The US-60 Bridge is in the right background of this photo.
The lock is 600' long, but only 84' wide and the dam was completed in 1970. [TheTownTalk] Normally a USACE lock is 110' wide because barges are 35' wide.
The USACE claims the existing dam was built in 1956, but I believe the 1970 date in TheTownTalk because the dam uses a cell structure. I thought the cell structure construction technique was a 21st Century development. I wonder if this 1970 dam was one of the first applications of that technique.
|1:14 Aug 2022 video @ 0:14
The river gauge located here not only measures the usual stream data of gage height, discharge and stream velocity, it measures water quality data as part of the Mississippi River Basin Healthy Watersheds Initiative. The water quality data is "dissolved oxygen, nitrate plus nitrite, pH, specific conductance at 25°C, turbidity and water temperature."
In this flood, the dam and lock walls are completely submerged.
While editing the Spottsville bridges notes, I noticed you could not see the dam in a satellite image. But you can see the lock walls. I fired up Google Earth to get a date for this image. It was May 2022.