Potters Creek Park

 There are 25 Corp Of Engineer lakes in Texas and I think all of them have campgrounds. Prices range from free to about $40.00 depending on the amenities. Most of them are located along the I-35 corridor starting north of San Antonio and going all the way to the Texas/Oklahoma border. 

The COE website is not user friendly. It has a map but some information is out of date. Pay campgrounds are listed in recreation.gov but most of the free ones aren't. If you're planning on camping in COE campgrounds, which I highly recommend because they are usually well designed, well maintained, and reasonably priced, an actual book is the best resource. 

There are three campgrounds on the shores of Canyon Lake. Potter Creek and Cranes Mill are RV/tent campgrounds and North Park is tent only. Potters Creek Park has 114 sites, some under the trees, others in full sun. All have electric and water hookups along with tables under shelters, a dump station, flush toilets, and showers. 

The COE does a poor job making accessible sites. Most of the time there's very little difference between the sites listed as accessible and the ones that are not accessible so we chose a site for the best view of the water which has dropped so low that many of the boat ramps had to be closed. The parking pad was wide enough to deploy a wheelchair life. The crushed gravel around the table was okay for rolling but the design of the shelter made it impossible to get close to the table top. Campground  29.90423, -98.26678