Build the Bridgwater Tidal Barrier at Combwich

The option of building the Bridgwater Tidal Barrier at Combwich  was always affordable and as we now see the full whole life cost of the present scheme being made public its clear the best location was never considered.

Why Combwich?

Combwich would be a conventional location for a tidal barrier as its near the mouth of the River Parrett.  Combwich is a unique site that would offer Somerset a long term solution to protecting the southern Levels as a barrier and associated embankment would close the narrow gap between Stockland Bristol and the Polden Hills via Pawlett Hill. The location also offers an appreciable increase in the fluvial conveyance capacity of the existing River Parrett catchment river system.

COMBWICH & BRIDGWATER TIDAL BARRIER LOCATIONS

Original image is courtesy of the British Geological Society.

The yellow colour in the above image is the soft clay deposited around 11,000 years ago. The existing river banks will see the new flood defences from Combwich up to the site of the proposed Bridgwater Tidal Barrier built on this soft material that is up to 20m deep. Defences that due to settlement will need to be  built back up every 30-35 years  defending  land that will have been flooded  with saltwater. 

The argument is that it’s the cheapest solution where it is in Bridgwater. 

People continue to believe the width of the river and the length of the barrier structure is the only driving cost of the scheme. Whilst size does matter it is not all that matters. Like most schemes that start without a clear direction the final cost proves to be significantly more expensive than expected and the Bridgwater Tidal Barrier is no exception. The EA project team didn’t understand its costs just its objective. They are not the same and nor are they aligned with securing Somerset’s long term future.

Most people are aware that present scheme  originated from a 2009 scheme that was little more than a knee jerk reaction to climate change and the long-standing need for a control system in the river. What we have seen is that inexperience in project delivery saw the early focus on one element of the scheme rather than the scheme as a whole. Effort was exclusively focused  on the barrier, the type of gate and location within a short length of the River Parrett and it clouded objective thinking about  an holistic scheme. It was so bad that the EA team doing the barrier were unaware of the test bank being done by the EA and Team Van Oord;  there was simply no joined up thinking.

Nobody at  that time or since has been willing to stand back and take a cold hard look at what was needed when the Cameron Government’s political promise of post 2014 flood money removed critical thinking from the delivery process.

The simple fact is that every activity has a cost and the choice the client and the designer has is where you spend the money today and tomorrow. A simple comparison of where our money will be spent is produced below. You can spend money on lawyers and land agreements for secondary flood defences or spend the money on a better barrier. Paper does not keep the sea out.

Combwich offers a number of advantages that offset the barriers extra length and the constraints of the present location in Bridgwater. These advantages include the use of precast concrete construction, the  availability of space for construction, no need for an expensive diversion channel and the long periods when the river is empty make considerable cost savings.

The key savings are given below.

Where the barrier money goes

a barrier structure could also support a future bypass.

Barrier and replacement Dunball Wharf at Combwich

The good thing about the River Parrett and there are very few is that its possible to work on the river bed without the need for a coffer dam. If you have the space and you’re in the infrequently used navigation channel of the Parrett you move and do things in the water during high tide and then drive down the bank onto a prepared river bed. and work during low tide.

 

Bridgwater Tidal Barrier Cost; an unacceptable defence

The January 2018  news that the estimated cost of the Bridgwater Tidal Barrier (BTB) had reached £100M caused the BBC last week to interview stakeholders at the EA, Sedgemoor and Bridgwater Town Council. Anyone who heard the interviews and knows anything of the history of this project will be as equally concerned as Bridgwater’s Town Council. The risk regarding withdrawal of funding is real; Government will not accept being led on and neither should the ratepayer which is becoming the real story of the Bridgwater Tidal Barrier.

EA and SDC interviews.

  1. The EA chose somewhat disingenuously to blame the hike in price on the Government making a perfectly normal and responsible demand regarding cost information. Information not previously provided to the SDC ratepayer. It was clear during the public consultations (the boards are still available on the SDC website) that the selection method (river width) was flawed in ignoring the cost of the downstream works and the associated maintenance costs that went with them. Cost confusion about this project has been a problem ever since work started on developing options and presenting the options to the public. Previous written responses raised this issue in March 2016 and nothing was done to clarify the situation in subsequent public consultations.
  2.  The well known poor ground conditions of the Parrett Estuary were again blamed. Ground conditions have become a convenient hook to hang cost increases on. If the costs associated with ground conditions are being continually underestimated at such a late date there is clearly a management issue that needs to be fixed. 
  3. SDC again conflated Cameron’s “never again “statement made in 2014 with the Bridgwater Tidal Barrier. People will continue to imagine that the Bridgwater Tidal Barrier will somehow mitigate a 2014 flood when that isn’t the case.

Readers can listen to the program on BBC iPlayer for a few weeks. Move the bar along to hear the EA at 40min and SDC is around 140min

The defence of the cost is indefensible.

