Ask Phoebe: King tides the culprit in cycleway floods on motorway

King, or perigean, tides usually appear over a period of two days when the moon is either new or full and closest to the earth. Photo / Richard Robinson

I used to think all high tides flooded the cycleway alongside the Northwestern Motorway so I avoided it at those times. But apparently this isn't true. Using the Herald tide tables, what [level] of high tide floods the cycleway? Tony Cooper, West Auckland.

It is the king tides that tend to flood this section of motorway, not all high tides.

The most recent king tides, at the end of January and early February, were 3.7m. This is about 0.6m higher than normal. King, or perigean, tides usually appear over a period of two days when the moon is either new or full and closest to the earth. The weather - low pressures or strong winds - can also influence the height of the tide.

Areas most at risk from flooding during king tides include a section of highway and adjoining cycleway on the Northwestern Motorway (SH16) causeway between Great North and Rosebank Rds, and the Northern Motorway (SH1) near the Onewa Rd interchange. In the city, some parts of Tamaki Drive could also flood.

I am trying to track the word Lynn and its derivation in Grey Lynn and New Lynn. Grey as in Governor is quite clear but where does Lynn come from?

Tony Hopkinson, Tauranga.

The place name Lynn (as opposed to a person's given name) is derived either from the old Celtic word lenna, meaning pool or lake, or, if located in Scotland, from the Scots Gaelic word meaning a water feature or pool.

However, interesting as this may be, it is not why New Lynn is so named.

Some time after European colonisation of the Auckland Isthmus began, the area of New Lynn was surveyed by Frederick Utting in 1863, who named it after King's Lynn in Norfolk because he thought the countryside was similar.

And as you surmise, Grey Lynn was indeed named after Governor Sir George Grey, who was variously Governor of South Australia, twice Governor of New Zealand, Governor of Cape Colony (South Africa), Premier of New Zealand and, towards the end of his life, the Member of Parliament for Auckland West.

The Lynn part of the name may have come from the fact that the area was very wet, and had to be drained before construction of dwellings could begin.