Irresponsibile or Incompetent? Local councillors role in the Bridgwater Tidal Barrier

An old boss of mine says unintended consequences is merely the failure to adequately consider the implications of the decision being made.

The location of the Bridgwater Tidal Barrier (BTB) is probably the most significant decision Sedgemoor District Council has made in many years. Rarely can such an important decision have been made with so little debate. If it’s in the wrong place we and the following generations live with the consequences for the next 200 years or so. No one is giving us another one if its wrong.

On the 26th July 2017 a full Sedgemoor District Council meeting agreed the location of the Bridgwater Tidal Barrier. This decision according to the minutes was apparently waived through without discussion. That the EA and SDC gave a superfical 3 page briefing document with so few key facts indicates just how confident EA and SDC officers felt able too simply ignore the longer term collateral environmental and economic impacts of this scheme. It is a clear indication of the low esteem our councilors are held in. Councillors lack of oversight of this scheme does indicate the officers probably wernt wrong. Silent oversight committees seems to have presided over continued and unsatisfactorily explained cost rises. The cost almost doubled in the the six months after the decision was made. Barely a word was said.

The Issue

Abandoning 1,400 acres of valuable land next to a motorway junction capable of supporting £1B of future investment (jobs) whilst unnecessarily forcing future housing onto the Quantocks foothills extending Bridgwater to absorb Cannington, Spaxton and North Petherton.

This decision will be seen as one of the most irresponsible and reproachable acts by councillors of any local authority at any time. SDC knowingly made a decision to convert the Parrett Estuary into an Intertidal Habitat and behind the the secondary flood defence create more areas of habitat suitable for freshwater mosquitios such as the Zika and Denge carrying Asian Tiger Mosquito to take up residence.

Limiting economic expansion, building on the Quantocks, poisoning the fresh water ecology of Chilton Trinity and Pawlett Hams and creating a future health hazard is hardly what we people voted councillors into office for.

If they did know why did they do it?
If they didnt know why not?

Why is this case?

The BTB design uses farmland downstream of the barrier to allow incoming saltwater to spill over riverbanks onto the farmland. It destroys the economic value of around 2.400 acres of land either to continue as low-grade farmland or 1,400 Acres of that total to the south of the Parrett providing land for nearly a £1B of economic development accessible from J23. Would any town throw such an economic legacy away with so little concern? Bridgwater has. The longtime environmental Impact of this scheme is equally as bad; the land being flooded will ultimately become saltmarsh and a large part of the local Quantock foothills unnecessarily developed

The December 2018 public consultation asked for feedback on three basic points

The details of the proposals for both the barrier and the downstream flood defences.
How you think the proposals may affect you, your land or your business.
What additional improvements you would like to see delivered as priorities, in addition to the barrier and the downstream flood defences, subject to funding.

Context

Large civil engineering projects influence long-term economic development as we have seen with development taking place around our motorway junctions; the proposed Bridgwater Tidal Barrier (BTB) will influence Bridgwater’s future development in a similar way for at least the next 200 years. The Bridgwater Vision published in 2015 and referred to in the presentation identified land for future development most of which is either now approved or starting to be built out under the local plan. Bridgwater is already reaching the limit of land that can be easily accessed from the town and the M5.

Assuming Bridgwater continues to develop economically at even half its present rate, during the design life of the BTB, an additional 25,000 houses will be built and together with land for employment and Bridgwater’s footprint will grow by around 40%.

Under the present BTB scheme low quality farmland directly beside Junction 23 that could have provided space for at least £1B of economic development, housing and jobs will be lost to the town. Alternative land over the next 100 years will need to be found and that will invariably mean development moving on to high quality agricultural to the south and west of Bridgwater. We will build on the land that feeds us whilst living ever farther from planned and established centres of employment to the north and north east of Bridgwater (Horsey). Building at Horsey will require a new bridge over the King Sedgemoor Drain; money that could be used to cross the Parrett and bring forward a much needed northern bypass.

Location

The reader should take cognisance that the two options studies done for this scheme, the first included highly improbable options such as the Bridgwater Bay power lagoon and outside the influence of the authors. The second option study looked at the same solution at a limited number of locations and would always arrive at the narrowest part of the riveras the prefered solution. It was a superficial study and lacking rigour and at the time of this note the final information used by an SDC sub group remains unpublished despite an FoI request to Sedgemoor District Council remaining outstanding.

