Citing new federal insurance requirements, Clatsop County will soon make alterations to land use rules that will affect several hundred property owners in flood-prone areas.

County commissioners voted unanimously Wednesday to update flood-hazard maps and revise land use rules, including requirements for property owners to pay for a permit when developing their land or seek approval before altering structures. In order for roughly 700 property owners in unincorporated, flood-prone areas of the county to be eligible for the National Flood Insurance Program, the Federal Emergency Management Agency has mandated the changes.

At a crowded county Planning Commission meeting in March, several people spoke in opposition to the changes. County staff has also fielded hundreds of written comments.

Still, planning commissioners voted 4-1 to recommend the changes, citing the need for the flood insurance program. County residents have been a part of the program since the 1970s.

The county has asked for some regulations to be loosened, but the federal agency did not budge, Community Development Director Gail Henrikson said. However, the county has discussed combining and lowering the prices of some fees.

The revisions will become effective June 20.

In other business Wednesday, commissioners:

• Agreed unanimously to set a maximum price of $1.1 million to start construction of a household hazardous-waste facility next to the Astoria Transfer Station on Williamsport Road.

Construction is scheduled to begin in August and finish by January. When completed, the facility will allow residents and qualifying small businesses to drop off hazardous waste, such as pesticides and paint, once a month. After temporary storage, the waste will be transferred to a disposal facility outside of the county.

Commissioners approved a design-build contract with Helligso Construction in 2017. At the time, the proposed 2,500-square-foot facility had an estimated cost of $600,000.

Initial design estimates, however, were higher than previously budgeted, county Public Health Director Michael McNickle said. Since commissioners approved the project, the state Department of Environmental Quality informed the county of additional underground work that needed to be performed at the former landfill site. The need for structural plies and methane mitigation drove up the project’s price.

Money from the project will come from the county’s special project fund, fee collections at the waste site and loans and grants from the state.

• Held a work session about how to publicize the upcoming $23.8 million bond measure to relocate the county jail to Warrenton. A representative from DLR Group — the architecture firm that designed the proposed jail — advised commissioners, among other things, to focus most of the campaign between September and the election in November.