Local officials continued their effort to address flooding issues in the city Thursday.
Commissioner Rich Jankovich, who also serves as the co-chair for the Wildcat Creek Watershed Areas Working Group, presented city and county officials with an update on the group’s progress at Thursday’s intergovernmental meeting. Chad Bunger, city planner and floodplains administrator, also presented the Manhattan Urban Area Planning Board with two proposed projects aimed to assist local efforts to better understand flooding risks. Bunger made a similar presentation to the Manhattan City Commission Tuesday.
City and county officials were supportive of the efforts of the working group. Jankovich noted the group has been working with Silver Jackets initiative through the National Flood Risk Management Program. Via that initiative, the city received grants for monitoring gauges for Wildcat Creek, which are now in place at Seth Child and Wildcat Creek and at the bridge on Scenic Drive and Wildcat Creek.
The city also received funds for mapping the watershed area. Jankovich said the Silver Jackets program will provide valuable information including crest history, identification of impact areas as well as advance warning from Topeka through the National Weather Service.
He said it will improve evacuation planning. “We can start working with Riley County and the city and property owners on having a plan of action if and when that would occur so they can be moving out much quicker,” Jankovich said.
Board members were glad to see the city investing time and resources into flooding issues. Although some still had reservations, the Board forwarded a unanimous recommendation to the City Commission for the projects.
Bunger said the first project is enhancing the city’s flood insurance rate maps (FIRMs) via “future conditions mapping.” He added the technique has been utilized by other cities with flooding problems.
The mapping will calculate the stormwater runoff generated from a full development build-out of the Wildcat Creek Watershed and Marlatt Ditch drainage basin based on the future land use map included in the Manhattan Urban Area Comprehensive Plan. Bunger said it will identify future conditions for the 100-year floodplain, other wise known as the 1 percent annual chance floodplain.
The second project involves the creation of a mapping tool called depth grids, which Bunger said will show boundaries of flood events and graphically represent the depth of stormwater from a flood event.
Bunger said the future conditions mapping and depth grids provide several benefits including: informing current and future property owners of flooding risks, using the models and maps to design developments that are better protected from flooding, using the information to potentially identify future policy for the city, using the information to design infrastructure to protect against future flooding, planning emergency evacuations more efficiently and potentially adopting stricter local floodplain regulations.
Lind Morse, board member, said it was great to finally see some science behind the city’s approach.
However, Mike Hill, board member, questioned the inclusion of future conditions mapping with the FIRMs. Hill speculated that it would only result in high flood insurance rates.
“Why do we have to have it tied to the insurance rate maps?” Hill said. “That’s what scares me.”
Bunger said actuary rates for flood insurance are only based on the two current Federal Emergency Management Agency standards. He said just because the city adds the future conditions doesn’t mean they will affect insurance premiums.
“I would like to believe that, but I’m reluctant to believe that,” Hill said.
Hill said he is concerned residents won’t be able to afford flood insurance, one of the few options they have to protect their property. Mike Kratochvil, board member, also showed concern about the city’s efforts focusing too heavily along the bank of Wildcat Creek.
“I would be more worried about the Marlatt ditch because of population surrounding that,” Kratochvil said. City officials assured Kratochvil they shared those concerns.
The City Commission will vote on a contract for the two projects at its Jan. 24 meeting.