Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Stormwater Resilience topic
No spam. Unsubscribe anytime.
Residents, Flood Defenders tell commissioners county code and DOT need newer rainfall data for drainage design
Summary
Flood Defenders and residents said engineers are designing ponds and drainage systems with archival 1979 rainfall data, asking the county to require modern precipitation and sea‑level projections per state law and NOAA guidance.
A member of Flood Defenders and several residents urged the Board of County Commissioners to ensure the county and local engineers use up‑to‑date rainfall and sea‑level rise data in drainage and subdivision design, citing a change in Florida law and Federal guidance as a reason to reject designs that rely on archived 1979 precipitation tables.
Chris Kerr of Flood Defenders told the board county and subdivision drainage ponds designed with older rainfall frequency tables are failing and washing sediment onto properties and into creeks. Kerr cited recent legislative changes and said the Department of Transportation has archived its 1979 rainfall dataset and directed agencies to use NOAA’s more recent precipitation frequency and sea‑level projections for resilience planning.
Why it matters: Drainage design standards — including the precipitation frequency data used to size stormwater ponds and outfalls — underpin whether subdivisions and solar or other large‑scale land clearance projects flood neighboring properties or downstream creeks. If designs use older, lower rainfall intensities, ponds and culverts can be undersized, increasing the risk of failures and downstream damage.
Speakers’ examples: Kerr said multiple local projects, including a solar farm and subdivisions in District 3, used archived rainfall data that was “marked do not use” by FDOT. He described a specific case where pond embankments “blew out” after clearing and heavy rainfall, leaving silt on private property and in Wilkerson Creek. Kerr asked the county to enforce current data and to re‑examine prior designs that may now be undersized.
County role: Commissioners and county development staff were asked to confirm which rainfall tables the county requires for drainage design and whether code language and engineer submittal requirements have been updated to reflect newer NOAA precipitation frequency and sea‑level guidance. Speakers said a 2022 statutory change required DOT to form resilience action plans and adopt updated data; Kerr said DOT archived its 1979 data in 2024 and contractors should not be allowed to design to the older tables.
Ending: County staff did not announce an immediate code change during the meeting. Flood Defenders and residents requested follow‑up from Development Services and the engineering review team to verify which datasets are accepted, and to flag previously permitted projects that may need reassessment.