The reality is that neither the EA’s technical management team, those responsible for providing senior project management/Governance (EA/SDC) or the councillors providing oversight have the necessary experience for a project like this. (£29M was beyond their reach and £100M is farther still and requires experienced management).  The BTB  was always going to get away from under them as it clearly has.

As a contributor to the EFRA Future Flood Prevention report in 2016 I highlighted the issues that are deeply embedded in this project. Entitled Managing local UK infrastructure; the Client Deficit.  it highlighted the lack of  an independent adviser to stakeholders as a continuing problem with UK locally managed infrastructure projects, it is a situation repeated elsewhere and in Somerset the SRA is a particularly good example of people being responsible for delivering projects that they are not experienced or qualified to do and not being provided with the support they need. The KSD  expansion project seems to be struggling in a similar way to the BTB. Googling ones mobile phone is not a valid substitute for experience nor is having laid a patio in earlier years.

We all now understand that the Bridgwater Tidal Barrier solution (location) was driven solely by the promoted idea that “river width”  somehow equated directly to project cost;  getting the barrier as far upstream (narrowest point) was the cheapest option for the EA. it was always a flawed strategy and the cost we are now seeing is the result of that approach. It is the result of not doing work that should have been done during the options study.  The initial cost of the downstream raising of the river banks and the cost associated with the intent to continue to do so does not appear to have been fully considered in the original location decision.

Unfortunately, valuable and costly time was spent on what sort of gate we should have had rather than looking at the overall solution and there was no challenge to the 2009 B&V spread of locations. Long term costs and the EA’s rather ambiguous position regarding the long term raising of the river banks were conveniently ignored in the 2016 public consultations.  Consultations that completely ignored the principles set out in  Government guidelines on public consultations.

This situation was compounded by the obvious client project inexperience shown in the rush to engineering studies before an outline plan was agreed that always results in the cost escalation we are seeing. The sudden arrival of the secondary flood defences is something that should have been highlighted in the option studies, it may not have been needed at sites farther downstream and was not shown in the early public consultations. After 30 years of managing the design process on much larger projects than the BTB starting a project without a real plan is always a trap waiting for the unwary. Sadly, as a result of the BTB execution strategy what we now have is less normal project delivery and more an episode of Grand Designs.  At least the consultants should avoid any blame.

What was striking in last week’s radio interview was the lack of any new arguments after all the work that has apparently been done to support the scheme in its present form. What is equally impressive is that both the EA and SDC imagine that Bridgwater will not want to grow beyond the line of the barrier over the next 100 years or that a critical piece of infrastructure should be located so close to the town. Shouldn’t someone have asked how big will Bridgwater be in 100 years? The whole BTB project appears to have now deteriorated to the justification of an original poor decision. It is most disappointing.

The information the ratepayer has seen to date raises questions of transparency or competency neither of which seems to have been achieved or available to any degree. 

Ratepayers should not be paying for all the people involved in the BTB project and the broader Somerset Flooding issues to be learning on the job which seems to be the case.

Its well past the time that the Bridgwater Tidal Barrier including its location is independently reviewed before it is presented to the ratepayer one last time.  Its time we considered moving the Bridgwater Tidal Barrier downstream to Combwich.

The questions of

  • transparency with regard to cost and economic impact.
  • management team  competency
  • oversight competency and relevant experience 
  • the approved barrier location
  • what happens at the end of the 100 year design life; Bridgwater Tidal Barrier 2?

clearly needs to be looked at as the information previously provided to the public and one assumes our councillors did not reach the standards we should expect and was wrong.

Projects do not suddenly almost double in price in 15 months without good reason. The defence of the cost increase presented in the interviews was as unacceptable as the scheme itself has now become.

Bridgwater Tidal Barrier cost reaches £100M

Sedgemoor District Council  and the Environment Agency  recently reported at the Somerset Rivers Authority (SRA) meeting  in January a 50% increase in the cost of the Bridgwater Tidal Barrier. The reported cost appears to have increased from  £70M in October 2017 to £100M in January  2018  (five months) and yet it went through without comment .

The cost escalation of a scheme that does nothing to address the 2014 fluvial flood is eye watering and yet, according to the minutes, no action is taken to explain why this escalation had occurred and what action was being done to mitigate it. The mere acceptance by our elected members is not acceptable if the delivery of our infrastructure is to be managed locally rather than through central government.

Bridgwater Tidal Barrier Cost History

  1. March 2014 the cost of  barrier was reported at £26M
  2. September  2016 The EA  gave the public figures during a public consultation  various options with costs;  site 5 the selected site was costed at £45M – £60M.
  3. October 2017 the BBC reported on the cost of the scheme to be  in the order of £70M  “Bridgwater tidal barrier costs ‘could go up by £10m”
  4. January 2018  indicates the cost is now around £100M as noted below from the published SRA draft minutes.

In a period of around 15 months from September 2016 to January 2018 the cost of the Bridgwater Tidal Barrier scheme rose by around £50M or 100% and not one word of concern is  expressed or recorded in the public domain. This cost is now  nearly 4x  the original cost estimate in 2014.

