Imwalle spent a decade on the Oaks sideline, building one of the region's most powerful NAIA programs while being named California Pacific Conference Coach of the Year four times. Under Imwalle, Menlo compiled a 144-87 record for a .623 winning percentage and won five Cal Pac championships - all in the last six seasons. The Oaks competed in the NAIA Tournament each time they finished at the summit of the Cal Pac standings and won 71-of-72 conference matches over their five title-winning seasons. During the 2009 season Menlo won the first ever Cal Pac Tournament.

In addition to the stunning success Menlo volleyball achieved since Imwalle's arrival in 2000, a bounty of Oaks student-athletes earned individual honors at the conference, regional, and national level. Imwalle's teams garnered 37 All-Cal Pac honors, nine Cal Pac Player of the Year awards, nine NAIA Academic All-Americans, two NAIA All-Americans, and numerous American Volleyball Coaches Association All-Southwest Region selections.

While Imwalle cemented his coaching legacy at Menlo, he arrived on campus with an equally impressive pedigree as a player. Imwalle was a two-year starter at Long Beach State, helping the 49ers to a runner-up finish at the 1970 NCAA Tournament prior to graduating with a degree in history. He later excelled on the beach volleyball circuit, winning four tournaments and being named a "Legend of Beach Volleyball" for the 1970's. He would go on to attain All-American status in 1992 when his Masters-level team captured the United States Volleyball Association (USVBA) title.

Imwalle began his coaching career as an assistant at Long Beach State in 1981 for a team that reached the NCAA West Regional final. He later coached at Estancia High in Costa Mesa, Calif. Imwalle also has a wealth of experience coaching golf and tennis.