University of Kentucky
OP-27: Rainwater Management

The University has adopted the LID practices of the Lexington Fayette Urban County Government (LFUCG) and requires that new development treat 100% of the runoff from the site. 50% of that runoff must be treated through Infiltration, Bioretention, or other LID methods. These are fully described in the LFUCG Stormwater Management LID Guidelines (http://www.lexingtonky.gov/Modules/ShowDocument.aspx?documentid=21984). These guidelines designate specific stormwater BMP’s as LID. These BMPs replace impervious area with engineered pervious surfaces or are designed to provide storage for water quantity and/or quality. Along with reducing the impervious area, they utilize the concepts of infiltration, evapotranspiration, and/or reuse. UK has also developed Campus Landscape Guidelines that promote LID with the goal of detaining, cleaning, and facilitating the infiltration of rainwater. The intended outcome of these guidelines is a stormwater strategy featuring increased overall permeability and above-ground stormwater management in association with landscape solutions. These guidelines call for a stormwater master plan to create a comprehensive approach to rainwater or stormwater management. This master plan is currently being developed and will incorporate LID concepts as part of University development standards. UK is undergoing a massive transformation by way of a $1.7 Billion capital construction project. Starting in 2012 and continuing through 2018, the University will build at least twelve new residential facilities, a new Academic Science building, a new Student Center, and several other structures. Each of these projects must conform to the University’s development guidelines and either implement LID practices for 50% of the runoff for new development or reduce impervious surface by 20% or implement stormwater BMP’s for redevelopment. One example of current construction is the UK FEMA Flood Mitigation Project on the south side of campus. Its purpose is to address drainage and flooding problems caused by an undersized system. The project includes the introduction of a number of water quantity and quality control measures including 8.3 acre-feet of underground stormwater detention, bio-infiltration swales, bioretention, vegetative buffers, hydrodynamic separators, and stream restoration. When completed, the project will serve as a passive park with concealed stormwater management attributes. Estimated completion for the project is October 2015.

The University has recently adopted Campus Landscape Guidelines whose purpose is to encourage the orderly development of the landscape in a way that serves the functional, aesthetic, ecological, and management requirements of the university in a consistent way over time. These recently adopted guidelines focus on managing water resources through the use of LID. They recommend the completion of a stormwater master plan that eventually will be coordinated/integrated with the guidelines. They are intended to improve the quality of stormwater, reduce the rate and volume of stormwater runoff, and assist in compliance with the University’s MS4 permit. This is done through design recommendations of infiltrating stormwater onsite wherever possible, utilizing the landscape to improve water quality, using green roofs for roof replacement projects and new buildings, disconnecting externally drained roofs from storm sewer systems and draining to rain gardens and bioswales when feasible, and decreasing impervious area. The intended outcome is a stormwater strategy featuring increased overall permeability and above-ground stormwater management in association with landscape solutions. It should be noted that UK is also very dedicated to maintaining tree cover on campus. A tree advisory committee is maintained and the Landscape Guidelines contain a detailed policy for tree protection during construction activities. UK was recently named Tree Campus USA for the Fourth Consecutive Year.

The Ronald McDonald House located on UK’s south campus maintains rain barrels onsite for irrigation use. Discussions for the new Academic Science Building currently being constructed indicate that it will reclaim and reuse 100% of its stormwater.

Several different types of filtering systems are utilized at the University. They include hydrodynamic separators, a baffle box treatment system, Stormtech Chamber systems, and multiple inlet filters. Both the hydrodynamic separator and baffle box systems are flow through structures designed to remove settleable solids, floatables, oil, and other pollutants prior to discharge into the storm drain system. This is done through swirl action in the case of the hydrodynamic separator and through a series of baffles and screens or filters in the case of the baffle box system. The Stormtech Chamber systems are underground detention basins that utilize an isolator row to trap sediments and other pollutants prior to the waters release into other chambers where it infiltrates into the soil below the basins and/or is released into the storm sewer system. Inlet filters are utilized in several locations throughout the University and are designed to capture debris, sediment, and other pollutants at the entrance to the storm sewer system through the use of filter fabric bags and/or filter media.

UK’s Chandler Hospital houses a 22,600 square foot green roof system on the roof top of its 4th floor. This system utilizes trays of native sedums to create a ninety percent reduction in stormwater runoff while providing aesthetic views from patient rooms, prolonging the roof life up to 100 years, and improving the rooftop insulation. UK also has a Green Bus Stop or “Garden Stop” that utilized reused/recycled content for the structure and a green roof consisting of locally grown sedums and aloes.

Porous paving is installed on campus following the guidelines found in Chapter 10 (http://www.lexingtonky.gov/Modules/ShowDocument.aspx?documentid=1981) of the LFUCG Stormwater Manual. The types of paving installed include porous pavers, permeable asphalt, and permeable concrete. Porous pavers can be found in the Sigma Alpha Epsilon Fraternity House parking area, along the entire concourse of the Track & Field Facility/Hagan Baseball Stadium, along the main drive of the Ronald McDonald House, and in the W.P. Garrigus Building plaza. Permeable asphalt has been used at the Ronald McDonald House for the main parking lot while permeable concrete was utilized in the construction of the Farmhouse Fraternity Amphitheater.

Any downspout disconnects on campus must follow the guidelines set forth the LFUCG Stormwater Manual. Downspout disconnects are employed at the Sigma Alpha Epsilon Fraternity House. There, gutter downspouts discharge onto stone dissipater pads located in landscaped areas.

Rain gardens on campus follow the guidelines set forth in chapter 10 of the LFUCG Stormwater Manual and the LID Guidelines. Rain gardens located on campus include those located at the David Marksbury Building, the UK Arboretum, the Ronald McDonald House, and on Farm Rd. near the Gluck Equine Center. The latter being a collaborative effort between UK faculty, staff, and students to create a storm water control that is used as a living learning laboratory.

Stormwater detention ponds, both above and below ground are utilized at UK when appropriate and in accordance with LFUCG Guidelines. There are approximately thirty detention basins on campus.

There are two areas where vegetated bioswales are used on campus. The first is located adjacent to the Ronald McDonald House and was installed as part of a LFUCG water quality incentives program. One of several components installed, the bioswale includes the incorporation of rain gardens to filter rainwater runoff from the property. The other bioswale on campus is part of the UK FEMA Flood Mitigation Project that is currently under construction and due to be completed in October 2015.

Due to the urban location of the UK campus and the need to use space efficiently when designing new construction, underground detention in conjunction with water quality devices is often used. One such method being employed is the use of enlarged conveyance systems to provide underground storage during rain events. These systems are designed to hold water during flash precipitation events and slowly discharge them to the storm sewer system. The water quality devices are in place to capture pollutants prior to discharge. There are approximately seven variations of this type on campus.