WAIMAK. ROSE 23 FEET DURING LAST HEAVY FLOOD.

Star (Christchurch), Issue 18011, 23 November 1926, Page 14

WAIMAK. ROSE 23 FEET DURING LAST HEAVY FLOOD.

REPORT FROM OTARAMA OBSERVING STATION. A report on the recent heavy flood in the Waimakariri, based on information obtained from the curve-drawing instrument at Otarama and on the observations of officers of the Municipal Electricity Department, was presented to the City Council at its meeting last night. It was stated that one of the factors contributing to the exceptional flood on Friday, November 5. was that heavy rainfall was added when the river was still carrying part of .the previous Sunday’s flood. The report was a? * follows : “-The chart taken from the recording gauge on November 5 shows that about mid-day oil Sunday, October 31, the river began to rise rapidly. By 9 p.m. on Sunday the river had risen to a level of 1042.4. The flood receded as rapidly as it had risen, and by midnight on Monday had fallen to 1033.5, and continued to fall more slowly until about S a.pi. on The piorning of Thursday, November 4. From that hour until 9 p.m. on the same day the river rose rapidly until it reached a level of 1051.5, making a total rise of 23ft above normal low-water level of the river. “The gauging station was visited on Friday, November 5, about noon. It was then found that the chart had stopped, and there had been about six inches of water in the gauge house. This confirmed a total rise in the river of 23ft, which at this point is approximatelv 340 feet wide. With the velocity that is to be expected, from previous velocities and levels, this indicates a flood in the neighbourhood of 120,000 cusecs. “As in previous floods, the outstanding feature was the rapid rise and fall, the upper fourteen feet in this case having risen and fallen again in the space of only twenty-two hours. Owing to the instrument having been stopped by the flood, it was not possible to determine the exact way in which the flood receded. Though an exceptional flood, it is interesting to note that its volume is still well within the capacity of the flood gates provided in Messrs Hawley’s design.