On August 15-18, 1950, Waimea River on the island of Kauai, T. H., had one of the severest floods in its history as a result of torrential rains, caused by a storm associated with the only typhoon ever recorded in the proximity of the Hawaiian Archipelego. At one rainfall station in the basin, 50 inches of rain was recorded during a 72- hour period. Kawaikoi Stream, in the headwaters of Waimea River basin, reached a maximum discharge of 7, 980 second-feet, or 1,950 second-feet per square mile.
A rubble wall along the right bank of Waimea River just below the mouth of Makaweli River, constructed to contain the flow, was overtopped and the entire town of Waimea was flooded. The water was about a foot over the top of the wall at most places. No lives were lost, but damage to property was about $200, 000.
This report presents detailed records of stages and discharges at four gaging stations in the basin during the flood period August 15-18 in the Waimea River basin, a summary of flood discharges at gaging stations on the principal streams on the island of Kauai, a description of the physical features of the drainage basin, a description of the two types of storms that prevail on the Hawaiian Islands, and a section on the meteorology of the storm of August 15-18. Figure 46 is a map of the island of Kauai, which shows the location of the gaging stations referred to in this report, the location of .rain gages in the area where rainfall was the greatest, and lines of equal rainfall for the period August 14-19, 1950.