Borough floodplain maps get much-needed update – Mat-Su Valley Frontiersman

“Erosion was a really hot topic. We saw how beneficial (remapping Butte) was to get accurate data. We asked FEMA (the Federal Emergency Management Authority) to help,” Strawn said. He said with the borough’s immense size, officials told the feds if it wanted the Mat-Su to enforce federal flood guidelines, it would have to help secure the needed data. With that began the largest federal mapping project of any local municipality in the country. In addition to terrain, things like the frequency of earthquakes, wildfire and landslide susceptibility figured into the equation.

Key Takeaways:

  • In 1985 the borough joined the National Flood Insurance Program and adopted the only maps the Mat-Su has ever used in establishing federal guidelines on floodplains and floodways.
  • Over the years, serious flaws in the borough’s floodplain maps were found.
  • In 2013, the borough joined forces with the US Army Corps of Engineers to remap the Butte area, one of the Mat-Su’s worst erosion-prone areas.

“Today, extreme map accuracy can be obtained using a combination of boots-on-the-ground surveys and historical flood data, as in the originals.”