c1900-15 4th Street & 1950s 11th Street Bridges and Bladder Dam on Cedar River in Waterloo, IA

4th: (Satellite)

11th: (Satellite)

Bladder Dam: (Satellite)

4th Street Bridge

Lisa Hawks posted
A vintage postcard of the Dam and Fourth Street Bridge area in downtown Waterloo, Iowa, likely from the early 20th century (circa 1900-1915). This area was historically the main commercial hub of the city. The first bridge at this specific crossing was built in the 19th century. The current Fourth Street Bridge has undergone several renovations over the years, including the addition of new lighting in 2023.

11th Street Bridge

Judging by the flood wall on the far right, this river has some significant floods.

Trail View, Feb 2021

I normally don't note UCEB (Ugly Concrete Eyesore Bridges), but I normally don't come across a construction photo. At least these steel girders have some character with the bottom chord curve.

Bridges Now and Then posted
Photograph of the 11th Street Bridge under construction, Waterloo, Iowa, 1953. (Waterloo Bridges Project)

Bladder Dam

They raise the river by 4' (1.2m) in the Spring and lower it in the Fall.

The bladder dam cost 15.8m, and it benefits recreational boaters. [TheNewWaterloo]

Oct 13, 2026:

Waterloo-Cedar Falls Courier posted
The dam will be slowly deflated at a rate of approximately 2 ½ inches per day, Monday through Friday, and should be completely deflated by Nov. 17, weather permitting.
wcfcourier.com/news/local/article_790007c4-639a-46ee-97a4-293eb413fd5b.html [paywall]

City of Waterloo, Iowa - City Hall posted

The City of Waterloo will begin to deflate the Cedar River bladder dam on Thursday, October 15, 2026. 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 Tuesday, November 17, 2026, 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.

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

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

Sharmondus D Sal: Why so early? [I saw that the river is normally lowered in November instead of October.]

Pete Wilkins: Sharmondus D Sal because the skiers are done for the year and they don't care about people fishing.

Sharmondus D Sal: Pete Wilkins well that blows since fall fishing on the river is perfect for walllies and pike.