Judging by the contours, looks like you may have a terrace or two going across your place, you could build a dug out pond at the end of one of the terraces...? To build a good embankment pond, you really need a field drain or other channel coming into it. There are some places that will let you build in the floodplain as long as it is a pond for agriculture. Meaning that you have livestock and the pond is a “livestock sized” pond, most of which are an acre or less. Check with your local floodplain admistrator. They work for the county in Texas.
A good local dirt work (pond) contractor should be able to steer you in the right direction.
