Erosion, coastal and flood hazard services
Alongside environmental assessments and stormwater management, we prepare the erosion, coastal and flood assessments Auckland Council asks for with resource and building consent applications. The same team carries out the geotechnical and civil design, so the recommendations fit the rest of your project.
Erosion and sediment control plans
Erosion and sediment control (ESC) plans for earthworks and land disturbance consents, prepared in accordance with Auckland Council's GD05 guidance (Erosion and Sediment Control Guide for Land Disturbing Activities in the Auckland Region) and the land disturbance rules of the Auckland Unitary Plan (Chapters E11 and E12).
- Earthworks staging and progressive stabilisation
- Clean-water diversions, silt fences and super silt fences
- Decanting earth bunds and sediment retention ponds sized to the catchment
- Inspection, maintenance and monitoring requirements
Coastal hazard assessments
Assessments for coastal and clifftop properties covering coastal erosion, cliff and slope instability, and coastal inundation from storm tide and waves, with allowance for sea-level rise over the design life. We follow the New Zealand Coastal Policy Statement 2010, the Ministry for the Environment's coastal hazards and climate change guidance, and the natural hazards provisions of the Auckland Unitary Plan (Chapter E36).
- Coastal erosion and clifftop setback assessments
- Coastal inundation and minimum floor level advice
- Combined coastal and slope stability assessment for clifftop sites
- Reports supporting resource and building consent
Flood and overland flow path assessments
Where a site sits in a flood plain or flood-prone area, or an overland flow path crosses it on Auckland Council GeoMaps, we assess the flood hazard and the effect of the proposed development on flows, then set floor levels and design measures to meet the Auckland Unitary Plan (Chapter E36) and Building Code clause E1 Surface Water.
- Overland flow path and flood plain assessments
- Minimum floor levels and freeboard
- Effects on neighbouring properties and flow path diversion design
- Input to stormwater management plans and soakage testing
Need an environmental assessment for consent? Call 09 278 1072 or send us your project details.
Frequently asked questions
What is a preliminary site investigation for contamination?
A preliminary site investigation, or PSI, is a desktop and walkover assessment that establishes whether an activity on the Hazardous Activities and Industries List has ever occurred on the site. It reviews historical aerial photographs, council and regional council records, titles and previous reports. If a HAIL activity is identified or cannot be ruled out, a detailed site investigation with soil sampling is usually the next step.
When does the NES for contaminated soil apply?
The National Environmental Standard for assessing and managing contaminants in soil to protect human health applies where land is or has been subject to a HAIL activity and the proposal involves subdividing, changing the use, disturbing soil above the permitted volumes, or removing or replacing a fuel storage system. Where it applies, a PSI and often a DSI prepared by a suitably qualified and experienced practitioner are required with the consent application.
What is erosion and sediment control and when is it needed?
Erosion and sediment control is the set of measures that keep disturbed soil on site and out of watercourses during earthworks, including stabilised entranceways, silt fences, clean water diversions, sediment retention ponds and progressive stabilisation. It is required by regional plan rules for most earthworks and is a standard consent condition. Regional council guidance sets out the design and sizing expected.