Belle Isle project will open a channel from Detroit River to inland Lake Okonoka

It's a muddy, torn-up mess now. But lovers of the picturesque eastern side of Belle Isle will eventually see a rehabilitated Lake Okonoka featuring improved fishing habitat and recreational opportunities — and an open channel leading to the Detroit River, officials say.

Out will go a historic weir that has blocked Detroit River fish from entering the small, shallow lake on the southeastern section of the island. In will go a 45-foot-wide, free-flowing channel — spanned by a new bridge elevated enough for canoers and kayakers to easily paddle under — that will connect to the Blue Heron Lagoon and eastward to the Detroit River, according to the Michigan Department of Natural Resources and Friends of the Detroit River.

In a different section of the lake, a new culvert will add another connection to allow free flow of river water. Gravel spawning beds and dredged, deeper holes will create improved fish habitat if water levels ever drop.

The work is another major phase of projects on and around Belle Isle and elsewhere on the Detroit River, designed to improve fish habitat and recreational opportunities. The goal is to alleviate conditions that led the U.S. and Canadian governments to call the Detroit River an Area of Concern, or area of significant environmental degradation, in 1987.

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"Two hundred years ago, the whole shoreline of the Detroit River was wetlands, in some areas as much as a mile wide. Ninety-seven percent of that has been destroyed," said Sam Lovall, project manager for the nonprofit Friends of the Detroit River.

The $5-million Lake Okonoka project is being paid for through federal funding via the Great Lakes Restoration Initiative, administered by the National Oceanic and Atmospheric Administration.

An earlier, similar project to transform the Blue Heron Lagoon on Belle Isle's far eastern end, completed in 2014, has had dramatic results, Lovall said.

"It's been incredible what's happened since then — the clarity of the water, the quality of the water, the number of fish living in the lagoon," he said.

The channel being built off Lake Okonoka will connect to the Blue Heron Lagoon, allowing movement corridors and spawning habitat for fish. The new channel will circulate Great Lakes water via the Detroit River into Lake Okonoka, Lovall said, "which will greatly improve the water quality, both aesthetically and will increase oxygenation, resulting in a better environment for fish."

And with the new 45-foot wide opening into the Blue Heron Lagoon, kayaks and canoes will be able to freely traverse between the interior lakes of Belle Isle and the Detroit River.

"Although the emphasis of this restoration is for fish and wildlife, recreation opportunities (kayaking, fishing, birding, hiking, photo-taking, etc.) and aesthetics will be greatly enhanced," Lovall said.

In addition, the project will include the construction of a new stop-log structure in the Nashua Canal, which connects Lake Okonoka to Lake Tacoma to the west and Lake Muskoday to the north.

"In conjunction with new structure, there will be a footpath allowing the Nashua Trail to cross the canal and universally designed kayak launches on each side allowing for easy portage via kayak or canoe," Lovall said.

Rendering: What the Lake Okonoka project on Belle Isle would look like when finished.

Collaborating on the project with the Friends group and DNR are SmithGroupJJR, Wade Trim and Z Contractors.

The work is slated for completion before fall 2018, Lovall said.

"The weeds will be gone, there will be Great Lakes water filling the lake so the water will be blue, not the crusty brown stuff," Lovall said.

The Nashua Trail canal crossing near Woodside Drive on Belle Isle is closed to facilitate the excavation and other work. Later this winter, bridge and culvert construction will require vehicular traffic to redirect from The Strand onto Woodside Drive, a detour that will continue into the spring. After work on The Strand is completed, work will switch to Woodside Drive.

Upon completion of this project, the next work on Belle Isle will feature hydrology improvements for a unique, 200-acre stand of what's known as wet-mesic flatwoods, a small forest just to the north and west of Lake Okonoka.

"It's basically a hardwood wetland," said Amanda Hertl, urban area field planner for the DNR based in Detroit.

Once more common, such flatwoods are now rare, lost to development along with more conventional wetlands, she said.

"At 200 acres, it's one of the largest, intact ecoystems of that kind," she said. "Because of the roads and trails built up in there, the hydrology has been changed. We'll be looking to improve that."

The Lake Okonoka project has required the removal of some large trees, but that was a necessity to construct the channel between the lake and the Blue Water Lagoon, Lovall said.

"It will be just as beautiful as ever — it could be even prettier when it all matures," he said.

Contact Keith Matheny: 313-222-5021 or kmatheny@freepress.com. Follow on Twitter @keithmatheny.