Baseline Water Quality

With more than a decade of experience, Milwaukee Riverkeeper has identified pollutants of major concern that consistently do not meet water quality standards within the Milwaukee River Basin. Our citizen-science based baseline water monitoring program is more than a tool to educate citizens on river health, it is an essential source of data used by state and regional decision-makers. Milwaukee Riverkeeper is uniquely situated to fill the monitoring role in the northern half of the Milwaukee River Basin, as well as many of the smaller tributaries, where MMSD or other government agencies do not currently monitor.

In 2006, Milwaukee Riverkeeper established a network of trained citizen-science volunteers who monitor streams and rivers throughout the Milwaukee River Basin during the months of May through October. Our volunteer Water Quality Monitoring Program is part of the statewide Water Action Volunteers (WAV) Stream Monitoring Program managed by the Wisconsin Department of Natural Resources (WDNR) and University of Wisconsin-Extension (UWEX).

Monitoring sites are located within the three major watersheds and corresponding subwatersheds of the Milwaukee River Basin:

  1. Milwaukee River Watershed:
    • North Branch Milwaukee River Subwatershed
    • East and West Branch Milwaukee River Subwatershed
    • Cedar Creek Subwatershed,
    • South Branch Milwaukee River Subwatershed
  2. Menomonee River Watershed
  3. Kinnickinnic River Watershed

Our volunteer water quality monitors aid in keeping tabs on our water quality throughout the year and serve as additional “eyes, ears and noses” in the field. Our volunteer water quality monitors help recognize and identify questionable practices, erosion control violations, illicit discharges, and more. Our volunteer water quality monitoring program builds on the WDNR’s and UWEX’s efforts to improve the quality and quantity of citizen science data used to monitor the health of our waterways.


Baseline Water Quality Parameters

We monitor for many different parameters, including temperature, dissolved oxygen, pH, turbidity, phosphorus, and streamflow. We also monitor aquatic macroinvertebrates at select sites.

Each aquatic organism’s survival is limited by its tolerance to changes in water temperature. As a result, temperature ranges can be used to classify aquatic ecosystems where drastic changes in water temperature can have significant impacts on biodiversity.

Monthly measurements taken at each monitoring site are compared to temperature standards for warm or cold water fisheries depending on the classification of the stream at which they were taken.

Maximum Temperature
Warm Water Sport Fisheries: 31.7 C
Cold Water Trout Fisheries: 22 C

Dissolved oxygen is a measure of the amount of oxygen dissolved in a volume of water. The amount of oxygen found in our rivers depends on the atmospheric exchange (generally influenced by a stream’s velocity and substrate), and on water temperature. Oxygen is essential for every organism’s survival in some concentration. Therefore, not only is dissolved oxygen an important water chemistry parameter, it also limits habitat.

Dissolved oxygen measurements are taken using a dissolved oxygen Hach test kit, a YSI 550 dissolved oxygen probe, or other WDNR approved meters calibrated before entering the field.

Warm Water Fisheries: 5 mg/L
Cold Water Fisheries: 6 mg/L

pH measures acidity, or the number of hydrogen ions (H+) present in the water. Measurements range from 0 (most acidic) to 14 (most basic). Sudden changes in the pH of a waterbody can have drastic impacts on the survival of organisms that live there. Extended changes to pH can impact the function of that system.

pH measurements are taken monthly at each site using either an Oakton Acorn 5 or 5+ pH sensor.

pH must be between 6.0 – 9.0

Water clarity or turbidity is an important ecological parameter, an indicator of many water quality issues, and a defining characteristic of stream habitat for many aquatic organisms. Turbidity measurements quantify the degree that light is scattered by particles suspended in water, therefore measurements of turbidity will use different units depending on the methods and equipment being used.

Milwaukee Riverkeeper volunteers take monthly measurements of water clarity or transparency using a 120 cm transparency tube, those measurements are converted into NTU. MMSD procedures utilize electronic meters at each site that measure turbidity in FNU because of their specific light source.

≥ 54.7 cm in a 120 cm transparency tube (<10 NTU) is ideal for aquatic life. MMSD uses sensors to test turbidity, so a target of <10 FNU was used for their data.

Phosphorus (measured as Total Phosphorus) is recognized as a limiting nutrient for plant and algae growth in freshwater systems. It is generally low to absent in natural systems. Phosphorus can enter our waterways naturally from leaf litter and sediment, but when found in high levels, it is more commonly associated with anthropogenic sources like fertilizers, soaps, anti-corrosion inhibitors, and industrial discharge.

A subset of Milwaukee Riverkeeper volunteers collects samples monthly that are sent to the Wisconsin State Lab of Hygiene for analysis. Phosphorus measurements from the WDNR SWIMS database and MMSD’s routine surface water monitoring are collated and analyzed.

The Wisconsin State Standard for phosphorus is 0.075 mg/L in streams, and 0.1 mg/L in larger rivers specifically designated in state rule NR 125.

Measurements of the health of macroinvertebrate communities can be an outstanding way to reveal the long-term health of aquatic ecosystems. Although a stream’s aquatic community may not be able to define exact environmental problems, it does give us a sense of when a stream ecosystem is healthy or undergoing changes or stress. Milwaukee Riverkeeper volunteers monitor macroinvertebrate communities using a biotic index method recommended by the WDNR’s Water Action Volunteers Program. This index assesses the health of streams by monitoring the presence/absence of specific organisms with known tolerance to pollutants and dissolved oxygen levels. Based on the type of organisms that are found (tolerant, semi-tolerant, semi-sensitive, and sensitive to pollution), sites are assigned a grade ranging from 0-4. Using this scale, a grade below 1 means that no organisms were present, 1-2 represents a stream with poor community health, 2.1-2.5 indicates a stream with fair community health, 2.6-3.5 means a stream has good community health, and any values 3.6 and above are representative of excellent community health.

Milwaukee River Basin Report Card

Each year, Milwaukee Riverkeeper staff analyzes the baseline data collected by our more than 100 volunteer water monitors, the Milwaukee Metropolitan Sewerage District (MMSD), the Wisconsin Department of Natural Resources (WDNR), and Ozaukee County Parks and Planning Department’s Fish Passage Program. Milwaukee Riverkeeper staff compares data to state and federal water quality standards and guidance and then assigns letter grades based on how frequently the data meet those standards.

In addition to the baseline water quality parameters, Milwaukee Riverkeeper factors in targetted parameters such as chloride, specific conductivity, and bacteria.

2016 Milwaukee River Basin Report Card

Read the 2016 Milwaukee River Basin Report Card.

2015 Milwaukee River Basin Report Card


2014 Milwaukee River Basin Report Card

View the 2014 Milwaukee River Basin Report card

2013 Milwaukee River Basin Report Card

Download a copy of the 2013 Milwaukee River Basin Report Card.

2012 Milwaukee River Basin Report Card

Download a copy of the 2012 Milwaukee River Basin Report Card.

2011 Milwaukee River Basin Report Card

Download a copy of the 2011 Milwaukee River Basin Report Card.

2010 Milwaukee River Basin Report Card

Download a copy of the 2010 Milwaukee River Basin Report Card.

Sign up to be a volunteer water quality monitor!

Let us know you are interested becoming a volunteer water quality monitor. We’ll add you to our email list to receive more information about upcoming training sessions and other opportunities to get involved. If you have additional questions, please email our Water Quality Specialist Zac Driscoll or call (414) 287-0207 x4.

Thanks to our funders for their generous support of this program!