New Water Year

The new water year starts on October 1st. Generally soil water and ground water levels are low at the end of the summer season, and it is convenient to start the new water year when storage in the basin is low and similar from year to year. During October the autumn rains arrive, and as temperatures drop, the levels of ET decrease and streamflow levels rise. Look at the hydrograph above and see how the low flows between the rainy peaks are increasing through October.

Taking a discharge measurement in light rain

Landslip zone upstream from the gauging point which supplies fine sediment

Fine autumn weather

The past two weeks have been almost continuous sunshine, with very little precipitation. You can see from the hydrograph above that discharge has been steadily decreasing, although 18mm of rain fell on the 3rd October giving a small blip. Flows now are close to the yearly minimum flows. But the autumn rains are on the way soon, and as the temperatures cool then evapotranspiration decreases. This leads to more water in the river as runoff as we go through autumn.

Stage = 36cm, Ta = 15.6C, Tw = 14.5C