Wettest month on record at >700mm

Stage = 0.705m, Q = 4.91m3/s (grey coloured suspended sediment is common after a large flood)

Much of northern Niigata Prefecture has recorded the wettest July and the wettest month ever recorded. So far the Miomote gauge has recorded 710mm and the Takane gauge 743mm this July. The previous wettest month for Miomote was 639mm in July 2013.

The wet weather culminated in a prolonged downpour over a 48-hour period during 26-28 July, when Miomote and Takane recorded 185mm and 206mm respectively. Maximum hourly precipitation was not so extreme, at 18mm/h and 26mm/h respectively. This resulted in a peak stage of 1.816m for Takiya River at 14:20 on July 28.

In measuring the discharge, we found a large accumulation of fine gravel in the channel with active bedload transport for this pea-sized gravel. The flow was especially shallow and with high velocity compared to our previous measurement on July 9 at similar stage.