Ongoing dry conditions put strain on lakes and rivers
Environment Canterbury media release: 29th July 2024
Ongoing dry conditions – due to lack of rain and snow melt – continue to put significant pressure on lakes and rivers across Waitaha/Canterbury.
“While we have since seen some localised rainfall, there hasn’t been anywhere near enough to recharge our lakes and rivers and this is having a significant effect across the region,” Surface Water Science Manager Elaine Moriarty said.
“Lakes and rivers throughout Canterbury are still at record low levels and there’s no saying when this will improve, with early winter not producing longed-for rainfall.”
In their June to August Seasonal Climate Outlook, NIWA is forecasting below normal river flows and soil moisture levels, and near normal or below normal winter rainfall, with soil moisture deficits and long-term dryness that will be slow to improve.
Find out more about NIWA's June to August 2024 Seasonal Climate Outlook.
“The lack of rain is having widespread impacts,” Elaine said. “For farmers, it’s reducing feed available for stock and there is likely to be less water available for irrigation later in the year. For recreationists, the rivers and lakes may not be as suitable for water sports and recreation when summer comes – and some areas may be more vulnerable to the growth of nuisance algae.
“Those effects flow through to our aquatic life, which can be negatively impacted by low river levels and, for mana whenua, it will most certainly affect mahinga kai.”
While we will continue monitoring water levels closely, it’s not an easy fix. Creating diversions from other rivers and streams requires careful management to balance any potential negative effects elsewhere. As such, resource consent is required under the Resource Management Act (RMA) to take water from any other waterway.
“With all of our rivers and lakes region-wide experiencing lower than normal levels, we can all play a part in conserving water resources,” Elaine said.
How this looks on the ground: Lake Camp/Ōtautari
Lake Camp/Ōtautari is a small alpine lake in the Ōtūwharekai Ashburton Lakes region experiencing low water levels due to lack of rain and snow.
Locals and nearby hut holders are becoming increasingly concerned the lake levels will be too low for recreational activities such as water skiing and boating later in the year and are calling for organisations to take action.
“While we can certainly understand the concern being expressed by residents, at this stage we are not seeing a negative impact on Lake Camp’s water quality or macrophyte community as a result of the low water levels. This is because Lake Camp is very deep in the middle, going down 18 metres, which helps support aquatic life, such as fish and plants, during dry times.
“We are continuing to monitor Lake Camp closely.”
It’s not uncommon for small lakes like Lake Camp, which either have small or no permanent inflow, to have large variations in lake levels throughout the year. Because of its depth, Lake Camp is more tolerant to these variations than shallower lakes, such as Lake Emma and Lake Lyndon.
Find out more about the current water levels in Lake Camp.
Local community proposes new water diversion
In recent weeks we’ve been talking to local hutholders, Te Rūnanga o Arowhenua, the Department of Conservation (DOC) and Fish and Game NZ, about the lake and its current state, and a proposal from hutholders to divert water to raise water levels for local recreation purposes.
Fish and Game previously held a resource consent to operate and divert water into Lake Camp from the nearby Balmacaan Stream, which was relinquished in 2020.
While any individual or organisation can apply for resource consent to divert water to Lake Camp for recreational purposes (such as boating and jet skiing), Resource Management Act (RMA) processes would need to be followed to ensure the local environment and other lakes would not be negatively impacted by a new diversion.
A permit to build any necessary structures would also be required by the landowner – the Department of Conservation – as the previous structure was damaged by flooding and subsequently removed.