If you don't have a boat the Guadalupe below Canyon is fun this time of year for rainbows.
Otherwise, state parks offer access. Guadalupe River, Blanco and Pedernales Falls offer decent bank fishing.
Calaveras and Braunig can be good from the bank but you're mainly going to have to soak baits in deeper water away from the bank. Which means using considerable weight or wading out to cast. The water isn't contaminated as incorrectly stated above.
The white bass run is starting now (well, it's already started down south) and if you can find access to rivers above the reservoirs you can do well.
If you have a boat that's a game changer and your opportunities increase big time. There are some ponds on the south side that get stocked with channel cats. Otherwise, unless you have the ability to fish on private property, it's slim pickings unless you want to research and locate access points and be able to drive a ways to get there. Or fish from the bank from one of the lakes which can be super challenging most of the time.
Gig 'em! '90