Portland’s Urban Growth Boundary: Room to Live or to Discriminate?Introduction to Portland and Urban Growth Boundaries:

Portland is often mentioned when discussing urban sustainability due to its innovative approach to urban sprawl via the establishment of an urban growth boundary (UGB). A UGB is a line that delineates the extent a city can expand urban development. Portland’s city government, Metro, is in charge of managing this boundary, and has been expanding it since 1979, when it was first established. Figure 2 shows the expansion of Portland’s UGB up until 2014.

UGBs have been promoted as the remedy to urban sprawl, a product of suburban development, as UGBs “[promote] compact and contiguous development patterns.” However, many experts have stated that UGBs do not directly address issues associated with urban sprawl.1 In my analysis of Portland’s UGB, I demonstrate that Portland’s UGB does not address one key issue of urban sprawl: preferential treatment of whites

Hypothesis:In tracts where Metro is most likely to expand

their urban growth boundary, there will be a majority white population within the neighborhood radius (1.5 miles) of potential expansion area.

References:1Jun, M.J. (2004) he Effects of Portland’s Urban Growth Boundary on Urban DevelopmentPatterns and Commuting. Urban Studies 41(7), 1333-1348.2Oregon Metro. (2015). Urban Growth Boundary. Retrieved fromhttp://www.oregonmetro.gov/urban-growth-boundary3http://quickfacts.census.gov/qfd/states/41/4159000.html

MethodologyIn order to test my hypothesis, I had to make several methodological assumptions. The methods referred to in this section can be seen visually in figure 3.• Heavy industrial buffer (4 miles) and limit to largest

20 tracts:• Largest 20 tracts: these areas were

clustered around the industry centers, and were thus most likely to be the most representative.

• 4-mile buffer: far enough away that environmental pollutants would not affect neighborhood quality

• Measures of likeliness to be expanded into• RRFU zones are the most likely to be

developed for urban use• Zones over-bounded by Metro are already

incorporated into the city, and are therefore likely to be developed

• Neighborhood radius:• The 1.5 mile radius was chosen due to the

sizing of the 5 districts of the city• Race data

• The use of census tracts are notoriously spatially and temporally inexact, however, this study did observe any spatial relations that would merit more exact measures

Zoning and UGB expansionExpansion is determined through a complex

process, but two types of reserves, urban and rural, which are labeled as future urban development (FUD) and rural residential or future urban (RRFU), respectively, are used to designate where expansion will occur.2 In addition to these two types of reserves, there is a third called exclusive farm use (EFU), which is an area of low priority for urban development. RRFU zones largely exist outside of the UGB. However, some areas within the UGB are zoned this way; these areas were recently brought into the UGB, which we can see if we compare figure 2 and 4. This map shows an overwhelming number of RRFU zones exist in the areas south, east, and southeast of the city of Portland.

Figure 2: History of the expansion of Portland’s UGB

Figure 3: Flowchart of analysis of spatial data

Industry and over-bounded areasAfter applying the 4 mile buffer of the 20

largest HI tracts and intersecting over-bounded areas, there were multiple of tracts that fit our hypothesis. However, there were only two areas with RRFU zoning and outside of the HI buffer, which can be seen in figure 5.

Findings:In the areas within a 1.5 mile radius of the

tracts chosen from the zoning and IH buffer processes, zone 1 was nearly 90% white and zone 2 was ~88% white, while the whole city of Portland is 76% white. This can be seen above in figure 6. In addition, the tracts of interest are areas of low density residential zoning, indicating that not only are these potential expansions of the UGB in primarily white neighborhoods, but they are also in neighborhoods of quasi-suburban development.

Cartographer: Ben CampbellProjection:Figure 1: NAD 1983 USA Contiguous Albers Equal Area, Figure 1 extent through figure 7: NAD 1983 HARN State Plane Oregon NorthDatum: NAD 1983 2011 and North American 1983 HARNData: the City of Portland , the State of Oregon, and Census Bureau ACS 2010

Figure 4: RRFU, FUD, and EFU zones, as well as the Metroand Urban growth boundaries

Figure 7: Single family and Multi family residential zoning

Figure 6: Neighborhood radius buffer overlaying nonwhite as a percentage of total by census tract

Figure 5: RRFU majority RRFU and 4 miles from 20 largest IH tracts

Figure 1: City of Portland, Oregon in relation to the contiguous United States