The feature conversation on the podcast today focuses on Belle Isle and pervasive flooding on the east side of the island park.
Below, you’ll find audio of the conversation in Tuesday’s Daily Detroit podcast (it starts at about 4m50s in) and a lightly edited transcript.
Sven Gustafson: Brian, you write about some of the ecological restoration work going on on Belle Isle that has been kind of complicated by the high water levels on the Detroit River. But before we kind of get into that, set the stage for us. What does it look like over there on Belle Isle right now with the high water levels?
Brian Allnutt: Well, yeah, that ring road that goes around the the island that people use to get to a lot of different locations has been closed since last year. It’s been closed for over a year at this point, I think you know, so people’s access to the island just isn’t what it used to be and especially that really wild eastern end of the island where you have the lagoon and that big field, the woodlands, just high water all over the place. It was really this Lake Okonoka restoration projects opening up that lake and the canals to the river and that led to high waters and last year that caused this flooding.
Sven Gustafson: Yeah, talk a little bit about that project. Lake Okonoka, where is that and what were they trying to do?
Brian Allnutt: So Lake Okonoka is across the ring road, it’s called The Strand, the name of the road right there across from the Coast Guard Station. It’s a pretty large body of water on the inside of the island, and in the past it had been kind of stagnant with a lot of weeds and stuff. The Blue Heron Lagoon, which is on the eastern end of the island was opened up to the river several years ago to create fish spawning habitat. And then this project was connecting the Blue Heron Lagoon with Lake Okonoka and the canal so that essentially all the major lakes and waterways in the interior of the island are now connected to the Detroit River.
Sven Gustafson: And what was the goal of that project?
Brian Allnutt: Well, I think the the primary goals were to create fish spawning habitat. These sort of sheltered areas away from the main channel of the river can be really important for breeding for a lot fish in the Great Lakes system. It also creates habitat for shorebirds and other birds. And then it’s also going to create what’s sometimes referred to as a blue trail, basically a kayaking group so that people can go through the blue heron Lagoon, the lakes, the canal system and paddle throughout the island.
Sven Gustafson: Yeah.
Brian Allnutt: I think in a lot of ways, it’s a really cool project. It’s just created these difficulties.
Sven Gustafson: Right. So in your article for Planet Detroit, you spoke with a lot of shoreline engineering experts. What kinds of things are people looking at doing by way of solutions to try to stem the problem of flooding?
Brian Allnutt: Specifically for this project, they’re putting in a coffer dam, which, you know, that can mean different things in different situations. But for this use, it’s basically an inflatable temporary dam. That’s gonna re-close off Lake Okonoka from the Detroit River.
They’ve got a culvert connecting Lake Okonoka to the Detroit River that’s going to remain closed, which that can be closed off again in the future. And then they’re doing pumping. But basically all of this stuff is to make the system of waterways better able to respond to high water in the future. And that’s what shoreline engineers are saying we need to be doing is that we need to make our systems and the Great Lakes more adaptable to either very high water or very low water.
So that can mean things like floating docks and marinas, that can mean these sorts of like temporary flooding structures. But then it also means like a lot of kind of soft engineering solutions. So rather than having like concrete and steel that can just get battered over the years by floodwaters and stuff. You create kind of a softer shoreline with rocks and native plantings that can absorb some of that water and hopefully limit flooding going forward.
One of the things that’s kind of ironic about this project is that doing things like this, getting rid of hard elements, putting in plantings and other kind of like soft infrastructure is really what can help with flooding in the future. But in a place like the Detroit River that just receives a ton of water from the rest of the Great Lakes system, no amount of local controls are going to be able to make up for historic floodwaters coming through.
Sven Gustafson: So it’s mostly a matter of learning to live with all the water and be able to adapt to it as opposed to try to push it away and prevent it.
Brian Allnutt: Yeah, exactly. And I think that is going to be the key to dealing with either really high or really low waters, which we’re probably going to be seeing both of in the future. But then we also have to accept the fact that as much as kind of the softening of the shoreline is a good idea, in the Detroit River, we still need to have some hard elements. There is just so much water. I think it’s over a million gallons of water per second that moves out of the Detroit River.