The cost of the proposed ­Bottineau Blue Line light-rail extension between downtown Minneapolis and Brooklyn Park has increased by about 2 percent, to $1.54 billion from about $1.5 billion.

The $40 million increase was revealed to members of the Blue Line Extension Corridor Management Committee, a Metropolitan Council advisory committee, on Thursday afternoon.

The increase will require an additional $20.4 million in local funds from Brooklyn Park, Hennepin County and the Minnesota Department of Transportation (MnDOT) to pay for parts of the project.

It also increases federal matching funds by $19.6 million, to $752.7 million.

Reasons for the increase include bridge refinements, parking ramp and traffic signal adjustments, noise-reduction and retaining walls, and the relocation of the Bassett Creek stormwater tunnel in Minneapolis.

The Bottineau line is slated to begin service in 2021. It would provide connections to existing Green and Blue LRT lines that serve downtown St. Paul and the Minneapolis-St. Paul International Airport, respectively.

Planners also proposed to lower the project's contingency budget from 30 percent of its overall cost to 28 percent, freeing up an additional $31 million. This would not affect the overall price of the project, however.

The $31 million would go toward pedestrian improvements at the 63rd Avenue station in Brooklyn Park, a pedestrian bridge at Bass Lake Road with an elevator in Crystal, and modifications to the Hiawatha maintenance facility in Minneapolis, among other refinements.

This is the second time the cost of the Bottineau line has increased.

Last October, the price jumped by nearly $500 million after environmental and engineering work was completed. The project added a station in Minneapolis as well as seven bridges and additional light-rail cars, causing the increase.

The Federal Transit Administration is expected to pay 49 percent of the project; the Counties Transit Improvement Board will cover 30.19 percent through a metro-area transit tax; Hennepin County Regional Railroad Authority and the state will each contribute 9.74 percent; MnDOT and Brooklyn Park, 0.53 percent each, and Hennepin County, 0.27 percent.

Because the Met Council failed to garner the needed state share for the Southwest light-rail projects during this year's legislative session, there's some question whether the same fate awaits the Bottineau line at the Capitol.

Met Council Chairman Adam Duininck said he still hopes the Legislature will reconvene in a special session in coming months to tackle Southwest funding, and perhaps funding for Bottineau through a metro-wise transit sales tax. "We're still hoping that happens," he said.

The Met Council is expected to vote on the revised project cost in September. The Corridor Management Committee will decide later this month whether to recommend the revised budget to the full council.

Janet Moore • 612-673-7752