Bridgwater Tidal Barrier Final Public Consultation

Ahead of the forthcoming last public consultation on the Bridgwater Tidal Barrier (BTB) the rate and tax payers might consider asking what becomes of Bridgwater after the BTB reaches the end of its design life?

The answer is simple.  

if there  is no barrier capable of keeping the rising sea out there will be no house insurance, no mortgages and Bridgwater the town will not be a viable place to live. 

Our present proposed EA flood defence scheme is based on retreating as far back from the sea as we can, it deliberately  puts our backs to the wall  On one side of the barrier we will ultimately have the inter tidal habitat (the sea)  and on the other our housing and industry.

No space is being provided behind the proposed barrier to create another bigger one. As a consequence there will be nowhere to go with a replacement that does not have a huge and unnecessary price tag. There is an irony that land at Chilton Trinity returned to the sea under the present scheme  and the planned managed realignment in 2055  will be inadvertently reclaimed  under a downstream replacement barrier albeit land now poisoned with salt.

With sea level rise continuing for hundreds of years past the design life of the BTB one would expect that as responsible people we would give some consideration to what happens next. Unfortunately, like so many things in need of fixing and investment we seem content to kick the problem into future refusing even to consider how we might make some provision to help those that follow us.

Many years an Arup engineer called Poul Beckmann wrote  the opening sentence of a  document with the line “Human nature is that we put off until tomorrow what we should do today”. Never has that been more true today than in Somerset. Somerset’s failure to develop a realistic, affordable and sustainable long-term strategy is unforgivable.  It really is time for some of the promises made by our political leadership on this issue to be delivered and people stop making excuses why things cannot be done. Simply working our way through the Somerset 20 years plan and saying the future is not our business is irresponsible and unacceptable.

what was the question?

The SRA was asked “What is the SRA and its partners working assumption for the replacement of the existing scheme and barrier?

The written answer received from the SRA  answer is in blue

From day one, the tidal barrier will be designed in such a way that it will still provide a 1 in 1,000-year standard of protection in 2125. The design includes an allowance for climate change up to 2125.

  • Climate change does not stop in 2125!!!! 
  • 1:1,000 sounds good but its just the margin on the starting point and degrades over time. The Dutch use 1;10,000 and maintain it as the level of protection.

The downstream defences will be designed in such a way that they will still provide a 1 in 200-year standard of protection in 2055, with allowance for further adaption for climate change over time.

  • 2055 is important because this is the date from which managed realignment is implemented under Policy 7d39  of the Shoreline Management Plan.
EA explaining the scheme in 2017

It is to be expected that any piece of infrastructure would need updating after 100 years. We cannot decide now how future generations may wish to live or what their priorities for infrastructure will need to be. This is why, for example, there are plans for the Thames Barrier to be re-built in future decades but decisions on exactly where and what will be required are deliberately being left for later.

  • Building the barrier in the town as planned does not  give those in the future choices but leaves them no choice to but to go downstream and  use land we have previously given back to the sea and to abandon the £100M investment the present scheme will have cost.
  • The response attempts to conflate the need to replace the  1970’s Thames Barrier as a reason not to make provision today for a replacement  in Somerset. if you know you have to replace something why would you not plan for the replacement? Its an excuse. 
  • We should be learning the lessons of the past rather than making a  virtue of repeating the failures that the SRA reply implies.

The Thames Barrier Myth

The continual portrayal Thames Barrier shown on TV as an iconic single barrier solution is misleading; the barrier is actually part of the Thames Estuary flood defence system comprising not one but eight individual tidal barriers that all shut together. Five of the eight barriers are closer to Bridgwater’s  situation than the “Thames Barrier”. They are however where they should be at the mouth of the rivers they defend not 5 miles upstream as with Bridgwater’s Tidal Barrier.

Thames Estuary Flood Defence

Using the Thames Barrier as an excuse for not planning a replacement in Somerset is particularly disingenuous  for a number of reasons.

  1. Nearly 60 years ago  when the Thames Barrier was designed climate change was not understood as it is now. There was little provision for sea level rise just the post Ice Age tilt of the south of England to consider.
  2. The  Thames Barrier is upstream of what were active docks  that had navigation rights in the Thames Estuary.
  3. In Somerset we have a topography in the form of the Polden Hills, Pawlett Hill and Stockland Bristol that we can link and use to our advantage.  London does not have such a luxury.
  4. All the Thames Barrier replacement options  move the replacement barrier  downstream perhaps as far as Tilbury. (July 2016 update)
  5. The  most frequent use of the Thames Barrier is now the management of fluvial flood water rather than tidal surge. Something Bridgwater is not designed to do.
  6. Sedgemoor District Council is able to reserve space for a bridge over the Parrett south of Dunball should its not be doing the same for a replacement barrier?

