2.7.27. Sixmile Creek

2.7.27.1. About the Sixmile Creek

Figure 2.61
Figure 2.62 The Sixmile Creek Tributary (WBID 2411).
  • East of the St. Johns River in St. Johns County
  • Primary Land Use: Forested/Wetland
  • Current TMDL reports: None
  • Verified Impaired 2016 (final): None
  • WBID Area: 59.5 sq. mi.
  • Beneficial Use: Class III F (Recreational – Freshwater)

2.7.27.2. Data sources

Result data were downloaded from the FL STORET website (DEP 2010e) and filtered based on the stations (DEP 2010f) in the Sixmile Creek WBID 2411 (DEP 2014c) shown above. The filtered dataset was used to generate Table 2.24.

2.7.27.3. Discussion

Water quality data for Sixmile Creek are shown in Table 2.24, but no new water quality data have been added to STORET since 2015. Historically, dissolved oxygen levels in Sixmile Creek were relatively low compared to other tributaries.  As only one sample was reported in 2015, no adequate conclusions can be drawn regarding the condition of Sixmile Creek.  Chlorophyll-a and silver levels exceeded WQC in the past, but both had been decreasing. No new silver measurements have been reported since 2011.

No recent measurements were available in STORET between 2015 and 2017 for the following parameters:

  • Arsenic
  • Cadmium
  • Copper-Lead
  • Nickel
  • Silver-Zinc
  • Fecal Coliform

Historical water quality data for these parameters in Sixmile Creek are available in previous versions of the River Report.

Table 2.24 Water quality data for Sixmile Creek (2015-2017).

 Water QualityAverage and Number of Samples º
ParameterCriteria201520162017
Dissolved Oxygen (mg/L)≥34% sat.
(≥3.0) FW
8.00
(0 of 1 sample)
No dataNo data
Nitrate-nitrite N (mg/L)§§0.06
(1 sample)
No dataNo data
Total Phosphorus (mg/L)<0.120.05
(0 of 1 sample)
No dataNo data
Chlorophyll-a (µg/L)<20 FW0.59
(0 of 1 sample)
No dataNo data
Turbidity (NTU)<294.60
(0 of 1 sample)
No dataNo data
Note: Hardness-dependent freshwater criteria for cadmium, copper, lead, nickel, and zinc were generated based on a hardness concentration of 100 mg/L.
º = Number of samples below WQC for Dissolved Oxygen, Number of samples above WQC for all other parameters
FW = freshwater; SW = saltwater (marine). Values denoted with (*) indicate a proposed criterion, which has not yet been adopted.
Values denoted with () are reference values based on EPA criteria (EPA 2010b), but the water body is not regulated by this standard.
§ = No water quality criterion has been established for Nitrate-Nitrite nitrogen. No Total Nitrogen data were available in STORET for 2015-2017.