Approximate - nearest available gauge. Use as general reference only.
Almost as soon as you clear the S.108th Street culvert, start looking for a good place (river-left) to land, exit your boat, and carry up to your 'drop vehicle(s)' in Kulwicki Park.
FWIW, right around the corner (at 4353 S.108th) is Organ Piper Pizza. They open 5pm T/W/Th, 4pm F/Sa/Su.
Music on the Wurlitzer Pipe Organ starts a half-hour after they open. It's quite an experience.
(There are menu options besides pizza, and they do have adult beverages: beer, wine, mixed drinks.)