After months of behind-the-scenes debate and fine-tuning, the Denver City Council on Monday gave an initial green light to significant changes to how the public works department will bill Denverites to pay for the city-led sidewalk repair and construction program. That means doing away with annual fees that would have been charged to property owners based on the size of their lots in favor of a — mostly — flat rate that would charge the largest properties extra money. But even as the council voted 13-0 to approve the changes on first reading Monday night, members noted that the heavy lifting — including future rounds of property acquisition needed to widen sidewalks in places where they are too narrow today — is still years in the future. “I am looking forward to the implementation aspect of this because I think there’s a lot of challenges there as well,” Councilman Kevin Flynn said before voting yes on Monday. Flynn opposed the 2022 ballot measure but also served on the task force that came up with the program changes considered on Monday night. Pending the outcome of a second and final council vote next week, the city Department of Transportation and Infrastructure will get to work setting up the first round of bills for a program that voters approved almost two years ago in November 2022.