University of Louisville
OP-27: Rainwater Management

The Metropolitan Sewer District (MSD) requires new development projects to have post-developed flow not to exceed pre-developed flow based on 100-year storm modeling. These standards have applied to several projects on campus and are contributing to reduced stormwater runoff from projects such as the HSC Garage II and Clinical & Translational Research building. The University is working with MSD to determine ways to fund installation sub-surface inflitration basins to accept stormwater runoff and replenish the aquifer.

UofL is working with Louisville's Metropolitan Sewer District (MSD) on a variety of "green infrastructure" projects to help keep stormwater runoff out of the combined sewer system. In the past, every raindrop that hit UofL's rooftops (over 2.2 million square feet on Belknap campus alone!) and pavements was channeled into the same sewer system that handles our sewage which truly needs to be treated. But, as our former Vice-President for Business Affairs, Larry Owsley put it, "When you have that much rain in that short a time, the sewers — which are large sewers — just back up and there's no place for the water to go." Even if the sewers can handle stormwater from UofL, the treatment plants at the end of the pipe often cannot, leading to dangerous releases of untreated sewage into the Ohio River - a threat to human health and ecological integrity. UofL has pursued means of lessening the risk of flood and reducing our campus' contribution to the problem by diverting stormwater from the sewer system all together through infiltration and rainwater harvesting projects, or by slowing its release through water absorbing changes to our campus landscape. Around campus, we have disconnected downspouts, installed vegetated green roofs, and built rain gardens and bioswales to facilitate groundwater recharge through infiltration. In recent years, UofL made several changes to campus landscaping, parking lots and rooftops, with the help of $1.25 million in cost-sharing from MSD. We think that this significant investment will essentially pay for itself by helping prevent millions of dollars in future flood damage. We are also hoping the projects at UofL will serve as an example for similar projects across the city on both public and private property. MSD's investment in Belknap campus stormwater projects is part of an $850 million agreement that MSD made in federal court with the U.S. Environmental Protection Agency and state regulators in 2005 to reduce the incidence of combined sewer overflows into waterways during storm events.

Both the new Student Rec Center and the Clinical & Translational Research building (both LEED Gold) have large tanks for storage of rainwater and condensate from the air-conditioning system. This water is used for irrigation of the surrounding landscaping. Students can see and interact with smaller-scale rainwater harvesting systems at our two largest campus gardens: the Garden Commons and the Urban & Public Affairs Horticulture Zone. Both gardens have multiple rain barrels holding hundreds of gallons of water for use in the garden.

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1. A green roof that is sprouting on the first building at the new Nucleus Innovation Park-Market Street, a subsidiary of the UofL Foundation. The eight-story, 200,000-square-foot, LEED building is expected to open in May 2013 and Bernheim Forest nursery specialists are advising building contractors how to design and maintain the roof, which will feature Kentucky native plants; 2. The new M. Krista Loyd Sky Garden atop the College of Business Equine Addition, is a 942-square-foot area of pre-vegetated sedum mat with 4”-6” fill material installed in 2012; 3. An accessible roof patio planted with sedums and a vegetable garden atop the Early Learning Center at Family Scholar House, at the northwest corner of Belknap Campus; and 4. A huge vegetated roof installed atop the new Cardinal Towne affiliated student housing and retail facility which opened on Cardinal Blvd. in 2011.

We installed permeable paving at two pedestrian plazas on Belknap campus and in the drop-off traffic circle in front of the Dental School entrance.

Infiltration Basins: Many traditional-looking parking lots, plazas and lawns across campus now conceal advanced stormwater infiltration systems to capture water from disconnected downspouts. Instead of draining to the combined sewer system, these areas drain to large underground infiltration basins capable of handling huge rainfall events and the water from surrounding rooftops. These designs were included in the following projects (with the square footage of impervious surface area mitigated in parentheses): Ekstrom Library western lawn - completed in fall 2012, this infiltration system captures roof run-off from surrounding buildings (108,000 sf) The UTA/Ville Grill plaza renovated in 2011. (14,550 sf) The Red Barn plaza renovated in 2011. (4,120 sf) The Grawemeyer Oval lawn renovated in 2011. (76,368 sf) The College of Business parking lot renovated in 2011. (86,052 sf) The parking lot behind Bettie Johnson Hall, the Urban Studies Institute, and University Planning, Design & Construction renovated in 2011. (67,629 sf) The Speed Museum expansion project has been designed with a large infiltration basin beneath the plaza which will be able to handle roof drainage from Strickler Hall, Life Sciences, and the College of Business. (94,304 sf) The new Student Recreation Center opened in October 2013 with an infiltration system that is larger than originally planned. It has a connected load that captures rainwater from most of the land surrounding Billy Minardi Hall as well. (317,115 sf)

None currently installed. However, pending funding, rain gardens are planned for the area between the Duthie Center for Engineering and the J.B. Speed building.

UofL's Papa John's Cardinal Stadium parking lot has been designed as a retention pond on the south end. The University worked with MSD to install a large retention basin on the Shelby Campus to alleviate flooding in the middle fork of Beargrass creek. During 2011 the university installed sub-surface detention/infiltration basins in 6 locations on Belknap Campus.

Ditch swales adjacent to Papa John's Cardinal Stadium parking lot were developed with grass vegetation and serve as detention areas. Shelby campus has several grass swales that drain into the large retention basin. During 2011 the university installed vegetative swales at College of Business.