Due to the low water level in the area of the Congost de Montrebei we cannot assure you that it is possible to navigate inside the Congost.
The Congost de Montrebei can be approached by kayak and the Congost hiking route and the Montfalcó stairs and footbridges are still open.
If you want to do a kayak route without problems in terms of water level you can take a look at the spectacular route of Finestres which is very close to the area.