In the race for the 11th District state Senate seat, Supervisor Scott Wiener has picked up three big-name endorsements from Bay Area mayors.

San Francisco Mayor Ed Lee, Oakland Mayor Libby Schaaf and San Jose Mayor Sam Liccardo on Tuesday threw their support to Wiener. They noted his work on expanding the region’s transportation and tackling water issues as reasons for the endorsement.

Wiener represents San Francisco on the Metropolitan Transportation Commission, a nine-Bay Area county transportation planning and funding agency. He was also recently appointed to the Bay Restoration Authority, which helps restore wetlands.

“San Francisco’s congestion and housing affordability problems cannot be solved in a vacuum, and the region needs to work together,” Lee said. “I’ve seen Scott’s ability to bring regional leaders together, and that ability will serve him, and San Francisco, well in the state Senate.”

Supervisor Jane Kim, a progressive also running for the state Senate seat, has clashed with Lee in recent months on a number of issues, including the price tag of Super Bowl 50 and the minimum number of below market-rate housing units that should be included in new developments.

Wiener and Kim are shoring up endorsements and donations for the primary on June 7. While Wiener has more money and endorsements, Kim could gain momentum if her ballot measure to designate 25 percent of units in new developments as affordable housing passes.

— Lizzie Johnson

Email: cityinsider@sfchronicle.com, ljohnson@sfchronicle.com Twitter: @SFcityinsider, @LizzieJohnsonnn