Rain in Wellington is doing more harm than good, leaving the rivers too dirty to drink.
The Greater Wellington Regional Council has stopped taking water from the Wainuiomata catchment this morning because run-off caused by the rain has left river water too muddy to treat.
Council water supply manager Chris Laidlow said the quality of water coming from the Hutt catchment is also deteriorating rapidly and the plant that treats the water at Te Marua, north the Upper Hutt, will likely be switched to drawing from the emergency supply lakes this afternoon.
"Because the catchments are so dry the rain runs across the ground and takes the dust with it. It means we will be taking no water from the rivers."
Together the two catchments supply 60 per cent of Wellington, Porirua and the Hutt Valley's water. Without them, the region will be reliant on an emergency supply expect to last 10 days and underground aquifers, which are already at risk of dropping to dangerously low levels.
It comes as the region continues to face a record dry spell and a dwindling water supply that has not been significantly replenished since early February. Today's fall unlikely to make much difference, Laidlow said.
"The rain is useful for people's gardens but I don't see it being very useful for us."
While the rivers have risen with the rain they are expected to subside to low levels in a few days. The council should be able to resume drawing water from the rivers by Wednesday, once the dirty water has washed through.
- The Dominion Post