Story County approves Dayton Ridge Plat 2 with financial guarantees and safety review

The Story County Board of Supervisors on Sept. 23 approved Dayton Ridge Plat 2, the final major subdivision plat for a portion of land in Franklin Township, subject to conditions requiring (1) updated Dayton Parkway maintenance agreement and restrictive covenants, (2) an irrevocable form of financial security acceptable to the Story County Attorney’s Office, and (3) a county-engineer review of an existing transformer to identify any safety mitigations for the developer to implement.

The board’s action formalizes approval of SUB25-000003, the Dayton Ridge Plat 2 final plat, after staff reported that the applicant has already completed several road improvements and submitted financial-security documents that need revision. Planning staff said the development agreement requires an irrevocable letter of credit in the amount of $97,000 to secure remaining work and a warranty bond of $90,000 to guarantee workmanship for two years after final acceptance.

Staff said the applicant, represented by Emily Harding of Civil Design Advantage, filed on behalf of property owners including Jeff and Mary Gibbons and the Connie J. Prohaska Underwood Revocable Trust. The plat creates several new lots off an extended Dayton Parkway and includes portions in R-1 (residential) and AR (agricultural-residential) zoning. The county engineer, Darren Moon, reviewed the submitted work and recommended approval contingent on completing the final two lifts of asphalt and shoulder touch-up after the final asphalt lift is placed.

Planning staff explained the applicant followed an allowable two-path process: rather than installing improvements after final-plat approval, the developer completed many roadway improvements in advance. Staff said that approach is unusual but permitted. The development agreement requires the applicant to complete remaining improvements within two years of the board’s final-plat approval; once the improvements are accepted by the county engineer, a two-year warranty period secured by the $90,000 bond begins.

Neighbors raised safety concerns at the meeting about a transformer vault near the new alignment. Liz Peel, a resident at 2017 Dayton Parkway, said the transformer “did not get moved. The road got moved,” and described the transformer as a visibility and safety concern because the paved surface ends at the cul-de-sac and the driveway beyond is gravel. Jeff Gibbons, a property owner and participant in the subdivision, told the board the transformer “has always been there” and said the cul-de-sac was required to provide a turnaround for emergency vehicles; he described the road as a privately maintained dead-end used by residents.

In response to public concerns, the board added a condition that the county engineer review the transformer’s location and recommend hazard mitigations to the developer prior to recording. Staff also noted that erosion-control requirements under section 88.05 apply to development of all lots.

The City of Ames had previously granted a conditional waiver of certain infrastructure standards at the preliminary-plat stage and later adopted a resolution indicating acceptance of the plan pending county action; staff said the county retains final authority over recording. The final plat cannot be recorded until (1) the maintenance agreement and restrictive covenants are revised to reflect the current year and required signatures, and (2) the county-attorney–approved form of financial security is submitted.

The board approved the resolution with the conditions on a voice vote (all supervisors present voting aye).