City administrator Howard Lazarus’s fiscal 2018 budget calls for an 8.5 percent increase in storm-water fees–$585,000 a year, or $24 annually for the average household. It’s a down payment on implementing the priorities identified in the city’s 2015 storm-water calibration report. At the top of the list: fixing the flooding on the city’s southwest side, where heavy storms in 2012 filled basements and turned streets into rivers.
The Churchill Downs neighborhood will get a system of ponds designed to hold and slow future flooding. “That neighborhood was built with no retention,” explains city water quality manager Jen Lawson. Built in the Churchill Downs Park area and south of Scio Church next to I-94, the project will “detain the storm-water before it gets into the Lansdowne neighborhood,” she says. “We’ll see design over the next year and construction the year following.”
Considering the destruction it caused, it’s a wonder that no one died in the 2012 storm. However, a crated dog drowned when low-lying units at the Park Place apartments off Pauline flooded. Fixing the storm drains there, Lawson says, “is going to be a partnership with the private property owner. There are some up-sizing and pipe modifications that need to be done.”
Plans also call for storm-water storage at Edgewood and Snyder, off S. Seventh north of W. Stadium. “There’s a lot of water that comes down to that point that finds its way out through surcharging through manhole covers,” Lawson says. “We’re looking to reduce the risk of that.”
Though the work on the southwest side is the highest priority, it’s not the biggest project. That, Lawson says, will be lower Allen Creek–which includes “most of the downtown area. It’s a very gray scape: a lot of roads and buildings. About half of the surface there is impervious–which means that “for every two raindrops that fall, one doesn’t have anywhere to go.”
Continued implementation of the city’s “Green Streets” policy will help. “Every road [rebuilding] that is completed in the city also has a component to address storm water–rain gardens, bioswales, infiltration, porous pavement, bottomless sumps, anything to get the rainwater off of the road surface and into the ground.” Expect more streets in the future to look like the recently reconstructed section of Miller east of Maple.
The rate increases won’t all go to ponds and pipes: some will be spent on trees. Kerry Gray, the city’s urban forest and natural resource planning coordinator, explains the connection: “Trees help to improve the quantity and quality of storm runoff. Trees help to slow the rainfall and help capture water. The street tree population intercepts about 65 million gallons of storm-water per year.”
The “urban forest” was devastated by the emerald ash borer invasion in the early 2000s. Many postwar subdivisions were planted with fast-growing ash trees–until a fungus spread by the invasive beetle killed them. Of the 22,000 ashes that died, 7,000 were on street easements or in parks, and so were the city’s responsibility to cut down. After voters rejected a 2005 millage, “resources were shifted and focused purely on removal of ash trees,” Gray says.
As the trees came down, replanting started. Gray says they’ve been putting in about 1,200 a year, 1,000 planted by contractors and the rest by city staff. They’ve kept up that pace for “at least the last seven years,” she says which means “we’ve probably replaced all the ones we lost to the emerald ash borer.”
Bob Grese, director of the U-M Nichols Arboretum and Matthaei Botanical Gardens, says he noticed the difference. “My neighborhood (VA Park) was a recipient of many young trees,” he emails. “We originally had elm trees and then Norway maple trees. We also had lost many ash trees. After many years of gaps in the street tree canopy, the city planted dozens of trees in 2015.”
What got lost in all this was routine pruning. Catching up on the removal of dead and overgrown branches is now the top goal of the city’s urban forestry plan. “We are doing reactionary pruning right now based on service requests [and] addressing the backlog, but no routine pruning,” Gray says. “We want to get into a pruning cycle so a tree would be touched every seven years. We want to be more systematic about the work we do instead of being so reactionary.”
They’ve also learned not to plant any one species too heavily. “We always look for diversity in our planting stock,” Gray says. “We plant different species of oaks, black gum, coffee trees, redbuds, and some crab apples that are disease resistant.
“It helps to keep us from getting into situations that leave us with streets that had no street trees at all because they were entirely lined with ash.”