The expected growth of the city must be determined. These projections are usually done by using available state and federal information. When the amount of vacant land needed is determined, planners subtract it from the vacant land available in the current city limits. What's left is called urbanizable land. After the amount of land is determined, a decision must be made as to which areas to include within the UGBs.
Some areas are more costly to develop than others are.
This urbanizable land isn't immediately used. It may be two, five, or even ten years into the future before the land is fully developed. With this in mind, the land must be actively managed to ensure that haphazard or premature development doesn't take place. The cities and counties usually sign agreement in which both coordinate the planning and zoning of these areas. Success stories relating to UGBs abound.