The collective response is No ; there is no plan.

The SRA, EA and SDC were conformed as having contributed to the response

Bridgwater Tidal Barrier; the Questions the public need to Ask

Once  the question “how will the proposed Bridgwater Tidal Barrier be replaced?” the present  scheme simply looks out of date and poor value for money.

The Bridgwater Tidal Barrier is repeating the same mistake as was made with the Thames Barrier system setting it as far upstream as possible. Because of the selected location  a replacement would like the Thames Barrier have to go downstream towards Combwich. Confused? We should be.

When you go to public consultation some questions worth asking;

  1. How will the proposed Bridgwater Tidal Barrier be replaced?”
  2. What becomes of Bridgwater after sea level rise exceeds the design basis of the Bridgwater Tidal Barrier?
  3. Why is there no long-term plan or vision for what comes next?
  4. Why is the ratepayer required to provide money to raise river banks money protecting land at Chilton Trinity when the planned sea water flooding will make it of no economic value?
  5. Why is not improving fluvial flow in the river system  part of the scheme?
  6. Why did the cost of the scheme almost double after the location was decided on?

Sustainable Flood Defence

The UK has a serious problem with leadership and sustainable construction where flood defence is concerned. There is a profound lack of critical thinking in the delivery of future UK flood defences and an unwillingness by agencies to get their  hands dirty at a local level. As a consequence government continues to fail regarding sustainability and value for money; taxpayer funded agencies seem unable or unwilling to work together.  It is a situation compounded by wildlife and environmental organisations who have seen an opportunity to gain control of and modify land in much the same way that monasteries such as Glastonbury once did.

Flood defence schemes are invariably seen in terms of a definable project that can be closed rather than the first step of a sustainable long term solution. The protected community needs to live with and manage these schemes  for 100’s of years after they are built. Our thinking on delivery is just too short and too expensive when it is a 300 year or so problem and especially when the initial solution only has a 100 year design life; it makes little sense. There is an obvious gap. That gap  means that today’s options should at least consider what happens next. Should we really  be adopting a solution today requiring the construction of a  replacement barrier tomorrow rather than a scheme today that has  provision or a plan for extending it already built in? Our current scheme takes planned obsolescence to a new level.

We should not be closing out future options for the generations that follow and we should follow our own rules for sustainable development

“Sustainable development is development that meets the needs of the present, without compromising the ability of future generations to meet their own needs.”

Delivery of the Bridgwater Tidal Barrier continues to be an exemplar of non-sustainable thinking. Part of the scheme requires the river banks between the tidal barrier and the village of Combwich to be maintained. The EA’s plan to do this work as part of the barrier construction contract. Material is to be dug from the adjacent protected fields  and where a future Northern Bridgwater Bypass might be routed.  Sedgemoor District Council (SDC) have protected in the Local Plan a potential crossing point on the River Parrett just south of the  A38 roundabout at Dunball.

Clearly excavating Chilton Trinity’s fields and creating a series of salt water pits that creates an ideal future breeding ground for salt marsh breeding mosquito’s is not what people have considered the consequence to be. It is far from impossible that in a generation Chilton Trinity and Combwich may ultimately become uninhabitable because of this excavation process rather than from the increased flood risk. Managing mosquito borne diseases may well become the larger challenge in low lying areas as our climate warms up. It is difficult to see how the EA could contemplate the creation of such a situation.

With whole life costs of the Bridgwater Tidal Barrier reaching £100M for a barrier, secondary banks and the raised river banks; banks that need continual raising means we need to consider modification of the delivery model to get the costs of this project under control.

That whole life cost  also ignores the 100 year economic impact,  both locally and nationally, of losing 1000’s  of acres of productive agricultural land  notwithstanding the questionable morality of a food importing country  choosing to export more of its food production offshore. 

If we are going to build the solution we have we need better and more economic delivery solutions than is currently proposed. We can then at least  ameliorate the present situation with a better delivery system.

