Some Juneau residents urged to evacuate as Alaska's Mendenhall Glacier releases floodwater
apnews.com
A huge basin of rainwater and snowmelt dammed by Alaska’s Mendenhall Glacier has started to release, sending a potentially record surge of flooding toward parts of Juneau.

Residents in some parts of Juneau prepared to evacuate ahead of what could be a record surge of flooding as rainwater and snowmelt in a huge basin dammed by Alaska’s Mendenhall Glacier started to flow downstream toward the capital city.

Officials in recent days have been warning people in the flood zone to be ready to evacuate. On Tuesday morning they confirmed water had started escaping the ice dam, with flooding expected into late Wednesday. They advised people in the city’s flood zone to leave.

  • tal@lemmy.todayEnglish
    3·
    21 hours ago

    I believe that a number of places have different “levels” of flood zone based on the frequency of the floods one expects in that zone.

    kagis

    It looks like FEMA does that:

    https://efotg.sc.egov.usda.gov/references/public/NM/FEMA_FLD_HAZ_guide.pdf

    FEMA flood zones are geographic areas that the FEMA has defined according to varying levels of flood risk. A flood is any relatively high streamflow overtopping the natural or artificial banks in any reach of a stream. Each zone reflects the severity or type of flooding in the area.

    It looks like they have variants on a 100-year floodplain and a 500-year floodplain here.