River/Stream: South Skunk River
Owner: U.S. Geological Survey
Height: 3 feet
Length: 50 feet
Hazards: drowning, varying
Warning Signs: standard signs in place
Portage: on river right
Comments: ruins of very old rock crib mill dam capped with concrete; also known as US / General Filter Dam
"The accident occurred at what we call the US Filter dam, just north of Ames & almost visible from Hwy 69 opposite Ada Hayden Park. I'd say it's a 3-4 ft drop at most levels. It is obvious as you approach from upstream & is routinely run by canoes, kayaks, and tubers, but for those that choose to use it, there's an EASY portage river-right accross the dam structure itself.
"We're told that the concrete structure caps the original rock-and-crib mill dam, and that the four large timbers sometimes visible on the downstream side are part of the original cribbing. The concrete cap has a sloping downstream surface but does create a small hydraulic at it's base.
"I think it's fair to say that as low-head dams go, most of us never considered this one particularly dangerous. I suspect Tom had run it before on numerous other occasions. I don't know if the hydraulic could have been a factor, but it is easy to imagine someone swamping as they scraped across the dam (the water was relatively low on the 17th) or hit a standing wave or timber at it's base. Capsizes here are not uncommon."
- April 17, 2005 - canoeist Thomas Manatt
- May 3, 1963 - floater David Barnhart