Chattahoochee River at Capps Ferry Monitoring

In March 2008, EPD established a continuous monitoring station on the Chattahoochee River at Capps Ferry Road (River Mile 269.32). This station was established to monitor dissolved oxygen concentrations in the River to verify that reduced releases from Buford Dam to achieve a flow of 650 cubic feet per second would not adversely impact water quality. The station was established at Capps Ferry because it is near the point at which EPD’s RIV1 hydrodynamic model predicts minimum dissolved oxygen levels will occur downstream from discharges to the River from the metropolitan Atlanta wastewater treatment facilities. Our programmable in-situ water quality monitor records the dissolved oxygen levels at the station every hour and data from the monitor is collected manually from the monitor once per week. This page contains all dissolved oxygen information collected at the station thus far and will be updated with new data on a weekly basis.

The above graph shows what the EPD RIV1 hydrodynamic model predicted dissolved oxygen would be at Capps Ferry between March and August 2008 plotted against actual dissolved oxygen measurements at Capps Ferry during the same period. In making this prediction, the model was run using March through August 2008 conditions which includes meteorological information, streamflow data, wastewater treatment facility water quality monitoring data, water withdrawal permit data, tributary flow data, and instream water quality data. Major discrepancies between modeled and measured dissolved oxygen values, represented by sudden dips in measure values, are attributable to major precipitation events that cannot be predicted by the model. The data gaps in measured dissolved oxygen results indicate periods where problems were experienced with one of the sampling probes deployed at Capps Ferry being clogged by silt in the River. This problem has been corrected with the use of a probe that is less prone to silting and moving the probe to a location on the bridge at Capps Ferry that is more representative of flow conditions in the River. With the exception of dips caused by major precipitation events and data gaps resulting from sampling problems, dissolved oxygen measurements at Capps Ferry showed good correlation with what the model predicted would occur. Therefore the model serves as an accurate tool for predicting dissolved oxygen concentrations in the River.

This graph displays dissolved oxygen data collected from September 1, 2008 to present. It is plotted against what the model predicts will occur assuming 2007 and 2008 conditions such as streamflow, meteorological conditions, discharges withdrawals, etc. Differences between the 2007 and 2008 predictions occur because of different conditions that occurred in those years. This graph will be updated on a weekly basis with new dissolved oxygen measurements from Capps Ferry.

The following link contains a pdf file with all validated dissolved oxygen data collected at the Capps Ferry station. This document will also be updated weekly as new data is made available. Please direct any questions about this project to Brandon Moody at brandon_moody@dnr.state.ga.us.

Click here to download the current Chattahoochee River at Capps Ferry dissolved oxygen data set.