Water Quality Projects

The Chattanooga Water Quality Program is always looking for innovative ways to enhance our environment & community, as well as improve water quality for our City. Below are current & past projects meant to meet those objectives. 

• Contact 423-643-5854
• Email chattanoogawq@chattanooga.gov
  

Understory Gardens

• Completed 2020

What are the Understory Gardens?

The Understory Gardens are an example of using sustainable land management, where each piece of land is encouraged to be healthy from the soil to the treetops. The project began as a collaboration between Water Quality, Parks and Forestry using biodiversity to help support healthy trees and people downtown. Street trees are a critical tool in managing stormwater runoff pollution downtown. They help intercept, evapotranspire, and infiltrate rainwater to reduce flooding. Caring for downtown trees is another way to protect our water resources.

The problem was that many trees in downtown Chattanooga were infested with a pest insect called lecanium scale. The first attempt to eradicate the lecanium scale used chemical treatment, or pesticides. But while commonly used, pesticides can inadvertently cause more harm than good. While meant to kill the scale, it also killed any insect that came in contact with the poison, including beneficial insects like lacewings and tiny wasps that prey on lecanium scale and help keep a balanced insect community. 

Beneficial insects are like support staff that help the trees survive in a difficult urban habitat. But the beneficial insects needed support as well. They depend on plants with specifically shaped flowers for nectar, so gardens of these flowers were planted near trees affected with the scale. 

Where are the Understory Gardens?

There are currently 2 parks where you can find Understory Gardens, at Main Terrain Park near 13th Street and Jefferson Park near E 19th Street.

Why were these sites chosen?

These locations are near trees known to be infested with lecanium scale or have been treated in the past to eradicate the insect.

What was done?

The following species were planted to promote beneficial insects and in turn help decrease the presence of leucanium scale on City street trees:

• Echinacea tennesseensis - Tennessee Coneflower
• Echinacea purpurea - Purple coneflower
• Echinacea pallida - Pale purple coneflower
• Eryngium yuccifolium - Rattlesnake Master
• Pycnanthemum tenuifolium- Slender Mountain Mint
• Solidago speciosa - Showy Goldenrod
• Symphiotrichum novae-anglae - New England Aster
• Tradescantia subsapera - ZigZag Spiderwort
• Zizea aurea - Golden Alexander
• Conoclinum coelestinum- Mistflower
• Monarda didyma - Beebalm
• Monarda fistulosa - Wild Bergamot
• Penstemon digitalis - Beardtongue
• Rudbeckia fulgida - Orange Coneflower
• Bouteloua gracilis - Blue Grama
• Schizachyrium scoparium - Little bluestem
• Nassella tenuissima - Mexican Feather Grass
• Tradescantia ohiensis - Ohio Spiderwort

Before Installation

After Installation

Agawela Stream Restoration

• Completed 2017

What is a stream restoration?

Stream restoration is meant to restore a degraded ecosystem by naturally stabilizing the stream channel & establishing a ripariam buffer using native vegetation. A stable stream with a healthy buffer can help prevent stream bank erosion & filter pollution found in stormwater.

• Reduces erosion
• Reduces sediment loading (sediment is a pollutant)
• Restores habitat
• Helps reduce flooding
• Stabilizes stream banks

Where is the Agawela Stream Restoration?

This project addressed approximately 1,500 linear feet of an incised stream channel within an urbanized watershed of the City- South Chickamauga Creek- near the intersection of Wilcox Blvd and Shallowford Rd.

Why was this stream chosen?

The unnamed tributary to South Chickamauga Creek was deeply entrenched from the years of flashy, urban stormwater runoff. This contributed heavily to the sediment load in South Chickamauga Creek, a 303-d listed stream with a siltation TMDL (Total Maximum Daily Load) or maximum daily allowance of a pollutant to meet the stream's water quality standards. South Chickamauga Creek is also the only known location of the threatened Chickamauga Crayfish.

What was done?

Completing the restoration entailed reconnecting the channel with the floodplain, installing multiple grade controls, planting native vegetation, and establishing a meandering pattern within a tightly confined corridor. 

Before restoration

After restoration

East Lake Park

• Completed 2020

What is East Lake Park?

East Lake Park is a 18.5 acre park in district 7 with a 1.75 acre pond. It is the City's first park and it has a rich cultural heritage (see picture's in the Public Library's catalog). The lake is spring fed and much of the park is covered in trees. It bustles with community members, geese, ducks, and fish in the pond.

Where is East Lake Park?

Located at the intersection of E 34th St, 13th Ave, & E 36th St, East Lake Park is located in the East Lake community of our Dobbs Branch and Chattanooga Creek Watersheds.

What was done?

With community input as a key and driving factor for guidance, this project improved conditions for the pond and surrounding water quality features. The pond was dredged and cleaned. The natural spring that feeds the pond was "daylighted", restoring it to an open waterway, and a native meadow was planted. A new playground area was created, as well as a new board walk. Improvements for East Lake Park were explored under the lead of the Water Qualtiy Program in the Public Works Department's Water Quality Engineering Division. 

Trees are an important piece of the puzzle when it comes to water quality; they transpire or uptake rain water, provide habitat and shade. The trees in East Lake Park have been labeled so that the public can identify which species they are. Check out our map of the trees here. 

Sunbeam Green Infrastructure Improvements

In order to alleviate the risk for potential flooding in the area, the Water Quality Program was tasked to provide a cost affect solution since the traditional grey infrastructure (underground pipe network) was limited given the severity of the slope.

This alternative design approach on this project was green infrastructure. By utilizing a green infrastructure approach, these features will mimic the natural water cycle, prior to development, allowing for ground water recharge.

Green Infrastructure Story Map