Water Dam Deflation

The City of Waterloo will begin to deflate the Cedar River bladder dam October 4, 2021. The dam will be slowly deflated at a rate of approximately 2.5 inches per day, Monday through Friday. The dam should be completely deflated by October 29, 2021, weather pending

River biologists have requested the dam to be deflated slowly in response to previous fall drawdowns that have caused mass stranding of freshwater mussels on exposed river bottom. This slow deflation rate will allow upstream aquatic life to adjust to the changing river level.

The bladder dam is also being deflated in preparation for the Park Avenue bridge replacement and the Cedar River Marina projects. Demolition of the bridge is slated to begin in late fall 2021 with construction to be completed late 2022. The Cedar River Marina project is proposed to begin in spring 2022 with construction finishing in fall 2022. These projects will be impacted by river levels, thus the bladder dam will not be reinflated until spring 2023.

If you have questions concerning mussel stranding, please contact Dan Kirby at (563)-927-3276 for additional information.

Other questions should be directed to Wayne Castle in the City Engineer’s office, (319) 291-4312.