The Columbus Regional Airport Authority (CRAA) called on Gresham Smith to evaluate potential long-term stormwater management and regulatory compliance solutions for planned future development at John Glenn Columbus International Airport (CMH), including the eventual construction of a new midfield terminal. When developing solutions for the airport, our firm had to consider multiple constraints including regulatory pressures from multiple agencies, lack of space for stormwater detention, numerous buried utilities and land reserved for long-term development activities.
The planning ultimately focused on a permanent diversion of 180 acres of stormwater runoff from the new terminal areas to Big Walnut Creek, which is located more than 1.5 miles from the planned terminal location. The project team evaluated CMH’s current stormwater management practices, considering potential needs for stormwater conveyance, storage, BMP treatment and discharge of the stormwater collected from the apron surrounding the new terminal and adjacent development. A significant element of the evaluation was determining whether the City’s stormwater storage requirements could be reduced without causing an adverse impact to peak flood elevations for the discharge point at Big Walnut Creek. The team also determined the route for the piping transferring stormwater from the Mason Run watershed to Big Walnut Creek.
The final stormwater management masterplan integrates water quality control measures for the new development, as well as long-term stormwater infrastructure needs for the remainder of the airport. Gresham Smith’s long-term stormwater management approach is also intended to meet the requirements of the August 2012 City of Columbus Stormwater Drainage Manual, which minimizes long-term impacts to CMH operations.
Gresham Smith’s evaluation resulted in plans that not only meet CMH’s stormwater management needs but also align with other airport development plans, including construction of a new taxiway, sewage conveyance and a communications system.