Racing to bury council mistake

The drowned wetland at Grey Lynn Park will cost an extra $25,000 to fill in again. Picture / Glenn Jeffrey

Just days out from the popular Grey Lynn Festival, the Auckland City Council is racing to fill in a $30,000 wetland built at the park site that flooded with polluted water.

Officers yesterday admitted that no one had bothered to find out if Grey Lynn Park was on a landfill site before the wetland was built and it was being filled in at an extra cost of $25,000.

The wetland, a shallow bowl about 20m in diameter, was built last summer and completed in May. The project team of council officers and consultants planned it as a centrepiece at the Williamson Rd entrance as part of a $500,000 upgrade of the 10.5ha park.

But as one local resident described events, "come the rains of winter, the expected happened".

"The semi-dry wetland became a lake, inundating all of the plantings and flooding over the edges and into the park.

"Eventually when the lake started to collect shopping trolleys - they can't seem to resist water - residents complained, the plants died, council investigated, pumps were brought in to drain the lake, and excavators opened up the drains," the resident said.

A senior recreation project manager, Ian Steer, yesterday effectively owned up to what Western Bays Community Board chairman Graeme Easte called a "collective cock-up".

Mr Steer said that during the two-year planning and public consultation process, no one checked to see if Grey Lynn Park had been a landfill, nor was it was brought to the attention of the project team. The Grey Lynn management plan states "natural vegetation in the park was destroyed by grazing and landfill years ago".

"We clearly did not do our homework. We should have done," Mr Steer said.

The wetland was meant to drain through an existing pipe but that became blocked with silt and other debris in heavy rain so the wetland filled with water. Investigations showed groundwater was also leaking into the pond from the old landfill.

Given the high cost of excavating further into the landfill and capping it with an impervious material, health and safety issues, and the looming Grey Lynn Festival on November 26, the council decided to fill in the wetland pond and replant the area.

The pond will be capped with clay to prevent leachate flowing from the landfill and contaminating the park.