Intense rainfall in the early hours of August 10th caused a moderately sized flash flood, peaking at nearly 1.5 m stage. During one 10-minute interval, the stage rose by nearly 0.5 m! Rainfall intensities measured at Miomote Amedas gauge were up to 29 mm/h, with a daily total of 104 mm.
Today we measured discharge and we observed that there had been much new scouring of the streambed towards the left bank (looking upstream), and in the pool beneath the road bridge. However, the new measurement plots within 4% of the rating curve value, so no change in the H-Q curve detected.
I was glad to see that a developing potential log-jam at the lower end of the riffle below the gauging section had been shifted by the flash flood. The fallen cedar tree was rotated into a new position parallel with the bank, where it is less likely to cause a blockage.
|Stage = 0.468 m, Q = 1.17 m3/s|
|Developing log-jam cleared from the main channel|