I'm not sure that is entirely correct. I live in San Jose, CA and we have groundwater recharge ponds. Throughout the city the water company has plots of land that they keep entirely covered with water. The idea is it soaks in, and then other people pump it back up.
That's interesting. I wasn't aware that there was significant recharge from human-managed/created basins. It looks like >50% of the recharge in Santa Clara county is non-natural. But it also looks like it still falls short of the demand from pumping.
I think the point is there is a specific rate at which that type of process is viable, and it is limited by available land and geography. As population grows, that becomes less doable.
http://www.valleywater.org/Services/Groundwater.aspx