Maybe it's because we are loaded with livestock in TX, there's very little water permits we have to deal with. IIRC, all you need to do is stay under 200 acre-feet of water, stay on your own property, and don't dig a hole that affects an active river or stream. Other than that, dig a hole however you want. We actually built a berm at the top end of our big pond so water wouldn't back up onto our neighbor's pasture. We have 2 24" drain pipes into our pond from his pasture, but the pipes are high enough so that water can't backup on his property.
