Waiting for the rain

Stage = 33.25cm, Discharge = 0.374 m3/s

Depending on the arrival of the rainy season downpours, mid to late June can have the lowest discharge levels of the year for Takiya River. The snowmelt season has ended, and conditions can be extremely dry and hot. Levels of ET (evapotranspiration) rise and this reduces groundwater levels and the amount of flow in the river. The hydrograph below shows some rain fell on 13-14 June (45mm), but it is not enough to prevent the continuing fall of river discharge towards annual minimum levels.

A walk in the river

Discharge measurement in the tributary, Takiya 2 (basin area approx. 1km2)

A walk in the river can teach you many things. Today we walked the several hundred metres from the gauging point on Takiya River to the point where irrigation water is taken, close to the confluence with the Miomote River. Along the way we walked in the flowing water through riffles and pools, observing the changing channel form and channel bed materials, and the ecological environment.

Gauging point on Takiya River

Right bank with staff gauge and pressure transducer inside the steel pipe

Left bank with stable bedrock and moss

Dozens of small frogs were spotted in the river

Huge keyaki tree interrupts the plantation cedars

Channel becomes wide and shallow upstream of the irrigation diversion dam

Irrigation diversion dam made from gabions - wire crates filled with local rock material

Irrigation canal headworks gate

Settling pond for sediment below the headgate

Pure mountain water flows off towards the paddy fields