  for stream monitoring and the  Milwaukee Riverkeeper Water Quality Monitoring Program .

Land and water management information, resources, and technical assistance is available in the project area, through Ozaukee County Land and Water Management Department, Washington County Land and Water Conservation Division, and the USDA Natural Resources Conservation Service.