High levels of E. coli at Minneapolis’ Thomas Beach have soured the annual Milk Carton Boat Races.

Instead of paddling their way across Bde Maka Ska on Sunday, participants will be forced to foot race while carr- ying their homemade ships on dry land.

Twin Cities Beach Blast, the event organizer, is rebranding the beloved tradition as “Milk Carton Boat Portage Races.”

“We are saddened to be out of the water, but safety comes first,” said Charlie Casserly, the group’s executive director. “We worked with the Minneapolis Park and Recreation Board to find another site for this iconic Minnesota race, but no other suitable location on any other Minneapolis lake was available.”

The move comes amid extended closures at the 32nd Street and Thomas beaches at Bde Maka Ska, formerly known as Lake Calhoun, and the Lake Hiawatha Beach. All three beaches will remain closed through at least July 22, or until E. coli levels stabilize.

City park officials closed the popular recreation spots to the public three weeks ago after large volumes of stormwater flowed into the lakes.

Boat race competitors are expected to run their elaborate floating masterpieces for a short distance to win a speed prize. Awards also will be distributed for creativity.

Sunday’s first race will begin at 10 a.m., and the event will culminate in a 3 p.m. showdown. (Get details at tcbeachblast.com.) A sand castle competition is unaffected by the beach closure.