Chippewa Lake Upper Watershed Stream Restoration Project
HISTORY
Chippewa Lake is a large, natural inland lake created some 14,000 years ago by the melting of glacial ice sheets as they retreated north. The lake and wetland complexes to the north encompassed a much larger area than what is seen today.
Around 1869, settlers in the area saw the wetland areas to the north of the lake as potentially-valuable farming land. About that time, a twenty-foot wide ditch was dug to the north and south of the lake to drain the wetlands and lower the lake to permit farming activities. Later, lateral ditches were added to accelerate the drainage. Much of the area, even with the improved drainage, did not support typical farming activities. The area was likely seeded with reed canary grass (Phalaris arundinacea) for forage crops. While this was an acceptable practice at the time, it later became apparent that reed canary grass is a highly-invasive species and is now considered a nuisance plant.
The project area was almost entirely covered by reed canary grass and had very few native plants. The lateral ditch on the north side of the project carried normal and stormwater flows directly to the Chippewa Inlet and then into Chippewa Lake with little filtration of sediments and nutrients.
THE PROJECT
After several months of study, it was determined that the Chippewa Watershed would benefit greatly from a stream restoration of an area owned by the park district. The project would remove the lateral drainage ditch established many years ago and re-create a more normal stream channel. This channel would meander through the field and work its way to the wetland complex to the south. Stream flood plain would be restored along the new stream channel allowing higher flows of stormwater to be contained within the area.
A diagram of the new channel area is shown to the right. Over 3,400 lineal feet of stream would be created, and over 2,000 lineal feet of flood plain would be restored. The planting of a multitude of wetland plants and elimination of the reed canary grass would improve filtration of sediments and nutrients from the water before it entered the Chippewa Inlet and flowed to the lake.
A Section 319 Clean Water Act grant was awarded to the park district in 2011 to complete this multi-year project. Work was completed in June of 2014 with all of the goals being met.
WATER FILTRATION
The primary goal of the project was to improve water quality in the Chippewa Watershed by increasing the filtration of stormwater runoff from a tributary of the Chippewa Inlet. By removing the flow from the ditch that was created many years ago to accelerate the drainage of the flood plain area, the water will be slowed
down and passed through a recreated stream and wetland complex that will greatly enhance filtration.
To this end, over 3,400 lineal feet of stream channel were created to replace the 600-foot channel that previously drained the flood plain area. The new meandering channel will pass the water flow though fifteen stone-mix riffle structures and a diverse system of wetland and flood plain plants that will replace the reed canary grass monoculture. The stream now empties into the existing wetland complex to the south, improving hydration in that wetland complex and further improving water quality.
BIO-DIVERSITY
The vegetation selected is designed to be as robust as possible with many different species native to the region and was chosen for its ability to thrive in the anticipated hydrologic regime. Most of these species are wetland-loving plants commonly referred to as “hydrophytes.” By selecting the appropriate species and factoring in enough diversity to cover a wide range of expected and unexpected microhabitat features, the site is better insulated against invasion from exotic species. Moreover, a diverse mix of plant species correlates with a diverse mix of animals that relies upon the plants for food and shelter.
The species range from woody plants including four different species of oak, three species of birch, various wetland shrubs like buttonbush and red-osier dogwood, and more. Numerous species of native grasses, sedges, and rushes (collectively known as graminoids) provide food and cover for waterfowl and small mammals. Various forb species including asters, coneflowers, lobelias, and more serve as important nectar sources in addition to their attractive blooms.
These plant species are also ranked with a coefficient of conservation (CofC) according to how well adapted they are to wetland ecosystems (higher score meaning more likely to find that species in a wetland). Higher ranking species help the wetland achieve higher VIBI (vegetative index of biotic integrity) scores in assessments that are designed to determine how effectively the restored wetland is functioning (in relation to natural wetlands).
CLEAN WATER ACT, SECTION 319 GRANT PROGRAM
By amendment to the federal Clean Water Act in 1987, the Section 319 Grant program was established to provide funding for efforts to reduce nonpoint source (NPS) pollution, commonly referred to as stormwater runoff pollution. The U.S. Environmental Protection Agency provides funds to state and tribal agencies. States and Tribes then allocate funds via a competitive process to public and non-profit organizations to address current or potential NPS concerns. Funds may be used to demonstrate innovative best management practices (BMPs), support education and outreach programs, establish Total Maximum Daily Loads (TMDLs) for a watershed, restore impaired streams or other water resources, or conduct NPS assessment or applied research. In Ohio, the 319 Grant Program is administered by the NPS Section in the Division of Surface Water.
This publication was financed in part or totally through a grant from the Ohio Environmental Protection Agency and the United States Environmental Protection Agency under the provisions of Section 319(h) of the Clean Water Act.