"It won't happen this year, and it might not happen next year, but eventually, Boise will move to annex the 6,000 homes and roughly 27,000 people living in [the Southwest Planning Area of Ada County]. The land has been in the city's area of impact - meaning it's been identified for annexation - for 36 years," reports Sven Berg.
In question is the use of resources, such as parks, by residents of the unincorporated area of Ada County, as well as county taxes on city residents that are then spent on resources for county residents, such as the Sheriff's Office.
The idea of annexation is unpopular with county residents, who think they will gain less than they'll pay for if they have to start paying the city's taxes.
Land use planning decisions dating back to the 1970s have allowed for city levels of density in Boise's unincorporated "areas of impact."