Williamson County Flood Dashboard

Research prototype · not official warning guidance
Maximum predicted flooding in the 18-hour National Water Model short-range forecast, matched to precomputed inundation, road, and bridge thresholds.

Flood limits

Bridge warnings

Max water surface vs. bridge low chord

Flooded roads

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Model

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Forecast end–
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MRMS radar rainfall averaged over each county HEC-HMS subbasin. Updates every 2 minutes.

Show

County

–mean (selected window)
–max subbasin
–subbasins ≥ 2-yr storm
–subbasins ≥ 100-yr storm

Data

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Age–
AEP compares the subbasin's rainfall for 15 min to 24 hr against the depth-duration table of the county HMS 24-hr Atlas 14 design storms; the rarest window controls. The indicative local peak is the subbasin's own outlet peak from the county HMS results at that AEP (local runoff only, no routing or upstream inflow, average antecedent conditions).
Flow layers: UT Austin CWE WilcoFlood (NWM + HAND). Rainfall: NOAA MRMS. Subbasins and design storms: Williamson County HEC-HMS models (advisory, not final). Waterway Engineering, PLLC.