Cobb County Stream Monitoring follows the Stream Cross-Sectional Measurement Procedure as it is described in Georgia EPD’s macroinvertebrate sampling standard operating procedure. A cross section is established around the 50 meter mark in an area representative of the sample reach.
Enough measurements are made so that the topography of the channel is captured. A tape measure and level line is stretched across the stream channel and labeled as a cross section. At each cross section vertical measurements are taken to indicate critical data points such as entrenchment of channel and various water depths. Horizontal measurements are also taken to indicate important locations such as edge of bank, edge of water, and edge of sandbar. This data is used in the laboratory to create detailed maps of the stream channel. As more data is collected, maps may be used to compare changes that occur within the channel. Analyzed along side other data sets such as land use, impervious surface, or high flow events, one may be able to correlate a cause and effect relationship with specific actions occurring in the watershed.