Here is One Answer to Inundation

Some thirty or more years ago a subdivision was approved north of Thames on what was a combination of old mine tailings and a rubbish dump.  Subsequently the unstable land sunk, leaving the residential houses at great risk of inundation by the sea.

The top of the seawall looks about 2.5 metres above the road level.

The top of the seawall looks about 2.5 metres above the road level.

The Council’s answer to the problem was to build a massive rock bund about a kilometre long to keep out the sea, and a pumping station to make sure that any water encroaching could be pumped out. The seriousness of the situation also meant that a huge standby generator was installed in case of a power cut at the wrong time.

A concrete pump house is in the foreground, with a large standby generator further along the road.

A concrete pump house is in the foreground, with a large standby generator further along the road.

It is difficult to judge when standing on the top of the embankment just how much difference there is between the sea level on the outside of the bund and the street and property levels on the inside. I was there at about half-tide rising and the levels looked pretty close at that stage.

It is difficult to judge the relative heights of the sea and the road, but this is only half tide rising.  What would it be like on a king tide with a storm?  I would think “scarey!”

It is difficult to judge the relative heights of the sea and the road, but this is only half tide rising. What would it be like on a king tide with a storm? I would think “scarey!”

Perhaps this is a picture of what people may expect as sea levels rise and endanger low-lying coastal properties? Such hard engineering solutions may be feasible in some cases, but hideously expensive. Managed retreat will have to be the ultimate solution.

 

Comments

  1. Stay calm Roger it reinforces what we have always known, if there is a buck to be made we,ll find a way to waste a Million.There,s always the Moon to start on and it,ll be easier there because the tide wont be comin in and out. Len.

    On 02/09/2014 10:44, Whangateau Harbourcare wrote:

    > Roger Grace posted: “Some thirty or more years ago a subdivision was approved north of Thames on what was a combination of old mine tailings and a rubbish dump. Subsequently the unstable land sunk, leaving the residential houses at great risk of inundation by the sea. ” > >

  2. Lindsey Britton says:

    Recent work on Maraetai Beach, Manukau, where the shore properties are literally a couple of feet above sea level and have been close to inundation many times! A few vertical logs, a bit of concrete and gravel, locals are wanting more wonder why! It’s a beautiful coast line – wonder what they will say however when engineering work as you describe becomes essential!

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