Normally I would agree but, after a heavy rain things change a bit. You already know this from the regular well-known rivers here in CT.
I am not saying these exist. Only that I think they exist. Just so you know I am no expert in white water. I have done several commercial raft trips from Northern ME to the Pacuare River in Costa Rica. Added to all the knowledge I have amassed from TV and the Internet.
I am about to give away a spot where we have been walking our dog in peace. Not many people around. It is a public space very scenic and popular year-round for a short walk and in the summer for swimming. But not too popular! Yet.
From the parking area, it is an easy three-tenths of a mile walk to the waterfall. But for your first look turn right after the creek you have to cross and walk along the water’s edge. I have not explored downriver from this point. My guess from just looking is that downriver would also be fun with good 2 and 3s. The fun part is up river which is narrow and steep. Looks to me like an easy entrance above or below the waterfall. If you go in on top my guess is an easy drop of 6ish feet to the pool below. Then it happens fast. There are several good drop-offs with room to stop between them. The exciting part is short I admit. But the easy in, easy out, and easy path back makes this a place where you could do the run several times or extend your trip downriver just two miles (ish) to the Salmon River at Machimoodus State Park, a good take out if you are dropped off up river. Or Both!
Remember this is only after a good soaking rain. As I write this the last year has been nothing but rain. The ground is soaked and runoff is at its best. This cannot be the only place like this but this is the place I found. Who knows what the future holds? Perhaps this will be known as Joel’s Run.
Start here. https://www.newenglandwaterfalls.com/ct-pinebrookfalls.html
Check the map and see how much land is drained through that small gap.
https://www.google.com/maps/place/Sexton+Hill+Rd,+East+Hampton,+CT+06424/@41.5193847,-72.5005479,15.87z/data=!4m6!3m5!1s0x89e647f3fb808201:0x3a7db5e9ba8d6275!8m2!3d41.5173753!4d-72.5016158!16s%2Fg%2F1tf3ckj1?entry=ttu
The map link gets you close. Pine Brook runs under Rt 151. Sexton Hill Rd is on the right.
I am new here and don't know yet if I can post any photos.