Argo Cascades still closed: Ann Arbor parks manager says Huron River might be at lowest level in a decade

This has been brought on by the drought-like conditions we are experiencing that has resulted in extremely low flow rates in the river. In order for the city to comply with the Federal Energy Regulatory Commission and the MDEQ minimum flow requirements across Barton and Argo dams, the low flow in the river necessitates closing Argo Cascades. Staff will continue to monitor river flows and the flow will be restored to the cascades when flow in the river improves.

The lack of rain in the Huron River Watershed has resulted in unprecedented low flows that we have not seen since the 1980s. As operators of four dams on the Huron River, the city is required to pass what is called “run-of-river” by each of the dams. This means that whatever flow approaches each dam must be passed by the dam. The city is not permitted to store water behind any of its dams and release the water at its discretion for future use.

What does closing the cascades mean from a recreational standpoint? Given the extremely low flow currently in the river, it actually doesn't impact livery operations significantly at this time. As of two weekends ago, the river flow was already so low that we were only allowing single kayaks (less weight) down the river from Argo to Gallup — not because of the cascades, but because the river was so low at points downriver (Island Park, Riverside, the Arb) that people were getting stuck and having to get out and carry their boats to deeper water. We were planning on not allowing any river trips between Argo and Gallup this past weekend unless we received some rain that brought the river levels up significantly.

So, in short — cutting off some of the flow to the cascades until we get some much needed rain in order to comply with dam water passage requirements is not that impactful to us. On a related note, this is the lowest park staff remember the river being over the last 10 years. We have often had to limit or not allow river trips based on dangerous high water conditions, but this is the first time we have had to restrict river trips due to low water. Another example, I suppose, of extreme weather fluctuations.