Other options and locations to protect Bridgwater and the downstream villages were available but not considered.

Description

The Bridgwater Tidal Barrier is a 7mile long inland tidal surge flood defence scheme with a 100 year design life based on sea level rising around 800mm during this period. Similar to the current Thames Barrier it consists of two elements.

Riverbanks profiled to preferentially spill seawater, during extreme tidal surge conditions, onto farmland at Chilton Trinity and Pawlett Hams.
A small double vertical floodgate barrier located in the industrial and employment Express Park area of Bridgwater and approximately 1 mile from the town centre.

The replacement Thames Barrier will be sited more conventionally at the mouth of the Thames; Combwich is Bridgwater’s equivalent location.

Key features

The riverbanks are expected settle and need reconstructing every 35 years
The height to which the riverbanks can be raised is limited by the poor ground conditions.
Although needed no provision of any kind for a replacement is considered.
Contaminates around 2400 acres of farmland with salt water
Constrains economic development to the northwest of the town.
Significant loss of existing freshwater habitat in line with managed realignment policy 7d39 of the Shoreline Management Plan to create an intertidal habitat.

**EA DIAGRAM SHOWING SALTWATER FLOWING ONTO FARM LAND**

Operation

The closure of the barrier at low tide creates a separation of the two types of water that use the River Parrett. Upstream freshwater from the Parrett and its tributaries such as the Tone; Yeo and Cam will be impounded behind the closed gates. Downstream the freshwater will finish emptying into the Severn and the then the empty river filled with seawater on the incoming tide.

All flooding shown downstream of the Bridgwater Tidal Barrier will therefore deposit salt water onto the land. This is saltwater and the impact should not be confused with the 2014 event.

The land in question at Chilton Trinity has not been flooded with salt water in this way within living memory. Pawlett Hams was briefly flooded in the early 80’s and flooded Pawlett from the north where no flood defences are planned.

Summary

What is clear is that considerable ambiguity remains in the proposal. Many issues are simply ignored or the messages contradictory. The following summary and notes provides some comments that should be addressed.

It is disappointing that such an important scheme appears to have been given so little strategic thought whilst the barrier appearance and immediate landscaping seems to have received considerable if unsuccessful attention.

Clearly the priorities of the design and client team are not those of the ratepayers who do not need a solution where the medicine kills the patient which is what we appear to have.

River Banks

One consistent underlying theme is that once the barrier is built the land to the north and south, Chilton Trinity and Pawlett Hams, will ultimately become intertidal habitat in line with existing published policies.

The key supporting facts are

The cost estimate that does not include for future riverbank reconstruction
Planned flooding of agricultural land with saltwater.

The claim made “Bridgwater and the surrounding area will be better protected against a severe flood by building the barrier and improving the downstream flood defences. These works will also maintain the current standard of defence to agricultural land”.is misleading to landowners indicating that farming will simply carry on as normal. With the frequency of saltwater flooding increasing the land will not support the type of grass needed for agricultural. Areas of Norfolk are still recovering from single sea water incursion 65 years ago.

Borrow Pits

No location for the pits was given, which side of the secondary flood defence. It would not be unreasonable to assume between the river bank and the secondary flood defence. A rough estimate would indicate that the scheme will need around 100,000m³ to 150,000m³ of clay creating a large open area (7-8Ha) of stagnant water that will through our now warmer summers become more saline as they will operate as a large evaporation pond. That mechanism does not allow the wildlife enhancement described to occur.

Locations were shown to stakeholders but not the public

Environment

A number of claims are made regarding the lack of environmental impact that this scheme has on the ecology however changing the habitat from freshwater to saline will fundamentally change the area in line with the published strategy of changing the land to an intertidal habitat.

2,400 acres of fresh water habitat is destroyed through repeated seawater flooding.

Cost or Intention

An estimate of £94M is given in the EA presentation. Through a FoI request (03 April 2018) The EA provided an estimated whole life cost closer to £160M. That estimate assumed £12.4M Net Present Value or £55M cash cost over 100 years including for maintaining and rebuilding the riverbanks that is around 4x the value of the land. Economically this statement on maintenance costs makes funding the future bank rising impossible. If the circa £100m estimate is correct this would cover the gate maintenance and not the riverbanks.