Brexit allows the modification of the EU water and waste directives  that have now been written into UK law. We can now change the way in which we manage waste for the better.

Sustainable Construction

Every year Sedgemoor will build 5-600 houses and the excavation of foundations and drains for each of these houses will create around 15-20m3 of waste material (clay) suitable for re use as bank raising fill material. Sedgemoor’s  planned housing developments  will create around 9,000m3 per year that currently must be paid for to be disposed of. Housing developers could supply all the material needed to raise the banks. That is sustainable construction.

Over the 100 years life of the barrier there could be as much as 900,000 m3 of material we need to find a home for; material that could be used to build up the banks and preserve the land we have at Chilton Trinity for future generations. Even if the volume is  only 10% of the possible amount its probably enough to avoid digging up land at Chilton Trinity.

Under present EA proposals the EA is going to pay landowners for material that other organisations with similar material must pay to dispose of. We are meant to be reducing this sort of activity not making the situation worse.

We simply don’t need to get all the work in place in 2024; we need just enough to maintain the flood defence need and then use local resources to progressively deliver the longer-term solution with a local benefit to the economy. This work could be collectively done by local contractors under the supervision of either the EA or the Drainage Board. There is simply no engineering need for the EA to wantonly and unnecessarily destroy our landscape when cheaper and more sustainable alternatives are available.

NB there is only an intent to continue to raise the river banks 

To put this into perspective that recycled material would

  • build a bank 5m high bank from the Bridgwater Tidal Barrier to Combwich.
  • raise the banks and build the secondary flood defences up to match climate change.
  • raise the banks, build the secondary flood defence and start building new defences north from Pawlett Hill towards Highbridge.
5m high and nearly 5 miles long, 100 years of digging house foundations

Sea Level Rise

Sea level rise is not expected to slow for at least 300 years making both the barrier redundant as the river banks can only be raised perhaps another metre before they overload the poor ground conditions of the Parrett Estuary. Ultimately the long term plan for Chilton Trinity and Pawlett Hams’s will be realised.

The continued conditioning of the population by the EA to passively accept surrender to the sea as the first option for non-London areas of the UK is disingenuous and defeatist and never mind its land we need to grow food on.

Way Forward

At £100M the present solution for the  Bridgwater Tidal barrier is clearly neither sustainable or affordable. A situation that needs to be laid at the door of the Government, Somerset Rivers Authority and specifically the EA and Sedgemoor District Council (SDC) who provide joint project oversight.  We need

  1. Sustainability in what we do is placed at the centre  of our plans
  2. An independent inquiry into how flood defence is being delivered in Somerset.
  3. A peer review of the BTB project  into how it has arrived where it has.

Bridgwater Tidal Barrier Drop in Session 10th July 2017

On the 10th of July at Bridgwater Town Hall (2-7pm) the EA and SDC will reveal the final form of their scheme for the Bridgwater Tidal Barrier. Its construction will shape the town for the next two hundred years. It is planned to be commissioned in 2024 and designed to operate for 100 years. The operational date is a political one rather than climate driven and unlike most similar structures it will be located within the town rather than at the mouth of the river.  Mitigation of a similar fluvial flood event to 2014 is not part of the barrier’s function.

People have been focused on the barrier yet the river banks are the important bit; what happens to them will decide how radically our existing landscape will change and have far greater impact than a set of gates. The downstream river banks are being maintained in accordance with the FCERM Strategy (the national flood and coastal erosion risk management strategy for England).Individual polices are detailed in the local 2010 Shoreline Management Plan covering the next 20, 50 and 100 years.

For the Parrett those policies say that within the operational life of the barrier “The long term vision is for a more naturally functioning estuary, through construction of set-back defences under a policy of managed realignment.” Land is being returned to the tidal zone.

EA maps produced in 2010 show how that will be achieved at Pawlett Hams and Chilton Trinity. The recently released BTB secondary flood defence plan and residual flood risk maps show the long term policies are being put in place. Only the river banks close to Combwich and Chilton Trinity housing will continue to be raised. Farmland will ultimately be flooded and lost as the majority of the river banks will cease to be raised to match climate change. Steart Peninsula’s habitat will in due course be extended to Dunball and Chilton Trinity.

