Jan 13, 2009

High Tide a'comin

The devastating scene in the resort town of Phan Thiet in Binh Thuan Province Sunday morning. Another 100 houses are under threat as more strong waves and high tides are forecast to hit the area in coming days

By Dave Riley

This week we are experiencing a succession of high high tides. Although we are five kilometres from the sea, Moreton Bay, at the end of our residential street is a tidal creek bordered by mangroves.

So t0 catch the high tide I went out walking the dogs at 11.15am local time.

The creek used to be a series of fresh water lagoons with waterlillies and tortoises, but when the airport was expanded in the late seventies the creek was dredged into a deep canal as part of local water works ,and the whole riparian ecology changed.

Because it was deepened the tide now comes up the creek each day.

But what's so 'useful;' (I guess) about this week of high high tides is that we get to experience the world's mean water level ten - fifty years hence (depending on the [bi] polar melt).

While our creek has also been given this shallow lip to hold flooding from upstream catchments, today's tide took the water over the creek's banks and the water trickled into the flood plain.

But there was no flood. What if there were more water coming down the creek? What then?

If you consider that option then a lot of the cities built on waterways are going to be inundated by this generic universal tide a'comin. If not always, at least sometimes.

That's the Dutch disease.

Today the islands of the Torres Strait will be smaller than their norm as the tide crosses the coast line and inundates the shorelines. Where we are, inundation of wetlands is the ecological norm as the local mangroves forests rely on the occasional wetting to sodden the mud flats.

It is a natural element in the mix here despite the fact that my suburb and a few more like it was laid out on mud flats built up by the process of mangrove colonisation and silting. As it is my front door is probably only less than a metre above today's sea level .

If I climb the local hill --atop which sits the Catholic University -- and look out to sea the area is so flat that its mesmerizing. Hectres of mangrove forest out of which rises or lands like a migratory bird, the occasional Boeing jet and the airport traffic tower. That we are only 10 kilometres from the Brisbane CBD isn't evident at all. Behind you the great suburban sprawl but seaward is...the sea, Moreton Bay and its islands and this green patch, less than a metre above sea level. A little higher in topography is us and the expanse of Brisbane suburbia.

Flat, wet country

If you check this Google search, you'll get a feel for the consequences of this week's tides across the planet.

This report tells us a lot of what we can expect:High tides hit S Vietnam, driving hundreds of people into misery . But in Australia the spin is all about protecting valuable coastal real estate.

Our house like some other wooden houses in the area are removables -- that is they were built somewhere else and served another family well from the fifties or before then, and have now been unstumped, put on the back of a very big truck and taken to another location. Their original patch is now two or more smaller, brick or cement houses. This is common here in Queensland: house recycling and removal. It's a product or light wooden construction (or light wood and fibro board asbestos) and the penchant to stump houses high above the ground.

Our house arrived by courier very early on a Sunday morning.

Our last house -- built originally in 1924 -- in another nearby location has also been removed by truck and now a eight , three story high, unit block sits on the site.

Our house comes from the next door suburb and was built in 1950. It moved here in 1995. (Psst! We only paid $AUD500 for the house.Moving it was somewhat more expensive.)

My neighbour's house had a previous life as the post office on Bishop Island. It came to the mainland by barge!

I don't know if such transportability is relevant to our impending waterworld future but let's just say, that it may indeed be to a domicile's advantage.