What might happen to the supply of water for agriculture in a region with a rapidly growing city?

The most likely thing that can happen is that the water supply is quickly depleted, due to causes such as deforestation or likewise due to the high consumption of the liquid because of the population growth.

producers: apple trees, potatoes, carrots, grains, acorns, cabbage, grass, corn, lettuce

consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls