Making a Splash: Watershed Health on the Chattahoochee-Oconee National Forest

By Colette Blackmon

Chattahoochee-Oconee National Forest, Ga. – On an early Saturday morning in May, a group of U.S. Forest Service employees, volunteers with Trout Unlimited, and local university students gathered on the side of a mountain road on the Chattooga River Ranger District.

After a safety briefing and hard hat distribution, the group gathered their supplies – shovels, mallets, and log peaveys, to name a few – and began clambering downhill towards a stream running underneath the road. Soon they were waist-deep in the cool water, rearranging fallen logs and installing wooden structures that improve habitat and the flow of the stream.

Projects like these are one part of a wide-reaching strategy to maintain watershed health on the Chattahoochee-Oconee National Forest.

UGA Forestry students moving a log to help improve stream flow. U.S. Forest Service photo by Colette Blackmon.

What’s in a watershed?

The U.S. Forest Service defines watersheds as “universal, well-defined areas that provide a common basis for discussion of water-related resources and landscapes.” Also known as basins, these are land areas that channel rainfall into streams and rivers which are eventually deposited into outlets like oceans or bays.

Analyzing watersheds is a way for hydrologists, wildlife biologists, and other experts to understand the environmental conditions of an area.

“When watersheds are functioning properly, they sustain functional terrestrial, riparian, aquatic, and wetland habitats,” said forest soil scientist Taylor Hughes. “[Functioning watersheds are] capable of supporting diverse populations of native aquatic and riparian dependent species.”

Taylor Hughes. U.S. Forest Service Photo courtesy of Taylor Hughes.

Valuable natural resources

The Chattahoochee-Oconee National Forest consists of 52 distinct watersheds, four of which are designated as priority watersheds by the U.S. Forest Service.

“[Priority watersheds are] typically identified based on the importance of water and watershed resources, the urgency of management action to address conditions and threats, and economic considerations,” Hughes said.

For example, the Emery Creek-Holly Creek watershed on the Conasauga Ranger District is considered a priority watershed. This basin is home to rare wildlife like the federally endangered blue shiner and the state endangered bridled darter. Just downstream, there are a number of federally endangered freshwater mussel species which are impacted by the watershed condition. Other wildlife, like local bat species, also rely on high water quality.

In addition to ecological considerations, watershed conditions directly impact the health of human communities. As of 2014, an estimated 6.1 million people receive water from the Chattahoochee-Oconee National Forest. The Chattahoochee River alone, which has its headwaters on the Forest, provides drinking water to the majority of metro Atlanta residents.

Furthermore, clean watersheds empower recreators to enjoy opportunities like swimming, boating, and fishing on the National Forest. When watersheds are in good condition, visitors can view thriving local wildlife.

Experts on the Chattahoochee-Oconee National Forest design maintenance and improvement projects to address specific threats to watershed quality on the Forest.

Infrastructure impacts

According to Hughes, many challenges to maintaining healthy watersheds link back to infrastructure. Culverts, which are the pipes or tunnels that run underneath roads to allow streams to flow, and bridges have major impacts on waterways.

“Most of our culverts on the Forest are undersized,” Hughes explained. “Undersized culverts lead to further incision of our streams, which in turn increases the amount of sediment in the stream.”

Sedimentation, the most common form of pollution in waterways, is when rocks and soil end up deposited into a stream. Excessive sedimentation can threaten the quality of drinking water, damage aquatic habitat, clog fish gills, and increase the risk of floods.

Undersized culverts don’t allow enough room for heavy waterflow. When water levels rise, rivers and streams erode their banks, resulting in sedimentation. When culverts or bridges are overtopped, this can lead to road damage and potentially block access.

Undersized culverts also restrict aquatic organism passage (AOP). According to the U.S. Forest Service, “AOP is the ability of fish and other aquatic organisms to migrate and swim freely upstream and downstream through or beneath human infrastructure.”

When a culvert is too small, water levels can fall below its base. That restricts the ability of fish to swim freely, interrupting migration patterns and keeping them from the habitat they need to access for breeding.

The Chattahoochee-Oconee National Forest is working to replace undersized culverts across the four ranger districts. Forest staff perform in-depth site assessments to ensure that projects like these will be safe and effective.

“It’s all about [understanding] land use history,” said natural resource specialist Jennifer Houts. “[We] try to figure out what the water wants to do. It wants to be connected to the floodplain, otherwise it’s going to keep incising [the streambank] and causing sedimentation.”

