Watershed Concluding Thoughts

Marsh Creek and Long Island Creek Watershed Concluding Thoughts
Over a span of six weeks, students of Kennesaw State University conducted a watershed assessment of six different locations, conducting different physical, chemical, and bacterial testing. Geographically, the Marsh Creek watershed abuts Long Island Creek watershed to the south. A layperson's description of the two watersheds would find them very similar. Both watersheds flow in a south-westerly direction; both confluence at the Chattahoochee River. Both creeks see a similar distribution of land use between suburban neighborhoods and more dense urban commercialized areas. Distinctions in the topography between the two watersheds should also be remarked upon. Marsh Creek has sloping hills throughout the majority of the watershed, with few flat areas. In comparison, Long Island Creek includes fewer hills, primarily at the headwaters, and relatively flat near the mouth of the creek. The similarities greatly outweighing the distinctions suggest that, when summarizing the watersheds it is better to discuss their inherent similarities and shared issues, and point out unique issues or features as warranted. Both streams run through densely populated areas. However the phrase "out of sight, out of mind" is applicable when referring to the relationship between these creeks and the community at large. There are, of course, notable exceptions where homeowners on both creeks have attempted, and succeeded, restoration projects small and large along the creeks. The issue with individual property responsibility is that it only fixes the issue at that given point in the waterway, thereby displacing any problems to another location. Another issue unique to Long Island Creek would be the point at which it passes through Whitewater Palisades Recreation Area, and flows into the Chattahoochee. This site provides a fantastic place to get respite from the urban hustle and bustle. However, when one more closely analyzes the situation, one sees that that there is an extreme and direct level of human and pet interaction with the waterway proper. Throughout both watersheds, biodiversity and aquatic life are in abundance. Amphibians, reptiles, waterfowl, fish, mammals, and insects are thriving on both creeks. Lastly, invasive species e.g. privet, kudzu, and English Ivy are found on all sites.

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Bacterial testing revealed some of the most unnerving results of the entire assessment. Almost all samples from site locations at both creeks came in at over 1000 cfu/100ml. This was significant, as the Georgia AAS partnership requests that any results in excess of 1000 be reported immediately and warrant special action. As is a common occurrence with all watersheds, coli-form counts showed still greater increases after a rain event. The accepted scientific rationale for the aforementioned increases is that, due to the high levels of impervious surfaces located within the watershed, non-point runoff is an increasing problem that is exacerbated by any rain event. Due to the age of the Atlanta area sewer and storm water system, there is an elevated risk of integrity issues and possible intermittent leaks. Additional sources that contribute to high coli-form counts are human landscaping and poor personal property maintenance (e.g. the dumping of yard waste). The flashing*1 nature of these urban streams is the root cause of sediment and debris deposition into the water, and of major root exposure of many of the trees on the stream's edge. Testing results throughout both watersheds were similar to those found in urban streams throughout Georgia (Georgia Adopt-a-Stream). This indicates that problems recorded during the duration of the course research are not isolated.

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Overall, the health of both watersheds during the duration of this course seemed to exhibit what one might refer to as a split personality. The physical characteristics of the water were good: PH levels, conductivity, temperature, etc. were normal. Meanwhile, the biological results were enough to warrant action. The stream bank conditions are at high risk, with severe undercutting and channeling. However, biodiversity at all sites was very good considering the urban location. With each subsequent offering of the Watershed Assessment course at KSU, we hope to expand on the breadth of data collected so that we can better understand these unique and ever-changing waterways and surrounding ecosystems.

Overall, the health of both watersheds is considered to be in good condition. The water quality, specifically, would be advised as impaired. The stream bank conditions are at high risk.

*1 Flashing - a rapid rise and fall of water levels due to runoff

Land Use / Remote Sensing

The Marsh Creek Watershed has experienced a definite increase in impervious surfaces and a decrease in vegetation over the last eight years. However, the western section of both remains somewhat undisturbed. In the southeast center there has been a significant increase in impervious surfaces.

The Long Island Watershed has seen significant urban growth near the headwaters. Urban growth has been slightly reduced due to the heavy suburban areas of Sandy Springs.

It is very evident that there has been an upward trend of impervious surface percentage over the last eight years. The Long Island Watershed has increased from 10.08% to 14.22% impervious surface. The Marsh Creek Watershed has increased from 14.86% to 21.47%. Marsh Creek has seen a 2.47% increase in impervious surfaces than Long Island Creek over the last eight years. This significant increase may be attributed to the fact that much of the Marsh Creek Watershed lies within and around the city of Sandy Springs proper.

With the current rate of increase in impervious surfaces in both watersheds, the runoff and the devastating results therein will continue to impair these cherished resources.

Urban Tree Risk


After assessing forty trees in the riparian area at each site, common detrimental strains were observed. The first observation was the growth of vines (e.g. English Ivy), on the trunks and branches of the trees. These vines are invasive species and over time, the vines ultimately choke the life out of the tree. The vines are also known to reduce the amount of soil, nutrients, and water available to the trees, which are needed for them to thrive. In some cases, the excessive vine growth made it impossible to identify the species of several trees.

Root exposure was another serious issue among the trees on the banks of both streams. The roots were being exposed due to the undercutting of the stream banks by the high velocity of water during rain events. The high velocity occurs due to the runoff from the impervious surfaces which are ever increasing in the watersheds. Other, but less often occurrences were cankers, poor tree architecture, cracks, fissures, decay, and deadwood. All of which can be

The overall condition of the trees within both watersheds was found to be flourishing and healthy, with the exception of trees along the stream banks.

Looking to the Future

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When studies of this magnitude are conducted, one might consider the task at hand overwhelming. However, one must understand the current environmental state to understand how to change the future. The 2013 "snapshot" that has been taken of both Marsh Creek and Long Island Creek Watersheds should only be viewed only as that, a snapshot. The most concise answer to how one can help is through community involvement. While the work of individuals is very, inspiring and undeniably progressive, without the support and involvement of the entire community, forward progress is often temporary and unlasting. When an entire community takes interest and responsibility for the environment around them, changes can become permanent examples for others. This picture that we have seen in great detail may be proactively rectified one detail at a time. With the collaboration of active and concerned organizations such as the Watershed Alliance of Sandy Springs and Georgia Adopt-A-Stream, anything is possible.

Introduction | Stakeholders | Land Use Maps | Methods | Study Sites | Results | Conclusions | Restoration