Yale University
OP-23: Rainwater Management

Yale University envisions a campus where stormwater runoff is reduced sustainably through green infrastructure. To move toward this vision, the Stormwater Management Plan advocates for investment in green infrastructure in a comprehensive manner throughout Yale’s campus. The following principles, adapted from Pennsylvania’s Department of Environmental Protection (Pennsylvania Department of Environmental Protection 2006),will guide Yale’s approach to sustainable stormwater management on campus and are intended for both the initial phases of understanding stormwater on campus as well as the future goal setting and strategies to be defined in 2016. Further, they support the sustainability values reflected in Yale’s Sustainability Strategic Plans and are in alignment with the Planning Principles stated in the 2013 Sustainability Supplement to the Framework for Campus Planning. The Sustainable Stormwater Management Principles are as follows: Recognize Stormwater as a Resource: Stormwater has great impact on the health and economic vitality of the campus, the region, and the environment. Yale shall manage stormwater as a resource in order to enhance its positive effects on the environment and to reduce associated risks to Yale assets and infrastructure. Prioritize Restoration of Watershed Function: Watershed function is restored with low-impact stormwater management strategies, including natural features, landscapes, and green infrastructure systems. Yale shall implement stormwater management strategies following a fundamental order of priority: first infiltration of stormwater where it falls, then storage for infiltration or reuse, and finally temporary detention and gradual release of stormwater to New Haven’s combined and separate storm sewer systems. Promote Stormwater Research: Sustainable stormwater management offers and necessitates robust research and educational opportunities for students and faculty. Yale shall encourage university-wide participation and stewardship of stormwater management strategies on campus. Incorporate Adaptive Management: Data gathered by surveying campus infrastructure, monitoring stormwater discharge, and modeling campus performance provide a foundation for future goal setting. Yale shall commit to collecting data, sharing data, and using an iterative decision-making process for ongoing stormwater management. With a vision of moving the campus away from compliance and toward reducing the campus’s stormwater runoff impact using green infrastructure techniques, Yale University intends to set a specific quantitative goal similar to the green infrastructure goal set by New York City in 2010 (NYC Department of Environmental Protection, n.d.): “Capture the first inch of rainfall on 10% of the impervious areas in combined sewer watersheds through detention or infiltration techniques over 20 years.” To achieve the New York City goal at Yale, the university would need to manage approximately one million gallons of stormwater runoff from its impervious surfaces or, for example, the first inch of rainfall from 1/3 of its 5.2 million square feet of roof space. At this point, little is known about the level of work and capital necessary to achieve a goal of this magnitude. Before committing to a goal that at this time may be unachievable, Yale must build its understanding of green infrastructure techniques on campus, and with that knowledge set a goal in 2016. Creating this knowledge base can be accomplished through the implementation of a combination of engineered, vegetated landscape techniques that include rain gardens, bioswales, enhanced tree pits, and green roofs or through the structural techniques that include downspout disconnection, rain barrels, cisterns, blue roofs, infiltration trenches, and pervious pavement. Descriptions of these potential green infrastructure techniques and information on their associated design considerations are included in Appendix B. This plan advocates for an adaptive management approach for stormwater management. Each phase of the stormwater runoff mitigation effort beginning with this plan’s strategies is intended to build off the previous phases’ work. The intent of this plan is to serve as the groundwork for sustainable stormwater management on campus with subsequent plans incorporating the knowledge gained over the next three years. The recommended process to achieve this adaptive management approach is further explained in Appendix C.

Please review the plan here: http://sustainability.yale.edu/sites/default/files/files/Sustainable%20Stormwater%20Management%20Plan.pdf