We have had the same problem Luccagr. With the drought our ponds are stagnant and the lakes have little water. My two have not been allowed to swim since we got them! I am keeping my fingers crossed that the small rains we have gotten so far will help us for the spring.
I have heard the the KOA campgrounds at Lake Whitney are still doing well & have cabins, but haven't been in that part of the state recently so haven't seen for myself the shape the lake is in, but most are very low and a lot of the campgrounds are now pretty far from the good water. Uck! Hope we Texans are all praying for LOTS more rain, we need it so badly. The state is suffering so much.
We've gone to Galveston for the past two falls with Toby, stayed at the LaQuinta on the seawall. The hotel is very dog friendly. You can walk and play along the beach with a dog, but we tend to go during non-peak times and go to the less populated areas with Toby. When we are in areas with guards and lots of people we put Toby on a lead. He LOVES it once he remembers not to bite the waves!
Edit: I probably wouldn't let a puppy off leash in Galveston though unless he has super-100% plus recall.