Rockwall County, TX: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Rockwall County scores at the 61.3th percentile for flood hazard, rated "Relatively Low" — below the national norm for flood hazard. The hazard here is driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 1 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
Homes with a federally backed mortgage inside Rockwall County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 17.9% of them do — 59 active policies against 329 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.5% of all residential structures in Rockwall County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Rockwall County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Rockwall County ranks 1271 — 1 being the highest hazard nationally — and 486 by population among all 3144 counties covered here, where 1 is the largest. Rockwall County, Texas is home to about 137,044 people across 127.229 square miles of land.
Checking a specific address in Rockwall County
158 of Rockwall County's 33,711 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Rockwall County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.