Watershed map
Sampling sites
Water quality data

Salt Fork River Watershed
Water Quality Data

This page is a directory to the data that are being collected on the Salt Fork. The data will be continually updated as new results are available.

Stream flow data from the USGS gages at St. Joseph and the Saline Branch

Continuous dissolved oxygen data for 2008 at the St. Joseph gage

Continuous dissolved oxygen data for 2010 at the St. Joseph gage

Continuous dissolved oxygen data for 2011 at the St. Joseph gage

The data below are for the period April, 2008 through July, 2014 with samples collected every 1 to 2 weeks. For our primary site, Salt Fork #4, we have been sampling as much as several times a day during high flow events since spring 2010. All samples were collected more frequently in 2011 and on. For more information about these measurements, see our information sheet (pdf). We now have more than 5 years of water quality data.

The summary table below has the median value of each water quality parameter for the sampling period by site. Most sites have been sampled about 260 times. See links for summary figures, including box plots and time series graphs.

Box plots are a good way to see median values and the range. Box plot shows median (line in center of box), 25th and 75th percentiles (bottom and top of box, respectively), 10th and 90th percentiles (bottom and top error bars, respectively), and values < 10th percentile and > 90th percentile (solid circles below and above error bars, respectively). Time series graphs show how water quality parameters change over time at each site.

Site 0 is a newer site, with sampling beginning in June 2010. It is on the Saline Branch, but north of Champaign before it enters the city. It represents the agricultural portion of the Saline.

Below are median values for each of the sample sites for the period of sampling
Sample Site
Turbidity (NTUs) 6 9 6 6 9 12 11
Fecal coliform (CFU/100 ml) 80 667 585 480 137 470 137
Nitrate-N (mg/L) 8.8 4.9 10.1 10.4 5.7 7.7 7.4
Ammonium-N (mg/L) 0.02 0.07 0.07 0.06 0.05 0.07 0.04
Total phosphorus (mg/L) 0.03 0.07 0.87 1.01 0.16 0.54 0.40
Dissolved reactive phosphorus (mg/L) 0.01 0.04 0.72 0.80 0.11 0.40 0.31
Dissolved oxygen (mg/L) 10.3 8.6 8.4 8.7 10.2 8.7 10.3
Sestonic algae as chl-a (µg/L) 1 2 2 2 2 2 3

Last modified August 29, 2014