The Cobb County Stream Monitoring program performs habitat assessments at 24 biological monitoring stations located throughout the county. Primary instream physical characteristics such as epifaunal substrate/available cover, embeddedness, velocity/depth regime, and pool/substrate variability directly affect the biological community. Secondary parameters relate to channel morphology and include channel alteration, sediment deposition, channel flow status, frequency of riffles, and channel sinuosity. Tertiary parameters such as bank stability, bank vegetative protection, and the riparian vegetative zone indirectly affect the amount of sediment input and habitat availability within the stream. All parameters are evaluated over the designated area (100 meters) of stream.
Ten habitat parameters are given a condition category rating of Optimal, Suboptimal, Marginal, or Poor. Scoring individual parameters enables comparision of variability of habitat characteristics from year to year and stream to stream. These 10 parameters are then tallied to determine a habitat assessment score for the monitoring station. Habitat Assessment scores give insight as to what may be affecting biological populations. Parameters that score poorly may not provide the required habitat necessary to support certain organisms; therefore, habitat assessment scores, particularly individual parameters, may help explain the presence or absence of some aquatic species.
Important information such as date, season, assessor, parameter score and overall score are recorded and stored in a database for evaluation. Changes over time may indicate trends in the availability and/or stability of habitat accessibility to aquatic organisms. Combined with observed changes in chemical and biological data over time, there may be correlation of impacts of external changes or significant events impacting stream health in a particular watershed.