An expected decline of groundwater levels in the Moutere Eastern Zone has prompted a shift to higher restrictions for Tasman water consent holders next week, while a Cease Take for the Moutere Surface Water Zone is also set to commence.
Water Shortage Directions which come into effect on Monday 5 February, 2024 will mean Stage Three rationing – or a 50% cut from authorised weekly usage for the Moutere Eastern Groundwater Zone.
This is in line with Moutere Deep Groundwater levels now at their lowest on record – the Eastern Groundwater Zone is now below the Stage Three trigger of 31 metres.
The adjacent Moutere Western Groundwater Zone is also dropping and if dry weather and high water demand continues, rationing is likely to be introduced in that zone soon.
With flow in the Moutere River dropping below 20l/s, the Council has also issued a cease take to those users taking surface water from the River. This action, encoded in each of the associated water user consents, is to support the health of the River as the flows continue to drop.
Stage One restrictions – or a 20 per cent reduction in authorised weekly water usage – remain in place in the Dovedale and Motupiko management zones, including the Rainy River area.
Rain over the Nelson Anniversary long weekend provided some assistance to areas such as Golden Bay (between 30mm – 81mm) and lesser amounts to the east of Takaka Hill – Motueka to Waimea.
However, the rest of the district averaged 3 – 10 mm, which offered minimal boosts to river flows.
Dry areas continue to be Moutere/Dovedale/Motupiko, with the latter falling below trigger levels after an initial boost last week.
If the Dove River drops much further, we will have to consider the next step for this zone.
Some rain is predicted for Friday/Saturday this week (between 10 – 20 mm) – this may help some areas.
However, the Moutere Deep Groundwater is likely to decline further until demand starts to ease. With the Tākaka River flows declining the Upper Tākaka River takes will continue to be affected by the flow which is governed by what the Cobb Dam releases. This is not an unusual situation at this time of year.
The Wai-Iti River is also getting low but has the benefit of the Kainui Dam being full to augment flow. The initial flow release starts this week so there is good storage available to be used.
Wairoa River is being helped by Waimea Dam spilling which is greater than 1000 l/s with the river flow being 3700 l/s below the Wairoa Gorge at present.
Staff will continue to monitor and update information, with the Dry Weather Task Force team next reviewing the situation on Wednesday 7 February.
In the meantime, it is important that consent holders were familiar with their Resource Consent conditions.
These restrictions do not apply to users of Council-managed reticulated water supplies, which are subject to alternative restrictions.