Small sites struggle with effective sediment control
Posted at 1:54pm Tuesday 06 Aug, 2019
The problem of sedimentation of our waterways is growing and an Auckland Council report shows that it is not only made worse by large-scale development and construction.
Recently it was revealed that the vast majority of small residential building sites are providing poor or average controls when it comes to preventing sedimentation, run off and litter entering waterways. This also has a cumulative effect on the health of our waterways.
A scheme called the Small Sites Ambassador Project (HM July 4, 2018), funded by the Hibiscus & Bays Local Board in the 2018/19 financial year, aimed to find out more about the problem and why people with small building sites are not complying with environmental controls.
So far there have been 50 site visits to residential building sites in the Hibiscus and Bays area – these include high growth areas in Orewa – West Hoe Heights and Grand Drive – and Silverdale.
The visits found that only around 15 percent of the sites had good controls in place, 60 percent were average and 25 percent poor.
One of the leads on the project, Auckland Council's senior healthy waters specialist Libby Caldwell, says educational materials were provided to contractors on site around appropriate environmental controls and the results were also passed on to the Council's licensing and compliance staff.
Since then a report shows that 34 of the properties have had enforcement action taken which will be followed up to ensure compliance. The enforcement involved the issuing of abatement or infringement notices (or both).
Eleven more properties had completed their works at the time of inspection and two received letters advising that their erosion and sediment control measures were of an acceptable standard.
Further tests coming
A further project, also funded by the Hibiscus & Bays Local Board will analyse the quality of water leaving small building sites.
The sediment-related water quality testing programme is budgeted to cost $25,000 in the first year of a three-year programme. It will see water quality tested on small scale developments (up to 500m2 or 250m3) that include earthworks permitted under the Unitary Plan. The aim is to gather evidence about which contaminants in local waterways are related to sediment discharges from such sites.
The results will provide data in the first instance, but Council staff told the local board last month that where issues are identified, compliance will be sought if deemed necessary.