Will Hillsboro pass Gresham by the next census?
A few weeks ago the U.S. Census Bureau released its latest estimate for cities. As I expected, Hillsboro jumped over the 100,000 mark and now has an estimated population of 102,347. Note, these are different than the estimates the state uses which are determined by PSU's Population Research Center, and these figures reflect an estimate as of July 1, 2015. So nearly a year old at this point.
As a bit of a statistics geek, I like to look at these and trends. I also like to look at how Hillsboro is relative to its neighbors, and with Beaverton firmly in the rear view at this point, it is time to look ahead at Gresham.
What I mean is this, Hillsboro overtook Beaverton (or re-overtook as the two have traded places a few times over the last century or so) about 2007 as the fifth most populous in Oregon, which is why the official name for the Portland area is the Portland-Vancouver-Hillsboro MSA. Number four on that list is Gresham, which had passed Hillsboro at the 1980 census count. So the big question seems to be when will Hillsboro overtake Gresham as the fourth most populous city in Oregon?
PSU's estimates peg that has happening in the 2020s. However, looking at the latest data from the Census folks, whose numbers vary considerably from PSU's, I think there is a very good chance Hillsboro passes Gresham at the next census in 2020. This assumes growth continues around what it has been, with some caveats.
First, the numbers:
| 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | |
| Hillsboro | 91,611 | 93,455 | 95,327 | 97,368 | 99,393 | 102,347 |
| 1,844 | 1,872 | 2,041 | 2,025 | 2,954 |
| Gresham | 105,594 | 107,439 | 108,956 | 109,397 | 109,892 | 110,553 |
| 1,845 | 1,517 | 441 | 495 | 661 |
What this shows is the year, the population, and from 2011 through 2015 the raw increase in residents. This clearly shows Hillsboro is catching up, and doing so fairly quickly since 2011. This is not just some short term anomaly either, as Hillsboro's growth at the 2000 census was about 87% compared to about 32% for Gresham, and about 30% at the 2010 census compared to about 17% in Gresham. This also tends to relate to larger trends of faster growth in their respective counties.
Given those historical trends, clearly Hillsboro will catch Gresham at some point, assuming the growth continues as it has. That is not a given, as the growth rates between the two cities have varied much over the last 100 years, and any number of things could alter what ends up happening.
This then gets us into the more recent trends of much more rapid growth in Hillsboro versus Gresham. Hillsboro has seen a lot of apartments go up in the last five years or so. That explosive growth ass started to wain a bit in the last year, but some of the new apartments would not be part of the 2015 numbers yet, as the Platform District was largely unfinished a year ago. Thus, it is safe to say some of the growth will continue at least into the next estimate in a year.
Meanwhile, while multifamily housing boomed, single-family residences took a back seat, still suffering from the Great Recession. However, that seems to be waning as well, as a drive around town will show many new housing developments going in, and this all without South Hillsboro starting yet.
Speaking of South Hillsboro, it appears construction might finally kick-off this year, or next year at the latest, providing a boost to growth later this decade. Even outside of the actual boundaries of South Hillsboro, the Witch Hazel area that was planned circa 2005 is also only about half built-out, so there is still relatively large tracts of land there as well, which largely already has roads and other infrastructure in place.
Next, we have annexation. To-date, Hillsboro has largely avoided annexation, other than at the request of property owners. That compares to Beaverton where much of its growth came from annexing existing neighborhoods, with plans at one point that could have made it the second biggest city in Oregon. That included the failed attempt to annex Nike, and those plans seemed to have cooled since that time. Hillsboro could easily see an increase in annexations around the Reedville area as South Hillsboro builds out, and as people in Reedville and Aloha see the value of city services. At the end of the day, annexations will likely not significantly add to Hillsboro's population,put there is potential.
Taking all of these elements into consideration, I put together my own rough estimate as to growth in Hillsboro versus Gresham for the later part of this decade:
| 2016 | 2017 | 2018 | 2019 | 2020 | |
| Hillsboro | 105,347 | 108,347 | 111,347 | 113,847 | 115,847 |
| 3000 | 3000 | 3000 | 2500 | 2000 | |
| Gresham | 111,303 | 112,053 | 113,053 | 114,053 | 115,053 |
| 750 | 750 | 1000 | 1000 | 1000 |
As you can see, even without adding 3,000 plus residents each year, Hillsboro does catch Gresham by the next census. This even assumes a slowing of growth in Hillsboro and an uptick in Gresham. And this is not far off from just projecting the growth rates from the last census, which would put Hillsboro at about 120,000 compared to about 124,000 in Gresham. If you use the slower growth rates for both over the last five years, you end up with about 117,650 for Hillsboro and 116,500 for Gresham.
Ultimately, only time will tell what happens. Meanwhile, we statistics geeks can ponder these things.
