Vehicle access to precious lake to end

A Far North dune lake – one of just 12 in Northland officially classed as being in an outstanding ecological state – is at increasing risk from people unaware of its special status, including those using it as an unofficial car wash.

 Local runanga Ngati Kahu and the Northland Regional Council are just two of the partners working to protect the taonga that is Lake Waiporohita, off Inland Road on the Karikari Peninsula.

Ngati Kahu and its marae hold the 6.9 hectare lake in especially high regard and in September last year the regional council approved a $52,850 project via its Environment Fund project to improve water quality and ecology there, as well as in Lakes Rotokawau East and West on the north-western corner of the peninsula.

Ngati Kahu is central to a partnership on the project, which also includes the Department of Conservation (as current manager of the lake-bed and marginal strip) and Landcorp (which farms the Rangiputa Station surrounding the lake).

The project includes fencing, exotic tree removal and riparian replanting which will allow the lake to recover the ability to filter land-based nutrients and a management plan is also being written to protect and restore it.

Anahera Herbert-Graves, Chief Executive for Te Runanga-a-Iwi o Ngati Kahu, says dune lakes are under already multiple stresses, including nutrient runoff, invasive pest fish and water weeds, and cumulative effects from use by the wider public.

However, Lake Waiporohita has an added threat in that it is one of only several dune lakes in Northland that are easily accessible to the public.

"Unfortunately, this means that the lake is all-too-often used as an unofficial car wash by passing 4WD vehicles that have used nearby beaches or boat-ramps."

Peter Wiessing, the regional council's Kaitaia Area Manager, says this puts the lake at increased risk of transfer of water weeds and pest fish (which it is currently largely free of) as well as exposing it to oil and other lubricants from the vehicles and trailers themselves.

"This practice is very detrimental to lake environments as it disturbs both the marginal reed beds and native plants in the lake bed. Sediment is re-suspended, adding to nutrients which feed algal blooms."

Mr Wiessing says vehicle owners should use public carwashes or wash down their vehicles and trailers at home.

Anahera Herbert-Graves says, in a bid to better protect the lake, the next phase of the improvement project will see the project’s partners working to landscape the riparian strip in the open area along Inland Road where 4WDs tend to access the lake.

“This area will be landscaped shortly using locally sourced materials, native plantings and signage to let the public know that vehicle and boat access will no longer be tolerated in the lake.”

Similarly, they are keen to work with Fish and Game officials to try to better manage large numbers of Canada geese which gather at the lake and foul it with their waste.

“We really appreciate the goodwill and great co-operation we’ve already had from so many members of the public in working to keep this marvellous lake in the best condition possible and we hope that others will understand and support these latest steps we’re planning.

“Lake Waiporohita is a treasure not just to local tangata whenua, but to all Northlanders.”