Silt traps to help restore threatened peat lakes

The silt traps, which Fonterra says are "great looking", are for Lakes Ruatuna and Rotomanuka.

Described as 'critically threatened' under the Land Environments of New Zealand Threatened Environments Classification, peat lakes are globally rare ecosystems.

The Waikato region is home to more than 30 of them.

The Waikato Peat Lakes area is one of five key catchments where Fonterra and DOC work in their Living Water partnership programme.

Living Water Fonterra North Island project manager Tim Brandenburg says the peat lakes are an integral part of New Zealand's landscape, with silt traps a key contributor to restoring lake water quality.

"The majority of pollution comes from sediment and excess nutrients that drain off cleared lands surrounding the lakes. Silt traps are like a vital organ the ecosystem needs to recover – they act like a kidney," says Brandenburg.

"We're artificially creating what would normally happen in nature – when a stream meanders through a wetland, and filters out silt coming downstream."

These culturally and historically important peat lakes are a significant focus for Living Water, as part of its mission to improve water quality and increase the abundance of native wildlife in five catchments where intensive dairying exists.

DOC Living Water Waikato site lead Mike Paviour says, "We've given the lakes the equivalent of a kidney transplant."

"On top of that, we're planting both the silt traps and lake edges with thousands of native wetland plants to provide habitat for native wildlife.

"We're excited to see the native species thrive as habitat becomes established, and we'll be working to improve public access so everyone can enjoy it."

Living Water works with farmers, iwi, hapu, community groups and key stakeholders to improve the abundance and variety of native wildlife and water quality.

The Waikato Peat Lakes catchment includes three lakes where Living Water continues on its mission to help restore Waikato's unique peat ecosystems.

The other Living Water catchments are Kaipara Harbour's Hikurangi catchment, Tīkapa Moana (Firth of Thames) Pūkorokoro/ Miranda catchment, Waikato peat lakes focusing on Lakes Areare, Ruatuna and Rotomānuka, Te Waihora (Lake Ellesmere) in Canterbury focusing on the Ararira LII catchment and Awarua -Waituna in Southland focusing on Waituna catchment.