Lake Management Plan
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8.1 Bob Creek
Bob creek is sampled at the outlet of Burton Lake, and the inlet into Pelican Lake. A small operation cattle pasture is located upstream. The Burton Lake site was added in January 2005 to gage the cattle farm impact on the watershed.
8.1.1 Bob Creek Inlet
Calculator
Bob Creek flows underneath South Pelican Drive and into Pelican Lake through a steel culvert. From years of traffic the culvert has been crushed and filled with sediment. The calculator uses an ellipse to simulate the crushed culvert. view site calculator
Total Phosphorous
Bob Creeks TP concentration ranges from 0.005 to 0.05 mg/L. This is half of other typical streams in the ecoregion. Bob Creek can output 0 to 7 lbs of TP per day. 2009 was a typical year for phosphorus loading at this site, and loading peaked in April with the spring thaw. view graphs
Chlorophyll A
ChlA concentration (algae) at the Bob Creek inlet ranges from 0 to 0.8 ug/L. This concentration is relatively low. Algae grows better in calm water than flowing water. For comparison, the ChlA concentration in Pelican Lake ranges from 4-12 ug/L.
Because of the low concentration of chlorophyll-a detected in Bob Creek from 2002-2006, this test was dropped from analysis in 2007. view graphs
E. coli
Escherichia coli (E. coli), a bacteria, is the EPA recommended indicator of fecal contamination in fresh waters. It is present in high numbers in the gastrointestinal tracts of vertebrate animals and therefore provides a senstive measure of fecal pollution. E. coli data that we have collected from the Bob Creek inlet shows elevated levels during heavy precipitation. On several monitored occasions concentrations approached or exceeded 123 MPN/100ml, the EPA standard for safe water. This expresses a minor health concern. However the loading in not constant and the bacteria has a limited life span. We have not sampled the inlet after every rainfall, but it is safe to assume that E. coli levels are elevated during heavy rainfall. The cattle pasture is most likely the source of the E. coli since it is upstream, and the cattle are a source of E. coli. Other possible sources of E. coli could be wildlife, or a malfunctioning septic system. view graphs
Total Suspended Solids
Bob Creek TSS concentrations typically range between 0.5 and 4 mg/L. The water clarity is excellent even up stream into the wetlands area. Bob Creek can output 0 to 200 lbs of TSS per day. view graphs
Flow
Bob Creek typically outputs between 0 to 35 cfs of water into Pelican Lake. view graphs
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Calculator
Burton Lake outlet is a circular concrete culvert. view calculator and photo
Total Phosphorus
Burton Lake outlet TP concentration ranges from 0.01 to 0.03 mg/L, which is relatively low because it is an outlet of a lake. The phosphorus in the lake is diluted as opposed to a stream that picks up erosion and runoff along it's banks. TP loading is generally between 0.2 and 1.2 lbs per day. view graphs
Chlorophyll A
ChlA concentration (algae) at the Burton Lake outlet ranges from 0.001 to 0.012 ug/L. This concentration is extremely low. Algae grows better in calm water than flowing water. For comparison, the ChlA concentration in Pelican Lake ranges from 4-12 ug/L ( see Pelican Lake comparison ).
Because of the low concentration of chlorophyll-a detected in the Burton Lake outlet from 2005-2006, this test was dropped from analysis in 2007. view graphs
Total Suspended Solids
Burton Lake TSS concentration ranges from 0.5 to 5 mg/L. TSS loading is generally between 0 and 250 lbs/day. The TSS at the Burton Lake outlet is relatively low. It is probably so low because it is a lake outlet and the water is diluted. view graphs
Flow
Burton Lake outputs between 2-20 cubic feet per second. view graphs