A bumper 36 hour period of rainfall has seen a number of water shortage direction orders lifted in Tasman.

The previous restrictions for Motupiko and Rainy consent holders have been removed with immediate effect.

Stage One restrictions for Dam Unaffiliated A Permits on the Waimea Plains have also been lifted.

Unaffiliated A Permits cover the Delta, Golden Hills, Waimea West, Reservoir, Upper Catchments and Upper Confined Aquifer zones.

However, Stage 2 rationing or a 35 % cut in water use continues for Moutere Coastal and Eastern water management zones from Monday 24 February.

It is important Consent holders are familiar with their Resource Consent conditions as some may be subject to higher restrictions thresholds.

These restrictions do not apply to Tasman urban water supplies or Council-managed reticulated water supplies beyond the conditions of consent.

The region enjoyed two significant periods of rain between the evening of Monday 17 February and the morning of Wednesday 19 February.

The range of precipitation varied between 140 mm at Tākaka Hill, 100 mm at Dovedale, 55mm at Motupiko, with 41 mm falling at Appleby.

All rivers across the district had reasonable flow rises. Tākaka River at Kotinga got to 240,000 litres per second (l/s) and Upper Takaka 130,000 l/s, while Te Waikoropupū Springs rose from 9000 l/s to just over 10,200 l/s.

After a peak of 2600 l/s earlier in the week, the Motupiko River flow reached 1140 l/s - well above the pre-rain level of below 200 l/s.

Due to the rise in river flows and the connected adjacent groundwater increases, we have been able to lift the restrictions in the Motupiko and Rainy zones.

The two periods of rain saw the Waimea Dam receive a double spike in water spill, reaching 22000 l/s before and after dropping to 4000 l/s on Tuesday.

The Wairoa at Irvines flow was 140,000 l/s on Wednesday morning and the unmodified flow 11,610 l/s.

Because of the large spike in river flows at Irvines over the 36 hour rainfall period, the unmodified flow reached the lift trigger of 6000 l/s - based on the running seven-day flow average - by Tuesday afternoon.

The Waimea Flow at Appleby reached 180,000 l/s and the Lower Wai-Iti river flow peaked at 18000 l/s.

The Wai-iti Dam is currently at 68.8 % full, and soil moisture in Waimea and Tākaka has increased.

Generally, all unconfined aquifers from Golden Bay to the Waimea are rising at a variable rate.

Moutere Western has risen from 2.8 m to 3.6 m above mean sea level (amsl), while the Moutere Eastern Groundwater has only shown a small rise re from 32.6 to 32.7 m amsl . This is still below the stage 2 DWTF trigger of 33 m.

The slow recharge of the deep aquifers has driven the need to keep restrictions on in these management zones.

The recent rain would have alleviated need for irrigation water for the time being, while water needs especially in the horticulture areas of Tasman will be slowly decreasing as early horticultural crops begin to be harvested.

The long-term weather forecast indicates generally fine weather with only some minor rain for the next two weeks.

Staff will continue to monitor river flows, groundwater and soil moisture levels in the coming days to ascertain the need for further measures.

Decisions will be reviewed at the next meeting of the Dry Weather Taskforce, provisionally scheduled for Tuesday 25 February 2025.

You can keep up to date with groundwater and river flow data by visiting our environmental data portal www.tasman.govt.nz/my-region/environment/environmental-data-portal.

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