Robust Population Growth in Tri-Cities Continues

By Dr. Kelley Cullen

It is probably no surprise that the combined counties of Benton & Franklin continue to grow at a brisk pace compared to the state. Local residents likely see signs of growth pressures everywhere. But recent data from Washington’s Office of Financial Management (OFM) collected for Benton Franklin Trends 0.1.1 Total Population & Annual Growth provides insights into the magnitude of recent population growth in the Tri-Cities. The data can tell just how much growth is happening and how fast.

With over 316,000 residents in 2023, Tri Cities is the third most populous metropolitan statistical area (MSA) in the state, just behind Seattle & Spokane. Over the past five years, the region’s population has grown an average of just over 9% (about 1.8% per year), besting all other MSAs and over two percentage points above the state average of 7% (about 1.4% per year).

While both counties are experiencing robust growth, Franklin County (101,100) is the fourth fastest growing county in the state and is growing at a slightly higher rate than Benton (215,500) which is the seventh fastest growing county over the past five years. The combined counties added over 4,500 new residents in the past year alone. For reference, Spokane County is experiencing similar robust growth and is the 6th fastest growing county in the state.

Of the three largest cities, Kennewick has been experiencing the most moderate growth of just over 1% annually, in the last five years, below the region average of 1.8%. Growth is higher in Pasco where population has been increasing around 2% annually. Richland has been experiencing the fastest growth averaging 2.7% annually over the last five years.

Using data from the OFM’s Population of Cities, Towns & Counties, a little more detail can be had about individual communities. In Benton County, the fastest growing cities by percentage are Prosser (2.5%) and West Richland (2.2%) annually over the last two years. In Franklin County, growth is being fueled largely by increases in Pasco where growth has averaged 1.6% annually over the last two years.

There are signs that growth in the Tri-Cities might be slowing slightly. In just the last two years, population only grew at about 1.4% annually, still above the state rate of 1.2%. Both Pasco and Richland have experienced growth of around 1.6% annually over the past two years alone. For Richland, this is a full percentage point below the five-year average growth rate.

It is helpful for policymakers to understand the nature of the population growth in their communities. For example, growth due to births is different from growth due to in-migration in the types of goods and services these groups might need from the community.

Data can be found at the OFM decomposing population growth into these distinct components of population change. From 2022 to 2023, the Tri-Cities saw an overall increase in total population of 4,550 residents. Of this increase, nearly 30% was due to natural change, or the difference between births and deaths. The natural increase in population in the Tri-Cities is higher than any other metropolitan area in Eastern Washington.

Benton Franklin Trends 0.3.1 Residual Net Migration provides detail about the other 70% of population change. In just one year, over 3,000 new residents migrated to the region from somewhere else. While the 70% refers to the Tri-Cities as a whole, the two counties are experiencing different rates of in-migration. While Benton County’s in-migration represents over 85% of their total annual population growth and is comparable to the state average of 83%, Franklin’s in-migration only constitutes one-third of their annual population growth.

What about the future?

Forecasts by the OFM predict another 19,000 in Benton and another 14,000 in Franklin by 2030 for a combined total of over 33,000 new residents in the region over the next seven years. This would be the equivalent of adding a city one-half the size of Richland presently to the Tri-Cities.

While population growth that is fueled largely by in-migration could bring welcome workers and incomes, communities also need to be prepared to manage that growth in terms of housing, schools, roads and other infrastructure. It is probably not a bad thing that the robust population growth of the past five years is showing signs of a little dampening. This might allow the area to better respond to the challenges that growth, and especially in-migration, might bring.