Planning panel approves final plat to replat Arbolada into 23 single‑family lots

LOS ALAMOS, N.M. — The Los Alamos County Planning and Zoning Commission on Aug. 20 approved a final subdivision plat to replat the previously approved 85‑lot Arbolada subdivision into 23 single‑family lots and four tracts, a change the applicant says is a prerequisite for a separate application to develop 114 cottage units on one of the tracts.

The commission voted to approve case SUB20250022 on a 5‑0 roll call. Commissioner Burrell moved to approve the final plat and Commissioner Nelson seconded; commissioners Hill, Nelson, Easton, Adler and Bruhl voted yes.

The replat covers a 17.07‑acre parcel in the North Mesa neighborhood, most commonly addressed as 659 San Ildefonso Road. County staff said the proposal would create 23 single‑family lots fronting a 50‑foot public street named Arbolada and three tracts designated as open space; Tract 4 — roughly 9.54 acres — would remain as a single, larger tract to be the subject of a later development application.

Desiree Luhan, senior planner with Los Alamos County Community Development, summarized staff findings and the decision criteria the commission must use. "The 23 lots will be for single family dwellings," she told commissioners, and added that the lots range from about 5,783 square feet to an average of 6,057 square feet. Luhan said public utilities are available via San Ildefonso Road, that the Department of Public Utilities reviewed capacity and that a waterline upgrade plan is planned to support growth in the area.

Staff told the commission the application satisfies the county development code criteria for final plat approval, citing prior approvals in the entitlement sequence: a preliminary plat approved June 11 and a minor zone map amendment approved July 23 that rezoned portions of the site to SFR‑5 to meet lot standards. The community development report recommended approval, and staff said public notice requirements were satisfied.

Commissioners asked clarifying questions about the relationship between the final plat and the separate conditional use permit for the cottage development that followed on the agenda. Commissioner Hill asked why the eastern lots were being created as single‑family lots rather than rezoning the area to multifamily; staff and the applicant explained the final plat creates legal lots of record and that Tract 4 must exist before an application for the 114‑unit cottage development can be filed.

Several residents addressed the commission during public comment with concerns focused on school capacity, drainage and construction impacts. Melissa Boswell, a Broadview Estates resident whose property borders the site, told the panel the development would occur directly behind her home and raised concerns about class sizes at nearby Barranca Mesa Elementary and about potential drainage and grading impacts on adjacent yards.

The applicant and staff responded that drainage and grading plans were reviewed by the county's interdepartmental review committee and that Los Alamos National Laboratory and DOE had been consulted regarding canyon drainage. The applicant said a six‑foot concrete masonry unit (CMU) wall is planned along the eastern edge adjacent to Broadview Estates and that grading and drainage plans will be finalized in later permitting stages.

The final plat approval authorizes the county to prepare a final written order and findings of fact reflecting the commission's decision. The commission's approval can be appealed to the county within 15 calendar days of the final written decision by the property owner, anyone who received mailed notice for the application, or any person with a recognized legal interest under New Mexico law.

The commission proceeded immediately to a separate conditional use permit hearing for Tract 4; that application was considered and decided at the same meeting.