The present scheme means that the opportunity to increase the conveyance capacity of the Parrett capacity by moving a future replacement barrier downstream is lost. Taunton Deane and South Somerset may have to build fluvial storage on their land in the future. Opportunities for a cost effective bypass will be lost to the detriment of Bridgwater and West Somerset. As a naturally occurring event Somerset land owners will not receive compensation. Bridgwater will pay around £20m in lost land values towards the present scheme. A major economic impact on Somerset as a whole is just being ignored.

It is simply not true or credible that the BTB can somehow be divorced from the EA’s longer plan for the Parrett Estuary; a plan prepared in 2010 predating the 2014 flooding of the Somerset Levels.

The Bridgwater Tidal barrier in its present form passed its sell by date in 2014 when fluvial flooding moved from management on the Levels to flooding within our homes. Even today people still imagine that the Bridgwater Tidal Barrier is somehow part of the scheme to mitigate the 2014 flood, it could be but it isn’t. The Levels’ will still flood as they did in 2014 if we get similar weather conditions.

With little information in the public domain including the option studies that supported the original 7 location and the shorter list of 4 it is not unreasonable that this scheme has many questions of transparency.  it  is unacceptable that important and relevant information is not available to the public ahead of the final consultation on the 10th of July. That flood maps produced in September 2016 have only just been published giving people little time to understand the implications of what is planned.

If the FCERM Strategy and Parrett Estuary Flood Management Strategy are executed in their present form 1000’s of acres of agricultural land will be lost to food production. Is it morally right that the UK which cannot feed itself should export even more of its food production overseas and possibly deny food to others? This lack of responsibility on our part will no doubt be further compounded when our overseas aid budget has to be used to relieve a famine we as a nation knowingly or perhaps worse unknowingly contributed to.

To reach this situation there is a clear lack of leadership, vision, scrutiny and oversight by those organisations and people charged with delivering the plan and the infrastructure for Somerset. Neither SDC nor the SRA has any engineering or qualified staff able to lead on flooding and  has chosen not to bring in people that could. There is also a clear engineering  deficit in the delivery of Somerset’s flood defences.

People should go along to the consultation and ask

  1. Is turning the River Parrett back 500 to 1000 years and extending the Steart Peninsula wildlife habitat to Dunball whilst constraining economic development really what Bridgwater and wider Somerset need?
  2. Why wasn’t a barrier considered at Combwich and extending to Pawlett Hill that would protect the whole area. Arguments that we might impinge on the edge of the SSI is not an argument for not even looking at the possibility.
  3. Why does the barrier only do TIDAL and not  FLUVIAL (2014 rainfall) with equal importance?
  4. What is the extra cost of building a barrier with a bridge on it?

 

Steve Trowbridge CEng MICE MIStructE

 

 

Chilton Trinity and Pawlett Hams

The EA’s 2011 document Managing flood risk on the Severn Estuary provided the EA’s vision for Steart Peninsula  including what subsequently became the Steart Marshes salt marsh  scheme.

Pawlett Hams no longer protected after 2030

Under present plans six  years after the completion of the proposed Bridgwater Tidal Barrier Pawlett Hams will cease to be defended. That means that the river banks will no  longer be maintained and the process of handing more farmland back to the sea  will start again. The estuary will in time return to the state it was in more than 500 years ago before the levels were drained. According to the EA this will see 387 Ha or just under 1000 acres of farmland lost to food production and the local economy although only 47Ha  is actually required to make up for coastline squeeze.

The Parrett Estuary Flood Risk Management Strategy   (PEFRMS) is a document remarkable for its narrow  vision that is more interested in extending the habitat for birds  whilst  completely failing to understand or chooses to stay silent on the impact of saltwater on agricultural land. The only economic impact considered seems  to be tourism.

Parrett Flood Management Recommended Strategy

Section 2.1.6 (b) notes that

North Devon and Somerset Shoreline Management Plan (Hartland Point to Anchor Head), Halcrow, due 2010. We are concurring with their emerging policies.

As such much of the real detail  is provided in the EA’s Shoreline Management Plan rather than the overarching Parrett Estuary Flood Management Strategy which is a long term plan to let down the flood defences along the River Parrett allowing the sea up to the edge of Chilton Trinity and trading off land in Sedgemoor for economic development elsewhere around the Severn Estuary. It is a step back in time with individual communities afforded  long term term flood protection rather than comprehensive  flood defence.  The high level strategy  for the PEFRMS is provided below  following on is information from the shoreline management plan and recently available information for the preferential flooding of farmland as part of the Bridgwater Tidal Barrier Scheme.

