Urban growth boundary
From Wikipedia, the free encyclopedia
An urban growth boundary, or UGB, is a regional boundary, set in an attempt to control urbanization by designating the area inside the boundary for higher density urban development and the area outside the boundary for lower density rural development.
An urban growth boundary circumscribes an entire urbanized area and is used by local governments as a guide to zoning and land use decisions. If the area affected by the boundary includes multiple jurisdictions a special urban planning agency may be created by the state or regional government to manage the boundary. In a rural context, the terms town boundary, village curtilage or village envelope may be used to apply the same constraining principles.
Some jurisdictions refer to the area within an urban growth boundary as an urban growth area, or UGA. While the names are different, the concept is the same. Another term used is urban service area.
Urban growth boundaries have come under an increasing amount of scrutiny in the past 10 years as housing prices have substantially risen, especially on the West Coast. By limiting the supply of developable land, critics argue, UGBs increase demand and therefore the price of existing developable and already-developed land. As a result, they theorize, housing on that land becomes more expensive. Planning experts counter that when properly managed, UGBs have a minimal impact on property value. In Portland, Oregon, for example, the housing boom of the past four years drove the growth-management authority to substantially increase the UGB in 2004. While some point to affordability for this action, in reality it was in response to Oregon State law. By law Metro, the regional government is required to maintain a 20-year supply of land within the boundary. Even with the addtion of several thousand acres housing prices continued to rise at record-matching paces. Supporters of UGBs point out that Portland's housing market is still more affordable than other West Coast cities, and housing prices have increased across the country.
[edit] Places with urban growth boundaries
The U.S. states of Oregon, Washington and Tennessee require cities to establish urban growth boundaries. However, in states such as Tennessee the boundaries are not used to control growth but rather to define long-term city boundaries. States such as Texas use the delineation of Extra Territorial Jurisdictional boundaries to map out future city growth with the idea of minimizing competitive annexations rather than controling growth. Notable US cities which have adopted UGBs include Portland, Oregon; Minneapolis, Minnesota; Virginia Beach, Virginia; Lexington, Kentucky; all cities within Ventura County, California, and in Miami-Dade county. In the San Francisco Bay Area there are several examples. In particular, Livermore and Pleasanton have voter controlled UGBs as well as their surrounding Counties of Alameda and Contra Costa, creating a robust "double" UGB. Outside the US, Vancouver, British Columbia and Toronto, Ontario have boundaries to preserve greenspace. Controls to constrain the area of urban development existed in London as early as the 16th century. In the middle of the 20th century the countryside abutting the London conurbation was protected as the Metropolitan Green Belt. Melbourne has recently introduced artificial growth boundaries to limit urban sprawl and introduce green wedges.
[edit] External link
- Metro: Urban growth boundary: information on the Portland, Oregon-area boundary
