As the population grows exponentially and development sprawls across the country, the amount of renewable water available per person is decreasing substantially. Communities rely upon groundwater, which is replenished by rainfall and is the lifeblood of a region's rivers and streams. As communities grow, they begin to exceed their local supply of water, depleting the water levels of rivers and streams, harming fish, wildlife and plants. As growth sprawls outward, the amount of groundwater withdrawn increases drastically.
Every person has a significant and lasting effect on the water supply.
Smart growth policies can alleviate this problem. For example, water quantity is a huge problem in San Diego, CA, the local government is aware of the problem however and trying to fix it. There are currently 2.7 million people living in San Diego and an estimated increase of 15 million people is expected in the next 20 years. The demand for water is very high due to the lack of a natural water supply. In turn, water supply is a deciding factor where growth will occur.