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Tuesday, February 5, 2019

Flooding

It would appear that we are going to have ever increasing flooding on into the future.  On land, rain is coming in more extreme bursts and, as warm air can hold more moisture than cold air,  in many locations there will be more total rain.

On the sea shore, the sea is rising and storms are becoming more intense so higher storm surges will be added to an ever higher sea level.  Areas that were never flooded before will be..

In addition we are seeing a further effect of climate change.  Weather systems are sometimes getting stalled over certain geographical areas instead of continually moving around the globe.  If this is a 'ridge' you are likely to have prolonged drought.  If it is a 'trough', you are likely to have prolonged rain.  We saw this in Townsville in Australia (beginning of Feb, 2019) where they had almost 400mm of rain on each of 4 consecutive days.  I can't even imagine that much rain.

So what are we to do.  We can build up levees to hold rivers in their beds and build walls to keep out the sea but just look at the cost.  And with an ever increasing problem, any such solution will be overcome in the future.  There is a far better and less expensive solution.

In areas that get flooded, the insurance companies should be held to account by the government and forced to honor their commitments.  We saw in the Christchurch earthquake how reluctant insurance companies are to pay up and how they delay any way they can.  In addition to the insurance the government should top up the pot so that the victims are generously compensated but that is it.  The area is then zoned as un-insurable.  The people can stay if they want but they have had their one time pay out.  If they get flooded again, (and if it happened once, it will only be worse in some future event), they are on their own.  They had the option to take the money and move to higher ground.  If they didn't take it, too bad.

Of course, any area that is flood prone but hasn't yet been built on (if there are any such) should be declared un-insurable for floods and no buildings ever allowed on them.

This is a far less expensive option than trying to hold back the floods and the tide.

Better still, the expense is spread over time rather then local and fedral authorities having to come up with huge tranches of money to do major civil engineering works that will be obsolete sooner rather than later.

So what about the land that remains empty.  If it is on a river flood plain (where we never should have built in the first place), it can be used for agriculture, turned into a park or left to regenerate native vegetation.  Incidentally, allowing a river to spread over it's flood plain, reduced the height of the flood downstream and so protects other properties.  This is even more effective if the area is well vegetated with shrubs and trees.

Alternately, shore areas can become nature reserves. Sea shore areas, if vegetated, will tend to collect silt and build up over time, aiding in the defense of landward properties.  On the sea shore, salt tolerant plants can be introduced.  They hold the soil, reduce wave damage and moderate the force of subsequent storms.  They can become mud flats with all the benefits this brings to the bird life of the area.

It doesn't seem likely that we will take the necessary measures to reduce our carbon output to the atmosphere.  In fact, following a few years of steady output, in 2018 we actually increased Carbon dioxide production once again.  This in spite of more and more renewable energy coming on line and ever increased efficiency in lighting our streets and buildings and powering our machinery.

We are so clever individually but so abysmally stupid in the collective.  Let's at least be sensible in reducing the cost of flooding and spreading it over a longer period.