So I have been thinking about checking out Pedernales River Nature Park (not the state park). I see on the map it may also be called lake Johnson City. Anyways, I was wondering if anyone has an info on it, just basics like is it worth fishing, is it free and are there any rules about boats there? I have an inflatable kayak and some places (mainly in SA) don't allow inflatables which is really annoying. Google claims it's only an hour and 25 minutes from my house.

Driven over the 281 bridge 1,000 times but never been on the water.
I've never noticed much of any cleared out areas on rivers edge. So entry onto the water may be a little tough.

If you take the yak, be careful and don't get to close to the dam. With this rain we've had, current maybe a little swifter. You don't want to be in a position where you get swept over the dam because you can't get out of the current. If that happens the walk back to the truck will be longer, harder and not as fun...

There is a somewhat of a flat spot in the dirt a few yards up river from the bridge to launch a yak or similar. NOT the dam/park side but the up river side of 281. The entrance is near the fair/ag/ rodeo building. Very poor bank access in the park itself, high bank very brushy. The water depth is very deceiving from up on the bridge, extremely shallow. I hardly had enough for a trolling motor alot of 2ft water. I think the better fishing water is up river from the bridge but not for very far, goes back to very shallow progressing to unnvavigable . The deepest part is directly under the bridge.

If you want to give it a try, I would have a plan B Like maybe Boerne lake so you don't waste the whole trip. Hill Country Cupboard is a good lunch spot.