The Kalispell City Council held off on starting a special improvement district for the Willows on Monday, wanting to first agree on how much money the city will commit to help upgrade the subdivision’s stormwater drainage system.

Residents petitioned Kalispell to form an SID after their neighborhood flooded in spring 2011. The flooding was caused by a willow root ball that clogged a stormwater discharge pipe.

They want to bring the neighborhood’s inadequate detention pond and discharge pipe up to standards so Kalispell will take possession of the system and maintain it. Preliminary engineering found that upgrading the system would cost $392,556.

The certainty and size of Kalispell’s contribution may impact some residents’ desire to proceed.

“I don’t feel comfortable moving forward without an understanding of what the city’s contribution would be,” Willows resident Mark Armstrong told the council.

That feeling was shared by some council members who don’t want to pay $37,000 more for final engineering only to see residents sour on the project if costs escalate or the city’s contribution is seen as not enough.

“Considering the unknowns, we’d be putting these folks in an awkward position,” council member Randy Kenyon said of starting the SID without a defined contribution. “They may end up paying a lot for the entire thing or paying part of it with our support.”

If an SID is created, Kalispell would issue bonds through Montana’s revolving fund program to pay for the work. Willows residents then would pay that debt off with extra property taxes.

With the present cost estimate for the work and no solid city commitment to contribute money, residents would be on the hook for about $30 a month in extra taxes.

The most contentious part of the project is the installation of an 18-inch pipe that would collect stormwater from an adjacent county-owned property and the Leisure Heights and Muskrat Slough neighborhoods and run it around the Willows and down to the Stillwater River.

That pipe would cost about $129,000 to install and also function as an overflow for the Willows whenever its existing and inadequate 12-inch discharge pipe cannot handle stormwater flows.

City officials said the Willows would be the pipe’s biggest user, consuming up to 36 percent of its capacity during a 100-year rain event. But the pipe would handle significant off-site flows. The county property would use as much as 32 percent of its capacity. Leisure Heights would use up to 23 percent and Muskrat Slough up to nine percent.

Willows residents argue that the county, Leisure Heights and Muskrat Slough — or Kalispell in their place — should pay for that major part of the project.

That request is complicated because the Willows would use the pipe and because the Willows sits at the lowest end of a natural drainage swale. At least some of those adjacent areas, such as Leisure Heights, were built to city standards and discharge stormwater into the swale at a rate that does not exceed predevelopment flows.

The situation also is complicated by the Willows’ inadequate 12-inch discharge pipe. Kalispell called for the installation of a 15-inch pipe, but that never materialized as the subdivision was built and approved by the city years ago.

In a report to the council on Monday, City Manager Doug Russell and Public Works Director Susie Turner recommended Kalispell agree to pay for about two-thirds of the cost to install the 18-inch pipe using money generated from stormwater impact fees and annual stormwater assessments.

Council members weren’t ready to settle on a fixed dollar amount or a fixed percentage of the project the city would pay for and voted 9-0 to table the issue until they can work that detail out in a work session.

Similar to discussions during a prior work session, council members seemed to agree that Kalispell should make a fair contribution to the project.

Mayor Tammi Fisher asked Russell and Turner to come back with a breakdown of how much each neighborhood has paid in stormwater impact fees and annual stormwater assessments to see “what’s equitable.”

“I can’t make that financial determination tonight,” Fisher said. “I think there is some consensus we want to contribute, but we need to see this [resolution] tabled to get that information.”

Reporter Tom Lotshaw may be reached at 758-4483 or by email at tlotshaw@dailyinterlake.com.