Road users are reminded by the NZ Transport Agency that there is a risk of flooding on a section of the Northwestern Motorway (State Highway 16) because of unusually high tides in the Waitemata Harbour later this week.
High tides of up to 3.4m – about 0.4 metres higher than normal – will occur from Wednesday, 14 July to Monday, 19 July. Tides like this occur in Auckland every six to seven years.
The area on the Northwestern Motorway most likely to be affected is the causeway across the Waitemata harbour between the Patiki Road Interchange and the Rosebank Road bridges.
The cycleway beside the highway will be flooded, and the NZTA is advising cyclists to try to avoid using it 90 minutes either side of the high tide mark.
"It is unlikely the motorway itself will be affected, unless weather conditions like strong winds have an impact on the tides," said the NZTA's State Highways manager for Auckland, Tommy Parker. "There is a traffic management plan to re-direct traffic away from the causeway if there is flooding."
The NZTA is planning to raise the causeway by 1.5 metres and increase the width of the motorway to provide extra lanes as part of the Western Ring Route development.
The unusually high tides will occur throughout 2010 on the following dates.
