Faced with a proposal for steep increases in Denver’s storm drainage and sewer fees, a City Council committee on Wednesday stalled the issue for two weeks, until May 18.

The panel’s members said too many of their questions remained unanswered by the end of a session that included comments from the public, most in opposition.

Council members’ requests included details on the proposed sewer and drainage projects’ benefits for water quality, information about specific projects across the city and clarification about potential flood plain changes affecting Globeville. Some also had concerns about the biggest project the rate hikes would help cover.

Opponents of that project — the Platte to Park Hill flood-control plan for northeast Denver — were well-represented in the audience at the Infrastructure and Culture Committee meeting. Several wore buttons opposing the state’s Interstate 70 expansion, which is linked to the city plan because of drainage challenges.

“To ensure all of our questions are answered is the least that we should be expecting before council moves a rate increase forward,” Councilwoman Debbie Ortega said, prompting applause from much of the audience.

The delay at committee means the earliest the full council could vote would be in early June, if the committee advances the proposal. Some members spoke up about the need for sewer system improvements while saying they weren’t ready to move forward with the increases yet.

The Denver Post reported extensively on the rate increase requests earlier this week.

Denver Public Works is asking to raise both sewer rates between this year and 2020 to pay for six-year system improvement plans and increased operating costs. The separate systems handle storm runoff and sewer discharges from properties.

Storm drainage rates, which now are billed annually by the city but could be added to monthly Denver Water bills next year, would increase nearly 66 percent by 2020. Sanitary sewer rates, paid monthly through the water utility, would increase 24 percent by then.

Those include already-scheduled inflation increases set in city code that would amount to roughly 14 percent or more in that period, without council action.

But city officials say steeper increases are needed to dig into a project backlog and put the systems on firmer footing.

They say the combined rate hikes would increase the annual bill for a single-family home in the city to $116 in 2020.

Councilman Rafael Espinoza, though, said the real cost for property owners would be much higher, since each annual increase mounts above the last. Using the city’s estimates, the cumulative cost of absorbing the increases for the average home during the period would be about $340.

On the storm drainage side, the city’s six-year project plan totals $383 million. Of that, $206 million would go toward the Platte to Park Hill project, supplementing other sources.

But city officials say only about a quarter of the combined rate increases would go toward that project, because the money for it will be raised by borrowing the money and repaying it over 30 years. That leaves more money for other projects in the near-term.

Critics of that project, who have raised concerns not only about the I-70 connections but also components that include a detention area on City Park Golf Course, were blunt in their comments to the committee.

“Recall is in the air,” Bridget Walsh said. “I think it is a definite possibility for council people who are not inclined to have an open ear to their constituents. These are very serious issues which impact our lives.”

Justin Croft, a project manager at Zeppelin Development, questioned aspects of the proposed projects. He said Denver should look to other cities that do better at supplementing their storm drainage systems with cutting-edge, environmentally friendly “green” alternatives instead of by expanding underground drainage pipes.

Speaking more favorably was Jeff Shoemaker, The Greenway Foundation’s executive director. He said the rate increase proposal had the potential to do more to protect Denver’s waterways, including the South Platte River.

“One of the most important things the public sector leaders can do is focus on two areas with (the city’s) limited resources: the safety of people and the safety of property,” he said. “And this measure speaks to both. … We have a significant problem in Denver regarding inadequate and insufficient storm sewer systems.”

Jon Murray: 303-954-1405, jmurray@denverpost.com or @JonMurray