Jan 01, 2018

Study Shows Declined Quality for Milwaukee Rivers

Milwaukee’s estuary received a “D plus” grade

Milwaukee estuary awarded D+ water quality grade

A new study by the nonprofit organization Milwaukee Riverkeeper has awarded the water quality of the Milwaukee river basin a D+, down from the C grade it received the year prior. Milwaukee Riverkeeper crafts an annual study of the Milwaukee, Menominee and Kinnickinnic rivers, keeping meticulous data to determine the current state of water quality in the watersheds.

While noting a broader, significant improvement in water quality over the past century at large, this year-to-year decline is not encouraging for water quality practices in the area. However, the group is quick to point out that this year’s decline is not necessarily indicative of long term quality loss.

This is due to several factors, such as seasonal variation, expanded monitoring efforts, new water quality parameters and grading methods.

The Milwaukee estuary, a confluence of the Milwaukee, Menominee and Kinnickinnic rivers, is largely affected by its proximity to Lake Michigan when considering its water quality. This led to the discovery of exceptionally poor water quality in the Kinnickinnic River when considered separately from the estuary. This is likely because the Kinnickinnic River is the most urbanized of the three subject rivers.

Each river basin also failed the grading process when assessing the levels of phosphorous, bacteria and specific conductivity.

Seasonal variation also had a substantial effect on the quality of each respective watershed. The chloride measurements, which plays an vital role in biodiversity, were positive, achieving a B+ score from the organization. However, this level of quality is likely inconsistent throughout the year. In the winter, the dumping of salt on the roads leads to more salt being washed into the rivers, potentially spiking chloride to undesired levels.

Beyond this, construction increases in the summer months, leading to more frequent discharges of sediment into the rivers. This sediment can cause significant changes to the ecology of the rivers through plant and algae growth, affecting the temperature and oxygen levels, which inevitably impacts freshwater life.

Depending on these factors, along with water quality improvement efforts, the overall quality of the Milwaukee estuary could improve, decline, or level out.

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