Darien officials have a big decision to make over the next few months – either cut down and replace some of the city’s nearly 2,600 ash trees in the city’s parkways or commit to a six-year treatment plan to try to eradicate a pest that could ultimately destroy them.
Municipal Services Director Dan Gombac said the city has determined that 12 of its ash trees have already been affected by the Emerald Ash Borer. But since the insidious creature is virtually undetectable until it’s already done its damage, there could be more of them lurking out there.
“You can’t identify the bug until it’s visible, once the tree starts to lose its canopy,” said Gombac at a municipal services committee meeting Monday night. “There are no other visible signs.”
And, as Gombac said in his report to the committee, “When it comes to the potential devastation of Emerald Ash Borer, there is a lot at stake for the city.”
City staff has designed a response to the infestation that includes application of an insecticide once every two years, for three cycles. The goal is to treat all healthy city-owned trees ash trees beginning in April 2013, as well as to educate residents about treatments they can used on ash trees in their own yards.
But saving Darien’s parkway trees comes at a significant cost, which city staff has estimated at $531,800 over a six-year treatment cycle. The amount gave pause to some committee members Monday night.
“If we’re going to spend (more than) $500,000 and get six years out of the deal, what will happen in another six years?” asked Ald. Ted Schauer. “There’s no easy answer on this one. You could spend a boatload on this and it may not help.”
Ald. Halil Avci also worried about the uncertainty of treating only city-owned trees while privately-owned trees may also be affected.
“Even if the treatment is 100 percent effective on the trees you treat, what about the other trees?"
Currently, the city doesn’t have a count of how many affected trees may be in residents’ yards or in nearby forest preserves, which, according to Gombac, may not be treating infested trees at all.
“There is nothing mandating that a resident needs to treat their trees,” Gombac said. “When the branches start to fall, then it becomes a property maintenance issue.” And, he added, “It’s a matter of time before the pests go through all those (residents’ and forest preserve) trees and head to Darien. It’s a matter of when, not if.”
In the first year, it would cost $179,400 to treat all city-owned trees, and $1.5 million to remove them, Gombac said.
“To eradicate every ash tree – that’s not a plan,” he added.
Further discussions will take place at the city council level as well as at budget workshops in October to determine how much the city is willing to spend on fighting the Emerald Ash Borer.
How are other communities dealing with the pest?
The Emerald Ash Borer has been on a killing spree across nearly 40 percent of Illinois, and communities near Darien are divided on how to deal with the destructive pest.
- has been treating trees with an insecticidal soil injection and in April, trustees budgeted $60,000 to continue the fight against the Emerald Ash Borer.
- has committed funds for treating some of its affected trees and left the door open to budget for more.
- Naperville has implemented an aggressive multi-year treatment plan for all healthy ash trees in the city's parkways.
- has been removing damaged and distressed ash trees and replacing them with other tree species since 2007.
- Downers Grove has been tracking, treating and removing ash trees over the past few years.
- About 16 miles away in , hundreds of trees have already been lost to the Emerald Ash Borer and hundreds more may be cut down over the next year. The village has set aside $200,000 to replace parkway trees removed this year – and officials have said over the next five years, about 6,000 parkway ash trees will have to be removed due to infestation.