Pawlett Hams Realignment is the complete loss of Pawlett Hams as can be seen from the key plan in the Parrett Estuary Flood Management Strategy  and noted in item c above.

Applicable Shoreline Management Plan delivery of the Strategy that includes the loss of 387 Hectares (1000 Acres of land) at Pawlett Hams is  reproduced below.

Parrett Estuary (Combwich to River Brue) Policies 7d38 to 7d42

Individual policies for various  sections of the River Parrett and adjacent land are listed below. 7d39 is  worth noting as it has the next major realignment of the flood defences after Pawlett Hams allowing the River Parrett to come up within 1000m of the village of Chilton Trinity.

Policies 7d38 to 7d42

Full copies of the EA policies can be found at

Steart Peninsula (Stolford to Combwich) 7d34 to 7d37

Parrett Estuary (Combwich to River Brue) 7d38 to 7d42

Timescales 

all documents refer to timescales and these are

  • Short Term (to 2025)
  • Medium Term (to 2055)
  • Long Term  (to 2105)

Chilton Trinity

South of the Parrett the EA ultimately proposed to let the marshes return to the very edge of Bridgwater  whilst Sedgemoor District Council  and the EA’s Bridgwater Barrier team have left a space at site 4 for a bridge that is on the way to a planned inter tidal area  and represents the expansion of the Steart Peninsula scheme  up to Bridgwater.

EA presentation Severn Estuary Forum 2017

Managed Realignment

the planned retreat of the existing flood defences

Policy 7d42 Flood defences from Dunball To the River Brue
Policy 7d39 Combwich to Bridgwater (Parrett west) managed realignment.

Those two policies when implemented will along with Steart Marshes and the Bristol Ports land transform the Parrett Estuary.  There will be no new link possible between West and East Somerset.

Future (long term) Inter tidal habitat – salt marsh and mud flats

Total agricultural  land lost to agricultural will be around 5000 acres. There is a certain irony that the EA policies will in reducing UK agricultural land export food production abroad and potentially increase famine oversees.

In the short term  the  proposed secondary flood defences  shown below are required because the EA will not keep  raising the banks above the present levels. sea level rise will continue and the frequency of seawater flooding will increase. The route of the secondary flood defence is not dissimilar to the future managed realignment above.

Secondary Flood Banks based on Bridgwater Tidal Barrier at Site 5

The gap in the flood defences at Walpole still left open for floodwater to flood the area as it previously did in the 80’s

After the planned completion of the Bridgwater Tidal Barrier  a 1:200 flood is expected by the designers to flood land to the north of Chilton Trinity with saltwater. The maps below represent some of the 50 maps prepared by the BTB designers to support the decision on location of the BTB barrier; the complete set of maps can be found on the SDC Strategic Flood Risk Assessment page.

The maps below show the impact of the river banks not being raised to match rising sea levels apart from  the protected communities. The end result is the preferential flooding of farmland with saltwater during certain tide and storm conditions as presented during the Severn Estuary Forum 2017   held in Bridgwater.

None of this information was presented during the two EA/SDC public consultations in 2016. 

2025 1:200 Flood Return

The map below shows one of  breach locations modelled. A breach can occur anywhere, the map does not say its saline (salt) flood waters escaping from the river. They are merely designed to provide an idea of the  likely consequence of it happening. The full pack of maps shows a number of breach locations and these are yet to published by Sedgemoor District Council.

River Bank fails at Dunball at land to the north of Chilton Trinity flooded

One of the maps produced by the designer showing the safety risks associated with their present scheme.

BRIDGWATER TIDAL BARRIER ; SITE 5; FLOOD HAZARD 1 :1000 YEAR FLOOD EVENT

 

The River Parrett – how it works

Rivers that discharge into the Severn Estuary are very different from most UK rivers. With a tidal range in the estuary of around 11m  MLWN -3. 0 and MLWS -5.7 AOD and the river bed level at around 0.00 AOD.  These levels means that at low tide in the estuary the water level is always below the bed of the River Parrett and the river simply empties into the estuary. In the case of the Parrett its a process that goes as far upstream as Oath and the changing tide sees the river refilling from the sea.

