Sep. 13—Warrenton was the fastest-growing city in Clatsop County over the past decade with a 25.8% rise in population, according to data from the 2020 census.
The county's overall population grew 10.9%, adding 4,033 residents to reach 41,072. The growth rate was the largest since the 1970s, when the population rose by 14.1%
Oregon grew by almost the same rate as the county over the past decade at 10.6%, hitting 42 million people, the U.S. Census Bureau said.
Warrenton's population jump — from 4,989 to 6,277 — has taken place as the city's infrastructure has come under increasing strain because of development. The city's water capacity is nearly maxed out, Mayor Henry Balensifer said.
"It is going to become more expensive to do development in the city until infrastructure can keep up with the pace of the demand to use it in development," he said.
Part of the reason Warrenton was such an attractive place to build, the mayor said, was that the city had a lot of flat, undeveloped land. But it is becoming more difficult for developers to find sites that aren't on or near wetlands, so navigating the environmental red tape makes the process more expensive.
"All the easy property has been built on," Collin Stelzig, the city's public works director, said.
Warrenton has had trouble accommodating the high rate of growth. Some projects have been waylaid as developers waited for the city to upgrade pumping stations to bring sewer and stormwater service.
In the coming years, the state is expected to curtail Warrenton's water rights, scaling down the amount of water the city can pull from the Youngs Bay watershed. That puts Warrenton in a position where "the growth capacity you thought you had doesn't exist as much anymore," Balensifer said.
That reality drove Warrenton's decision to restrict water hookups for large developments in areas outside the city — Clatsop Plains, for example — because of the water system's limitations. "That's to protect capacity for existing residents within the city of Warrenton and business within the city of Warrenton," he said.
The city has raised monthly water and sewer rates in recent years to help pay for operational costs, though the city has frozen the increases amid the pandemic-stressed economy.
Warrenton has discussed various methods, including enlarging its water reservoirs, to increase water capacity and otherwise prepare for another two decades of growth.
Astoria's population grew 7.4%, hitting 10,181 in 2020.
Seaside's population gain topped 10%, arriving at 7,115. Neighboring Gearhart added 22.6% more residents, climbing to 1,793.
Cannon Beach lost full-time residents during the decade, declining almost 12% to 1,489.
The Knappa-Brownsmead area grew to 2,144 residents, or by 7.6%. Svensen had 853 residents in 2020 but wasn't counted as a separate place in 2010.
The Jewell area had 1,068 residents in 2020, a 10-year increase of 2.5%.
The portion of the county that experienced the largest overall growth rate — nearly 33% between 2010 and 2020 — was census tract 9506, a northwest rural area inland from the ocean. The population in the census tract expanded to 3,393.