Rivers predicted to dry out

CONCERNING: More Christchurch waterways like the Wai-iti stream, Fendalton, are predicted to dry up. PHOTO: GEOFF SLOAN

Environment Canterbury has predicted that more springs and spring-fed stream will dry up in coming months, particularly in the Selwyn and Christchurch areas.

In its latest report on Canterbury’s water resources, ECan said substantial rainfall on the Canterbury Plains during December had been excellent for replenishing soil moisture but had not affected the groundwater levels and spring-fed streams in any significant way.

Across Canterbury in December, 52 per cent of monitored wells had ‘low’ groundwater levels and 9 per cent had ‘very low’ levels.

ECan chief scientist Tim Davie said the fundamental reason that groundwater was at record low levels was a lack of rain during the past three winters.

“It is only during the winter when soils are wet enough, and evaporation low enough that rainfall filters all the way through the soil to groundwater,” Dr Davie said.

“The past two winters have seen virtually no recharge, this is unusual.”

The under stress Selwyn River has recorded its sixth consecutive month of record low flows at Coes Ford.

The Selwyn River recorded a monthly December mean of 0.131 m3s, following on from record lows in July, August, September, October and November.

All other monitored Canterbury rivers north of the Rakaia also recorded flows well below average for December, with the exception of Lyell Creek and Middle Creek in the Kaikoura area.

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