News release
22 March 2010

Southern Okowai Lagoon to become freshwater wetland

Work commenced today on Porirua City Council's southern Okowai Lagoon to create a freshwater wetland that will restore the lagoon’s appearance and improve water quality and habitat for its freshwater species.

The small northern and southern lagoons are situated below Gear Homestead on Okowai Road.

The work, paid for by Aotea developers Carrus Ltd, involves contouring the edges of the lagoon and creating a longer and flatter weir between the two lagoons.

This will provide a passage for fish and a better ecological connection between the two lagoons. Riparian and wetland planting will also be done to provide appropriate native wetland plant species habitat.

The contouring work is expected to take two weeks and make use of the current low water levels in the lagoons.

The lagoons have suffered from a range of visual, water quality, and odour problems since they were created when the causeway for the railway line (and subsequent State highway) was built. The problems are a consequence of insufficient tidal flushing of the lagoons combined with ongoing land clearance and earthworks within the catchments discharging into them.

“This is an opportunity to build a functioning freshwater wetland as well as improve the area as a place for the community to come together,” Greater Wellington Regional Councillor for the Porirua/Tawa constituency Barbara Donaldson says.
“The end result will be a much-needed improvement to the muddy and stagnant appearance of the lagoon.”
This is a good example of many government agencies and a developer working together to get a good environmental outcome, out of a bad situation, says Porirua City Council's Consultant Resource Planner Jason Harvey-Wills.

"Greater Wellington Regional Council, Department of Conservation, ourselves (Porirua City Council), and the developer (Carrus) have all been involved in working to get an efficient and effective outcome to enhance the southern Okowai lagoon. Some minor initial works have also been undertaken on the northern lagoon to enhance its environmental values."

Mr Harvey-Wills says excessive sediment run-off from various sources discharged into the lagoons in 2008 turning them into a chocolate brown colour.

"Carrus have been very responsible in the way they have sorted this issue once it was brought to their attention. They engaged an ecological advisor to write a remediation plan and have improved sediment control, added wetland areas and are now paying for this remediation work," he says.

"It's an example of positive and practical action by all the agencies working together to get the right result."

The Department of Conservation is applauding the initiative. “The value of small wetlands such as this can't be underestimated,” Wellington Hawkes Bay Conservator Alan McKenzie, says.

“As well as providing habitat for a range of species, wetlands act as nature's kidneys, filtering out sediments and pollutants.”

Barrie Shute, Project Manager for Carrus Corporation, said the company was keen to improve the state of the lagoon. “We are prepared to kick start the restoration by undertaking the first part of the work at our cost to rectify some of the past problems that have occurred.”

ENDS

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