Marine Parade

Introduction | Options

Auckland City Council has been investigating the flooding on Marine Parade since 2001.

Public consultations since June 2006 have led to a series of options being developed.

Overview

The Marine Parade catchment (where the rainwater runs into) overflows in heavy rain, discharging wastewater and stormwater into the harbour along the cliff between Cox's Bay and Herne Bay.
The catchment naturally drains rainfall to a low point along Marine Parade. Houses and roads interfere with the rainwater's natural drainage and the stormwater pipes cannot cope with the volume of surface water, leading to flooding in this area.
Many of the stormwater pipes along Marine Parade have roots in them or are blocked with sludge and rubble, or cracked.
A stormwater pipeline running down Short Street reserve is discharging onto the south-west corner of Sloanes Beach and flooding a property on Marine Parade.
The council has no immediate plans to separate the current system's combination of wastewater and stormwater pipes. However, planned new pipes need to be large enough to cope with the stormwater flow that would result from separating this system in the future.

Objectives

The objectives of the Marine Parade stormwater project are to:

address stormwater flooding of private property and the road
reduce wastewater overflows into the Waitemata Harbour to improve water quality.

Improving water quality

Reducing the amount of overflows (including untreated sewage) will significantly improve the quality of the water discharged into the harbour from the Marine Parade catchment. Options that achieve this should be viewed more favourably than those that do not.

The next step

Public feedback regarding different design options has been assessed to determine the community's preference. The feedback received has been generally positive with the majority of respondents supporting the decision to upgrade the local network.

Option 2 was shown to be the most preferred by respondents, in summary this option involves:

building new stormwater lines in Annan St
relining existing stormwater lines that run down to an existing outfall on the coast adjacent to the properties at 39 & 41 Marine Parade
repairing the current outfall and a broken pipe on the foreshore
construction of a new pipe line to a disguised outfall structure at Sloanes Beach to accommodate stormwater during heavy storm events only (with the existing outfall used for the majority of occasions).

This option was supported because it provides the best environmental outcomes, the level disruption caused during construction is limited, it is cost effective, and because it provides for the future separation of wastewater from the stormwater network. After consideration of the Project Engineer's Options Report and feedback from public consultation, Auckland City Council has decided to proceed with more detailed investigations of Option 2 as the preferred solution.

As a result of discussions with nearby residents, a couple of design variations to Option 2 are currently being explored. These involve removing the overland flow component from Short Street Reserve, and positioning the new outfall to Sloanes Beach behind the boat ramp in front of 33 Marine Parade instead of through the sea wall at the Reserve. This will help to move the discharge further away from the beach.

The next steps for the project are to carry on with investigations to ensure the feasibility of the revised Option 2, continue liaison with affected property owners, then lodge the necessary resource consent applications required from Auckland Regional Council and Auckland City Council.Further website updates regarding the final design decision will continue as the project progresses.

updated April 2009