The Low Impact Development (LID) Seminar was held June 9th and 10th, 2015. The two-day symposium covered topics concerning bioretention, LID stormwater controls, and permeable pavement.
Both days began with a talk on the evaluation of the performance of LID stormwater control measures in Northern Ohio. The implementation of credits and incentives is helping to promote newer stormwater runoff controls, which reduces the impact of runoff in Ohio’s coastal communities. By design, these resources will effectively remove nutrients, metals, and pathogens from stormwater and allow the rainwater to be reused through natural systems. Both days of the seminar ended with site visits that exemplify innovative stormwater management through permeable pavement and bioretention cells.
Perkins Township Visit
During the June 9th seminar, the group made a site visit to the Perkins Township Administration Complex. The site was an abandoned commercial plaza that the Perkins Township Trustees rehabilitated to be the new location of the Township’s administrative offices. The soil from this area drains into Pipe Creek, a warm water habitat stream that flows into the East Sandusky Bay. Because of the site’s proximity to this stream, an LID approach was implemented to create functional site drainage that encourages the natural movement of water within the stream. During the rehabilitation project, part of the existing parking lot was replaced with pervious concrete. The renovated system allows runoff from the roof and impervious concrete lane to drain through the previous concrete area.
The design of the new drainage system incorporates much of the existing infrastructure. Originally, the site was to have a bioretention cell under the pavement. The depth requirement for the cell, however, could not be achieved due to a lack of elevation change between the control measures and the existing sewer system. Instead, the site design incorporates impervious concrete drive lanes that drain into nearby pervious concrete parking bays. Other important design features include the roof runoff pipe to be plumbed into the subgrade of the pervious concrete. This practice is acceptable because much of the water is considered cleaner. With the construction complete, runoff from the western pervious concrete system has been reduced by 47 percent.
Orange Village Visit
On June 10th, attendees visited the Orange Village Service Facility. The parking area was retrofitted with permeable pavers and bioretention cells in the summer of 2013. The site was part of an Ohio EPA funded project that replaced 9,420 square feet of concrete with the permeable pavers. This included a permeable paver driveway, which had no prior stormwater treatment. Under the pavers is 520 square feet of bioretention cells to help clean runoff. The site also has two six-inch diameter curtain drains installed beneath the pavers to help dewater the groundwater table.
The Orange Village Service Center continues to be monitored by the CRWPs as part of their National Estuarine Research Reserve Science Collaborative research initiative. Due to the curtain drains dewatering a larger area than the SCMs, it has been difficult to calculate the total water balance. With that in mind, the site has seen over 98 percent of the inflow leave the LID system as exfiltration or evaporation over the past year. No runoff has been observed during the monitoring period.