Joined the Canadian PGA in 1967 as an apprentice under Bill Thomson, Head Professional at Southwood G&CC in Winnipeg. In 1968 attended the first golf business school organized by the PGA of America in Kansas City. In 1969 became Head Professional at the Wildewood Club in Winnipeg. In 1970 moved to the Calgary G&CC as an Assistant Professional. In 1971 moved to the Canyon Meadows G&CC as Assistant Professional under Head Professional Frank Fowler. In 1973 moved back to Southwood G&CC in Winnipeg to become Head Professional. In 1977 was elected President of the Manitoba PGA. In 1978 represented Manitoba PGA on the National Board of the Canadian PGA. In 1979 established new course record 64 at Southwood. In 1981 recognized as Head Professional of the Year in Manitoba. In 1983 elected to a two year term as President of the Canadian PGA. In 1985 became General Manager of Southwood, in addition to being Head Professional. That year undertook leadership of reinventing the Manitoba Open, under a 6 year contract with Southwood to host. Raised the purse to $100,000, first Canadian Tour event to go to 72 hole format and have live television coverage on the weekend. In November of 1990, resigned and moved the family to Qualicum Beach, Vancouver Island. In 1992 was named Director of Golf at Fairwinds Golf Resort on Vancouver Island. In 1995 managed the PGA of BC Trade Show and Consumer Golf Show under a five year contract. In 1997 became Executive Professional of Glengarry Golf Links in Qualicum Beach - later lead the rebuilding of the golf course and the rezoning of the property to be a destination resort with 18 hole championship golf course and golf academy with a new brand - Pheasant Glen Golf Resort. In 2006 left the company to pursue consulting opportunities. In 2008 joined the BC Golf House Society as Executive Director and stayed there until 2012. 
Continues to offer consulting services to clients in the Pacific Northwest. In 2019 Wedgewood Golf Management, a company consisting of McWha and partners Ray and Mike Riva undertook a contract to manage Morningstar Golf Club for the Court appointed Receiver. Wedgewood lead Morningstar through the pandemic, out of Receivership in less than two years, and now manages Morningstar for the new owner, the IUOE Pension Fund.