Orakei Basin Improvement Plan

A Brief history...The Orakei Basin is a 50-hectare volcanic explosion crater that was once connected to the Waitemata Harbour. The Basin was originally a tidal mangrove swamp before it was highly modified in the late 1920's, by the construction of the rail embankment and further in the early 1930s when a set of gates were installed to impound the Basin. The mangroves where then removed to create an area for water-based recreation. The basin was initially heavily used by a number of clubs and swimmers. However by 1945 water quality reached the point where few people used the basin, with council receiving regular complaints regarding odors, algae, water quality, sewer overflows and sediment deposition. Auckland city has strived to identify and address the causes of tidal problems, with recently andrew.stewart ltd playing an important role.

Orakei Dredging

In accordance with the recommendations of the Orakei Basin Environmental Improvement Strategy Plan, Auckland City sought consent for partial dredging of Orakei Basin and Creek, and algae removal in August 1998. This consent sought to remove 5,000 m3 of organic material and sediment per year for 35 years. The publicly notified resource consent applications received 450 submissions, a significant number of which were in opposition. A joint hearing was heard in May 1999. Following the positive outcomes the applications were granted subject to a series of resource consent conditions. No appeals to this decision were lodged with the Environment Court, and the first stage of dredging commenced April 2000.

However it was found that the consent conditions were overly onerous, and Andrew.Stewart Ltd were engaged to resolve the matter in 2001. Following consultation with the dredging contractor, we sought a consent variation to allow a more cost effective dredging operation with less impacts on basin users. This variation sought:

1.       Increased operating hours;
2.       Increased volume; and
3.       Winter based dredging.

After gaining support from the user groups, and key previous submitters, the variation was granted on a non-notified basis. This work resulted in approximately a 30% increase in dredging efficiency.

While 21,664 m3 of sediment has been removed from the Basin, the dredging did not addressed the problem of sediment migration into the Basin from the arms of the creek.

Andrew.Stewart Ltd then worked closely with Beca to investigate the dredging of the Creek, to remove the existing store(approximately 15,200m3) of contaminated sediments that has built up over the last 80 years of sewer overflows and stormwater discharges from the Waiatarua catchment At the time Metrowater were undertaking sewer seporation to address these overflows, and Auckland City were developing NZ's largest urban wetland in Waiatarua reserve to address stormwater pollution from this catchment.

However following extensive investigations and consultation, the entire creek dredging project was abandoned by Auckland City due to geotechnical instability issues.

Orakei Impoundment

The site has a long history of opposing viewpoints, with local Iwi, Forest and Bird, and DOC historically wanting the Basin returned to a tidal environment; and residents and user groups wanting to maintain the Basin as an impounded body. So ASL then worked with Beca and Kingett Mitchell Ltd to assess various flushing regimes and ecological responses for the basin. This was then used by ASL to undertake a significant consultation and communication programme, regarding the issues and options for the long term management of Orakei Basin. Following results of consultation, Auckland City Council adopted to maintain the impounded status of Orakei Basin. ASL identified and acquired resource consents for works to replace sluice gates at Orakei Basin and the continued impoundment of approximately 80 hectares of the Coastal Marine Area (Restricted Coastal Activity, requiring Ministerial approval). ASL also assisted negotiations with On-Track, including necessary design changes to accommodate double tracking and electrification above the gates.

The consultation and communication process fully met its objectives, with no submissions in opposition being received, avoiding the need for an expensive public hearing. This was a significant achievement, especially in light of the last two proposed impoundments being declined either via the Public Hearing process or at the Environment Court

orakei sluice gates replacements

Following the impoundment project, ASL were engaged to facilitate the replacement of the gates that impound the water in the basin, these are leaking badly and need replacing to preserve the recreational and amenity values.

The core objective of this role is to minimise delivery risks such as resident complaints, impacts on Basin users and working outside of the scope of the resource consents, and ensuring environmental compliance.

The physical works to are planned for June 2010.

However as The New Zealand Water Skiing National Championships were planned to be held in the Orakei Basin in April 2009, the leaking gates posed a serious risk to the success of this event. So in conjunction with Beca and Fulton Hogan we successfully implemented a temporary solution to ensure the event could proceed seamlessly.        

Orakei Walkway

Following the success of these projects ASL has now been engaged to assist with the successful delivery of the Orakei Walkway Project.

Consent was granted for the Orakei Walkway in July 2006. Subsequently an Environment Court order was granted in July 2007. Since the lodgment of the consent, the plans have been modified on various occasions. However, no copies of the plans referenced in the granted Resource Consent or the Environment Court order can be located or matched up to their corresponding counterparts. ASL have been engaged to effectively tidy up the mess and facilitate the smooth integration of a number of minor changes proposed by Frame Group to allow value engineering.

Due to the nature of the surrounding community and organizations that regularly use the basin, our role also includes a significant consultation and communication component to ensure works are coordinated with any events that may be planned in the Basin, and the public relation risks are minimized during construction. 

Physical works are also planned for 2010, and will be carefully managed in conjunction with the gates replacement project.

ORAKEI RESERVE MANAGEMENT PLAN

During consultation for the walkway, it was agreed that a management plan be prepared for the basin and surrounding reserves. Auckland City has called upon ASL's wealth of knowledge to assist with this process and in working with key groups to ensure community aspirations are met.