Richard Shingoose said it sounded like an explosion when the ice came out, followed by a gush of water that started to rush down the hill and into the valley.
The culvert is located at the base of an embankment about a kilometre from Waywayseecappo. The 30-metre-high ridge is holding back the swollen Birdtail Creek, which was engorged because the plugged culvert prevented the spring run-off from flowing away.
Band Coun. Barb Cameron said workers who were making sandbag barriers to protect the community's business centre had to leave before finishing the work, worried they would get trapped.
But Shingoose and nine others raced down to the community to finish it, which they managed to do by about 6 a.m.
He said it was a difficult task at times as the water started arriving and they almost gave up. But they did get it done and at this point have the water contained.
Parts of the Birdtail Creek embankment have been eroding away since the weekend. There are two sections where portions of the mud wall have slid down.
Water has been seeping through the weakened sections, raising concern the entire embankment could collapse and send a surge of water into the valley, first through Waywayseecappo and then the town of Birtle.
As a result, more than 100 people were forced to leave their homes in those communities.
The province brought in an excavator to cut a section into the embankment — a former railway ridge — overnight Monday into Tuesday.
The cut was made to release some of the trapped water and relieve the pressure on the dike.