Okura Effects of Development Investigated
North Shore City Council
The North Shore City Council in conjunction with Rodney District and the Auckland Regional Council is carrying out further investigations into the water quality effects of development scenarios on the Okura estuary after a NIWA (National Institute of Water and Atmospheric Research) modelling study has shown up risks under all three of its suggested zoning plans.
The council is carrying out further work to find out if more protection measures would reduce the risks associated with allowing development in the area. The results of these further studies will be available at the end of this month.
The NIWA study is aimed at finding the appropriate zoning (minimum lot sizes) for the Okura area. The issue has remained unresolved since a 1996 Environment Court decision placed the Okura catchment outside the metropolitan urban limits, and resulted in a need to develop a rural zoning for the area.
The brief of the NIWA model study was to predict the risks of environmentally-damaging effects on the Okura estuary as a result of earthworks associated with three development scenarios.
The scenarios were:
Development permitted under the existing District Plans (Rodney and North Shore City), minimum lot size approx. 4ha
2ha minimum lot size across the entire catchment
1ha minimum lot size across the catchment
The results of the initial study show that all three scenarios pose some risk of impact on the estuary, with the risk being slight with scenario 1, increasing with scenario 2 and markedly increasing under scenario 3.
The councils have decided to do further study to see if these effects can be reduced and to also find out the long term benefits of fencing and planting up watercourses and undertaking planting on individual properties.
The extra protection measures being investigated include:
* Limiting site disturbance
* Putting in site sediment control measures
* Controlling stormwater discharges
* Limiting the earthworks season.
Some of the measures being investigated may require a transfer of inspection and enforcement powers from the Auckland Regional Council to both Rodney District and North Shore City. The cost and resource implications of such a move is also being investigated.