Floyd River Channel Dams

River/Stream: Floyd River

Location: 4 dams within 1.2 miles in Sioux City, Woodbury County
        Latitude: 42.503837
        Longitude: -96.383678
        Click here to view an aerial map of the dams.

Built: 1950's

Owner: U.S. Army Corps of Engineers

Height: 1-2 feet to more than 4 feet

Length: varies from approximately 106 feet to 148 feet

Hazards: usage, visibility

Warning Signs: none

Portage: none

Comments: On June 8, 1953, the Floyd River again flooded when a torrential downpour in the Sheldon, Iowa area sent a wall of water down into the lower valley. Fourteen people lost their lives. This flood was a major impetus for the Floyd River flood control project, including the building of a straightened, rock-lined channel and high levee through the city. (source: Wikipedia)

General Description: All of the dams have very steep, eroding banks with large rocks. Portaging would be difficult as would rescue efforts. There are flood gates and levys on both sides of the Floyd River, so this is a dangerous place to be during heavy rain. Dams appear to be made of sheet pile construction because of zig-zag pattern seen in photos. All of the dams are very difficult to see from water level until you are right up on them. They are loud, but by the time a paddler would recognize the danger, it would be very difficult to escape. This is in a very industrial area and it would be hard to enter, exit, rescue, or even notice a paddler in the water. All four dams have debris and erosion around the sides of the dam.

Above 11th Street Bridge: Less visible debris than 6th Street. Very loud. Videos show that you can actually see the dangerous recirculation of water. Click here to see video of dam.

View of 11th Street Dam

Above 6th Street Bridge: Logs often lodged on dam. Large drop-off (2-3'). Very fast-moving, loud. This dam is especially deceiving because it looks like a still pool before ripples. Anyone would think this is a safe place to paddle, at least from water-level.

View of 6th Street Dam

Below 4th Street Bridge: This is the smallest dam of the four. 1-2 foot drop. Consistent flow across the river. Appears that there are rocks underwater about 5 feet past the dam, causes some boiling.

View of 4th Street Dam

Below Dace Avenue Bridge: More than a 4 foot drop. Logs trapped underneath. Rocky sandbar past dam creates a pool that debris, victims could get caught up in. Boil in the middle of the river. Rocks on all sides - hazardous! Click here to see video of dam.

View of Dace Avenue Dam