What is seen looking over the Bridgwater’s bridges is just one half of the normal tidal cycle you would see at the coast; at low (ebb) tide its purely fresh water going out and that can be seen on the West Quay tidal gauge where the graph flattens. Equally the point at where incoming seawater (saltwater)  takes over from the  freshwater of the Parrett and becomes  a relatively small component of the rivers water can also  estimated.

At low tides the river empties so completely that during periods of low fluvial flow it can actually dry out so much so that upstream of Combwich there is an old iron age path where people simply walked across the river at low tide.

High tides can be nearly 2m above the surrounding land and at Bristol Road nearly as high as the head of the doors and over the next hundred years that will  continue to grow .

Ecologically it is largely a  dead river. Nature likes, however bad, a consistent environment and the Parrett offers the greatest of changes twice a day from empty to full and freshwater to saltwater. The large amounts of Seven Estuary silt that arrives with the tides exclude sunlight and there is nothing to generate oxygen. Fish(salmon) and Elvers just transit the river on their way to the fresh water of the River Parrett and its tributaries.

It is a true challenge for The EU Water Framework Directive as  there is little negative actions that can be done to it. The lack of water does not deter unrealistic claims that fisheries exist in the river.

The images below show River Parrett tides ( courtesy of  GaugeMap)

West Quay One days Tides
West Quay One weeks Tides
HPC Tide Gauge

The Hinkley Point tide gauge above shows the full cycle of the tide in compoarison to the truncated cycle at West Quay which is caused by the river bed being higher than the sea bed in the Seven Estuary.

West Quay- One Months Tides

Looking along the river it could be shown

River Parrett at Low Tide

2014 Flood

In 2014 the Somerset Levels flooded, normally excess water is stored on the levels and then pumped back into the river  when the weather improves and fluvial flows have reduced. The floods occurred because the flood storage capacity  of the land was exceeded.

The response to the flood and still the current plan is pumps some more fixed ones and temporary platforms for hired pumps such as the permanent platform at Dunball made ready for the next time the levels flood and improvements made to how fast the flood water can be drained off the Levels.

One important question is whether its  possible to increase the  amount of water that flows  down the river without pumps? 

The answer is yes;  the Thames Barrier is used in that way when there is flooding and the Thames and its tributaries are at capacity. The barrier gates are closed at low tide creating a shallow reservoir normally filled by the incoming tide and floodwater coming down the river fills it up. Previous references to the Thames Barrier and the River Parrett were in relation to the type  of gate rather than how the system operates.

How might it work in the River Parrett?

There are two sources of fluvial floes into the Parrett. The Parrett and King SedgemoorDrain (KSD) /Sowy River.  Water unable to get down the River Parrett is diverted around Bridgwater via the KSD/Sowy and re-enters the Parrett at Dunball.

Dunball Clyce (River Parrett side)

Both  sources can discharge when the tide is out  but become tide locked when the sea re-enters the river.  Creating a large temporary empty length of river downstream of Dunball would allow both sources to continue flowing and when full and matched with the tide allowed to go to the sea.

River Parrett – Increasing the Flow

To do this a gate is needed downstream of Dunball and the best location would be Combwich or somewhere in between.  The Bridgwater Tidal Barrier is a gate that could  have been used to do this.

EA  Downstream  Scheme 

The   current plan is to build the Bridgwater Tidal  Barrier upstream of Dunball Clyce and with sea and tide levels continuing to rise  allowing the sea to reclaim the farmland  at Chilton Trinity and Pawlett Hams.  The existing  system returning to an inter tidal saltmarsh/mudflat covering the existing farmland at Pawlett Hams and most of the land to the north of the village of Chilton Trinity. The drawing below shows how the regime will change over the years to come.

River Parrett at Chilton Trinity & Pawlett Hams showing planned next 100 years

The information can be found in

The Parrett Estuary Flood Flood Risk Management Strategy

Full copies of the EA policies can be found at

Steart Peninsula (Stolford to Combwich) 7d34 to 7d37

Parrett Estuary (Combwich to River Brue) 7d38 to 7d42

further information with flood maps can be found in the article on

Chilton Trinity and Pawlett Hams

 

 

 

 

Somerset’s 20 Year Flood Action Plan is not a Plan

Has anyone noticed  there actually isn’t really a plan for managing flooding in Somerset  be it Tidal or Fluvial. Lots of headlines and pictures of grandstanding councillors on river banks  but little substance.  Our particular collective flood Emperor has no clothes whilst the myth that somehow the Bridgwater Tidal Barrier (BTB) is part of the solution to the avoiding a repeat of the 2014 flood is allowed to persist. People imagine that things are being done and there is a big picture somewhere. There isnt.

