Amended 10/9/2009 (Created 29/6/2008)
UNDER CONSTRUCTION
"The River Thames is just a drain"
The primary purpose of the River Thames (or any river, watercourse, ditch and drain for that matter) is to convey water from the land to the sea.
This is a natural process that has been going on for some time, (since rain started falling ) but unfortunately, human intervention has had a detrimental impact.
Natural rivers have a habit of 'doing their own thing'. Over time they will change in capacity and/or course dependent on circumstances.
Unfortunately due to ever-increasing human intervention over thousands of years, the Thames is no longer a natural river.
The Thames is now a highly engineered river with many weirs, locks and bridges.
Much bank protection has been installed, and many flood arches are blocked.
The water level in the Thames has changed over time in order to maintain navigation.
In the past, the National Rivers Authority, and prior to them the Thames Conservancy, used to continuously dredge the Thames.
The Thames was dredged using special rise/fall chain bucket conveyors (to enable bridge underpass)
The Environment Agency, without debate or consultation, has abandoned Thames dredging and disposed of the dredgers.
The EA claim that the Thames is self-scouring and that dredging is not a sustainable solution.
The truth is that the Thames is barely navigable and suffers significantly reduced capacity.
The EA have not got the equipment to dredge the Thames, or anywhere to dispose of the removed (contaminated) material.
The truth is that the Thames is just a drain.
Within the Thames catchment, the primary purpose of the River Thames (and its tributaries) is to act as a drain, with any commercial and recreational benefits being a bonus.
Since the EA took over from NRA over ten years ago, the centuries old practice of ‘flood defence’ has been replaced with ‘flood risk management’ where ‘risk’ is the combination of probability and consequences.
The EA claims to be reducing the risk of flooding, but in practice the probability of flooding is ever-increasing due to lack of watercourse maintenance, increased building and climatic variations.
Furthermore the EA has claimed that watercourse maintenance responsibility was confusing and needed improvement. In order to meet that objective the EA took over responsibility for over 3000km of Critical Ordinary Watercourses from local authorities and LDA’s, but then failed to ensure that those same watercourses were properly maintained. Indeed riparian owners of such watercourses now have to submit applications to the EA for permission in order to implement maintenance works such as dredging. Unbelievably permission is sometimes withheld.
The EA has only a ‘responsibility’ for flood defence and watercourse maintenance rather than a ‘duty’. In my opinion the EA is not even fit to take responsibility for watercourse maintenance, being firstly encumbered by internal conflicts of interest (e.g. consideration of water voles and Depressed River Mussels) and secondly believing that watercourse maintenance can be achieved remotely from a keyboard in a warm, dry, safe, office.
The EA claims that the Thames is a natural river and is self-scouring. The truth is that the Thames is extremely unnatural, being highly engineered, structured and controlled. The water is normally unable to achieve the velocities necessary for material conveyance. In fact over time, many of the structural flood arches have been blocked and back-water maintenance abandoned, thus the ‘within banks’ flood water conveyance capacity has been greatly reduced. Indeed I believe that even the ‘normal’ water level of the Thames has risen steadily during the last century in order to maintain navigation while avoiding dredging.
The EA claims that dredging ‘is not a sustainable solution’. In fact when the EA took over from the NRA, the EA disposed of and did not replace the existing Thames dredging equipment. So apart from not having dredging equipment, the EA now has nowhere to dispose of dredged material. Furthermore, the problem is compounded because low-level radioactive waste and other toxic run off has been discharged into the Thames for over fifty years, therefore ‘hot’ and polluted Thames sediment may be designated as ‘hazardous liquid waste’ consequently being difficult (and expensive) to dispose of.
Finally, having taken over responsibility for many watercourses (by re-designating critical ordinary watercourses as Main Rivers) the EA has failed to effectively utilise local knowledge and resources to in order to maintain the natural drainage process and thus reduce the probability of flooding.
