Coconino News

The Federal Emergency Management Agency (FEMA) has announced plans to provide financial assistance under the Hazard Mitigation Grant Program to the City of Flagstaff in Coconino County, Arizona. The initiative aims to mitigate flood impacts by enhancing stormwater infrastructure.

The project involves constructing an additional basin outlet structure at the southwest corner of the Killip Regional Detention Basins. A 42-inch pipe will direct 80-160 cubic feet per second (cfs) of storm peak flow away from the Spruce Wash storm drain towards the West Wash storm drain. This action is expected to reduce flooding in neighborhoods east, southeast, and south of the detention basins.

According to FEMA's Flood Insurance Rate Map Panel 04005C6828G, effective since September 2010, the project site is located within Zone X, indicating a low probability of flooding each year. However, local floodplain characteristics have likely changed due to recent events like the 2019 Museum Fire and subsequent installations at Killip Regional Detention Basins in 2022.

FEMA considered two alternatives: taking no action or using dual-walled high-density polyethylene plastic pipes instead of spiral ribbed pipes. The No Action Alternative was dismissed due to potential continued localized flooding without mitigation efforts. Alternative 1 was not recommended because it would increase excavation costs and complexity.

FEMA concluded that the Proposed Action is the only viable option and stated that it conforms with local floodplain standards. The City of Flagstaff will manage construction and maintenance work following a Stormwater Pollution Prevention Plan and best management practices.

Interested parties can inspect a map showing the project's location within the floodplain by contacting FEMA Region 9 Environmental Officer for more information.

Requests for further details should be submitted in writing within 15 days after this notice's publication date to ensure consideration before any actions are taken.