# # National Water Information System # 2024/11/12 # # # Date Retrieved: USGS Water Data for the Nation Help System # hyd_event_cd hyd_event_nm 1s 27s 1 Drought 2 Spill 3 Regulated flow 4 Snowmelt 5 Earthquake 6 Hurricane 7 Flood 8 Volcanic action 9 Routine sample A Spring breakup B Under ice cover C Glacial lake outbreak D Mudflow E Tidal action F Affected by fire H Dambreak J Storm K Backwater L Algal bloom X Not applicable Z Not Determined (historical)