Biological Monitoring
Clearwater Creek
| Monitored By | Centennial High School |
| Number of Years Monitored | 5 yrs |
| Background: Clearwater Creek originates from Bald Eagle Lake in northwest Ramsey County and flows northwest into Peltier Lake. Landuse is an approximately equal mix of residential and vacant/agricultural with some small commercial sites. The landuse immediately surrounding the sampling site is entirely residential and developed. A vegetated buffer 20-50 feet wide is present at the sampling site, but vegetation along much of the banks elsewhere is mowed grass. The banks are steep with moderate to heavy erosion in spots. The streambed is composed of sand and silt with a few areas of gravel. The stream is 6-12 inches deep at baseflow and approximately 10-15 feet wide. | |
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| Results Centennial High School classes monitored Clearwater Creek in both spring and fall 2006, with oversight by the Anoka Conservation District. Overall, this stream has slightly below average conditions based upon the biological data. The number of families found in 2006 (16 and 19), and in previous years, is more than typically found in Anoka County streams. The number of EPT families is typical of streams in this area. Still, the Family Biotic Index is poor. This is because there are few sensitive families. The families in high abundance are generalists that can survive in poor conditions. Limited supplemental stream water chemistry readings were taken during biomonitoring (table on next page). Most notably, conductivity was mildly elevated, indicating slightly elevated dissolved pollutants. Previously, notable water quality results included high turbidity in October 2004 and elevated conductivity in October 2003. |
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| Discussion This stream’s biological community may be impacted by intermittently degraded water chemistry. In our supplemental water chemistry measurements we have found occasions when one or more water quality parameters are substandard. The cause of intermittent water chemistry impacts is not necessarily runoff. For example, the highly turbid condition noted in October 2004 was during a baseflow period when the water was barely moving. Likewise, high conductivity in fall 2003 and 2006 was during very low water levels. The buffer of grasses and trees on either side of the stream at the sampling site probably provides habitat for a large variety of invertebrates which are able to tolerate occasionally poor water quality. The number of families found in this stream increased dramatically beginning in spring 2001. This is not necessarily due to an improvement in stream health. This coincided with increased sampling efforts (more students sampling) and improved execution of protocols. |
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