Stormwater Mandates Would Limit Impermeable Surface, Keep Rain Where it Falls

Written by Carol Kania Morency

Elmhurst homeowners who have been wanting to see more action from the city on flood mitigation efforts may soon get their way. A package of regulations aimed at keeping basements dry is making its way through city committees.

All of the ideas have been recommended by a city consultant and endorsed by a group of residents who have been studying how to combat flooding. Now, city policy makers are refining the proposals, which will affect both current and future homeowners.

The Public Works and Building Committee on Monday tackled how to get homeowners in the flood-prone southwest part of the city to keep their stormwater from flowing into the sanitary sewer system, which would ideally prevent sewage backups during heavy rains. Aldermen pressed to move quickly on a program that would target homes with sump pumps or footing drains connected to the sewer system, or drains in driveways or back stairs.

City staff originally recommended documenting the conditions of the more than 1,000 homes in the area to get an idea of how extensive these problem connections are. But aldermen are wary of taking at least another year before presenting a concrete program to homeowners.

“We need to get this off the ground,” said 3rd Ward Alderman Michael Bram. “I want to make these decisions now.”

Aldermen said they want homeowners to be given a set time period to correct a stormwater-to-sanitary flow problem. The city would encourage them with a cost-sharing program, and the city's portion of the cost would decrease over time.

Public Works Director Mike Hughes will come back to the committee after talking with the RJN Group, the city's sanitary system consultant.

Aldermen also are eager to move forward with new mandates for keeping stormwater on individual properties. These regulations would affect any new homes built in the city. After reviewing costs for various projects, from $10,000 rainwater harvesting systems to $3,000 rain gardens, aldermen expressed confidence that the mandates would not substantially affect housing costs.

“Every day we wait, there's another permit being pulled,” 5th Ward Alderman Chris Healy said.

Hughes will return to the committee with recommendations on how much water each lot should have to retain, which will be expressed in inches per 24 hours and will be based on a 10,000-square-foot lot.

Finally, the Public Works Committee was briefly joined by the Development, Planning and Zoning Committee to hear about regulating the percentage of lots covered by impervious surfaces. Any new mandates about lot coverage will be studied by both committees.

Currently, the city stipulates how much of a lot can be covered by buildings, Planning and Zoning Administrator Than Werner said. But there is no stipulation about the percentage of impermeable surface allowed. Theoretically, a homeowner could, under the current zoning code, pave over his or her whole lot, he said.

City staff has been researching impervious surface ordinances in nearby towns and is finding that Elmhurst's neighbors cap buildings, pavement and other surfaces at 50 to 65 percent of the total lot size.

Some residents are not waiting for the city to make changes that will hopefully ease their stress during heavy rains. One of the items on the DPZ's agenda was a setback variation for homeowners on Poplar Avenue, who have a downward-sloping driveway and have experienced severe flooding. The residents want to fill in their sunken driveway and construct a new, one-car garage.

Also in discussion is the city's plan to turn several Elmhurst parks and school properties into water retention areas. City staff will formally explain the proposal to park commissioners at the next Elmhurst Park Board meeting, at 7 p.m. Wednesday, Aug. 14, at The Abbey, 407 W. St. Charles Road. Members of the public are encouraged to attend.