The Somerset 20 Year Flood Action Plan is little more than a  maintenance list that should have been done and wasn’t; it is a complete misnomer. In three years since the 2014 flood  there is no  big plan looking forward  the next 200 years. There is no context that  explains where the value of all the money being spent is.

There is no excuse for such short sighted behaviour by our officials and elected representatives. At least the Somerset Rivers Authority (SRA) carried out an economic impact assessment of the 2014 flood which is more than the EA and Sedgemoor District Council (SDC) have done for the Bridgwater Tidal  Barrier.

The development of new ideas  seems to be more akin to those seeking alternative medicinal remedies; they seem to be ones that will turn the Levels into some theme park rather than look at something that can be delivered over the decades and centuries ahead. The  Managed  Retreat (Realignment) of our coastline is not a panacea to rising sea levels; it has its place but  needs to be challenged when there are viable options.  Giving the EA the excuse and licence to do little or nothing is not acceptable. Those involved with W&WT and the RSPB as consistent beneficiaries of these  EA policies and alongside Natural England makes an unholy alliance  that is no friend of Somerset’s people.

Plenty of councillors are sat on committees and they should be ensuring rigorous debate and the publishing of useful information rather than the almost complete lack of detail in the public domain. The private sector would not be allowed to get away with this lack of transparency or vision.

Since 2014 when it was rushed together for political expediency  little has been done or achieved whilst show case projects are not what they seem

Bridgwater Tidal Barrier

Despite knowing that  the rise in sea level  has no recognised end date Somerset has decided on a  100 year scheme. Our King Canute moment.

We are going to build a scheme that cannot be easily extended or modified knowing full well that something else will be needed in the future but we haven’t decided what. A scheme that  unlike any conventional tidal surge barrier  it is  actually to be in the town rather than down stream and at the mouth of the river. Bridgwater in  probably 10 rather than 100 years will have enveloped the proposed barrier site.  A solution with built in obsolescence that  can be bypassed on day one does not seem a great idea. Children born today may see the BTB torn down. Why would Bridgwater  buy it?”

Options such as closing the gap between Stockland Bristol  and Pawlett Hill less than 2 Km  ( 1.3 miles) long compared to around 15 km (10 miles) both banks from Combwich to the selected site in Bridgwater or 7.5 Km  if you allow Pawlett Hams to go the way of Steart Peninsula.

Two option studies paid for by the taxpayer and Combwich  not even considered as an option in either and the  backdoor flood route at Walpole still not acknowledged when the EA visits landowners. The credibility of the EA , its consultants and our oversight committees is very poor.

King Sedgemoor Drain Improvement

The King Sedgemoor Drain improvement is a Fluvial conveyance scheme that cannot reach its full potential because of the location of the tidal BTB upstream of Dunball Clyce. The EA in this matter described themselves in recent correspondence as the SRA’s sub contractor.

Silos

Flood schemes are kept in silos of fluvial and tidal rather than in developing a single holistic solution for Somerset. The EA and other organisations make it very difficult  to see the full picture. There is a serious lack of transparency,  accountability and independent review in the process.

By 2024 nearly £100m will have been spent and the Levels will still flood. The Bridgwater Tidal Barrier is seen and portrayed as a Bridgwater only scheme where as moving it downstream  of the KSD outfall would increase conveyance  under fluvial conditions benefiting the districts of Taunton Deane and South Somerset. The SRA is nowhere to be seen generating debate and  bringing together people to achieve a wider benefit to Somerset with state and local ratepayers money which was its reason to be created. The SRA’s one big opportunity missed. This is notwithstanding the missed economic opportunity for West Somerset

Transparency

There is more information in the public domain about EDF’s Hinkley Point C power station then there is about these schemes especially the Bridgwater Tidal Barrier. It appears  the EA did not want the Chilton Trinity  and Pawlett Hams landowners to be aware of  what would not be done to protect their land choosing to hide behind the rather opaque Parrett Estuary Flood Risk Management Strategy. Something noticeably low key to the point of invisibility  in the EA’s 2016 consultations at the Bridgwater Art’s Centre.

The reasons  that undertakings given by the EA and SDC in Protecting Bridgwater and the Somerset Levels & Moors from Tidal Flooding-Flood Risk Management Review -November 2014 were never followed through and just quietly dropped has never been explained.

