The deal is done.

The Maple Valley City Council approved a traffic improvement agreement Oct. 6 between the city and YarrowBay relating to the Black Diamond master planned developments, The Villages and Lawson Hills.

The two parties reached a tentative agreement, which was announced at the Black Diamond City Council closed record hearing Sept. 20. The Black Diamond City Council approved the two projects at that meeting.

The agreement lists 15 projects with YarrowBay contributing a varying percentage of the costs to each. The projects include work on state Route 169 and SR 516.

“This shows when parties have the direction to negotiate in good faith then agreements like this can occur,” City Manager David Johnston said. “This addresses significant concerns we had with traffic particularly on (SR) 169. This is a strong statement to the area that this MPD is recognized as a significant impact to our local jurisdictions.”

The two YarrowBay projects would add about 6,000 residences to Black Diamond, with a mix of commercial, office and open space.

Black Diamond currently has a population of about 4,100. Maple Valley’s population is about 21,000.

“We’re very happy to have reached an agreement with Maple Valley,” YarrowBay CEO Brian Ross wrote in an e-mail Wednesday. “We are now able to work together to improve the transportation corridor that serves the citizens in this region. This agreement is a creative solution, and we believe we’ve reached an outcome that we can all be excited about.”