Funding & Establishment
Colerain Township, the largest Township in the State of Ohio, oversees ten parks and seven public buildings and facilities. The Township has partnered in the past with the Mill Creek Watershed in the installation of signs at stream crossings in the Mill Creek and Great Miami watershed. Heritage Park on East Miami River Road was designed to include a rain garden component.
Colerain Township continued its partnership with the Mill Creek Watershed Council to further our compliance with Phase 2 Environmental Protection Agency (EPA) regulations to enhance water quality in our jurisdiction.
To that end, Colerain Township sought opportunities for a rain garden as a retrofit to an existing township structure as part of a Hamilton County Storm Water District (HSCWD) mini-grant project. The rain garden at Colerain Park was completed with funds from the mini-grant from HSCWD and donations of materials from our generous sponsors
- Alvis Landscape and Golf Course Materials Inc. for donating compost and topsoil
- White Oak Garden Center for donating plants
The rain garden site at Colerain Park serves as a demonstration and educational site for the Mill Creek Watershed Council of Communities for other municipalities and for local schools to visit.
The rain garden is located in the valley between shelter 3 and the large main parking lot at Colerain Park. This site was chosen because it receives water from two drain pipes at the west end of the garden and has an overflow exit pipe at the east end of the garden.
The rain garden collects storm water from 3 main areas:
- The entry drive leading into Colerain Park (from Springdale Road down to the rain garden)
- The rooftop of the Police Impound garage
- The surface area of the Parks Department parking and Police Impound lot
Prior to the rain garden, the park was designed so that the stormwater would flow through this valley directly to the existing stormwater drainage system. The rain garden will now capture much of this water and any pollutants from the runoff and allow the water to filter through the ground and be cleansed of pollutants before passing into the groundwater.
Design & Specifications
The rain garden is approximately 53 feet long by 25 feet wide at its widest point. We designed the shape of the rain garden based on the water flow from the two entry pipes to the overflow exit pipe. The site was excavated to a depth of two feet. We then amended the soil with approximately three inches of compost which we rotor tilled approximately a foot into the soil. We added another three inches of compost on top of the amended soil and then added another three inches of a topsoil blend (1/3 topsoil, 1/3 compost, and 1/3 sand). The soil amendments were done to break up the clay in the soil and to enrich the soil for the plants.
The rain garden depth was chosen to hold as much water as possible and still allow all of the captured water to drain in 24 to 48 hours, which is important to prevent mosquitoes from breeding.
We chose as many native plants as possible to inhabit the rain garden for two reasons:
- Native plants grow well in the soils we have in the area.
- Native plants have deep root systems, some as much as three feet deep.
As these plants mature, their deep roots will decrease the time to filter the water captured in the rain garden. Plants were chosen based on the following criteria:
- Bloom time
- Plant height
- Soil moisture
Plants Utilized in the Rain Gardens
|Astilbe||Moist to not dry||Shade to partial sun||June to July||Red||1.5 feet to 2 feet|
|Beard Tongue||Medium to well-drained||Full to partial sun||May to June||White||2 feet to 3feet|
|Blue False Indigo||Medium to well-drained||Full to partial shade||May to June||Blue||3 feet to 4 feet|
|Blue Flag Iris||Wet||Full||May to June||Blue||2 feet to 2.5 feet|
|Butterfly Bush||Medium to not wet||Full||June to September||Black||4 feet to 5 feet|
|Great Blue Lobelia||Wet to medium||Full to partial shade||July to September||Blue||2 feet to 3 feet|
|Joe Pye Weed||Wet to Medium||Full||July to September||Mauve||4 feet to 5 feet|
|Spiderwort||Moist to not dry||Shade to partial sun||May to July||Blue||2 feet to 2.5 feet|
|Spiderwort||Wet to medium||Full to partial shade||May to August||Purple||1 foot|
|Virginia Sweetspire||Wet to medium||Full to partial shade||May to June||White||3 feet to 4 feet|