American University
OP-22: Rainwater Management

American University follows the DC Stormwater Regulations, which require stormwater best management practices (BMPs) for all new construction > 5000 sq. ft. and for any building additions or renovations.

AU does not have a written policy that require LID for all new projects, but the DC Stormwater Management Guidelines, which AU adheres to, require it. New projects are all required to have at least LEED Gold certification, which covers rainwater management practices. With the entire campus being an arboretum, AU is committed to rainwater management.

Some of the notable stormwater management sites on campus include:
1. Two bioretention ponds at the School of International Service (SIS) collect and slow stormwater runoff on either side of the building before filtering it and ultimately allowing excess water to enter the stormwater system through a Bay Saver.
2. Green roofs on nine buildings on campus.
3. A rain garden in front of the Kogod Building captures run-off rain water and uses a Bay Saver. A rain garden outside of the Centennial Parking garage captures runoff. Parking has been removed between Clark and Roper Halls and replaced with rain gardens. There is also a rain garden behind McKinley.
4. Permeable pavement is installed in on walkways on main campus near Kay Spiritual Center and McCabe Hall.
5. Cisterns in Cassell and on East Campus are used to collect water for irrigation.
6. Campus is home to over 3,700 trees and all 84 acres of campus is a certified Arboretum.

AU uses a variety of strategies to deal with rainwater on campus. The university has rain gardens, cisterns, and bioretention ponds in place to help manage rainwater. Additionally, the university attempts to reduce impermeable hardscape altogether and use pervious pavers when possible.
American University is committed to responsibility manager stormwater onsite in support of DC's and the Chesapeake Bay region goals.

"The District of Columbia (District), like most ultra-urban areas, experiences increased stormwater runoff that results from development. This runoff places a burden on sewer systems and degrades aquatic resources when it is not managed adequately. Unmanaged stormwater runoff overloads the capacity of streams and storm sewers and is responsible for increased combined sewer overflow events and adverse downstream impacts, such as flash flooding, channel erosion, surface and groundwater pollution, and habitat degradation.

Recognizing this issue, the District first adopted stormwater management regulations in 1988. These regulations, Chapter 5 of Title 21 of the District of Columbia Municipal Regulations (21 DCMR), established requirements to manage both stormwater quality and quantity. Quality control focused on the removal of pollutants from up to the first 0.5 inch of stormwater runoff, often referred to as the “first flush.” Quantity control was mandated through detention requirements based on the 2-year, 24-hour storm event for stream bank protection (widely accepted as the channel shaping flow) and the 15-year, 24-hour storm event for flood protection (the typical design capacity of the District’s sewer conveyance system).

In 2013, the District’s stormwater management regulations shifted its stormwater quality standard to a retention-based standard. Major land-disturbing activities must retain the volume from a 1.2-inch storm event, and major substantial improvement activities must retain the volume from a 0.8-inch storm event. By keeping stormwater on site, retention practices effectively provide both treatment and additional volume control, significantly improving protection for District waterbodies. The Stormwater Retention Volume (SWRv) can be managed through runoff prevention (e.g., conservation of pervious cover or reforestation), runoff reduction (e.g., infiltration or water reuse), and runoff treatment (e.g., plant/soil filter systems or permeable pavement).

The Stormwater Management Guidebook (SWMG) provides technical guidance on the 2013 and 2019 revisions to the 1988 regulations."

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As per the AU Design and Construction Standards-
"Storm water Control: Comply with requirements of authorities having jurisdiction. Provide barriers in and around excavations and subgrade construction to prevent flooding by runoff of storm water from heavy rains."
https://www.american.edu/finance/facilities/upload/01-50-00-temporary-facilities-and-controls.pdf

DC Stormwater Regulations: https://doee.dc.gov/service/offv
DC Stormwater Management Guidebook: https://doee.dc.gov/node/610622

AU Design and Construction Standards: https://www.american.edu/finance/facilities/upload/au-design-standards-2019.pdf