Pomona College
OP-27: Rainwater Management

The Pomona College Sustainability Action Plan sets an objective of increased use of sustainable stormwater management technologies for 2020 and identifies stormwater management as a main issue concerning water at the College. In its 2010 Open Space and Landscape Guidelines, the College outlines basic strategies for stormwater management: incorporation of unique site conditions into open space design, restoration of the Wash to its original function as a drainage basin, use of bio-retention basins or vegetated swales in newly created natural areas, reduction of impervious surfaces, use of permeable pavement wherever possible, the elimination of curbs and gutters, the use of large lawns as stormwater percolation beds where possible, and the transformation of surface parking lots into open and green spaces. All of the strategies in the Open Space and Landscape Guidelines have been adopted to some degree, including bioswales, pervious pavement, and an increase in total permeable open space on campus. The College is currently working on a significant stormwater management project that will redirect all stormwater from the northern part of campus into an underground filtration basin, reconnecting this water with the natural aquifer.

According to the Pomona College Green Building Standards, all new construction and major renovation is required to abide by these standards and build to LEED Gold Standards. This includes achieving and prioritizing prerequisite (internal to Pomona) LEED credits. Of these, both storm water design credits are required (6.1 and 6.2 - quantity and quality control).

Careful grading and bioswales are incorporated into landscaping projects around campus, per the Green Building Standards. Land is graded to move water towards plants and bioswales are installed to direct rain through landscape to be filtered by plants and remain in retention ponds to be soaked into the ground to recharge the aquifer.

Pomona College has constructed numerous bioswales, infiltration trenches, and retention ponds in about a dozen locations on campus that employ soil as natural filters to treat storm water.

Sontag Hall, completed in 2011, and LEED Platinum certified, includes a rooftop garden which is operated as a mentoring program by the Draper Center for Community Partnerships. The program aims to increase activism and awareness around environmental justice, sustainability, and gardening; build leadership and presentation skills; and develop positive mentoring relationships between Pomona and Teen Green students.

Porous paving has been utilized across campus, including the use of Turfcrete, decomposed granite, and other permeable surfaces. In the past two years, 100,000 square feet of concrete and impermeable asphalt was converted to landscaped areas with permeable walkways and paving.

The campus makes use of designed detention basins within landscaping to collect water after a storm and reconnect that water with the natural aquifer. All landscaping renovations incorporate storm water management such as retention ponds and bioswales.

Vegetated swales are used in a number of places on campus to temporarily collect and channel stormwater runoff into basins that drain into the natural aquifer. An extensive system of new swales was recently completed for the southeastern corner of campus at Columbia Street across from the South Campus Parking Structure, and another large one installed to the east of Bridges Hall of Music in 2013.

The College has a long-term plan to significantly reduce the area of concrete and asphalt surfaces on campus, which will significantly alter the path of stormwater on campus. Runoff will be channeled into retention basins, pervious pavement areas, and swales.