Bridgwater Tidal Barrier is now a £100M scheme where

  • the financial investment makes no contribution to mitigating a repeating 2014 fluvial flood,
  • repeated saltwater flooding onto farm land from the River Parrett is seen as being an acceptable regime despite poisoning farmland and wildlife. 
  • there is no plan in place beyond the barriers  100 year design life
  • brings saltwater  onto our agricultural land

Looking at the numbers the only thing that can be concluded is that the cost estimates presented to the public and to councils for the purpose of decision making were widely inaccurate or inconsistent either of which is unacceptable for investment decisions; especially decisions that affect the long term future of Bridgwater and Somerset Levels beyond.

The selection decision of the current site (Site 5) was chosen purely on the basis of the width of the river and must now be called into question.  It would appear that the cost of the other downstream elements of the scheme must be causing this cost escalation. A cost and concern that were dismissed at the time of the consultation. 

Bridgwater Tidal Barrier is now a £100M scheme where

  • the financial investment makes no contribution to mitigating a repeating 2014 fluvial flood,
  • there is no plan in place beyond the barriers  100 year design life
  • repeated saltwater flooding onto farm land from the River Parrett is seen as being an acceptable regime despite poisoning farmland and wildlife. 
  • the EA wants to dig up the very land its meant to be protecting to win the soil  for flood defences.

No project should be seeing this amount of budgetary increase  without  challenge.  Cost escalation on this scale is unacceptable and unnecessary. There is clearly a continuing problem regarding a  lack of oversight both technically and financially in this project.

What should be done?

The extra £50M buys a much better scheme than the one Bridgwater is getting. £100M would allow

  1. the barrier to be located as is normal practice as close to the mouth of the river as possible which in this case  is Combwich. Combwich was never looked on the basis of cost, clearly that is an argument that can no longer be supported.
  2. elimination of most of the downstream river works that the EA’s tests indicate will need to happen every 35 years or so.
  3. increased fluvial capacity in the River Parrett and the King Sedgmoor Drain potentially benefiting communities beyond Sedgemoor
  4. a solution that can be economically extended beyond the 100 year design life currently offered.

£100M is £1M a year for next 100 years on scheme that will be rendered redundant once the river banks can no longer be raised to combat sea level rise; the scheme in present form is throwing money away 

The public expect that those on scrutiny committees to use there position to bring transparency  and accountability to the process of public expenditure. Such bringing to account appears to be sadly lacking together with visibility of any independent engineering review that a project of £100M warrants. The project is growing in value and the oversight is not growing with it.

Unfortunately what we see happening is the management of infrastructure projects by people, primarily councillors  and  officers who are unqualified to do so. The SRA is a prime example of an organisation primarily engaged in  the commissioning of engineering activities with no engineers in lead roles.  The Bridgwater Tidal Barrier has become a Grand Designs episode of Civil Engineering

Way forward

A  Public Inquiry  into the management  of the Bridgwater Tidal Barrier scheme should be convened that should look at

  1. Cost
  2. Management
  3. Consultation process
  4. Location  (including the examination of Combwich)
  5. Competency and experience  of councillors  and officials  to manage civil engineering works such as the Bridgwater Tidal Barrier and other SRA projects.,

 

 

Environment Agency – Landowner Information Pack

The Environment Agency (EA)  like the many  political parties with the word Democratic in  their title seems ever farther away  from what people imagine the organisation to be about. Protecting the Environment and the people seems not to be one of them if it gets in the way of its long term Parrett Estuary agenda  at Chilton Trinity north of Bridgwater.

However any doubts that the EA  doesn’t have a sense of humour or understands irony was firmly dispelled by its latest offering to the  Chilton Trinity landowners.  These are landowners whose land is impacted by downstream works  resulting from planned construction of the £100M Bridgwater Tidal Barrier close to the town rather than is conventional practice at the mouth of the River Parrett.

In March 2018 each landowner was the recipient of a document called BRIDGWATER TIDAL  BARRIER  DOWNSTREAM FLOOD  DEFENCES Landowner information Pack.

The EA’s  apparent lack of understanding of the impact of salt water flooding onto farm land. is worrying. The expected  floodwater  is not like 2014 when the water that covered the Somerset Levels was predominantly fluvial run off (freshwater). This will be seawater coming up the River Parrett from the Seven Estuary that over tops the river banks. 

This document also asks farmer’s to allow the Environment Agency to dig borrow pits in the land the EA are meant to be protecting.  Borrow Pits are meant to be refilled  with other less suitable soil so it does not lessen traffic as the EA claim but only if  they are left as  just open pits in which case they aren’t borrow pits.  Do we really need to excavate the land we are meant to be protecting?

The  alternative is a sustainable construction method that also seems to be a low priority of the EA.  Construction of the bank improvements could be phased over a number of years using local contractors and material reclaimed from new developments. 

The proposed pits will hold  the seawater (saltwater)  rather than see it quickly flushed away back to the river. Saltwater is poison to agricultural land and the habitat  we currently have in Chilton Trinity.  These  pits  will, according to the  trial embankment test done for the Cannington Bends improvement scheme, need to be reopened or enlarged every 35 years of so to make up the levels as the made up river banks settle.

