Started early in 2023, facilitated by Phil Everest, the catchment group  encompasses the large catchment of the Ashburton Lakes, some 58,000 hectares over four extensive sheep and beef properties.

The catchment group area includes 13 Lakes, the Te Araroa Walkway, numerous recreational hunting, fishing, water, tramping and snow opportunities and is enjoyed by many in our extended community.

Long considered an area of significance to the nation and local Iwi, our catchment has been under the spotlight recently due to concerns of deteriorating lake quality, something we have also been concerned about and are acting upon.

Since September 2023 we have been measuring water quality, where the water enters our properties, at a midpoint on our properties and as the water departs our properties.

These nitrate tests range from less than 0.002ppm to 1.05ppm, which is extremely low.

Some are less than 10 per cent of the nitrate levels in the drinking water of our town water supply.

In 60 per cent of areas measured the water quality does not change or improves as it travels through the properties.

This was not the result that many, including ourselves, expected.

In 40 per cent of the areas, water quality deteriorates slightly as it travels through the properties. In all cases this relates to the addition of spring water to the streams as it travels through the properties.  

We are researching this to identify the source of the nitrate (animals, nitrogen fixation,organic matter breakdown or from parent rock material) and the age of this water.

We hope that with this information we will be able to find ways to reduce nitrate levels coming from the springs.

While we run extensive low stocking rate systems, we are investigating ways to reduce our environmental impact further.

Many of our streams have already been fenced and we have installed large stock water systems to continue providing water for stock.

Next spring, with assistance from local Fish and Game and Forest and Bird members, we plan to plant almost six kilometres of Gentlemen Smith Stream above the Maori Lakes.

Although our winter feeding systems are less intensive than elsewhere, we are undertaking a monitoring program to determine the actual losses from crops.

We already sow catch crops with our winter brassicas to help mitigate possible nitrate loss.

These are exciting times in the basin as we complete our research and work to develop practices that will improve our environmental footprint in the basin we all love and care for so much.

We are greatly appreciative of the Mid Canterbury Catchment Collective for their continued help and support.

by Kerry Harmer

Ashburton Lakes Catchment Group chairperson