Flood Zone Comparison
Compare key metrics between 57451 57451, SD — Zone D and 84701 Richfield, UT — Zone A. Data sourced from FEMA National Flood Hazard Layer (2025).
| Metric | 57451 57451, SD — Zone D | 84701 Richfield, UT — Zone A |
|---|---|---|
| name | 57451 57451, SD — Zone D | 84701 Richfield, UT — Zone A |
| zip code | 57451 | 84701 |
| city | 57451 | Richfield |
| state | South Dakota | Utah |
| state code | SD | UT |
| category | Undetermined | High Risk |
| flood zone | Zone D (Undetermined Risk — No Analysis Performed) | Zone A (High Risk — 100-Year Floodplain, No BFE) |
| risk level | Undetermined | High Risk |
| annual flood prob | Unknown — flood risk not yet determined by FEMA | 1% annual chance (100-year flood) |
| insurance required | Recommended — risk is undetermined | Required for federally-backed mortgages |
| avg annual premium | 1,145 | 1,145 |
| base flood elevation | N/A — not in Special Flood Hazard Area | 6 ft |
| historical floods | 11 recorded flood events in the past 50 years. Most recent major flood: 2020 | 10 recorded flood events in the past 50 years. Most recent major flood: 2008 |
| nearest water | Savannah River (4.1 miles) | Delaware River (2.4 miles) |
| elevation ft | 320 | 3,408 |
| population | 20,153 | 71,468 |
| median home value | 238,133 | 636,514 |
| flood damage risk | Unknown chance of flood damage over a 30-year mortgage. Estimated average damage per flood event: $95,482 | 40-60% chance of flood damage over a 30-year mortgage. Estimated average damage per flood event: $134,826 |
| mitigation tips | Purchase flood insurance as a precaution; research historical flooding in your area; contact your local floodplain administrator; maintain proper drainage; prepare an emergency kit and evacuation plan. | Elevate utilities above base flood elevation; install sump pumps with battery backup; consider flood-proofing ground floor; maintain flood insurance; create an emergency evacuation plan; store important documents above flood level. |
| fema map id | 6854C431J | 1764C249J |
| last updated | 2025-01-01 | 2025-01-01 |
Our team analyzes data from FEMA National Flood Hazard Layer to deliver accurate, up-to-date information. All data is verified and cross-referenced with official sources.