Christchurch's Banks Peninsula water supplies 'dropping'

Akaroa's cumulative rainfall this year is the lowest it has been in a decade. Photo / Supplied

Stream-fed water supplies on Banks Peninsula are dropping, and the Christchurch City Council is pleading for residents to start saving water.

Data from the council show Akaroa's cumulative rainfall this year is the lowest it has been in a decade – it's total rainfall this year is 447mm, less than half the 10-year average of 957mm.

Duvauchelle's water supply was also under extra pressure, with the streams that supply it running particularly low for November.

"Most water supplies in Banks Peninsula are fed by small streams, which are usually at their lowest when summer water demand is at its highest," said Helen Beaumont, the council's head of three waters and waste.

"Right now, streams are exceptionally low and expected to keep dropping, so we need residents to get on board early and start saving water now please.

The council had not imposed water restrictions, but were watching weather forecasts, stream flows, and daily water use "very closely".

"Even if we get scattered rain over coming days, it won't do much to change the overall situation with the streams."

The council also needed to ensure it was not taking too much water from the streams, as doing so would have an impact on the plant, fish and insects that live in the waterways, as well as the long-term quality of the water.