The Flathead County commissioners moved forward Wednesday with the final phase of the Bigfork stormwater system, unanimously approving the annual assessments for a newly created Rural Special Improvement District.

The special tax district will raise $1.2 million of the $2.9 million total cost by levying taxes on 563 properties in Bigfork over a 20-year period.

The annual cost will be $138 per property annually for the construction of the stormwater improvements. A maintenance fee of $29.54 annually will fluctuate slightly each year, depending on the actual maintenance costs.

Construction is scheduled to begin Sept. 8.

The final phase will install new stormwater pipes along the north and south sides of Electric Avenue to the bridge, and from Montana 35 to Montana 209 to the steel bridge. Curbs and gutters will be installed, along with catch basins and filtration system.