Whau Valley Dam and other water catchments full after heavy rain

The stormy weather has filled up the Whau Valley Dam and other water catchments throughout Northland heading into the drier months. Photo / Michael Cunningham

Dams and water catchments across Northland are coping well despite the recent heavy deluge, which councils say puts the region in good stead heading into the drier months.

Whau Valley Dam is Whangārei is full and Wilson's Dam is hovering at 84 per cent, which Whangārei District Council water services manager Andrew Venmore was typical at this time of the year.

Despite heavy rain overnight Tuesday, he said the Whau Valley Dam has the capacity to handle large events and was designed for a one-in-10,000-year occurrence.

There was also an emergency spillway for extreme events but it has never been activated in the dam's 50-plus years of operation, he said.

"A good thing about the dam is even when it's full like it is now, it provides attenuation. We have no problem treating water during heavy rainfall with the new plant we've got."

Venmore said that before the stormy weather started on Tuesday, the dam, aquifers and rivers were already flowing well, which bodes well heading into summer.

"Normally at this time of the year, the average dam level is over 90 per cent. Our driest month is November but as long as we get some rain before Christmas, we'll be okay," he said.

There are no issues with water supplies in Kaipara where river flows are slightly up on last year.

The water treatment plant run by the Kaipara District Council has been working well, a spokesman said.

In the Far North district, there have been no reports of disruption to water supplies.

Most of the district's raw water is sourced from streams and rivers.

A Far North District Council spokesman said although silt and debris could be a problem at water intakes during heavy rain, there were no reports of that as of yesterday.