Canoe slalom competitions are supposed to be held in Kasai Rinkai Park Slalom Course.
You can go there by a subway Yurakucho Line, a train JR Keiyo Line.
Get on a subway bound for Shinkiba, “新木場” at Toyosu station, “豊洲” then get off at final stop Shinkiba station. The subway stops 1 station before arriving at the final station. Then change trains there. Get on a JR Keiyo Line outbound local train. Be careful. Never get on a rapid train. Then get off at Kasairinkaikoen station, “葛西臨海公園”. Kasairinkaikoen station is the next station from Shinkiba station. It takes around 20 minutes and costs 330 Yen.
The center is to the west of the station.
It takes about 12 minutes on foot from the station.