Marion County staff outlines multi‑million road-rebuild estimates and grant strategy; corrects mileage math on one estimate

County road staff presented rough design and cost estimates for three major road projects and discussed grant strategies with Marion County commissioners on Feb. 10, outlining construction approaches, drainage challenges and program timing for KDOT cost-share and other grants.

Staff described three candidate projects: a near‑mile segment of Nighthawk Road, a roughly 5‑mile segment on “March” (presented as a 5‑mile job), and a 3‑mile stretch of 1 Fortieth. For Nighthawk staff proposed removing up to 15 inches of material, installing a crushed base with geogrid, and a 3‑inch asphalt overlay; the construction subtotal on that section was presented at about $399,000 in the staff estimate.

For the 5‑mile March project staff showed a similar approach — crushed concrete base over geogrid with a 3‑inch asphalt cap — and presented a construction subtotal of roughly $2.5 million (about $500,000 per mile) under a locally managed design and inspection approach. Staff said KDOT design and inspection requirements would materially raise survey, design and construction‑engineering costs if the county submitted the project to certain KDOT programs.

On the 1 Fortieth stretch staff originally listed two estimates: about $2.0 million if a cement‑treated base were rebuilt for the full 3‑mile stretch, and about $1.1 million for an asphalt‑cap‑only approach. Staff later discovered a formula error: the spreadsheet had used four miles instead of three in some lines. After that correction staff said the construction cost for the cement‑base option would be closer to $1.56 million and the asphalt‑only option roughly $800,000.

Staff discussed tradeoffs in base design, moisture and long‑term performance: “If we've got any spot or spots where the sub the moisture stays high after we put that cement treated base in, … treated base is gonna fail,” staff said, and argued the crushed base plus geogrid approach performed better in wet spots. Staff added that a 12‑inch crushed‑concrete base is roughly highway‑grade and can carry very heavy loads, but that the county must weigh whether to design for rare extreme harvest loads (which would raise costs substantially).

On funding and timing, staff explained KDOT cost‑share cycles and limitations: cost‑share applications are typically due in April, awards announced about 60 days later, and awarded cost‑share funds are often not available until the following fiscal year; staff noted economic‑development grants can be submitted year‑round and, if awarded, may be available sooner. Staff also told commissioners the KDOT cost‑share program has a $1,000,000 maximum award for a single project.

Staff addressed recycled material reuse and logistics: material removed in rebuilds can be crushed and stockpiled for county reuse as base or shoulder material; staff said the county has existing crushed‑concrete piles north of Lincolnville and that reuse can lower project cost if sufficient quantity is available.

Why it matters: commissioners must decide project priorities, budgeting and whether to pursue cost‑share or economic development grants; the corrected mileage in the spreadsheet and the detailed tradeoffs on base design materially change expected local funding needs.

Ending: staff committed to return corrected estimates and a revised packet with updated numbers for commissioner review and capital‑improvement planning.