Friday, 14 March 2014

Soluble Solution

This is just one of a series of old and new newspaper articles looking at the inland waterways and the things that were and are effecting the rivers and canals. The most active periods for evaluation and change was always just prior to the two world wars. Between the wars the ownership of the canals changed hands and the railway companies bought up the canals to get rid of competition. Its good to take a look back at what people were saying and doing in the past. Most surprising of all, is that many of the problems that beset the canals are still prevalent today. Reading old newspapers can throw up some interesting stories. Here is what we would call today a public interest story.

Flooding on the the Somerset levels.

Flooding is nothing new its been going on for many millions of years. Its a well documented natural event. So well documented that flood risk has always been quantified as a one in a hundred (or similar big number) year event. Now, flooding and unusual rainfall events are happening much more frequently and with that uncertainty comes conjecture. 

We know and accept that the earth goes through periods of warming and cooling. The last ice age for out part of the planet ended about 10,000 years ago. The problem now is that we are supposed to be on the cusp of the next cooling period. What we don't know (because day to day records from the distant past are unavailable) is the more frequent changes we are seeing now is the  precursor to the next cooling event.

But, a new factor has to be added into the mix. Human activities have made millions of big and small changes to the environment and the habitat. After the last ice age the UK was covered in trees. The arrival of man and his change from hunter gatherer to farmer has had a huge impact on our country. As the population has grown hamlets led to villages which led to town that ultimately led to cities. Vast numbers of changes have been made to the habitat including the natural watercourses. Blocked, artificially created, contained, rerouted and dammed. Drains take surface water problem elsewhere, paved areas reduce ground absorption. More than anything else we have taken away or heavily restricted the natural flood plain. 

My favourite newspaper for interesting old articles 'The Spectator' has a very good up to date article on the flooding issue by Christopher Booker. Read Me: Click Here

The Guardian also has an interesting article by and which blows the whistle on what has gone wrong with government thinking. Read Me: Click Here

Each river has an associated catchment area. Where rain water is collected and runs off the land and is heading generally through gravity towards the main river channel. The main source of the water is created through natural rainfall. However, there is also a certain amount of water that may also bubble up through the ground. This is in the form of springs where the ground water table is close to the surface. There is a simplistic action plan for exerting a measure of control over flood water. Basically it goes something like this. Solve or mitigate the problem at source. Slow the speed of water at the head of the catchment as it travels towards the river. Speed up the flow at the river exit of the catchment. Have designated flooding areas along the river course to take up the overspill.

Now the real problems need to be identified, scoped and then addressed.

Getting consensus on the way forward for the future. Plus how we can provide meaningful help for the people effected after the event has been noticeable by its absence. Now that flooding has hit London with a much larger number of people and properties at risk. The problems on the levels will most likely get lost in the noise of London's problems.

Monopoly: Some of the waterways are managed by agencies, or conservators, or charities, or businesses. The problem is - each has its own agenda, each has its own funding issues, each has its own requirement for specialist support staff and each has its own requirement for specialist technological know how. Bring the whole lot under one agency and into one overarching strategic Nation Wide Policy. This should be the first step. 

Policy: There needs to be a complete rethink about building houses in flood plain locations. Local authorities  are in a headlong rush to build much needed housing. Local planning policy can be circumvented at a price. National planning policy guidelines for properties less than 25 metres above sea level. A change of approach is needed to improve flood protection in line with the rising risk from climate change. The current "fire fighting" approach to the crisis is crazy.

We have no control whatsoever over the weather and the ever more likely recurrence of equally catastrophic floods in the near future. I accept that these storms and extreme weather conditions are likely to become much more common due to climate change. The 'one in one hundred year' acceptance of flood risk for managing such events is sounding very hollow.

Politics: The politics is a two bladed sword. There is an EU environmental directive element as well as the UK political cash cutting element. As for the UK based upon
'the guidelines' provided for setting out how money is allocated for flood defences and then giving return on investment basis guidance in how the funds are to be allocated - which I understand were developed by the treasury a department not known for expertease in flood management. So the environment agency have little room left for actual manoeuvre. Regulation created by a bean counter to target the investment, is of no use when it comes to allocating budgets against emerging requirement for flood defences.

Aftermath: Floodplains are 'designed over millennia by nature' to flood and to absorb the flood water that would cause more trouble elsewhere. The fact is that we have created over many years the 21st century flood problems. Water from a whole plethora of places is now fast tracked to the rivers. The rivers however depend upon the 20th century river management infrastructure and know how. Floodplains intended by nature to flood and to absorb the flood water are used for building upon.

Solutions: The solutions must be seen as being a part of a coherent plan along the whole river catchment. There will never be a standard one size fits all solution. The broad brush stroke plans will need to be very adaptable and configured to be fit for purpose on a catchment by catchment basis. 

Barrage: The use large engineering solutions has been used in certain locations. Stand on any tidal river and you can see water ebbing and flowing in each direction. Change this to be a constant ebb in times of flood. In the case of the Thames barrage closing the gates allows the incoming tide to be held back and allowing the flood water to ebb and build in front of the barrage. The Humber and Severn could certainly benefit from the installation of a barrage. 

Multi Agency: The Forestry Commission could also have a part to play in developing a more suitable long term habitat. Large tranches of grasslands in key areas should be reforested and the old flood meadow habitat restored to encourage water absorption. Instead of farming sheep land owners in suitable areas should be farming trees. For which we will have to pay a price or alternatively compulsory purchase the land.

Buildings: Constructing buildings in flood plains is at best something of gambol. However buildings can be constructed to withstand a certain level of flooding.

I am convinced that flooding can only be mitigated by slowing down water at the upland end of the watershed and then speeding up the water flow at the outflow into the sea. So how do we hold back the water. One route might well be the use of variable height weirs that would release or back up water as needed. Essentially creating a series of temporary flood water storage areas at much a higher level which are deployed before any major conurbations come under threat.

No comments:

Post a Comment

Please put your name to your comment. Comments without a name may automatically be treated as spam and might not be included.

If you do not wish your comment to be published say so in your comment. If you have a tip or sensitive information you’d prefer to share anonymously, you may do so. I will delete the comment after reading.