No way to tell if the 65 gpm is enough until you can tell us how much gpm will be lost due to any leakage and evaporation.
Personally? I'd dig the pond at least 20' figuring that as soon as you finish digging, it will start filling back up (slowly). That's just mother nature at work. Providing you still have clay at that depth tho. If you hit a sand vein, stop digging in that area, note the depth and pack at least 18" of clay over the sand.
More water volume is better in the Texas climate, well or no well.
Dang Scott!! You read my mind so freaking well!! Are you sure you're not my lost twin brother? LOL
Indeed, for central Texas, I looked up the historical data, and man, the temperature is going to be a killer. The transevaporative process is reaching the 65gpm, but should be sufficient to handle the size of exposed surface area, as long as there's no leakage.
There is a formula out there somewhere that takes averages of air temperature, humidity, water temperature, surface area, wind speed, and light to calculate hourly evaporation rates. I read about it one time but can't recall where. That is information you will need to know.
Dwight, dead on! Man, you guys are brilliant when it comes to sciences. This forum covers pretty much the entire array of PhD to field-based experienced gurus. This is where historical data from NOAA comes in handy, as well as some Almanac info, since Texas is a bit behind on their information updates. Once the info get tabulated, you then utilize 4 equations to calculate for the speed of transevaporation. Unfortunately, it has to be done by hand. This is where calculus comes in handy.
Billy, 2 acres, with the constant 65gpm without leeching loss, you're golden, with a 25% of water to spare. 3 acres, based on the temperature peek between 95°F to 110°F, you may experience net water loss of -12%, at 65gpm. I'll have my coworkers in the geological department do some side calculations during their lunch time to verify. If they come up with something different, I'll let you know. Sorry, morning hours and not having the coffee hitting my brain yet makes me a bit slow.
