Green infrastructure report to help city implement improvements

By: Sarah Wojcik | Royal Oak Review | Published April 16, 2018

 The city of Royal Oak recently installed a rain garden on Vinsetta Boulevard, west of Main Street, to address surface flooding issues.

The city of Royal Oak recently installed a rain garden on Vinsetta Boulevard, west of Main Street, to address surface flooding issues.

Photo by Sarah Wojcik

ROYAL OAK — On April 9, the City Commission heard from representatives who worked on a 2017 Royal Oak stormwater management study for green infrastructure, which identifies green infrastructure and stormwater management options to reduce the amount of water entering the city’s sewer system.

The commission contracted Detroit-based Wade Trim Inc. Aug. 14 for $79,500 to investigate and design concepts for several pilot projects throughout the city, with the intent to implement similar projects where applicable.

The pilot projects include green infrastructure on major road right of ways, local road right of ways, city parks, city parking lots and alleys. Green infrastructure incorporates natural and man-made materials to infiltrate, absorb and detain stormwater runoff.

By implementing green infrastructure, the city hopes to improve the capacity of its sewers and minimize surface flooding.

The study also includes an evaluation of groundwater and soil conditions in the city, a planting guide for future installations, cost estimates for installation and maintenance of the green infrastructure options, and a summary of available funding opportunities.

“We developed a design approach so that other engineers and landscape architects could take our work and use it in planning for green infrastructure, as well as city staff when they’re planning a public improvement project to implement green infrastructure,” said David Anthony, of Wade Trim Inc.

His company also worked with Drummond Carpenter PLLC to complete the study.

“We’re just trying to do things the way Mother Nature intended, but using landscape architecture and engineering approaches for the opportunity to get the water into the ground,” said Don Carpenter, of Drummond Carpenter PLLC.

After looking into the soil conditions of Royal Oak, Anthony said three quarters of the city has the types of soil that allow for infiltration practices, which is a lower-cost option when it comes to stormwater management.

Carpenter said some of the methodologies the study includes are rain gardens, catch basins, permeable pavers, underground storage and bioswales. Bioswales are landscape elements designed to filter debris and pollution from surface runoff water.

When existing infrastructure, such as parking lots, is at the end of its life, he said it would be feasible to implement green infrastructure initiatives when looking into replacements.

Anthony estimated that more than 2 million gallons of stormwater could be removed from the city’s sewer system by implementing the green infrastructure outlined in the six pilot projects in the study.

“This could be used to inform our ongoing conversation on updating our ordinance and the kind of restrictions we want to put on developments, which is awesome and which is exactly what we’re looking for,” Commissioner Kyle DuBuc said. “I’m really excited that we’re on board with green infrastructure concepts.”

DuBuc added that reducing the water entering the city’s sewer system would also reduce the cost to treat the water.

Royal Oak Engineer Matthew Callahan said the city has already installed several rain gardens and bioswales in recent years, and city staff will take the direction provided by the study to implement future green infrastructure projects.

Callahan said there are existing bioswales at Eagle Plaza; in the parking lot of Total Soccer Royal Oak on Lexington Boulevard; one on Vinsetta Boulevard, just west of Main Street, to address surface flooding issues; and a large one on Fourth Street.

“We also have six of them down Main Street in biocells,” he said. “We had to build a concrete wall around them, so we call them a cell instead of a bioswale or a rain garden, but they function the same way.”

Come the summer, Callahan said the city would be building more bioswales along Fourth Street.

Mayor Michael Fournier said the city would be looking into allocating funds for implementing green infrastructure during its budget sessions, scheduled for May 9, 15 and 23.

“Royal Oak is quietly becoming the leader in green infrastructure in the area, if not the state of Michigan, and I’m really excited about our future,” Fournier said.

To view the report, visit www.romi.gov and search for “Green Infrastructure Report April 9, 2018.” For more information, call the city of Royal Oak at (248) 246-3000.