After only one season in the CMJHL, the Maryfield, Saskatchewan native joined the University of Denver Pioneers in 1967-68 and spent the next three seasons as a member of its varsity team.

In 1970-71, Powis joined the Western Hockey League's Denver Spurs a team with whom he played only one season with before suiting up for the American Hockey League's Nova Scotia Voyageurs the following year, leading them to the 1972 Calder Cup championship.

Midway through the 1971-72 season, the World Hockey Association's Dayton-Houston franchise selected Powis in the WHA General Player Draft before Montreal traded him to Atlanta during the off-season.

Following a successful season in Nova Scotia, Powis joined the Central Hockey League's Omaha Kights in 1972-73 where he set a career high for goals (34) assists (40) and points with (74) before being dealt to the Chicago Black Hawks during the off-season.

The 1973-74 season marked Powis' NHL debut with the Black Hawks. In 58 regular season and playoff games with Chicago, Powis scored eight goals while adding 13 assists for 21 points before the Kansas City Scouts claimed him in the 1974 Expansion Draft.

Powis improved on his rookie season totals in 1974-75, scoring eleven goals while adding 20 assists for 31 points before having his rights traded to the St. Louis Blues prior to the 1975-76 season.

After beginning the season with the AHL's Providence Reds, Powis was dealt to the WHA's Calgary Cowboys with whom he finished the 1975-76 season with before returning the following year.

During the off-season Powis signed as a free agent with the WHA's Indianapolis Racers after the Calgary franchise folded upon the end of the season. Powis played only 14 games with Indianapolis he was released by the club, only to sign as a free agent with WHA's Winnipeg Jets.

Even though he finished the season with Winnipeg, Powis spent the next five seasons in Europe with stops in Germany and Italy before calling it a career following the 1982-83 season.