Brown, who is at Victoria University, and trainee electrician Imrie train together in the capital, although this was only the fourth time they've raced together.
They backed up with another open podium finish, finishing third in the K2 200m, with Bicknell winning alongside Bay of Plenty teammate Taris Harker.
Imrie, who finished fifth in the K1 1000m at the junior world championships in August, also picked up two silvers in the under-23 individual events.
He finished behind Poverty Bay's Ben Tinnelly in the longer distance and Roy in the K1 200m.
Bicknell beat Roy in the open men's K1 200m, while McDowell edged Jasper Bats (North Shore) in the K1 1000m.
Rachael Dodwell (Eastern Bay) dominated the women's K1 200m, beating Kayla Imrie by 1.13 secs, although Imrie cleaned up in the K1 500m, with Rebecca Cole (North Shore) second and Ann Cairns third.
Among the younger age groups, North Shore collected plenty of silverware.
North Shore secretary Diana Foster said a recent move to employ 18-year-old coach Jamie Slessor-White had seen the junior ranks take off.