The  EA promise going forward regarding maintaining bank  levels quite rightly only talks about intent; the EA cannot provide a firm promise however they do know  that once the land is poisoned the cost for further expenditure on bank raising will not be justified.

No one can say that the EA does not have a sense of humour especially when  the Chilton Trinity farmers are encouraged  by the EA to act as turkeys to vote for Christmas.  The EA’s long term ambition of an inter tidal habitat remains our pantomime villain  – he is behind us and  we chose not to look around and see him. Whilst appearing to help the EA  are actually creating a self fulfilling prophecy that will see  the area become salt marsh.

This document

  • Only talks about 2024 and not 100 years in the future (2124)  which is much more interesting for long term prosperity of everyone including our farmers handing land onto future generations. ( nobody says what happens when the banks can no longer be raised)
  • Confirms the level of protection they are planning to maintain to farm land is very low.
  • Omitted the future flood maps.
  • Omitted to  mention that the flood water will be seawater .
  • Demonstrates on page 4 a complete lack  of understanding of the impact of saltwater onto agricultural land. (Some Lincolnshire farmland has still not fully recovered from the 1953 flood when the North Sea over topped the sea defences)
  • Encourages the formation of borrow pits (actually just pits) that, when the banks of the River Parrett are overtopped, will trap seawater and ultimately destroy the value of the land its meant to protect.  Destroying wildlife and fauna in the process that cannot handle saline conditions A case of the medicine killing the patient.
  • Creates through the use of borrow pits mores areas of stagnant water that in our warming climate will be a breeding ground for insects, one of the reasons given for not damming the River Parrett.
  • Fails to mention the pits will need to be used and extended at least 3x as according to the embankment trial the river banks will need raising every 35 years.
  • Does not mention the final height of the river banks in 100 years’ time, for every metre raised the bank get wider by  2 x 4.0m and the banks will need to be raised by around 0.80m. (2’6″) excluding the continued settlement of the river banks that always means 2 steps forward and always 1 step back.
  • Re-confirms that agricultural land will be preferentially flooded.
  • The EA commitment is qualified as only an “intent” . Will SDC ratepayers pay for the maintenance when they don’t get anything back? It’s a huge liability that SDC could end up with that has no benefit to the town.  In a very short period of time, the cost of maintaining river banks to protect a small area of land and some ponds (flooded borrow pits) will not be considered worthwhile.

No one can say we were not warned about this  EA scheme and still no one asks what happens after the proposed scheme, the Bridgwater Tidal Barrier, can no longer counter rising sea levels?

One can only appreciate the irony and the humour of the situation  along with the EA’s other recent bits of entertainment

  • The   gathering up the local newt population at Steart and their subsequent disappearance
  • Diverting migrating elvers away from their normal route to our freshwater river system into the Steart Peninsula scheme.
  • Planning to build a tidal barrier as far inland and upstream as possible contrary to all normal accepted good practice.

to paraphrase Churchill

never has so much money been spent in such a small place to so little effect 

This document is at best poorly put together and at worst a device designed to obscure the true impact of the  plan from those most affected

As this slow-motion environmental, and for Bridgwater, and economic car crash occurs we should not forget that three prominent members of the Wessex Regional Flood and Coastal Committee live within a mile or so of where this unnecessary and increasingly misrepresented process is going on.  No objection or question is heard regarding the impact of the EA Scheme; there is no visible oversight.

The Internal Drainage Boards are equally silent as is the Somerset Rivers Authority

Finally, you know its wrong when that well-known litmus test is applied; The  scheme in its present form  has the support  Ian Liddell-Grainger

 

 

 

Sedgemoor, will the HPC community monies provide a real legacy?

Bridgwater and the surrounding district area of Sedgemoor continues to be dominated by claims regarding the benefits of the HPC monies. This is money  the community received  as part of the planning process; will it actually be a tangible legacy?  The litmus test might be an imaginary HPC plaque similar to the blue ones put on buildings remembering that famous people were born or lived there. In a generation or so could we take our children around the district pointing to things that we got because of HPC? The answer is probably No.

HPC has for Bridgwater and the surrounding area been like winning the lottery and like many winners the win has been frittered away on things that would in time have come anyway. New Infrastructure is always good value but difficult to do cheaply in our crowded and over developed land yet Sedgemoor until recently had everything on a plate, time, available strategic land in the right place and money. Bridgwater Cellophane site (BCL) factory in Bath Road cleared and the old Bridgwater Livestock Market cleared on the other side of the railway provided a unique opportunity to do something constructive with our HPC legacy to the benefit of the local town., its residents, businesses and the  economy. Transport and communication is all.

