Urban Growth Boundaries
To limit urban sprawl and negative effects such as high per-capita water use arising from low-density development, a few municipalities, most notably Portland, Oregon, have proposed or implemented urban growth boundaries \[UGBs\]. The UGB around Portland and vicinity, administered by Metro Regional Government serving the lower Willamette Valley, serves to control urban expansion onto open space and promote efficient land use in the central city, existing suburbs, and other already-developed areas (Metro Regional Government \[Metro\], 2008). Portland's UGB, established in 1979, is not static; it has been expanded about three dozen times up to the present day (Metro, 2008). This series of expansions has not diminished the UGB's effectiveness; between 1990 and 2002, even as Metro added over 25,000 acres to its spatial growth limits, population in Greater Portland increased 17 percent while the addition increased the conurbation's land area only nine percent (Metro, 2008).
We maintain that economic incentives to limit water-intensive development would be similarly effective compared to UGBs and generate less public opposition than the latter. Portland's success can be achieved in other cities via our proposal to eliminate subsidies for open space development, from local to federal levels. For example, developers wishing to construct low-density housing would need to pay in entirety for new roads, utility lines, and infrastructure to accommodate expanded city services. Therefore, it would become more economical to utilize existing transport, power, and water infrastructure when planning new development projects. However, if water-intensive sprawl continues despite its increased costs to developers, we have the option of issuing mandates to check the outward expansion of cities. UGBs if implemented should be sensitive to local demands, thus ideally, any mandate on urban expansion shall best remain within the authority of regional and local governments. While we strive to avoid drastic mandates to curb urban growth in western North America, regional and local governments shall reserve the right to implement UGBs at the interest of their constituencies.