how long did it take to accumulate all the water that is currently in the ogallala aquifer
Ogallala Aquifer The water-saturated thickness of the Ogallala Formation ranges from a few feet to more than 1,000 feet (300 m) and is generally greater in the Northern Plains.[11] The depth of the water below the surface of the land ranges from almost 400 feet (120 m) in parts of the north to between 100 and 200 feet (30 and 61 m) throughout much of the south. Present-day recharge of the aquifer with fresh water occurs at an exceedingly slow rate, suggesting that much of the water in its pore spaces is paleowater, dating back to the most recent ice age and probably earlier.