Appleton Southeast Subwatershed Storage Analysis

Unacceptable levels of stormwater ponding occurred in the Southeast Subwatershed during past rainfall events. The City of Appleton conducted studies in 2004 and 2005 that examined stormwater ponding mitigation alternatives. Several changes have occurred in the subwatershed since 2005. This study incorporates these changes, updates the hydraulic evaluation (using XP-SWMM), evaluates floodproofing options, and examines underground storage of stormwater outside of the right-of-way.

GRAEF presented four possible underground storage sites to the City’s Utilities Committee using a Comparison Matrix that summarizes the impacts of each alternative. At this meeting the Committee indicated that the two most cost-effective underground storage options, the two sites on the Appleton East High School property, should be discussed with the school district.

GRAEF proceeded with preliminary engineering and design of 28.5 acre-feet of underground storage proposed to be placed under the Appleton East High School soccer field on Matthias Street, 20 acre-feet of underground storage (11.5 feet deep) to be placed in the northeast parking lot of Appleton East High School and inlet and outlet storm sewers to these facilities.