Other infrastructure changes, like paving gravel roads and parking lots, also reduce sedimentation by preventing rocks and dirt from falling into streams. Hughes urges visitors to the Forest to stick to authorized roads and trails.

“When people drive on closed or unauthorized roads, that can wreak havoc on a nearby aquatic system,” she said.

Members of the natural resources staff at the Chattahoochee-Oconee National Forest. U.S. Forest Service photo by Laura Fitzmorris.

Enhancing aquatic habitat

Watersheds encompass vital habitat for wildlife across the Forest, including many threatened and endangered species. But waterways can require careful maintenance to ensure they continue to support diverse ecosystems.

“Many of our streams do not have ideal habitat for various aquatic species and life stages,” Hughes said. “[They] lack Large Wood which help form important habitat within the stream.”

Large Wood (LW) refers to any wood, like fallen trees and branches, occurring in streams. These features provide vital services to aquatic and riparian ecosystems.

For example, LW slows the flow of water, which in turn reduces sedimentation. Slower waterflow also allows for fine substrate, like small gravel, to build up, which provides breeding habitat for fish species like darters.

By changing the direction of the waterflow, large wood also facilitates the formation of pools. Pools provide resting areas and hiding places for fish species like trout. Additionally, algae will grow on dead wood, which is an important food source for macroinvertebrates which in turn feed fish and other species. LW also benefits reptiles and birds, like a turtle basking on a log, or a bird looking for a place to perch.

LW has historically been removed from streams, due in part to public perception. Fallen logs may seem to some like an eyesore or even a safety hazard, when in reality, they make for cleaner, healthier waterways. The Chattahoochee-Oconee National Forest is restoring streams by installing LW in waterways when appropriate.

Bronze darter. U.S. Forest Service photo by Ryan Haggerty.

Monitoring progress

Measuring success in the watershed program requires long-term thinking.

“Everything here is pretty long term,” said Houts. “[We’re] creating the adaptability of our ecosystem for our evolving climate. A lot of our successes are getting things going.”

According to Hughes, the watershed team assesses conditions before and after project implementation. Forest staff measure the populations of aquatic species before and after installing AOPs, and conduct wood surveys before and after LW projects to track improvement.

Hughes emphasized that forest management practices are interconnected when it comes to protecting watershed health.

“When we do vegetation treatments to open up the [tree] canopy, we are reducing the number of plants taking up water which leads to more groundwater,” she said. “When we [conduct prescribed burns] we have the same effect by reducing the fuels within the stand which also take up or intercept water. That’s why it’s so important that we take an interdisciplinary approach to our work.”

A community effort

Partnerships empower the Chattahoochee-Oconee team to be more effective in their work.

“We would not be doing many of the projects we are currently working on without partners such as Trout Unlimited and The Nature Conservancy,” Hughes said. “Our partners fill any gaps we may have in positions or needed knowledge to complete a project.” Key collaborators also include the Georgia Department of Natural Resources, Atlanta Botanical Garden, U.S. Fish and Wildlife Service, National Forest Foundation and a number of local universities.

Visitors can also be partners in protecting watersheds, Hughes said. Next time you head to the Forest, keep her four tips in mind:

• Respect the rules and regulations in place on the Forest. If a road is closed or there is no road, please don’t drive on it. Many of our seasonal restrictions are during the wet time of the year and keeping those roads closed reduces the amount of rutting and therefore erosion and sedimentation that can get into our waterways.
  
• If you are dispersed camping, try finding a camping spot farther off the creek (ideally 100’+). You can still enjoy the creek and play in it, but your camping area and most activities will be off the creek and ultimately leading to less impact on the riparian vegetation and soil.
  
• Respecting the LNT guidelines is important to maintain healthy water quality. Leaving trash in the Forest or creeks can impact humans and wildlife. Going to the bathroom properly is also important. Leaving your poop buckets in the Forest is not helping our watershed health.
  
• Stacking rocks can be fun, but it can also impact aquatic organisms. Macroinvertebrates utilize rock surfaces for various stages of their life cycle. This is an important food source for fish and other aquatic organisms.

Supplementary sources:

Benefits of Large Woody Debris in Streams (psu.edu)

Watershed_Condition_Framework.pdf (usda.gov)

https://www.fs.usda.gov/about-agency/features/forests-faucets-where-does-your-drinking-water-come)