A small road through sugarcain fields leads to a parking lot on top of Bassin La Paix which is fed by the river Riviere des Roches. Although the short trail to the bottom of the falls (cross the river via the bridge) is officially closed, I think it is safe to go that trail. It's essentially a staircase which is broken at some points, however, there is always plenty of space for a workaround. It's not an easy stroll, though. Don't forget to bring your lunch because the bassin with its falls is really beautiful.
There is also a second bassin, Bassin La Mer, further up the river although it pretty much looks the same like Bassin La Paix. A short 30-minute trail leads to the second bassin (also featuring a small waterfall). Be sure to see that very faint sign (painted on a rock) after roughly 20 minutes on the main trail which points towards a small trail to your right, leading to the bassin. This last part is a short but steep downhill which can be slippery in places.