Wadeable stream habitat monitoring at Kennesaw Mountain National Battlefield Park: 2017 baseline report

McDonald, Jacob; Starkey, Eric

doi:10.36967/2267298

The Southeast Coast Network (SECN) stream habitat monitoring protocol provides guidance for wadeable stream data collection in Southeast Coast Network parks. The results of this effort are intended to provide resource managers insight into the status of and trends in stream and near-channel habitat conditions (McDonald et al. 2018a). Wadeable stream assessments are currently implemented at the five SECN inland parks with wadeable streams. These parks include Horseshoe Bend National Military Park, Kennesaw Mountain National Battlefield, Ocmulgee Mounds National Historical Park, Chattahoochee River National Recreation Area, and Congaree National Park. Streams chosen for assessment were specifically targeted for management interest (e.g., trail erosion issues and upstream urban development) or to provide a context for similar-sized stream(s) within the park or network (McDonald and Starkey 2018a). The objectives of the SECN stream habitat monitoring protocol are to: • Determine status of upstream watershed characteristics (basin morphology) and trends in land cover that may affect stream habitat. • Determine the status of and trends in benthic and near-channel habitat in selected wadeable stream reaches (e.g., bed sediment, geomorphic channel units, and large woody debris). • Determine the status of and trends in cross-sectional morphology, longitudinal gradient, and sinuosity of selected wadeable stream reaches. On May 17, 2017, data were collected at Kennesaw Mountain National Battlefield Park (KEMO) to characterize the in-channel and near-stream habitat on Noses Creek (KEMO001) and John Ward Creek (KEMO002). These data, along with in-office analysis of remotely-sensed geographic information system (GIS) data, are presented in this report to describe and compare the watershed-, reach-, and transect-scale characteristics of these two stream reaches. Noses Creek’s watershed (KEMO001) is steep and forested and Ward Creek’s watershed (KEMO002) has low slope/relief and is covered mostly by urban/suburban development. Based on the results of the pebble counts, the type/distribution of geomorphic channel units within each reach, and the presence or absence of large woody debris, in-stream habitat within the surveyed stream reaches were classified as “poor to fair” at KEMO001 and “poor” at KEMO002. These classifications are generalized interpretations of in-stream habitat and additional work is needed to determine how flow (e.g., flashiness of flow and baseflow conditions), water quality, and in-stream physical characteristics affect biodiversity and stream health at Kennesaw Mountain NBP. If the bed material at KEMO001 becomes finer and if the geomorphic channel units within the reach become more homogenous, the habitat classification may degrade to “poor”. Alternatively, addition of large woody debris to KEMO001 may increase habitat diversity and provide more stability to the reach that could upgrade the classification to “fair.” Habitat at KEMO002 will continue to be “poor” until stable (non-mobile) in-channel (non-bridging) large woody debris increases the diversity of habitat and upstream conditions reduce the amount of fine sediment that is delivered to the reach (Allan and Castillo 2007). Currently, much of the existing large woody debris spans the channel and has minimal influence on geomorphic channel units. Both streams are recovering from a legacy of poor land use practices, and their flow and sedimentation regimes are influenced by differing amounts of impervious surface cover and urban and suburban development within their respective watersheds. The surveyed reaches are beginning to develop a meandering planform inset within the entrenched channel-full surface. Additionally, Noses Creek is experiencing possible headward migration of a small knickpoint that may cause further bed degradation in the middle and upstream portions of the survey reach in the future. The rate at which this knickpoint migrates upstream is dependent

Wadeable stream habitat monitoring at Kennesaw Mountain National Battlefield Park: 2017 baseline report

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