Water Resources of the United States
Date: Wed, 10 Mar 2021 14:43:56 EST
Summary: Moderate-Major flooding ongoing in Hawaii
Heavy rain is continuing over the Hawaiian Island chain. The windward and North Shore areas of Oahu were impacted heavily on 3/9/21. The threat for heavy rain and flooding continues today as a slow-moving low pressure system lingers West of the State. All islands are under a Flash Flood Watch through 6 PM HST today.
Opaeula Stream (16345000) exceeded NWS major flood stage and recorded a provisional peak of record out of 58 years of record. Flooding from this stream and other ungaged streams in the area resulted in evacuations on the North Shore on 3/9/21. The provisional peak at Kahana Stream (16296500) was only 0.04 ft lower than the peak of record out of 60 years of record. Poamoho rain gage (213215157552800) recorded about 19" of rainfall in under 24 hours. Two gages were damaged during the flooding. Stage at two gaged reservoirs (Ka Loko Reservoir on Kauai 16094150 and Wahiawa Reservoir on Oahu 16210000) are currently over the spillway elevations
Two crews are deployed today to collect high-water marks and sediment samples, measurements on receding limbs where possible, and assess gages for damage.