Tuesday, 11 February 2014

Dutch Engineers - do they know best?

On various recent occasions there have been very public comments on the failings of the Environment Agency. Critics have argued that they would invite Dutch engineers to solve the problems of the Levels. The Dutch should be immensely proud of the reputation they have established in England and the esteem with which they are held in parts of English society.

It is certainly true that 17th and 18th Centuries Dutch engineers were in the vanguard of drainage of wetlands. Indeed, we might also reflect that the Dutch have probably played one of the most important roles in eliminating the wetland wildlife of England!

We are now in the 21st Century rather than the 17th Century. The engineering principles the Dutch employed are now very well known and there are plenty of UK engineering companies who have the same skills and expertise. They will happily sell this expertise to UK taxpayers and are already employed in a great many capacities. In some places, one almost gets the impression that they ARE the Environment Agency. So, why pay the Dutch and favour their economy to the detriment of our own exchequer?

Design principles are not particularly difficult. Water conveyance simply depends upon capacity within the channels, the fall of the land,  and whether water can be conveyed into major conduits using flap valves or if there is a need to lift it into rivers and major drains using pumps. The subsequent test is the design dimensions - what sorts of volumes are the systems designed to accommodate?

So, the key question is not where the engineers come from, but how much money you are willing to spend. The greater the planned capacity, the greater the cost. Furthermore, if you design a system of defence against flooding from rivers there is a question of the design of resilience to major events - how big should the flood defences be? The costs of flood defences are directly related to the level of protection that is aspired to: bigger schemes require more engineering clay and there will therefore be greater transportation costs and impacts of lorry movements on the communities along the way.

It is notable that even the Dutch, those masters of drainage and flood management, are talking about soft engineering and even using flood storage! Actually, the Dutch are probably at the cutting edge of such approaches. Many of their major defences are designed to a level of 1:1000 year return period and I have heard of levels of 1: 4000 years defence levels. The flood embankments in many places are like small mountains! The cost must have been astronomical and, of course, it does not stop there because defences have to be maintained and replaced. I have not got a clue what the yearly flood defence budget is, but I would guess it is much more substantial per-capita than in the UK. Small wonder that they are looking for greater cost-effectiveness and are exponents of soft engineering.

The Dutch have a relatively short coastline and invested huge sums in the Delta project to shorten their coastline still further. They also have relatively few rivers, so the river flood defences are relatively less onerous. A great deal of their problems relate to surface water drainage and therefore pumping because a lot of Holland lies at or below sea level. In the winter this challenge is immediately apparent when one flies into Schipol - huge areas of farmland under water or partially inundated. Even the Dutch cannot keep the floodwaters fully at bay in the winter.

Given the demands for vastly increased defences against flooding on the Levels, there is a need to look carefully at the relative costs. How many people and what land area elsewhere could be protected if the current level of defence is maintained on the levels and the proposed maintenance budget is spent on other capital projects? Would the money be well-spent on the Levels or better spent elsewhere? This is a debate that involves all taxpayers.

This is also the challenge that the Environment Agency grapples with on a daily basis across the length and breadth of England, with its huge coastline and numerous rivers and floodplains. They have been doing so in the face of ever-tightening budget constraints that are also compressed by engineering costs that rise at a pace that greatly outstrips inflation.

Maybe it is time to put the critics into the hot seat and let them make the decisions. Once they have made their decisions they would also have to defend them against uproar from the communities they choose not to favour! I doubt the critics would cope well because there innumerable deserving cases.

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