This project will construct an underground storm water infiltration system under the lawn area on the east side of State Street southwest of Angell Hall and northwest of Alumni Memorial Hall. Historically, buildings in this area have flooded because of the lack of capacity in the City of Ann Arbor’s storm water system that flows into the Allen Creek drain. With this project, nine acres of storm water flow from the west side of the Diag will be redirected to this infiltration system and taken out of the volume of storm water flowing to the Allen Creek drain. For a 100-year storm event, that will equate to approximately 750,000 gallons of water, which would represent about 1.75 feet of water covering a football field. Because the system relies on the relatively slow seepage of water into the ground, multiple rain events or more unusual amounts of rain could overwhelm the system. Noting that limitation, this project will reduce flooding in nearby buildings and limit significant disruption and restoration costs that result.