Like the Somerset Flood Action Plan that did little more than recognise the  EA’s lack of maintenance that had been permitted across the Somerset Levels whilst the EA had previously spent £20M on the Steart Peninsular project; the HPC legacy is more of the same, money is without doubt being squandered in the wrong places. Sedgemoor did it before with the now demolished Splash when it sold the Lido to Morrisons, its decision not to go for a Northern Bridgwater bypass a recent example and not to spend this money strategically and well when you have the opportunity is not a track record to be proud of.

A quick look back

Bridgwater over 40 years like most towns has changed. Once our manufacturing sites were spread throughout the town, Clarke’s beside the railway station, Wellworthy in Colley Lane, Gerber in Wembdon, Cryptons in Bristol Road, Van Heusen  and Leffmans in Bath Road. The multiple locations and predominance  of cycling to get to work meant our road system  could quickly absorb and dissipate traffic whether on two or four wheels. Employment and where we live have become divided, employment has largely migrated to the outskirts of town  mostly to the north and  we mostly live in the south and west with development slowly marching towards North Petherton.  If not we have to find our way over one of the inadequate number or river and rail crossings we have. The Railway and the River Parrett dominate how we live.as they divide Bridgwater into a series of strips running north to south.

Every day  the town get up and has to traverse the Cross Rifles roundabout whether to commute, shop go to school or  get to the bus and rail stations largely because of the Bath Road railway  bridge. There is no sign of  a plan to deal with this problem. 

What could have been done

In my view two related  and not too grand things to improve the town and areas with HPC money could have been done. and still should be  pursued.

  1. Move the Bridgwater Railway Station north onto the then empty BCL and market sites and include a  public foot/cycle path over the railway.
  2. Extend The Drove through to the market site linking the NDR directly to relocated railway station.
Alternative Bridgwater Railway Station Location

This would put the railway station near business, the Bridgwater College,  The McMillan Theatre and on existing bus routes. HPC workers could have arrived by train directly to the HPC accommodation on Bath Road.  Rail would provide a viable alternative to inward commuting. Encourage people going to work in the town to cycle. avoiding the Cross Rifles roundabout. If you cant fix the road at least give people choice of other methods to get to work  or to the station. There is no bus link to the existing station.

Bridgwater Railway Station is simply of the wrong era has short low platforms and is in the wrong place. It  serves nobody at the end of St John Street. Spending money on it is throwing good money after bad. Its time is up.

Bridgwater Railway Station

With the delay of HPC starting and the availability of these sites there was plenty of time to ensure the HPC legacy was used to secure long term infrastructure benefits that would generate increased economic activity. Activity that would in turn generate wealth that would have multiplied the HPC money many times over in the generations to come, there is simply no excuse for the lack of vision and competency shown at County and District Level.

 

 

 

 

 

 

 

 

 

 

Severn Estuary Forum 2017

The Severn Estuary Forum met for its annual meeting 2017 in Bridgwater, Somerset on the 5th October following hard on the heels of Question Time and the Antiques Road Show at the McMillian Theatre.

An event to see people working together to resolve climate change, flood risk and wildlife preservation it was not.

Richard Hickmet the High Sheriff of Somerset opened proceedings.

The day was split into three sessions and some notes on the highlights follow.

Energy and Climate Change

Session Chair SDC councillor Ann Fraser MBE introduced the session noting the increased trade (marine aggregates) going through Dunball now rising to 70,000T per year as a reflection of increasing economic trade. Fortunately, Ross Edwards in his following update on Hinkley Point C (HPC) noted that their aggregates jetty being built as part of the enabling works was still underway. The real reason for Dunball’s growth was more to do with HPC immediate need rather than some wider reason. The irony of the councillors assumptive claim was not lost.

Ross Edwards (EDF) was able to explain, whilst maintaining a serious face, the extreme lengths that EDF were going to protect the beach from the small feet of a jack up barge and a few discreet foundations. Yet another large corporate organisation feeling the need to succumb to the irrational demands of the modern environmentalist. He also noted that EDF had spent £20M on road improvements as part of the HPC project enabling works.

Dr Judith Wolf of the National Oceanography Centre in Liverpool provided a fascinating talk that actually dealt with the session subject. The moderating impact of the edge of the continental shelf in dissipating energy should make us all worry a little less about that large piece of a volcano that threatens to slide into the sea in the Canaries at La Palma causing a tsunami. The great flood of 1607 also got a brief note and it was not a tsunami.

What was more important was Dr Wolf’s comments on global warming and the best scenario of sea level rise being 0.5m and the worst at nearly  2.0m. Dr Wolf confirmed they really don’t know the figure as no one knows how the melting polar ice caps will impact on the world. It was received with little or no comment. 2.0m is around twice the figure that the EA is using for the Bridgwater Tidal Barrier (BTB).

Planning Governance & Flood Risk

Andy Hohl (EA) project manager of the Bridgwater Tidal Barrier project explained the mechanism of the floodgates but avoided the mechanism of the planned flood defence system.  A diagram was shown showing the planned flooding of Chilton Trinity and Pawlett Ham’s when there is coincident high tides and storm surges. It is an event that will increase in intensity and frequency as sea levels rise and after a few events will have poisoned the land.

