Water users in Marlborough checked to help conserve resource
Rural water consent holders will be checked to see if they are taking more water than they are allocated as Marlborough continues to be parched dry by a lack of rain.
Latest Marlborough District Council weather and water updates show water reserves in the region are holding despite little rain falling over the past seven days.
The rainfall on the weekend has postponed the likelihood of water being used for irrigation from the Southern Valleys Irrigation Scheme being shut off.
Water users were notified last week that river flows in the Wairau River could drop to 8 cubic metres per second in two weeks time prompting an early shut off from the Southern Valleys scheme.
However, rainfall in the Wairau River headwaters last weekend increased flow to about 40 cumecs and postponed any shut off for another 10 to 14 days.
But with little rain forecast in the coming weeks, council staff planned to make regular checks on rural water consent holders using more water than they were entitled to.
Council staff were praising Renwick residents who had averted restrictions by conserving water over the past week to 2500 cubic metres per day, or 2.5 million litres a day.
Residents were reminded not to water gardens during the hottest part of the day, or have sprinklers overflowing onto footpaths and driveways.
Water supply in Blenheim, Picton, Havelock and Wairau Valley had not yet reached critical levels and would hold steady if water was used conservatively, council staff said.
More seriously the low rainfall had affected the recharge rate for the Wairau River, and caused groundwater levels to recede rapidly.
The Wairau Aquifer level was down to the level of 12 months ago after previously running above 2014 levels for much of the year.
The aquifer normally reached current low levels later in the summer, around February or March .
Council hydrology staff were measuring natural water loss through the river gravels to assess the aquifers recharge rate, and comparing the position of the headwaters of groundwater-fed springs for the aquifer with 2001 measurements.
Elsewhere the Riverlands Aquifer level was causing concern, while Southern Valleys and Rarangi Shallow Aquifer levels were both higher than last year.
The Marlborough region received between four millilitres and 15mm of rainfall during the past week enough to bring a small lift to most rivers and offset any immediate water restrictions.
Most of the rainfall occurred in the Upper Wairau River catchment with little rainfall on intensive agricultural land use areas in the Wairau Plains.
Most rain during the past week fell in Havelock (11mm) and Rai Valley (10mm) with Craiglochart (4mm) and Awapiri, in the Awatere Valley, (4mm) receiving the least.
Blenheim received 7mm of rainfall over the past week.
- The Marlborough Express