Large section of land along Boise River will soon be vacant. The plan for what could be built is forming

Large section of land along Boise River will soon be vacant. The plan for what could be built is forming

A Treasure Valley city could soon have a plan guiding future development of a large vacated property and the surrounding area.

The Garden City City Council heard public testimony Monday on a draft of the Heron Commons Specific Area Plan and accompanying ordinances. The plan is designed to guide mixed-use development on about 34 acres of land adjacent to the Boise River Greenbelt. The council intentionally left the public hearing open and is waiting to make a final decision on adopting the plan so that staff can incorporate requested changes from the council, and the public can comment on them ahead of the council’s October 26 meeting.

The city began exploring the creation of the plan in the spring due to the Ada County Highway District’s move to sell its property, a vacated maintenance yard fronting the Boise River Greenbelt, as BoiseDev reported. Of the 34 acres, about 15 are currently owned by the highway district, according to county property records.

Monday’s hearing covered topics like the development process for parcels in the area, settling on allowed building heights and setbacks, the configurations and access for an Adams St. connection, and traffic capacity in the area.

Rezone and regulatory master plan

Initially, the city floated three potential approaches to the plan and how the land could develop. One would have divided the land into three subdistricts with different percentages of land uses allowed in each, while the second would have called for a regulatory master plan process, and a third would be a hybrid of the two, as BoiseDev reported. Following public input this summer, the ordinances recommended for approval by the city’s planning and zoning commission follow the hybrid option, with the council being asked to approve a rezoning of the land and to approve a regulatory master planning process for parcels greater than one acre that seek redevelopment.

The staff report describes this approach as ensuring that the district develops into a mixed-use area while allowing some flexibility on how different parcels develop.

“Prescriptive standards provide a clear and predictable path to compliance, while the regulatory master plan process allows flexibility to accommodate changing market conditions, innovative approaches, and site-specific opportunities and constraints,” the report said. “This framework recognizes that the district’s vision will be implemented over time and that multiple approaches may achieve the desired outcomes.”

Garden City Development Services Director Jenah Thornborrow said there are twelve properties in the proposed district area that would be subject to a regulatory master plan, while five would not be.

Thorborrow presented the regulatory master plan process as consisting of a neighborhood meeting, with a public hearing triggered if there were more than ten public comments from different households, if staff notes a significant impact from the proposed development, or if the council does.

Council Member Wendy Carver-Herbert said she would prefer to see the council as the final decision-maker on regulatory master plans instead of it depending on the number of comments, or staff or council members voicing concerns.

“This comes back to clarity, transparency, understanding the process an applicant has to go through,” Carver-Herbert said. “I believe it’s easier for them to just know that at the beginning … I think it’s fair for the neighborhoods around them to have a better understanding of where the process is going, rather than wondering, ‘Have you gotten 10 people responding? Or does the council want to hear this?’”

Height maximums, density minimums, open space

When the planning and zoning commission recommended approval of the specific area plan, it suggested creating a buffer between the city’s existing Waterfront District and the Heron Commons area via building heights: allowing 15-ft. setbacks with a maximum building height of 45 ft., or a 30-ft. setback with a maximum building height of 72 ft.

At Monday’s council meeting, the public and council members indicated that they would prefer to see a maximum building height of 45 ft.

According to the staff report, while the plan would not create specific density requirements, it would require that sites greater than an acre in size provide evidence of how a proposed development would contribute to creating a “mid-urban, mixed-use neighborhood.” Meanwhile, sites less than one acre have to be a mix of residential and non-residential uses, entirely non-residential development, or provide a minimum of 15 homes per acre, the report said.

Carver-Herbert expressed concern that having a minimum of 15 homes per acre could create challenges depending on the size of the lot. Thornborrow said the council could adjust that language.

The plan also requires that 25% of the gross total of the property be publicly accessible open space. Thornborrow said that is a step above the city’s current code, which doesn’t require open space for developments to be publicly accessible.

Adams St. connection, access to cars

As BoiseDev reported, part of the vision for the 34 acres is creating a connection between where Adams St. dead-ends into 37th to alleviate congestion on the Boise River Greenbelt.

Thornborrow told the council that there are multiple options for creating such a connection in addition to east-west. A diagram presented by Thornborrow showed one option that extended 37th St. north so that it intersected with Willow Bar Way, one that connects 37th St. to 36th St., and one that connects 37th St. to E. Thurman Mill St.

She said that ACHD is working on its master street map and is interested in making Adams a collector street that cars could use. Garden City Mayor Bill Jacobs said, however, that the city has heard from residents that they would prefer to see an Adams connection be limited to bikes, pedestrians, and emergency vehicles.

Jacobs said that if the council ultimately approves the SAP, he intends to reach out to ACHD to request that use of the roadway be limited, “but ultimately, it’s their jurisdiction.”

Calls for a traffic study

Thornborrow said the city had also heard extensive testimony calling for a traffic impact study to better understand how Heron Commons would impact traffic. She said residents are feeling the effects of more traffic on Adams St. with the opening of the Boardwalk, Proletariat, and The Ranch Club.

Thornborrow said staff are not recommending a traffic impact study, as it is most typical for the council to consider such studies when a specific development is proposed.

She said looking at capacity can provide clues as to how roads adjacent to the site are currently faring. Prior to ACHD vacating its Garden City property, the district conducted a 2026 study that found Adams St. at 85% capacity for vehicle trips and 35% capacity for 37th St., Thornborrow said. Other nearby streets were in the low 30% range, she said.

If a development application’s traffic study indicated that it would push streets over capacity, mitigation measures could be required, like adding turn lanes and intersection improvements, Thornborrow said.