River Parrett at Chilton Trinity and Pawlett Hams; EA flood model Bridgwater Tidal Barrier 5th October 2017; How the River Parrett will increasingly flood the Levels

The EA missed the opportunity to explain why a tidal barrier is to be built in Bridgwater rather than the conventional locations at the mouth of rivers such as at Newcastle and Barking.

Mr Hohl was asked what comes after rising sea levels makes the Bridgwater Tidal Barrier ( gate and river banks) ineffective in protecting the area from the sea. Apart from some irrelevant comments about things being done today, there was no answer about tomorrow. Tomorrow, if Dr Wolf is correct, will be only 50 and not 100 years away before a replacement solution is needed.

Wessex Water’s Lucy George gave an interesting talk on the construction of the new sewers being built around Bridgwater. Clever engineering in bad ground.

Protected Sites and Species
Alys Lavers the WWT manager at Steart gave an update on the last 3 years entitled Climate Change, Flood Risk and Community Action. It has obviously become a go to place for students studying for degrees and PHD’s. Even some elver’s have apparently decided it’s a great place deciding that the swim to Oathe and the freshwater rivers of the Tone, Yeo, Parrett and beyond was simply not worth the effort and turned right into the Steart reserve. Whether that was in the EIA and is safer than getting past the locals elvering is no doubt a study in itself. However a look at the IDB asset map apparently showing every route to freshwater blocked by a clyce  does not paint a promising future for the lost elvers.

Ms Laver was also remarkably candid about Steart. That there would be no facilities built there apart from the existing toilets. No chance of a place to shelter from the elements and have a cup of tea. Little chance then that Steart will deliver the promised economic contribution when planning permission was sought by the EA. Someone in the audience from Burnham on Sea said it was difficult to find and Ms Laver explained that the lack of signposting was deliberate. Apparently keeping the number of visitors down was done for the benefit of the locals.

What was apparent to many in the audience was that WWT Steart is really only interested in the right sort of visitor; academia and other suitable people. The ordinary taxpayers who paid for Steart from their taxes (that is where the EA get its money from) most definitely not welcome.

Rob Shore WWT, session chairman and coordinator of the Severn Vision introduced the document that was first published in January 2017. What is interesting is the ambition of this recent document. A saltmarsh from Dunball to Highbridge. The proposal outlined in this document is clearly in line with the EA’s and SDC’s current strategies set out in the Shoreline Management Plan and Parrett Estuary Flood Strategy.

The map below was generated from the Severn Vision interactive map. If you live around the Severn Estuary its worth checking out the aspirations of the various wildlife organisations.

Areas of Potential Saltmarsh

One cannot help but feel that the EA and various wildlife organisations including WWT  have the ambition to turn the coastal part of Somerset into a wildlife theme park.   Trading off the land in Somerset for planning gain elsewhere such the Bristol Ports deal where Bristol gets the economic benefit and people in Somerset beyond made to feel to feel uncomfortable in their own countryside is unacceptable. Climate change should not be used as  little more than a Trojan Horse by organisations with an overblown sense of morality and entitlement.

A question on the morality of an island that cannot feed itself flooding food producing farmland to create saltmarsh was quickly pushed to one side.

Finally a question about mitigating the noise from exploding old military ordnance being found as part of the HPC outfall construction work. Ordnance, when located, is subsequently blown up by the Navy’s bomb disposal team; it did not find someone willing and able to answer it.

Observations

What was quite clear was climate change and rising sea level is really only a device and agenda for wildlife organisations to pursue the expansion of wildlife habitat.

There was no big picture presented,  no key numbers and no one to provide context as to how the wildlife of the Severn Estuary, ordinary people and business might co-exist. Key local councillors present on all the flood committees, Wessex, the drainage boards and the SRA were with the exception of Ann Fraser notable by their absence. Perhaps there were no expenses paid for attendance. Councillor Fraser it was noted in the Speaker Summaries although not an engineer had been “instrumental in leading a technical review of the flood risk in Bridgwater”. The Somerset Rivers Authority is no better with regard to engineering. There is a disturbing and dangerous precedent of non-qualified people in influential positions shaping Somerset’s flood and climate change plans. Google and mobile phones do not make an expert. 

There is simply no leadership or vision when we should be looking forward not 100  years but perhaps 2 to 300 years. Sea level rise is not stopping and schemes such as the Bridgwater Tidal Barrier that just look forward 100 years and stop with no apparent reason defy reason and responsibility; what is the plan afterwards? there isnt one.

Perhaps worst of all for an event sponsored by my own institution, the Institution of Civil Engineers, there were no engineers representing the many companies making money from climate change. Engineer’s created the landscape we have and the current generation should be leading process of planning for our future but seem to have abdicated their interest or responsibility in shaping the land bordering the Severn Estuary.

Somerset and the other counties of England and Wales that border the Severn Estuary need to have a serious conversation and take control of climate change issue at a regional level. The situation needs a champion with authority and knowledge.

