Flood Zone Comparison
Compare key metrics between 21405 21405, MD — Zone A and 57476 57476, SD — Zone AE. Data sourced from FEMA National Flood Hazard Layer (2025).
| Metric | 21405 21405, MD — Zone A | 57476 57476, SD — Zone AE |
|---|---|---|
| name | 21405 21405, MD — Zone A | 57476 57476, SD — Zone AE |
| zip code | 21405 | 57476 |
| city | 21405 | 57476 |
| state | Maryland | South Dakota |
| state code | MD | SD |
| category | High Risk | High Risk |
| flood zone | Zone A (High Risk — 100-Year Floodplain, No BFE) | Zone AE (High Risk — 100-Year Floodplain) |
| risk level | High Risk | High Risk |
| annual flood prob | 1% annual chance (100-year flood) | 1% annual chance (100-year flood) |
| insurance required | Required for federally-backed mortgages | Required for federally-backed mortgages |
| avg annual premium | 2,898 | 2,898 |
| base flood elevation | 15 ft | 13 ft |
| historical floods | 10 recorded flood events in the past 50 years. Most recent major flood: 2023 | 10 recorded flood events in the past 50 years. Most recent major flood: 2004 |
| nearest water | Puget Sound (1.7 miles) | Tennessee River (3.6 miles) |
| elevation ft | 980 | 1,603 |
| population | 48,433 | 28,030 |
| median home value | 267,069 | 525,221 |
| flood damage risk | 40-60% chance of flood damage over a 30-year mortgage. Estimated average damage per flood event: $111,579 | 40-60% chance of flood damage over a 30-year mortgage. Estimated average damage per flood event: $166,667 |
| mitigation tips | 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. | 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 | 5193C402J | 7913C928J |
| 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.