Community groups have been documenting the sediment pollution and commissioned a year long study in hopes the report will help Auckland Council understand the problem.

Tonnes of sediment from developments around coastal Auckland are landing up in our waterways, and the system supposed to stop the pollution is "broken".

Auckland Council says the pollution can't be stopped. It can only be managed under the Resource Management Act.

But councillor Wayne Walker, deputy chairman of the council's Regulatory Committee, says the council's regulatory system is broken.

Supplied Sediment running off the WeitiBay development into Karapiro Bay.

Controls are process, not outcome driven, he said.

READ MORE: Residents enlist expert help in fight against development of Okura

"So you can still have enormous amounts of sediment and silt going into the ocean, and a marine reserve, and still have compliant subdivisions and developments."

Simon Maude Councillor Wayne Walker says Auckland Council controls are inadequate to protect sensitive ecological areas like the Okura Long Bay marine reserve.

Consents were also too permissive, Walker said.

"And there is too much room for interpretation. What seems to happen, especially when you have got commercial forces at work, is they'll really push the envelope."

Walker's call came after a deputation to the Hibiscus and Bays Local Board from Okura residents Lezette and Geoff Reid, who were concerned about sediment running off WeitiBay developer's land on to Karapiro Beach and into the Okura Long Bay Marine Reserve.

Save Okura Long Bay Residents hope footage of the effects of sediment on marine life will help bring support to marine reserve's plight.

The Reids said the developer had blocked a stream on the site to prevent sediment overflowing into it and destroying the Karapiro beach.

But now the stream was blocked, the sediment was flowing over and smothering wetlands, then entering the neighbouring Karapiro stream and flowing into the marine reserve, they said.

The local board suggested taking the issue up with the Regulatory Committee, but Walker said a report from it would be a "white wash".

Save Okura Long Bay The sediment plumes happen like clockwork after rain events, Pete Townend said.

"The officers there are certainly taking steps to block anything in that direction and say what is occurring is compliant."

Walker said he had tried to arrange a presentation to the committee by the The Long Bay - Okura Great Park Society over the same issue, but had been blocked by committee chairwoman Linda Cooper on the grounds the matter was being looked into by officers, and that the site was compliant.

A report on the WeitiBay site by resource consents compliance manager Steve Pearce said officers were of the opinion the site operated to a high standard and inspections reflected this.

ZIZI SPARKS Pete Townend hopes a privately commissioned investigation on the issue will help inform council officers there is an issue.

Sediment devices are not designed to remove 100 per cent of sediment, he said.

Devices like silt fences remove 50 per cent, and chemically treated sediment ponds might remove 90 per cent, but only in ideal conditions.

During storm events they are less efficient, Pearce said.

Consent for the damming of the stream to provide for a lake, stormwater pond and wetlands had been granted in 2007, he said.

Long Bay - Okura Great Park Society member Peter Townend believed a lack of understanding of the issue led to his group being blocked from the Regulatory Committee.

"I don't think the committee chairwoman actually understands what is going on.

"There is some really shocking stuff going on and it has been going on for over a year."

The society have been working to investigate the pollution of waterways in the area themselves by commissioning a year long study.

"We are trying to help the council see the problem and effect change."

A draft version has been presented to officials, while work continues to finalise the report.

Townend said the group would wait until the council digested the information before it was made public.

But he said the main issue was developers allowing an enormous amount of sediment to leave their sites.

With the area protected by the Marine Reserves Act, designated an area of outstanding natural landscape and a significant ecological area, it was surprising the activity was allowed to occur, Townend said.

"If this was Goat Island marine reserve and this was going on, the Department of Conservation, the council - everybody - would be all over it like a rash."

The society is also involved with a number of legal battles with developers.

The next off the rank is WeitiBay developer Williams Land Limited's appeal in the High Court over a Unitary Plan decision not to allow it to increase a planned development from 550 homes to 1750, between Okura and Stillwater.

The society has a Givealittle page for people who would like to help them cover the costs of lawyers and experts.