Why could the Ogalla aquifer not be replenished by watering its recharge zone?

First off, its spelled OGALLALA, which is in Nebraska................We use aquifers as a good source of water, and because we need that water, it's used too quickly. Ground water moves slowly, and as you know, it aquifers are a good source of ground water. Some think that it may take 1,000 years in the future to replenish.