Belle Isle to get new dam, pump repairs to stem flooding

Christine Ferretti
The Detroit News

Detroit — The state expects to sink upwards of $300,000 into work on Belle Isle to stave off flood damage amid near-record water levels.

In the coming weeks, the state Department of Natural Resources will begin repairing pumping stations for the canals on the 982-acre island. Soon after, a cofferdam will be constructed on the island's east end where water comes in through the canal, to help block rising levels in the Detroit River, said Ron Olson, the state's parks chief. 

"This is some of the highest and most impactful (water levels) that anybody has seen," Olson said Tuesday after giving his annual update on the island to Detroit's City Council. "We're concerned about the 'what ifs.'" 

Meredith Zammit-Julius, 29, of Royal Oak and her niece, Isabella Zammit, 11, of Lathrup Village were out kayaking on swollen waters of the Belle Isle canal in July.

The preventive measures for the island come after waters there reached a high point in July, threatening the city's public lighting substation, knocking out power to the U.S. Coast Guard station and flooding the Belle Isle Boathouse. The incident forced the facility to cancel about 18 weddings, Olson said. 

Michigan's Department of Natural Resources, which has managed Belle Isle since it became a state park in February 2014, relied at the time on three mobile pumps to help keep water levels down.

The flooding left large parts of the eastern half of Belle Isle underwater. The DNR dealt with high water on the island since the Detroit Grand Prix in late May and early June. 

The recovery took some months and the water remains high. 

Olson on Tuesday said the last time water levels in Detroit were this high was in the late 1980s.

Water levels in January were above the prior highest monthly average in 1987. Levels are projected to be potentially 12 inches higher than last summer, state officials said. 

Belle Isle isn't the only state park to be impacted by high waters. The state, he said, has spent more than $6 million in the parks system statewide dealing with damage and officials have documented about $35 million in damage in state parks and boating access sites over the past couple of years, Olson said. 

McLain State Park in Houghton County in the Upper Peninsula was redesigned after it lost about 18 feet of shoreline and sewer lines were compromised.

Olson estimates about $160,000 to $170,000 will be spent on the cofferdam and another $20,000 on the pumping station improvements. 

The improvements and others will be paid for with capital funding for priority projects. The Grand Prix is kicking in funds for the pump stations. 

It's unclear what impact flooding could have on events, including the Grand Prix. 

"Our goal is to try to prevent the internal canals from swelling beyond their banks. That would cause road flooding and picnic area flooding," he said. "That doesn't include the rainfall and things that might occur if we get heavy rains in the spring. If the water gets too high and goes over the seawalls on the north and south parts of the island, then that will flood anyway."

Belle Isle's parks manager Karis Floyd told council members Tuesday that some attendance figures were down for the summer due to flooding as were shelter rentals, which dropped from 814 in 2018 to 629 last year. 

On the plus side, park attendance remained steady, with about 4 million visitors for 2019, he said. 

Officials also gave an update on police interactions on the island. State conservation officers and Michigan State Police logged 25,716 total contacts in 2019. Police issued 232 citations and 1,265 warnings, primarily for traffic violations, officials said. 

Since 2014, more than $75 million has been invested on the island.