Using practices such as targeted and well-planned irrigation systems and storm water management, Purdue University makes the most of its water resources.
Purdue University has in place a number of technologies, measures, and initiatives to ensure that its use of water for on-campus irrigation is controlled and recycled, as much as possible. In particular, three measures stand out.
Purdue uses new irrigation heads that come in a variety of angles to better target areas needing water, as opposed to older heads that come in just forty-five and ninety-degree angles. Purdue uses thirty-degree nozzles to cover target areas, which wastes less water on sidewalks and other surfaces that do not require water. The irrigation heads also keep water from drifting, since they produce droplets of water instead of a steady stream that might drift from targeted areas. These measures, combined with a much better selection of nozzles for corners of the sidewalks and other impervious areas, ensure that the the system delivers a maximum amount of water to the proper areas.
Since the 1970s, Purdue University’s Grounds and Maintenance department has integrated clocks with the irrigation systems for better control. In the early 2000s, Grounds and Maintenance began using smart clocks, soil probes, and rain gauges to even more precisely control and conserve water. The department is responsible for over 1.9 million square feet of turf and over 680,000 square feet of shrub and flowerbeds. The irrigation systems on campus contain 67 control units and over 600 in-ground control valves, as well as more than 10,000 irrigation heads.
Central Irrigation Control System
Purdue previously managed 67 independent irrigation systems with on-site control units. The new Central Irrigation Control system allows us to conserve 18 million gallons of water annually by monitoring the weather and soil conditions and only calling for irrigation when needed to sustain turf and plant life. The system also saves labor expenses by alerting us to irrigation leak locations and allowing all irrigation systems to be controlled from one computer at our maintenance facility and/or a laptop in the field. Purdue completed this project ahead of schedule and under budget.
Purdue University created its campus-wide Sustainable Stormwater Modification Design in November 2009, investing more than $6 million in line with the university’s Strategic Plan for 2008-2015 and the 2009 Campus Master Plan. The new design is a significant step toward sustainabe long-term water resource management.
The Sustainable Stormwater Modification Design includes the following key recommendations:
- Manage the small, frequent rainfall events to improve water quality, protect Harrison Pond and other receiving waters and promote groundwater recharge. Capturing the initial volume of runoff will also reduce the impacts of larger events.
- Use a systems approach integrating stormwater management with landscape measures, campus improvements, and new projects.
- Distribute a number of stormwater options, large and small, throughout a drainage area rather than a single large solution whose failure would have far greater consequences.
- Capture water upstream near the source, to reduce the burden on conveyance systems and the potential for localized downstream flooding.
View the full Sustainable Stormwater Modification Design:
Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | References |
Key Features of the Design
In response to the design, Purdue has implemented a systemic approach to stormwater management comprised of bioswales, rain gardens, infiltration beds, and pervious pavement (or porous asphalt) throughout campus.
Yue-King Pao Hall
The bioswales installed in 2007 at the Yue-Kong Pao Hall, housing the Rueff School of Visual & Performing Arts, were the first true bioswales on campus. The bioswales were designed to capture and control the flow of surface water runoff, and to treat the water by allowing vegetation to filter oil and grease pollutants. By allowing natural filtration of pollutants, the bioswale prevents impurities from flowing into Harrison pond and municipal sewers, helping alleviate stress on aquatic life. Bioswales typically require very little water and care, are resistant to local pests and disease, and enhance bio-diversity.
Mann Hall/Discovery Park Bioswales
Completed in 2009, the bioswales on the west side of Mann Hall, at Purdue Discovery Park, help slow and/or eliminate excess stormwater, maintain the area’s hydrological profile, and clean the water off pollutants. The water is receded from the grassy mall area into the bioswale, and it then meanders slowly downhill before it goes into the drain, soaking into the ground along the way. The bioswales here also have plenty of native plants and boulders, adding to their aesthetic appeal.
Harrison Street Bioswales/Infiltration Planters
The Harrison Street bioswales and infiltration planters were included as part of the city’s project when the street was upgraded. The project included infiltration planters along Harrison Street, to allow excess stormwater to infiltrate into the ground, and the water is then piped away. The bioswales were completed in 2012, and used native sedge plants.
Stadium Mall Crosswalks
Four of the crosswalks along Stadium Mall have porous paving, as part of a long-term plan to convert the area to a pedestrian mall. In addition to allowing stormwater to penetrate into the ground instead of running off to drainage, the porous paving helps maintain the area’s hydrological system. The project was completed in the fall of 2011.
Horticulture Building Rain Garden
The Horticulture building boasts a rain garden in front, to be completed in 2013, which diverts roof runoff from the combined sewer and transfers it to the ground in front of the building. Student inputs were sought from two different classes on planting and layout construction design. Faculty inputs were also solicited.
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Harrison and Hillenbrand Rain Garden
The rain garden between Harrison and Hillenbrand residence halls is an entirely student-led project, under the auspices of the Boiler Green Initiative (BGI). BGI obtained grant funding for the project, designed the rain garden, and worked with Purdue University to install the rain garden. The group had also consulted with residence hall representatives to determine a suitable place for the rain garden, to accomplish both sustainable stormwater management and educate the Purdue community. Completed in May 2013, the rain garden consists of several native plants.
See news release
New Underground Retention Site
The infiltration system cleans storm water and helps maintain the hydrologic cycle by directing rainwater to enter the ground where it falls instead of transporting it, and its pollutants, through storm sewers to a remote water body. It collects storm water from Third Street Suites and Center for Student Excellence and Leadership roof drains and from drain inlets on surrounding plazas and greenspace. The water fills the containers and then seeps into the soil below. Should the buried chambers’ capacities be exceeded during high intensity storm events, overflow will be directed to a storm sewer which will transport storm water to Harrison Pond.