Commission approves rezone and preliminary plat for 7‑lot Costello subdivision, tables final development agreement to Aug. 5

The Ada County Planning and Zoning Commission and board advanced a rezone and preliminary plat for the Costello subdivision on Wednesday, agreeing to rezone roughly 35 acres near Kuna from rural residential (10‑acre minimum) to rural urban transition (5‑acre minimum) and to preliminarily plat seven lots.

Planner Amelia presented the staff report, noting the site at 12200 South Hawk Haven Avenue lies inside Kuna's area of city impact and abuts the Spring Rock planned community. The proposal rezones the property from RR to RUT and creates seven lots of at least five acres, with a private road providing lot frontage. Amelia said a small strip previously included in Lot 1 was removed and will instead be treated as an easement outside the subdivision; the change reduces Lot 1 and Lot 2 slightly but both remain over five acres.

Agency comments addressed wells, irrigation and future connections. ACHD asked that proposed future road rights‑of‑way be designated as no‑build areas because the private road does not connect to an existing public road. Central District Health requires land‑development submittals and septic review. The county engineer asked for a well adequacy evaluation; the applicant supplied a detailed well supply study that the engineer approved, Amelia said.

Neighbors raised concerns about irrigation and the potential for added domestic wells to affect existing wells and the irrigation cooperative; the applicant was told he could remain in the cooperative or submit a plan to show irrigation will not disrupt Kuna East Water Corporation's system. Commissioners asked about a recent state law on domestic wells (identified in the hearing as Senate Bill 1083); staff said the application was submitted in 2024 and predates the July 1 effective date, so county review followed previous standards but noted parties should address new law requirements going forward.

Counsel and the applicant, represented by Todd Lakey, argued the project conforms with Kuna's comprehensive plan and Ada County code and would produce high‑quality custom homes; Kuna replied with no objection. After discussion, the board voted to approve the rezone and plat and to table final adoption until an August 5 open business meeting so staff can revise the development agreement to reflect the changed Lot 1 boundaries and updated legal descriptions.

The board's motion approved the rezone and preliminary plat but directed staff to prepare a revised development agreement for the August 5 meeting, where final signatures and recording steps will be considered.