Bridgwater Northern Bypass – another opportunity lost

Bridgwater will not be getting a northern bypass anytime soon. Sedgemoor District Council’s HPC strategy to pursue in town traffic improvements in place of a bypass  is now widely known.  It was delivered in no small part by an option report commissioned by SDC and others Strategic Options Appraisal of Transport Proposals In Bridgwater that came up with a scheme whose cost and schedule ensured that both EDF and SDC could kick the bypass into the long grass.

Following on from the flood of 2014  the Government select committee Environment, Food and Rural Affairs Committee (EFRA) published its report in 2016  Future flood prevention.  It proposed that common infrastructure with multiple uses should be built that would maximise value for money; in Bridgwater’s case a bridge with a tidal barrier is value for money.  Despite the delay in the start of the Hinkley Point C and the promise of money for the Tidal Surge Barrier no councillor or official considered  looking at or revisiting the bypass option.

Logic said put a bridge on the barrier it makes sense.

B300 was a project that started life in 2013 six months before the 2014 floods; it is a commercially viable scheme that includes a proposal to relocate the proposed Bridgwater Tidal Barrier downstream of Dunball and incorporate a road bridge over the River Parrett. The road  bridge providing the important first stage of a Northern Bridgwater Bypass and allowing  the expansion of Bridgwater to the north of Chilton Trinity.

Bridgwater Tidal  Barrier and  Road Bridge

Technically there are no major issues with building a barrier downstream of Dunball and in someways  its simpler and easier than the proposed site. No need for a diversion channel.  The EA did work during its option studies that indicated that if the Bridgwater Tidal Barrier is sited downstream of Dunball  the flows in the river system of the River Parrett and King Sedgemoor Drain would be increased ; there was fluvial as well as tidal benefit . Nor is it difficult to put a bridge on the barrier structure. Experience gained on such projects as the Severn Second Crossing brought the costs of the alternative scheme towards the budget for the EA’s proposed site near the Police Station. B300 also proposed to close the gap between the end of the Polden Hills and Wembdon Hill sealing off the South Somerset Level’s from the sea. A proposal with considerable greater integrity than the present novel scheme of an in- town tidal barrier and raised river banks on ground that cannot allow the process of raising them to continue into the future . The B300 scheme would have seen everyone protected and new banks that could be raised in the future unlike the existing scheme that is limited by existing ground conditions.

There was a solution and the additional funding available to deliver a large more comprehensive scheme including tidal flood protection to 1:10,000 return  period compared to the 1;200 offered by the EA, a development including low energy homes and industry. The problem is that not all landowners want it. They reason that the ratepayer will ultimately build a bridge to their land and they will not need to make a contribution to the cost, The landowner taking maximum possible value whilst someone else (SDC ratepayers) pay.

Sadly with the EA delivering its Business Plan at the end of the 2017 those few landowners have run the clock down and the opportunity to implement the scheme is fading.

Beyond B300

If a bridge is built sometime in the future as part of a bypass linking the M5’s Junction 23 to Cannington both rate and taxpayer will have paid twice for work in the River Parrett that could have been done once. The aims of the EFRA report on taxpayer value for money will have been completely ignored and the rate and taxpayer left to pick up avoidable costs.

It will also mean that the opportunity will have been lost to protect a larger area of land from the sea  and with it the safeguarding of Bridgwater’s future economic expansion to the North West. Bridgwater’s economic expansion and long term flood security sacrificed largely through a sense of entitlement ingrained in many members of the farming community.

Landowners and farmers were recently given assurance on the long term protection of land Chilton Trinity and the Pawlett Hams. People cannot expect to be immune to their decisions; landowners should not expect those that foot the bill (ratepayers) to miss out on better tidal flood protection

Sedgemoor District Councils’s ratepayers should now carefully consider if supporting landowners at Chilton Trinity is acceptable or whether retaining the EA’s current plan to save money through planned managed realignment of the River Parrett is preferable.

There is good reason that the current managed realignment should be implemented as described in  Parrett Estuary Flood Risk Management Strategy. The economic benefit of maintaining the land is small and of no consequence to the majority of SDC ratepayers.

SDC ratepayers should therefore not be expected to provide long term financial support to protect landowners’ assets in Chilton Trinity  when a few landowners chose to do nothing and actively block improved flood protection to their land. It is an issue that needs to resolved  before the EA and SDC formalise the commitment to farmers in Chilton Trinity on maintaining the river banks and the liability of the maintaining the banks of the River Parrett is added to the tax and ratepayer’s  shoulders.

Squandered Opportunities  

This is the second time in a decade that Bridgwater has squandered an opportunity to create a bypass, HPC was the first and SDC chose road improvements over a bypass.  This time a few landowners are blocking  a possible £500M scheme moving forward that would have provided better flood protection for all and possibly a route for EDF.

Public money is being squandered on a single use structure ,Bridgwater Tidal Barrier, as well as the opportunity to secure the future of Bridgwater.

Peruvian Duckweed

Most of us, especially if you live on the Somerset Levels or the Norfolk Broads, often see our rhynes (ditches) and ponds covered in duckweed.

