MMSD Plans Estabrook Falls Fish Passage

Estabrook Park waterfall. Photo taken Jan. 14, 2025 by Graham Kilmer.

The Milwaukee Metropolitan Sewerage District (MMSD) is planning a fish passage through the Estabrook Park waterfall, removing the final barrier between Lake Michigan and roughly 60 miles of Milwaukee River and tributary streams.

The falls are a popular feature in Estabrook Park, visible from an overlook near the beer garden. It’s also one of the last remaining fish barriers between Lake Michigan and the upstream spawning areas for many native fish species.

“Fish need to move,” said Beth Wentzel, a senior project manager with MMSD

In 2023, MMSD built a fish passage around the Kletzsch Park Dam, opening up miles of spawning areas and tributary streams for the first time in decades. But downstream remained a smaller barrier in Estabrook Park that was still blocking some fish from swimming upstream.

The Estabrook falls represent a partial fish barrier, Wentzel said. When the water is high during periods of heavy rain, the falls are concealed beneath the roaring river and fish can easily cross over. But these events cannot be counted on, especially when the region is also experiencing periods of drought.

The falls aren’t even a natural feature of the river.

“It’s not actually a natural waterfall, but rather it’s a relic of historic bedrock mining in the river,” said Wentzel said. The falls are created by an outcrop of rock marking the edge of the riverbed that was mined for limestone around 100 years ago. “Basically they mined up to the location of the falls and stopped there.”

Historically, many of the fish native to the Milwaukee River would spend time in Lake Michigan and migrate up the river to spawn and feed, Wentzel said. Barriers in the river, even partial ones like the Estabrook Falls, have made this annual migration difficult, blocking off important habitat for these species and diminishing their population in the river.

“Fish like northern pike, lake sturgeon, bass, walleye, they don’t jump as well as, say, salmon,” Wentzel said.

In the case of sturgeon, they were extirpated from the Milwaukee river system. An intensive, long-term effort to reintroduce the species is underway.

In other areas of the Milwaukee River, and the estuary, when barriers are removed fish populations bounce back. The fish passage around the Kletszch Dam was installed only a little over a year ago and MMSD has already gotten reports of greater fish activity north of the dam, Wentzel said.

The Estabrook project, like the Kletszch fish passage, is part of a larger, regional effort focused on remediating pollution and restoring natural habitats in the Milwaukee estuary, identified by the U.S. Environmental Protection Agency (EPA) as an Area of Concern, or AOC. The designation was created in 1987, and local governments and nonprofit partners work with the state Department of Natural Resources and EPA to identify and plan projects that will eventually remove Milwaukee from the list of AOC’s. The fish passage being planned in Estabrook Park is one of those projects.

The plan is to excavate two channels through the outcrop of rock. On the west side of the river a deep channel for fish and on the east side a shallower channel will both pull water through, preventing the river from simply diverting through the new fish passage. It should result in a navigable passage for fish that maintains some of the falls as a water feature in the park, Wentzel said.

“We did do quite a bit of outreach… and one thing we heard is that people people do like the aesthetics of the waterfall,” Wentzel said.

MMSD does not have a firm cost, as the project has not gone out to bid, but it is expecting the project to cost somewhere between $500,000 and $1 million. If everything goes to plan, construction could begin this summer, Wentzel said.

And after that? The sewerage district’s experience removing fish barriers elsewhere serves as a guide for what happens next. There will be more fish, and potentially fish, like sturgeon, in parts of the river where they haven’t been seen in many years.

“It means a lot more fish getting upstream,” Wentzel said. “So for one, you’ll see more of these native fish getting further upstream. If you’re an angler, you might be able to catch more northern pike someday, maybe even sturgeon, although it’s not legal to fish for them in the river yet.”