New Census data confirming Colorado’s population has topped six million is fueling renewed debate over Gov. Jared Polis’ housing agenda, as he tied the population increases to home construction.

The governor said the counties experiencing the largest increases in new housing construction — Weld, Larimer, and Douglas — are also seeing the fastest population growth.

“This new data shows why it’s so important to remove barriers that prevent new homes from being built,” Polis said.

Douglas County, which began the decade with a population of 357,993 as of April 1, 2020, continued to grow steadily over the past five years, reaching 399,396 last year.

For context, the U.S. Census recorded the county’s population at 285,465 in 2010 and 180,267 in 2000.

Larimer County, which had a population of 359,069 in 2020, increased to 377,292 in 2025. That’s compared to 299,630 in 2010 and 253,140 in 2000.

Weld County showed the largest percentage growth, rising from 328,981 in 2020 to 378,426 in 2025. In 2010, Weld County had a population of 252,825, and 182,951 in 2000.

Meanwhile, some counties that have embraced Polis’ housing initiatives have seen population declines, including his home county of Boulder.

Boulder County, where population changes have been on something of a roller coaster for the past 27 years, declined from 330,761 in 2020 to 328,560. Eagle County’s population has dropped slightly, despite its embrace of the governor’s housing initiatives, from 55,721 to 54,291.

Of the 10 housing initiatives listed in the Department of Local Government-Division of Local Housing dashboard, Boulder is required to comply with seven. Eagle County is required to comply with six.

Pitkin County lost about 1% of its population between 2020 and 2025. The state dashboard now shows it’s exempt from some of those housing initiatives as a result.

The Polis administration noted that 24 counties have experienced declines, which, it claimed, reflect “national trends of slower growth, housing affordability, changes in immigration policy, and fewer people moving due to higher interest rates and aging in place.”

The state budget, which faces a $1.5 billion shortfall, according to Legislative Council economists, is now part of the discussion.

The Polis administration’s statement said Colorado has made a significant investment in affordable, much‑needed housing through Proposition 123, which has supported more than 10,000 new homes statewide, including in rural communities that previously had limited access to state funding for affordable housing.

The 2026–27 budget reduces Proposition 123 funding by $25.7 million. According to the Department of Local Affairs, 40% of Proposition 123 revenue goes to the Affordable Housing Support Fund, which is administered by local affairs department through its Division of Housing and Division of Local Government.

The fund includes three program areas: “Affordable Homeownership,” “Serving Persons Experiencing Homelessness” and “Local Planning Capacity Grant Program.”

Funding for the Prop 123 programs, estimated at $300 million per year, comes from a 0.1% tax on federal taxable income in Colorado. At 40%, that’s about $120 million per year for the affordable housing grant programs.

The Polis administration has tied compliance with housing initiatives to $277 million in housing grants. That prompted a lawsuit from six Front Range communities over concerns that the laws passed by the Colorado General Assembly in the past several years violate the state constitution’s provisions on home rule, a century-old authority that gives municipalities some control over local matters, particularly in land use and zoning. 

The laws adopted by the Colorado General Assembly put the state, rather than local jurisdictions, in charge of certain zoning and land-use policies.