PDM - Houck C301 Road Restoration and Flood Control Project Public Notice

FINAL PUBLIC NOTICE: Houck C301 Road Restoration and Flood Control Project, Apache County District 2, Arizona │ PDMC-PJ-09-AZ-2019-004

The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) proposes to provide federal financial assistance under the Pre-Disaster Mitigation Grant Program to Apache County District 2, Arizona to construct a “low water” crossing (including headwalls, apron, and cutoff walls with other erosion protection) on Houck C-301 Road at Burntwater Wash. Pursuant to Executive Order 11988 (Floodplain Management) and FEMA’s implementing regulations at Title 44 of the Code of Federal Regulations Part 9, FEMA hereby provides interested parties with a notice of its final decision and an explanation of the alternatives that were considered.

The purpose of the proposed action is to mitigate a flood hazard at Houck C-301 Road and Burntwater Wash. The road crosses the wash at-grade and experiences frequent washouts making the road impassable to those that rely on the road for daily use. The proposed action involves constructing a “low water” crossing, consisting of six 48-inch barrels of corrugated metal pipe culvert. The proposed action would also raise the roadway elevation at the approaches to the crossing and perform upstream grading and clearing of the existing watercourse. The culverts would be designed for a 50-year event. Channel grading may be required to improve hydraulic efficiency of the outlet. The upstream area would be regraded to accommodate riprap for erosion protection, as well as concrete aprons and cutoff walls. 

The proposed action is in an area with undetermined flood hazards as depicted on the Flood Insurance Rate Map (FIRM) Number 04001C2950E, effective September 28, 2007. This FIRM shows the proposed action lies within Zone D, an area that potentially has moderate to high risk of flooding, but where the probability has not been determined. The project area consists of a seasonal ephemeral channel that is subject to flooding and surrounded by desert shrub vegetation. Based on site photos, fluvial terraces appear to be present indicating the project is in a floodplain.

Three alternatives to the proposed action were considered: Alternative 1, No Action; Alternative 2, Steel Bridge; and Alternative 3, Detention Basin. Alternative 1 would not construct flood mitigation on Houck C-301 Road at Burntwater Wash. This Alternative is not recommended because residents would continue to experience flood-related road closures along Houck C-301 Road and the associated inaccessibility to critical services. Alternative 2 would replace the existing culvert and approach with a steel bridge. This Alternative is not recommended due to the significant cost. Alternative 3 would construct an upstream detention basin to attenuate peak flow. This Alternative is not recommended due to technical complexity, including the requirement for special permitting from the Navajo Nation. FEMA has determined that the proposed project is the only practicable alternative available, and because it is functionally dependent on its location in the floodplain, the proposed action must be located in the floodplain. The proposed action would have no significant adverse impact on the floodplain and would eliminate future road washouts and the associated health and safety risks to residents. Therefore, measures to minimize impacts on the floodplain are not necessary. Apache County District 2 has declared that the proposed action conforms to local floodplain standards, and is responsible for the management, construction, and maintenance of the proposed action.

Additional information about FEMA’s proposed action, including a map of the project area and its location within the floodplain, is available for public inspection and may be requested by writing the FEMA Region IX Environmental Officer at FEMA, 1111 Broadway, Suite 1200, Oakland, California 94607, or fema-rix-ehp-documents@fema.dhs.gov, or calling (510) 627-7027. All requests should be received no later than 15 days after publication of this notice. No action will be taken before this date.