Ada County Commissioners Wednesday unanimously approved updates to long-term capital improvement plans for the county sheriff’s office, coroner, jail and emergency medical service. For the first time, those plans include impact fees to help pay for growth in services needed to keep up Ada County’s population growth.
“We've seen strong support from the general public for this,” Ada County Planning Director Leon Letson told commissioners during a public hearing on the matter. “I think with the changing landscape of local funding, this has kind of moved up as a real big tool for a lot of service providers to get things done”.
The county projects 23% growth between 2023 and 2033, with 125,000 new people and more than 50,000 new housing units projected.
Other entities or districts already impose impact fees on new development, touted as a way to make growth pay for itself. Public safety funding in Ada County has relied on property taxes, but voters in the county and across the state have regularly been saying "no" at the ballot box to new bonds or levies proposed to pay for expanding public safety services.
Impact fees are one-time costs paid by developers when new property is constructed. How the fees are calculated is defined in state code; resulting funding is typically only allowed to fund capital improvements like land purchases, new buildings or equipment.
“The overall impact fee for a single family residence is right in the ballpark of about $750 for three services,” Letson said. “If you've looked at impact fees lately, that seems like a real steal.”
New single-family residential development in unincorporated Ada County will pay an additional $558 fee for the Sheriff’s office, a nod to impact fees already imposed by cities with their own police force or contracted law enforcement through the Sheriff’s office.
Rates for multi-family residences are slightly lower per unit, and new business development is charged for every 1,000 square feet with different rates for different types of commercial use.

“Every five years, we're required to jump in and look at [impact fees] and make sure that we've got growth projections right, that we're collecting the right amount of fees, and that we have the right facilities planned or expansions of those facilities planned,” Letson explained.
The impact fees will help Ada County EMS purchase land and build stations, he said. It will help cover some of the debt related to the new coroner’s building, and can be used to pay for jail expansion.
The county this spring decided to move forward with the first phase of renovations at the Ada County Detention Facility despite voters narrowly failing a proposed $49 million bond in November.
“Impact fees aren't going to get us all the way there, but they are going to be a valuable resource in order for us to achieve an expansion of the jail,” Letson said.
The fees are part of each agency’s comprehensive development plan, and County staff have been working on this update for more than a year. Each city in Ada County will now need to adopt the plan updates and pass local ordinances to implement the new impact fees.
Separately, commissioners Wednesday unanimously passed five-year updates to development plans for fire protection districts in Eagle, Star and north Ada County. Changes to existing impact fees in those districts were recommended in those plans but commissioners delayed a vote on those changes until Oct. 9 to accommodate another public hearing.