56,571
buildings with flood exposure (6.8%)
Total buildings832,102
Mean depth (flooded)3.52 ft
Max depth13.0 ft
Mean damage index0.117
MAPE vs USGS HWMs121.8%
NWM sourceRetro v3.0
Color mode
Legend
Per-building model error
Buildings colored by estimated depth error (model − observed), IDW-interpolated from 344 USGS HWMs within 15km. Circles = actual HWM locations.
■ Red: model under-predicts
■ Green: near-accurate (±2 ft)
■ Blue: model over-predicts
■ Grey: no nearby HWM (>15km)
Red ring: dry miss (model=0)
Buildings colored by estimated depth error (model − observed), IDW-interpolated from 344 USGS HWMs within 15km. Circles = actual HWM locations.
■ Red: model under-predicts
■ Green: near-accurate (±2 ft)
■ Blue: model over-predicts
■ Grey: no nearby HWM (>15km)
Red ring: dry miss (model=0)
Phase 1 calibration status
Rating curves: Manning's equation with stream-order d_bf caps and W_fp floors (Missouri: 10km). USGS gauge corrections applied (IDW, 85 gauges). Missouri q_scale overridden to 1.0 (NWM accuracy 99%). Structural MAPE floor ~120% — per-reach OWP FIM SRCs needed for production accuracy.
Rating curves: Manning's equation with stream-order d_bf caps and W_fp floors (Missouri: 10km). USGS gauge corrections applied (IDW, 85 gauges). Missouri q_scale overridden to 1.0 (NWM accuracy 99%). Structural MAPE floor ~120% — per-reach OWP FIM SRCs needed for production accuracy.