Rapid City Public Works Committee reviews flood analysis
RAPID CITY, S.D. — Rapid City’s Public Works Committee has received and been briefed on FEMA’s analysis of a special flood hazard area.
The study focuses on the area along Lime Creek, which starts near St. Martin’s Village and ending near Storybook island. In March of 2019, the city entered an agreement with Longbranch Civil Engineering to analyze the area located within the South Canyon Lime Creek drainage basin.
The last FEMA study was completed in the 1980’s with minimal updates. With updated topography utilizing LiDAR, Longbranch Civil Engineering was able to update the flood area.
In total, 355 properties are effected by the analysis with a 50% reduction in the amount of structures in the floodplain.
“As part of this study, we looked at how much water is actually flowing through the creek and then seeing where all that water goes,” said Staff Engineer at Longbranch Civil Engineering, Paul Kraft. “By knowing how much water there is and the new topographic information, we can get a better sense of where that water is going and by that we’re actually being able to take a lot of properties out of the floodplain.”
Structures removed from the floodplain may no longer be required to have flood insurance.
Those effected by the new mapping, which goes into effect April 4, will receive notification within the next couple of weeks.