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2003
Water Quality/Quantity Monitoring Overview
*
Sampleshed 5RP, representing 16% of the watershed area, contributed 74%
of the TSS load and 46% of the TP
load in 2003.
*
The majority of TSS and TP loading from the outlet area is occurring from
streambank and gully erosion, and erosion from cultivated and non-cultivated
highly erodible land.
* 72% of the TSS loading occurred during a two week
period in May 2003 (during the two largest storm events). This period
represented 36% of the total flow. The majority of TSS and TP loading
occurs during the peak flow of high intensity storm events.
* Reducing peak flows would reduce TSS and TP loads
in the Rush River Watershed.
*
A hydrology study by Bonestroo &
Associates consulting firm, suggests the peak flow during a 100 year storm
has doubled since pre-settlement due to artificial drainage.
*
A total of 2,561 acres of wetlands remain in the watershed, with 34,405
acres having been drained. Currently, about 7% of pre-settlement wetlands
remain.
*
Of the upland monitoring sites, sampleshed 2RP had the highest TSS and
TP levels. The source appears to be Lake Titloe. Further monitoring of
the lake outlet is needed in 2004.
*
Nitrate
levels were elevated across the entire watershed. The drinking water
standard for nitrate is 10 mg/L. The outlet of the Rush River Watershed
had an average nitrate concentration of 17 mg/L. The only areas with low
nitrate levels were the outlets of lakes and wetlands. Nitrate levels
of water passing through Lake Titloe were reduced by about 50%.
*
The Gaylord, Winthrop, Gibbon, Lafayette and Waldbaum treatment plants
accounted for 4% of the TP load at the outlet of the watershed. The majority
of TP load is occurring from non-point sources.
*
The surface water standard (200 cfu/100 ml) for fecal
coliform bacteria was exceeded at all of the monitoring sites. The
FC bacteria geometric mean at the outlet of Rush River was 655 cfu/100
ml in 2003.
Additional water quality
data from Minnesota Pollution Control Agency -
http://www.pca.state.mn.us/data/eda/index.cfm
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