Ada County is responsible for managing development within the unincorporated areas and the Area of City Impact boundaries of the six cities, in accordance with their adopted Comprehensive Plans and Future Land Use Maps. Area of City Impact boundaries designate area which cities anticipate annexing in the foreseeable future. There are 5 planned communities within unincorporated Ada County: Avimor, Cartwright Ranch, Dry Creek Ranch, Hidden Springs, and Spring Rock.
Frequently Asked Questions
Why have cities been able to annex land outside of their Area of City Impact boundaries?
The Idaho State Code allows cities to annex land outside of their Area of Impact boundaries in instances where all of the affected landowners agree to the annexation. The cities may transmit to the county for comment, but the city council is the final authority to make decisions regarding annexation.
Is unincorporated land within an Area of City Impact regulated by Ada County or by the city?
There are more than 90,000 acres of unincorporated land in Ada County. State law requires the application and enforcement of land use negotiations to be the responsibility of the county until the area is annexed into the city. However, when processing land use applications within an area of city impact, the county verifies conformance with the applicable city’s Comprehensive Plan and transmits those applications to the respective city.
Why does Ada County not always utilize a city’s most recent Comprehensive Plan?
When reviewing land use applications within Areas of City Impact, Ada County utilizes the Comprehensive Plans last negotiated and adopted by the Board of Ada County Commissioners. Cities may adopt updated Comprehensive Plans for use within their boundaries prior to them being renegotiated and adopted by Ada County for use within the Area of City Impact boundaries. In these instances, Ada County may be utilizing an older version of a city’s Comprehensive Plan.
Why are there so many county islands within city boundaries in Ada County, and how are services provided to them?
Idaho State Code allows property owners to opt-out of annexations in certain circumstances, such as when a property of five acres or greater is actively devoted to agriculture. This can result in unincorporated islands of land within a city, which creates unique challenges for service provisions for the county and the city. Ada County, with each individual city, has developed unique procedural arrangements for service provision to these islands.
How are Area of City Impacts created?
Idaho State Code Section 67-6526 (Areas of City Impact – Negotiation Procedure) establishes a framework for a county and its cities to negotiate planning and land use decisions within a city’s Area of City Impact (ACI). These negotiations are made with the intent of anticipating urban uses served by public services in the foreseeable future. Idaho State Code 50-222 (Annexation by Cities) establishes the annexation requirements for cities.
Comprehensive Plans & Land Use Maps
Ada County Comprehensive Planning Documents
Appendices
Appendices A (Trends & Forces Report)
Appendix B (Agriculture and Open Space Preservation Toolkit)
Appendix C (Map Atlas)
Appendix D (Planned Community Comprehensive Plans)
Appendix E (Impact Fee Capital Improvement Plans)
Appendix F (Transportation Action Plan)
Cities in Ada County
