In 1987, the Colorado legislature made changes to annexation law limiting municipal annexations to no more than three miles beyond the current municipal boundary in any given year.  Municipalities in Colorado are required to adopt a three-mile plan prior to annexing additional property into their territorial boundaries per C.R.S. 31-12-105 et. seq.  The three-mile plan is a document that outlines where municipalities intend to annex property and describes how they will ensure the adequate provision of municipal services within the newly annexed territory and the remainder of the existing city.

State law provides municipalities with the ability to consider extraterritorial property up to three miles from the current municipal boundary for annexation.  It has been the past practice of the of the City to focus on infill development and limit the consideration of annexation properties to no more than one mile beyond the existing boundary.

The three-mile plan is a long range planning opportunity for municipalities to consider where they want to annex, how they will provide service in the newly annexed areas, and how they will sustain adequate levels of service throughout the rest of the municipality. It ensures that the municipality will annex land only when it is consistent with pre-existing plans for the surrounding area. It also outlines any issues and conditions that may need to be addressed with future annexations.

Last year, staff broke out Areas 3 and 6 into further subareas. Area 3 (southwest Alamosa) is one of the primary growth areas for Alamosa. It was broken into three subareas in order to better match the Comprehensive Plan comments and visioning, existing uses within the city and compatibility with adjacent uses, targeted areas for future growth of various land uses, the hierarchy of needs of land uses (ex. Residential over Commercial), existing/required utility extensions and needs and capacity to serve future growth, and to reduce future conflicts between existing uses/zoning within the county. Area 6 (southeast Alamosa) was broken up into two subareas; subarea A is differentiated for the anticipated growth of the Downtown to the Rio Grande as envisioned in the Downtown Design Plan, whereas subarea B is in many ways well suited to be an additional outlet for residential growth that comes without the strain on existing infrastructure. The 2022 plan is nearly identical to last year's.

Planning Commission reviewed the draft 2022 Three Mile Annexation Plan on January 26, 2022 and has forwarded a unanimous recommendation to the Council to adopt the plan as presented. The 2021 3-Mile plan is attached for reference.