Flood peak heights in the Belubula River at Canowindra have been recorded since 1916 and were suspended during WW11. Regular recording then recommenced 2nd April 1950.
In the period of 1918 – 2001, flood heights peaked at 6.45m (17.06.52), 6.23m (03.08.90), 5.87m (02.04.50), and 5.80m (08.08.98). The first flood study that covered 10 flood years, which were between 1916 – 1998, was by Snowy Hydro Corporation, and this was really only valid to 1995, when the new John Grant Bridge replaced the old single lane bridge over the Belubula River.
The river’s channel and flow were completely altered as a result. 1990 was the last major flood year experienced with 12 peaks recorded ranging from 2.72m to 6.23m, the second highest ever recorded.
Of greater significance, and a major cause of local flooding in Canowindra, was when the railway was completed 1910. The Coocumber Creek trestle railway bridge caused a continuous major problem when debris dammed the creek’s flow. The last major flood to 2001 occurred in August 1998.
The 17m gap made in June 2001, now seen in the bridge, has reduced the effect of flooding in Canowindra and further bridge damage. This is seen in the five flood peaks recorded this year as 5.40m, 5.20m, 5.20m, 5.39m and 5.40m. These peak levels cannot be compared with flood peaks up to 2001.
There is an irony with the recurrence of El Nino events of which there have been six (dry times) since 1897, the last ending in November 2009 in which the Belubula River had stopped flowing, for the first time in a living memory of 64 years.
By Bill Barwood