Call for water take consents review as lake levels plunge
Posted at 8:00am Monday 05 Apr, 2021
Brent Morrissey says Lake Tomarata's water level usually reaches within half a metre of the barrier's edge on the shore during summer. The barrier was built to provide a shallow area for children to swim, but there is currently nothing for them to swim in.
Calls for Auckland Council to reassess groundwater take consents in Tomarata and Te Arai are growing in volume as local lakes suffer.
Former Auckland Regional Councillor Brent Morrissey has lived next to Lake Tomarata for 25 years and says he has never seen the water level so low.
“I freely acknowledge that in summer the lake subsides, but I've never seen it this low, even during last year's drought,” he says.
He says rainfall over the last three months ought to have topped up the lake, but it hasn't.
There are no direct inflows into the lake. It is only topped up by rainfall and groundwater.
“I think Council needs to be responsible and assess whether the current take of groundwater is having adverse effects,” Mr Morrissey says.
A number of farms draw water from bores for stock, while Te Arai Links golf course was given consent last year to draw 380,000 cubic metres of water a year across nine bores.
“When consultants made an assessment about potential adverse effects to the lake during the consent process, it may have been speculative,” Mr Morrissey says.
Margaret Fishlock has lived next to Spectacle Lake for 50 years and says she is also concerned by the drop in water levels.
She has noticed that the drop in lake level has coincided with a drop in her own bores and believes that increased groundwater take is responsible.
“At one time we had an artesian bore that flowed 12 feet above the ground, but this year we are seeing cracks in the ground we've never seen before.”
Last year, Auckland Council's Research and Evaluation Unit (RIMU) increased its water quality monitoring of the lakes from six weekly to monthly.
Water quality scientist Jane Groom says consistently low water levels could affect lake health, however she says low water levels were seen in 2010, 2013 and 2014 and Lake Tomarata recovered.
Up to date information collected in 2020 on the Lake Tomarata's health is due to be released around the middle of this year.
Last month, RIMU released a report using data collected over five years between 2015 and 2019.
Ms Groom says the report found the lake was above “the national bottom line” for all measurements, but showed signs of being “moderately impacted by increased concentrations of nitrogen and algae”.
However, the wording in the report is more grim. It says Lake Tomarata was the most degraded lake monitored in the Auckland region.
Lake Tomarata has been classed in “poor condition” and “very likely” to continue to degrade by most water quality parameters.
The report says vegetation in the lake was healthy up until 2012, but surveys in 2017 and 2019 classified it as “non-vegetated”.