Texas is pretty weird at that. I just moved to Durango from Arlington. # yrs down there was enough for me. You could make a fortune in just collecting beer cans for scrap aluminum. They're everywhere, the lakes, the rivers, the highways, parks, etc.
A lot of the paddlers I know down there swear by White Rock Creek (gag) not even with a tetnus shot before and after would I get into that creek. It's nasty. The Clear Frok of the Trinity is a lot better. Still lots of trash shows up after a storm, but the overall water quality is ok (albeit marginally) I took a field test kit down there and tested the water, no heavy metals and fertilizers present in excessive quantities. the Ph was actually well within normal ranges.
All in all.... it beats a blank for texas paddlers ... but it sure is good to be back home in colorado...