No imagination  and no vision for our children’s future

With a blank sheet of paper and little or no restrictions on what we might do to protect the South Somerset Levels including areas of Sedgemoor, Taunton Deane and  South Somerset there is still a blank piece of paper. Rarely has such an opportunity been squandered.

There is nothing that explains what happens to the Tidal Surge Barrier when we cannot raise the banks any longer which in reality we cant now and Pawlett Hams and Chilton Trinity have become mudflats/ salt marsh  and the cost of building downstream  prohibitive.

What we do have is lots of committees

Wessex Regional Flood and Coastal Committee (RFCC)

Board of the Somerset Rivers Authority (SRA)

SRA Joint Scrutiny Panel

Somerset Drainage Board Consortium (IDB)

Its interesting to note how many people sit  on more than one of these committees. These committees  have people with no engineering knowledge or experience apart from the EA & IDB and all EA’s donkey work is done by US and Canadian third party consultants with no attachment to the area. The EA’s contribution to Somerset is questionable now as they have been reduced to little more than a middle man.

we must also not forget the groups

  • SRA  Management Group
  • SRA Technical Group
  • Bristol Channel Strategic Coastal Group
  • South West Coastal Group
  • Southern Coastal Group

It really is time that Somerset had  a suitable organisation capable of bringing a long term vision to secure the future of Somerset. Whilst attendance at committees is so lucrative  nothing is going to get done .  The EA is not a delivery based organisation and needs to be changed or replaced.  The SRA has no structure or suitable people able to develop and execute the vision and solution we need. The system  we have is clearly not fit for purpose.

The situation for Somerset, the rest of the West Country and no doubt other regions of the UK is that they need their own independent Engineers with local knowledge. Engineers able  to provide continuity  in advice to the committees and oversee the EA and IDB and other agencies.

We cannot afford

  • that each agency (EA, Highways, Rail) continues to builds its own thing, we need to combine flood defence with other infrastructure works.
  • that strategic flood decisions can be left to seconded senior local authority officers  with little or no knowledge of the subject.
  • the lack of an independent peer review process.
  • The lack of transparency – there is nothing published on the BTB website that tells you why.  There is little value value in an undated progress report  that can be found there  that does not measure progress. 
  • all these organisations whose main purpose seems to be to invite people from other groups to attend their meetings at our expense.

WE NEED A PLAN and we need to end the Flooding Golden Goose. 

on the 14th of July 2017  a meeting of the Scrutiny Committee  will take place in Taunton . It is open to the public. 

http://www.somersetriversauthority.org.uk/about-us/sra-scrutiny-meetings-and-papers/

 

A Tidal Surge Barrier, A Bridge & Dunball Wharf

One of the problems with building the Bridgwater Tidal Barrier downstream of Dunball Wharf is the marine traffic to Dunball Wharf. Sedgemoor District Councils current draft local plan states “The Council will support the continued operation and potential development of Bridgwater Port including Dunball Wharf and Combwich Wharf (Policy D16 applies). It will also support the re-establishment of active commercial wharf’s at suitable locations elsewhere on the River Parrett. In all cases the construction or operation of new wharf’s should not adversely impact upon the Severn Estuary internationally designated site.”

The reality is that  the Dunball Wharf’s with their tidal drying berths, dependency on  high tides and difficult navigation is never going to be a commercial success but the 200m wide river at Combwich might. Construction of  the tidal surge barrier could enable the relocation of Dunball Wharf to a better location.

Much hangs on what is considered to be adverse.

Concepts of what the river structures might look like have not been forthcoming since 2009. Apart from the tower  and turning vertical gate Bridgwater’s gate structure will be considerably shorter than the Hull Barrier structure we have  been repeatedly shown.

What would a barrier with a road bridge  options look like?

Another wharf at Combwich, EDF have  one there already, would not require an opening bridge or clearance much more than Drove Bridge on the NDR. A tidal surge barrier with a 40m fixed navigation span and a road deck might look like

http://https://www.youtube.com/watch?v=sjX20a1a7sg

Keeping Dunball Wharf  would require a one larger gate and an opening bridge. Dunball currently sees 40 or so vessel movements a year so its operation would not affect the bypass traffic.

The engineering is relatively simple and with a purpose built wharf everything could be shipped in during construction.