Orakei Basin sluice gates project

Introduction | History | Ecology of Orakei Basin | Options considered | Proposed management approach | Technical reports

History

Orakei Basin.

Orakei Basin was a flooded volcanic crater with mangrove forest connected to the Waitemata Harbour by Purewa Creek and Hobson Bay.

The basin was highly modified in the late 1920s when it was isolated from Purewa Creek and Hobson Bay by the construction of the railway embankment, and further in the early 1930s when, at the request of Auckland City Council, a set of sluice gates was installed.

Auckland City Council then removed the mangroves from the basin to create an area for water-based recreation. This use is reflected in the original lease over the seabed between the Crown and Auckland City, due to expire in 2050, which requires that "the City maintain the Orakei Basin as a public boating and associated water related activities area" (clause 3).

For the first 15 years, Orakei Basin was heavily used for swimming and other water-based activities such as water skiing. However, pollution from the adjacent catchments resulted in a decrease in water quality and a decrease in use to current day levels.

Auckland City Council has committed significant resources to address this pollution. The most recent projects have been:

• separating the combined wastewater and stormwater system in the Meadowbank Catchment to reduce wastewater overflows
• improving the efficiency of the Waiatarua Reserve stormwater treatment system
• dredging sediment from areas of Orakei Basin.

Auckland City Council is also currently investigating the removal of contaminated sediment from Orakei Creek.

Various flushing programmes have been used since the installation of the gates. Most recently, at the recommendation of Auckland Healthcare, the basin has been flushed fortnightly to coincide with peak tides. 'Emergency' flushing occurs after heavy rainfall or when complaints are received from the community.

Reviewed - March 2007.