Sediment standards not working in Orewa

Recent heavy rain again turned Nukumea Stream in Orewa brown with sediment, although to a lesser extent than the major event in early April (HM April 17).

In April, Council issued the Sunny Heights developer, Changda International and its contractor a fine of more than $2000 for the high level of sediment that flowed from its site above the stream, and required the site to be closed over winter.

Despite this, in early June, more silt was seen flowing out to sea and residents, the Hibiscus & Bays Local Board and the developer agree that more needs to be done.

Local board chair Julia Parfitt convened a meeting with the developer, Council’s enforcement team and freshwater scientist Sophie Tweddle after the April event.

Mrs Parfitt says the developer was apologetic and said that although it is meeting its consent conditions, it will look at measures over and above this, including increasing the capacity of sediment retention ponds.

“It is clear that the Council’s standards for sediment control are not suitable where sites are steep and rainfall can be heavy,” Mrs Parfitt says.

Auckland Council is reviewing various aspects of its sediment control rules. A report will be presented to the Environment and Community Committee next month – a process Mrs Parfitt says “can’t come soon enough” for the local board.

Changda development manager, Olric Thomas, says the company is concerned about its impact on the environment and is trying to exceed Council’s sedimentation control standards.

“Since our rainfall events are becoming more intense, we are discussing with our contractor and Council raising the standards even further,” Mr Thomas says. “We may have to adopt more stringent measures, as an industry, to provide further capacity in our sediment retention devices to deal with the intensity of rainfall we are experiencing. We are open to innovation and suggestions regarding this.”

He says the company employed an environmental consultant to investigate the project with fresh eyes and while no major changes were identified, some minor improvements were made.

“We have committed to help reverse any damage our previous sediment discharge may have caused in Nukumea Stream by assisting with planting and signs,” Mr Thomas says. “We have made a significant investment in environmental controls and will continue to do so.”

He says some work has continued, with consent, to cover 99 percent of the site with mulch and grass so it can be closed down over winter.

Work at Sunny Heights will begin again in earnest from October.