Creekshed Health 

The Huron River is the central natural feature of the City. More than ten miles of this river are located within the City limits, traversing the City from northwest to southeast.

 The following creeks are tributaries of the Huron River within the City of Ann Arbor:

Long-term monitoring data on the physical and biological conditions for many of the streams emptying into the Huron River are available through the Huron River Watershed Council’s Adopt-a-Stream Program.

What is the Adopt-a-Stream Program?

Through the Huron River Watershed Council’s (HRWC) Adopt-a-Stream Program, more than 400 volunteers monitor biological communities, water quality, and stream habitat at 71 river and tributary sites across the Huron River watershed. Adopt-A-Stream teaches people about rivers through first hand experience, and empowers them to be advocates for river protection and restoration in their communities. On a single day in April and September of each year, a mix of trained volunteers and casual volunteers collect a sample of the benthic macroinvertebrate population at the stream sites. In January, volunteers search for winter stoneflies. During the spring, fall, and winter monitoring, volunteers collect a sample of stream water to measure conductivity. Volunteers also measure the weekly, in-stream maximum and minimum temperatures in July and August, and assess the habitat quality of each study site once every few years. Extensive monitoring allows the HRWC to:

• Assess the health of the Huron River and its tributaries
• Develop long-term records of stream conditions
• Observe changes in stream conditions over time
• Detect threats to water quality

How are Adopt-a-Stream data analyzed?

Using data collected over several years by trained Adopt-a-Stream volunteers, the HRWC staff ran the Wiley Stream Health Model, an integrative model created for the Huron River system by University of Michigan aquatic ecologist Dr. Mike Wiley. This model uses information about aquatic insect populations, stream habitat, stream temperature, and stream size to predict the overall health of a stream or river. Specific model inputs include biological and physical habitat measures.

• Biological measures include
• Number of insect families: insect diversity, as measured by the number of different aquatic insect families, indicates good stream quality. Greater diversity at a site means the water is unpolluted, and there are healthy conditions for a variety of creatures.
• Number of sensitive insect families: many benthic families living in the Huron River system are sensitive to organic pollution. The presence of these sensitive families at a site indicates that the site, and the upstream portion of it, has high quality.
• Number of EPT families: EPT denotes Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). Many mayflies, stoneflies, and caddisflies are sensitive to the quality of a site, and a variety of these families present at a site in another indicator of good water quality.
• Number of winter stonefly families: Stonefly nymphs are extremely sensitive to most pollutants, and they cannot survive if a stream’s dissolved oxygen concentration falls below a critical level. Presence of winter stonefly families is indicative of high water quality.
• Physical measures include
• Habitat assessment score: based on creekshed-wide measurements of land cover, land use, and percent impervious surface, as well as site-specific habitat measurements including stream bottom composition, water temperature, and width of riparian vegetation. Some indicators of a high quality stream include stable banks with a broad corridor of native vegetation, riffles free of silt deposition, and stable water temperatures.
• Conductivity: an estimate of the total dissolved salts, or ions, in the water. A conductivity measurement of 800 µS is considered normal for the Huron River system.

Adopt-a-Stream monitoring sites are rated as poor, fair, good, or excellent based on the Wiley Stream Health Model output.

Updated June 2009