The birds, fish and mollusks that rely on the Olentangy River are about to get a helping hand from Liberty Township.

The birds, fish and mollusks that rely on the Olentangy River are about to get a helping hand from Liberty Township.

The township will conduct a stormwater drainage project at Liberty Park on Home Road, designed to prevent soil and chemicals from entering the river. When complete, the project will include signs explaining how the drainage improvements work.

In particular, township administrator Dave Anderson said, the project can show developers how to keep pollutants out of the river.

A nearby section of the Olentangy has been designated an exceptional warm-water habitat by the Ohio Environmental Protection Agency. Anderson said the area includes rare mussels, a blue heron rookery and bald eagles. Seventy percent of the land draining into the habitat is in Liberty Township.

The demonstration project is related to "a comprehensive plan that takes great steps to protect that area of the river from development. ... A lot has gone into this," he said.

A local group, Friends of the Lower Olentangy Watershed (FLOW), participated in meetings that led to the demonstration project concept.

FLOW member Ann Dutt said the river habitat includes "a hugely diverse population of fish and invertebrates." The improvements are expected to prevent 500 pounds of suspended solids, including 90 pounds of nitrogen and five pounds of phosphorous, from entering the river each year, she said.

The project will use nine different techniques to either reduce the volume of surface water reaching the river, or to prevent it from traveling quickly across the ground. Water that moves quickly will expose the soil and carry more solids to the river, Anderson said.

Nearby Wildcat Run, for example, had been "deeply incised" by high-volume runoff, which greatly accelerated the creek's flow. Using an OEPA Stormwater Improvement Fund grant, the township recently did work to repair that damage.

None of the drainage modifications planned at Liberty Park "are very expensive in themselves," Anderson said.

Rain barrels, for example, will be used to capture water from the park building's roof.

Also planned is a rain garden, a slightly excavated area that can be planted with trees, shrubs or something like a butterfly garden, Dutt said. A rain garden will hold water and help it absorb into the soil.

Under Liberty Park's surface is a lot of clay, which Dutt said performs poorly in slowing stormwater. That will be improved by replacing some of the clay with a mixture of sand and soil.

Infiltration trenches, decorative stone, pervious concrete and prairie plants are among the project's other water-slowing mechanisms.

When township and FLOW representatives were meeting to discuss drainage strategies, Russ Martin of the OEPA Division of Surface Water said, he suggested the township had "a perfect opportunity to install these various practices, so when developers come into the township, they would be able to show them."

The township sought and received a $123,910 Clean Water Act Section 319 grant for the project. The township's match will equal $82,635, mostly representing in-kind work. The township will contribute considerable manpower, Anderson said. About $32,000 will go to subcontractors. Eco-Design Engineering of Plain City will perform design work, not to exceed a cost of $25,000.

The construction will be scheduled for this year. The entire project is expected to be finished during the winter, Anderson said.

He credited FLOW with playing a pivotal role in bringing the project's elements together.

"The work of FLOW technical volunteers first identified Liberty Park as a site that could be improved for water quality, and easily funded because it's a publicly owned property," Dutt said.

"FLOW connected me with Dave at the township, so I could help with design concepts and budgets for grant submittals. FLOW and I helped Liberty Township write the grant ... to do the in-process stream restoration of Wildcat Run. I believe Russ at Ohio EPA then noticed Liberty Township as a capable partner, and suggested they submit a Section 319 grant to do more," she said.