Wellington water supply situation update – 19 March 2013

Today's data:
Daily target water use (maximum) = 130 million litres (ML)
Yesterday's water use = 113ML
Change from Sunday = lower by 12ML
Change from last Tuesday 42 ML (or about 30% drop)

Wellington's households and businesses are doing a great job with water saving so far – we need to maintain this low level of water use despite the rain.

Yesterday’s supply was the second lowest supply total since we started recording daily supply in 1997. (The lowest day on record was 112ML on 30 December 2012, a wet Sunday in the Christmas holiday period)

Lower demand helps to preserve our water reserves longer. This is necessary in case we quickly return to pre-rain levels of river water availability.

Yesterday’s water supply came from:
Rivers: 13ML
Hutt aquifer: 64ML
Storage: 36ML (Lake 2 - 30ML, Balancing reservoirs - 6ML)

All supply from rivers is off at present, due to the rivers being very dirty, so we're supplying from the Hutt aquifer and lake storage. If the rain eases as forecast we would expect to be supplying from rivers again tomorrow.

The low demand meant that we could ease back on use of the Hutt aquifer and take less from Lake 2 than would have been the case otherwise.

We'll have a better idea of how useful this rain has been for water supply later this week, when we can assess how quickly water quality and flow rates are returning to pre-rain levels. Current indications are that water available from rivers should stay above pre-rain levels for at least 5 to 7 days.

If we get another rain event like this one over the next couple of weeks we will be discussing the easing of restrictions with the city councils.

There's another 10 days of fine and dry weather forecast after tomorrow.

Today’s supply graph is available below.

Click for big version.

ENDS

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