Staggering totals of rainfall recorded

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

Rainfall over the region in the past few days has reached historic record levels, and a Red heavy rain warning remains in place through Sunday.

Some relief came yesterday afternoon, with an easing of the downpour, and river levels were given a chance to start receding.

The headwaters of the Waipaoa and Waikohu Rivers in the inland hill country were the epicentre of the prolonged drenching.

The Waipaoa River rose to almost 9.5 metres, bursting its banks near Te Karaka, while the Waikohu River reached over 10.8 metres, nearing the 11.68m level of Cyclone Gabrielle.

The Waikohu was at a height similar to peak floods such as Cyclone Bola in 1988, and the major floods of 1960 and 1950, where thousands of acres were flooded and silted.

The Wharekopae, Waingaromia and Waikura rivers also rose to high levels, as did the rivers fed by the ranges inland from the Hikuwai at Tolaga Bay, and the Mata and Waiapu rivers further north.

Since the rain started, some staggering totals have been measured, and MetService warns more is yet to come, which is why the Red alert remains in place to Sunday night.

As an example, in the 24 hours to 2pm yesterday afternoon, Puketawa Station had 93mm, and since the rain started, almost 400mm.

The district council gauge at the Mata River totalled 408mm up to 2pm yesterday, with many other gauges from Tolaga northwards seeing totals of 200 to 300mm or more.

Most of the Gisborne flats, the surrounding hill country and the Wharerata ranges have had similar amounts.

Raukumara Station in the steep ranges near Mount Hikurangi recorded the largest total up to 2pm yesterday, with over 453mm in the gauge at that point.

MetService stresses the district’s residents should note the Red warning for heavy rain in force for Gisborne on Sunday.

The weather agency says on Sunday a low to the northeast of New Zealand directs a moist northeast flow onto the North Island and “there is a high confidence in warning amounts of rain for Gisborne.”