It is not the pest we think it is.

This week after nearly  two years preparatory work and 40 years of passion by Texas based  inventor of the system Paul Skilicorn. I am in Peru as part of Lyndon Water‘s management  team led by CEO  Ray Anderson working to deliver a truly unique water treatment project. Using duckweed as a key element in the treatment process we will  clean  urban  wastewater on an industrial scale and then turn it into potable drinking water to WHO standards. Water to the same standard that in Europe we take for granted 24 hours a day.

If all goes to plan in a little under 18 months people in an area of northern Peru will be free of a 30 year stench from its failed sewage treatment plant  and the region receiving additional potable water to increase availability of drinking water and reduce the strain on depleting aquifers.

October 2018 Update

Paul Skillicorn  recently left Lyndon Water and has set up a  competing business. with Ramiro Priale. 

Why Duckweed?

Duckweed is just about the fastest growing plant in the world. As duckweed grows it removes nutrients and  other contaminants converting suspended elements in wastewater  into usable biomass. We  separate and take the suspended solids for anaerobic digestion to generate power before the duckweed cleans the water. 

Duckweed under the Lyndon Water process is harvested and converted into fish food, animal feed, high protein superfoods or for energy generation. Some of the feed we produce will then be used to support Lyndon Water‘ s food  production at a new and nearby integral fish farm and Aquaponics facility that forms part of the Lyndon Water system. Nothing is wasted.

Glue 2’s  Duckweed Harvester and lagoon system.
Glue2’s vision of what future water treatment might look like this.

The harvester design  and the lagoon system design is by my  engineering consultancy  Glue2 Limited . We have also developed  a process for  concurrent transportation and processing of duckweed suitable for use in remote locations using minimal permanent infrastructure. All equipment and buildings are modularised and  based on ISO containers and dimensions.

We take wastewater and make drinking water, the waste we turn into food and power. What’s not to like?

When you  next see  duckweed covering a pond  or rhyne it’s not a pest but it’s cleaning up our water. It’s not all of the story of the process but it is the key.

Lyndon Water led by Ray Anderson off to see the Peruvian Government in Lima

Director Paul Bryant, CEO Ray Anderson, Lyndon Water in Country Manager Ramiro Priale & Chairman Lewis Jeffery

Letter of community support for our project just received 15th August 2017

Retention of Concrete Consistency

Designing concrete mixes for specific purposes often raises questions that you don’t know the answers to. Familiar products have fallen into disuse and new products are just new. A recent project in Shetland required a mix able to get into areas of heavily congested reinforcement that had previously failed the first time around.

Highly plasticised mixes look and behave differently from “ normal “ concrete and  the current mix was  a 100% Portland cement mix that  appeared to have followed me over from Abu Dhabi with the same original contractor having developed a similar mix for two different projects. Shetland and Abu Dhabi having in common a lack of cement replacements particularly in the oil & gas industry. A situation further complicated  as  the current mix had a very high cement content was plasticised but not retarded making it very difficult to use in all but the simplest pours. It has  very little time to be placed.

The rework had a number of challenges that followed from the earlier pour.

  • Hanging shutters that obstructed the passage of concrete.
  • A relatively small volume; less than 10m3
  • Over detailing of reinforcement; surplus reinforcement that had not been removed during original  fixing.
  • Complicated shuttering and finishing that required considerable time to complete after the bulk of the concrete had been placed.

For the revised rework mix a new mix  with the following requirements was developed.

  1. A 10mm aggregate for  congestion and cover issues.
  2. Place using the chute from the back of the truck.
  3. Delay the setting time to around 3 hours.
  4. Retain the waterproof qualities of the existing mix.
  5. Characteristic strength of 35N
  6. Satisfy durability requirements for a Marine Environment.

TESTING & APPROVAL

Sika provided a S4 mix design based on the above requirement;  to obtain client approval and to understand what we had and how it worked a simple test was done twice.

Batches of the revised concrete  mix were mixed and held in a truck mixer replicating a long discharge time on site.

The truck mixer was progressively emptied over 3 hours.

Slump test were taken every 20 minutes and cubes at hourly intervals (1, 2 and 3 hours) for testing at 7 and 28 days.

Testing at EMN Plant’s Scatska Batching Plant in Shetland April 2017

RESULTS

they were very good

  • the mix stayed at or around the design slump only marginally dropping off in the last two results  but still within limits.
  • cube results were consistent and all passed.

LESSON LEARNT

One important thing that was noted was that the consistency (slump) potentially drops for a short period below the specification ,about 1 hour after batching was completed, and then regains the required consistency. It occurred on both batches.

The lesson for Contractors, Consultants  and QA /QC processes is that

  • The time from batching to the initial test is important and that there is the potential to reject concrete that is actually ok.
  • When doing trial mixes develop tests that explore  what could happen when a concrete pour goes wrong and placing of concrete is delayed identifying any characteristics that might explain a rogue test result during placing operations.

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