Here in Central Texas and further west, there aren't that many "public streams" and some that are a "navigable waterway" do have low head dams built back when to operate cotton gins and mills, create swimming holes and such.
Most agricultural properties, even very small ones, do have small stock ponds ("stock tanks") created by excavating dirt to create a dam, in locations that are deemed to have sufficient runoff, like swales, gullies and the upper reaches of creeks. Really, they're everywhere. Here's a good overview: Stock Tanks Bring Water to a Dry Texan Landscape
I'd guess that the term stock TANK is regional and that a preference for the term "tank" rather than pond may be related to Spanish "tanque" (cistern, reservoir, water tank). Also, not to be confused with galvanized metal watering troughs available at the local farm and ranch supply store.
