Six years from now, city property owners should be paying more than seven and a half times as much as they do now to get rid of stormwater, according to a preliminary report prepared for the city council.

The study is one of a series planned by the city to gather information in an effort to bring its infrastructure into the 21st century.

“We’re looking to see where we’ve been, where we are and where we need to go,” Mayor Paul Samuelson said Thursday.

The stormwater study will be discussed at Monday’s city council meeting, 6:30 p.m. at city hall. It will be part of a presentation by the mayor of his 2009 Annual Plan for the city. Samuelson urged residents to attend.

“This is a discussion everyone in the city needs to have,” he said.

“The annual plan guides the city staff’s work for this year and gives the community an understanding of the city’s priorities,” Samuelson said. “It addresses both improvements in internal systems as well a strong focus on economic development.”

The stormwater report suggests gradually raising the residential fee to support and improve the city’s stormwater drainage system from the current $2.90 per household per month to $22.10 by 2014.

The suggested fee for this year is $10; for 2010, $14; and for 2011, 2012 and 2013, $21.60.

Over six years, the annual residential rate would increase in increments from $34.80 to $265.20.

The increase would help make up the $115,000 per year deficit for maintenance, operation and debt service for the current system, and to help finance $2.3 million for 20 expansion and improvement projects over 20 years, Samuelson said.

The report said the city collects $25,000 per year from existing rates, well below actual annual expenses of $140,000 per year. The difference has been coming from the road department budget, Samuelson said.

He said the stormwater rate structure has been in place since 1994.

“We need the stormwater department to stand on its own,” Samuelson said. “We need every department to stand on its own.”

The $90,000 report, which the city borrowed to pay for, was prepared by URS Corporation and Katy Isaksen & Associates of Seattle.

It said that last year the city had 615 stormwater accounts, including single-family and multi-family residences, and commercial, public and undeveloped property.

While suggested rate increases for single-family residences were the only ones broken down year by year in the report, rates in the other categories would increase by the same percentage if the fees are adopted, said Challis Stringer, Langley’s public works director.

Currently, those rates range from $1.50 per month for undeveloped property to $6 for multi-family buildings of more than two units, and for public facilities.

While Langley residents are paying $2.90 a month for a stormwater system, residents in Anacortes are paying $4, those in Mukilteo $7.85 and those in La Conner $11.55, the report said.

Langley’s current stormwater system was built in the 1960s and serves the 644 acres within the city limits. Because of the city’s bowl shape, most of the drainage flows through ditches and storm drains along roadways, converging at drains along Anthes and Park avenues downtown.

Stringer said the city has identified five or six trouble spots in the system that need work, including roads washed out and standing water in some yards during heavy rain.

“We don’t have the resources to maintain them as they should be,” she said.

Stringer said the city hopes to acquire grants to help pay for improvements in the next few years, and probably would look to borrow additional money, if the economic climate eases.

Samuelson said the city is long overdue for an update of its infrastructure.

“We’ll be reviewing all systems in all areas,” he said. “There are things that haven’t been watched that need to be watched.

“We have issues we need to put in front of everybody so we can deal with them collectively,” Samuelson added.