University of Connecticut
OP-27: Rainwater Management

UConn has an interactive tour of all LID developments and initiatives on campus available here (http://ecohusky.uconn.edu/development/lid.html) Over 400,000 square feet of campus area is covered using LID practices.The cumulative annual volume of storm water reduction by campus LID practices is equal to 65 Olympic swimming pools or 9.25 football fields. UConn has been committed to installing low impact design (LID) stormwater management features for several years, not only as part of new construction projects but also as retrofits and demonstration projects at older building sites. On the main campus, UConn has more than 20 engineered rain gardens and bio retention swales, three green roofs, the first large-scale porous concrete and permeable asphalt parking lots in Connecticut, two terraces constructed with porous landscape pavers, and interlocking brick pavers used for the snow shelf along Hillside Road on campus. A large underground infiltration chamber and a rainwater harvesting system were constructed for capturing roof runoff and intercepting ground water for irrigation purposes. From UConn's 2004 Sustainable Development Guidelines: "Goal-1 Reduce development stormwater runoff impacts on the quantity and quality of the area’s water resources. Strategies: • Prevent any increase in the rate of stormwater flow leaving the site. Provide for infiltration of stormwater runoff on both greenfield and previously disturbed sites. • Strategies for implementing both of these goals include: • Promoting permeable paving technologies in lieu of the conventional impervious surfaces for drives and parking lots. Perform a life-cycle cost analysis that recognizes the long-term maintenance costs with the resulting benefits when choosing the appropriate system. • Collecting rainwater from project roofs, where feasible, and store it for reuse or slow release. • Implement landscaping that has a higher rate of absorption than conventional turf grass. • Reducing the need for stormwater utilities and detention basins. Introduce stormwater bio-retention basins, swales, or rain gardens within the project site or within the adjacent campus or clusters of buildings. • Using a vegetated roof for flat or low sloping roofs. • Incorporate on-site stormwater treatment and infiltration to meet the guidelines of the Connecticut Department of Environmental Protection, Connecticut Stormwater Quality Manual, 2003. Strategies for consideration, in order of preference, for implementing this goal include: • Incorporating bio-retention areas, rain gardens, vegetated basins, vegetated swales, constructed wetlands, etc. on site to treat stormwater. • Including on-site mechanical filtration systems to treat stormwater to meet the standards as defined in the manual.”

UConn has utilized LID principles to improve and construct flood and water quality enhancements on the main campus. A Memorandum of Understanding with the CT Department of Energy and Environmental Protection was recently finalized to establish a drainage plan that quantifies the environmental benefits of LID features currently installed on campus as well as for the implementation of future LID measures.

The Oak Hall building, which is LEED Gold certified, includes UConn’s first rainwater harvesting system for irrigation of plants and lawn areas. Two 25,000 gallon tanks beneath the building collect roof runoff and intercept underlying groundwater, protecting the University’s investment in landscaping by using this non-potable water to keep the core campus green.

UConn has engineered rain gardens and bio-retention swales to provide natural filtration and reduce stormwater runoff.

The university has three green roof projects installed: • The Gant Plaza Green Roof project, which began seven years ago as a student led initiative of the UConn Soil and Water Conservation Society, is now a reality with the approval of a $50,000 grant from the federal Environmental Protection Agency. Natural Resource Management & Engineering (NRME) faculty member, Jack Clausen, also the advisor to the SWCS, led the effort on this project and is working with Civil & Environmental Engineering faculty and others to research the impact the green roof has had on reducing stormwater runoff from the plaza into the nearby Eagleville Brook. • The Laurel Hall classroom building was opened in December, 2011, with a permanent green roof: the building has numerous environmentally conscious and sustainable energy features, including an installed green roof, planted with sedum and other low-growing, drought tolerant, ground cover type plants. It is easily visible from the third floor of the new classroom building, which is used by 10,000 students per semester for classes. • Storrs Hall, home to the School of Nursing, was recently renovated, adding the 15,800 square-foot Widmer Wing. Storrs Hall is 103 years-old, one of the oldest structures at UConn, and now incorporates LEED features including a green roof patio for stormwater flow reduction and treatment.

Porous concrete and permeable asphalt parking lots were installed in the summer of 2009 outside the Greer Field House and Towers Residence Halls. Permeable asphalt was also recently installed at the Whetten Graduate Center and the Storrs Hall parking lots. These porous materials allow rain and melted snow to drain through the concrete or asphalt surface into the soil below, mimicking natural drainage. Porous concrete and asphalt are better for the environment than traditional asphalt parking lots, which cause water to accumulate and flow off of the parking lot surface and into storm drains, causing erosion and carrying sediment and pollution into our rivers and streams. Additionally, porous paving technology has been used in walkways and terraces surrounding Laurel, Oak, and Storrs Halls, as well as at the Lakeside building. Additionally, the newly completed reconstruction of Hillside Road in which approximately 2,700 linear feet of roadway was lined on both sides by permeable interlocking brick pavers interspersed with tree, lawn, and flower areas. The School of Business also put in porous pavers on its south side sidewalks. The Northwood Apartment complex also installed porous pavement. Finally, the newly completed Sundial Plaza in the center of campus also has porous paving technology.

The University employs downspout disconnections in conjunction with its green roofs and bioswale systems. Downspouts are routed through green roofs and bioswales for buildings with these features available.

The University has employed rain gardens throughout campus to treat runoff and help infiltration in a number of different areas around campus. Rain gardens have been put in at the Hillel House and the Hilltop and Mansfield Apartment Complexes to specifically deal with stormwater runoff from the apartment buildings. UConn has also put in a rain garden at the Whetten Graduate Center in a traffic turnaround to help treat road runoff as well as stormwater from the surrounding buildings.

Mirror Lake and Swan Lake are man-made ponds serving as both stormwater detention basins (UConn's largest) as well as central landscape elements on the main campus. The campus is a relatively densely developed area amid a more rural community with adjacent agricultural land uses - thus all drainage from the campus impervious surfaces needs to be captured in detention basins to ensure no net increase in off-site drainage rates during various storm events. LID goals are also to reduce both rate and volume of stormwater discharges by infiltrating as much as possible, in conjunction with conventional detention basins. The goal is improved water quality in the area's streams, lakes and other water bodies.

Several vegetated swales are located throughout the University to manage stormwater, including one behind the tennis courts, and another in front of the new classroom building. Vegetated swales were installed around Laurel Hall that was completed in 2011, capturing runoff from the impervious roof and surrounding area, as well as the newly completed Oak Hall, which opened for academic year 12-13, to serve the same purpose. Both swales are contained by gabion baskets and feature medium sized plantings and groundcover. A bioretention island has also been added to the Whetten Graduate Center parking lot to treat runoff from the road and the surrounding buildings.

Incorporating bio-retention areas, rain gardens, vegetated basins, vegetated swales, constructed wetlands, GrassPave® technology etc. on site to treat stormwater. Including on-site mechanical filtration systems (e.g., Vortech units) to treat stormwater to meet the standards as defined in the state's stormwater quality manual