The expected need to rebuild the riverbanks twice in the 100-year design life is not mentioned in the presentation and the assumption must be that the intention will not become reality and would conflict with clauses 1.10.1 and 1.10.2 of SDC’s Parrett Estuary Flood Risk Management Strategy

The whole life cost of the scheme is either

£100M with one set of the riverbank improvements at the time the barrier is constructed.
£160M with three sets of the riverbank improvements including the time the barrier is constructed and subsequently at 35-year intervals after that. That must be the budget.

Did nobody ask why?

Collateral Impact

This scheme is presented at completion in 2024 and looks only at immediate local impacts. Construction will have immediate and long term wider negative consequences for Bridgwater none of which have been raised or addressed despite written assurances that that would not be the case.

Economic Impacts

Loss of 1400 acres of key land suitable for £1B of economic investment for housing and industry that is directly accessible to Junction 23.
Creation of a working flood plain over which a potential bypass might need to be constructed.
Increasing separation of housing from employment by forcing development elsewhere.
Loss of economic food production on prime agricultural land
The loss of in existing land values of around £12m and potential bankruptcies where the land is used to secure business loans.

Environment Impacts

Destroys 2400 acres of fresh water habitat through deliberate seawater flooding initially during extreme tidal events but ultimately becoming within the normal tidal range.
Forces development to take place on high quality agricultural land to the south and west of Bridgwater.
Forces apart residential and employment areas with a consequent long term cost to the economy and the environment.
Places increased demand on the A38, A39 and Kings Drive as industrial development is forced east to Horsey and to the approved BAE industrial site.

Barrier Superstructure

The barrier superstructure is 2 to 2.5 times higher than it needs to be and lacks any shape that reflects its functionality. It achieves the rare combination of being both pretentious and mediocre. With a structural volume that must be four times what could be reasonably required to support its function it is bloated, unnecessarily expensive and will be difficult and expensive to maintain. Overhanging shapes require specialist access equipment for maintenance. Everything on the structure seems designed to cost more than is necessary. Its appearance seems to owe more to Mr Blobby and the Teletubbies than the Falkirk Wheel, it doesnt do anything like the Falkirk Wheel so hardly a tourist attraction.

The very large ovoid bridge structure will be particular difficult to maintain, it will be almost impossible for safe inspection of the lower quadrants to be made or worked upon. The form of the structure indicates little attention appears to have been taken with regard to the Construction, Design and Management 2015 regulations with regard to the safe operation and maintenance

The poor design of this structure extends to the gates, rather than protect the gates from the salt loaded wind driven rain, the site is classed as a marine environment, rain will be spilled from the ovoid bridge onto the gates increasing maintenance and reducing the life of the gates.

As a piece of architecture and a piece of engineering this structure almost certainly fails on cost, function, operator safety and buildability.

Storage Buildings are provided when the EA has a depot nearby at Bradney.

Did no one ask why we need additional buildings at the barrier site?
Presumably they would also attract rates?

Sustainability

The lack of sustainability in this project is very concerning;

The decision to excavate burrow pits to reduce construction traffic seems highly questionable. “Where possible, we will excavate material locally from ‘borrow pits’. This will minimise the need to bring in material to build the new downstream flood banks and reduce construction traffic.”

The EA was more than happy to bring excavated material from its Cannington flood project to Chilton Trinity yet the more sustainable option of building the banks over a longer period using spoil from building sites is not considered. It’s not as if the defences need to be at their final levels until the last planned rebuilding of the banks 35 years before then end of the design life. This work could be done on an opportunistic basis over the next 50 years or so in a sustainable cost effective method by local contractors.

The continuing reference to 2055 that is key date in the shoreline management plan indicates thatany future raising of the river banks is unlikely to occure.

This process would also assist in maintaining accesses and local resources able to respond to urgent requirements such as a breach in the river bank.

Finally just to prove the point the EA/SDC presented on page 7 of the stakeholder presentation three images of unrelated events to support its postition.

West Quay collapse, an old wall collapsed when it got too much water behind it; we see thse failures alongside our roads all the time but we dont try and link them to climate change or a tidal barrier.
The 2014 flood was a pluvial (rain) event and the Bridgwater Tidal Barrier is not designed to mitigate a repeating event. There is clue in the word Tidal. Unfortunately many people in Bridgwater and the surrounding area believe that it is part of a pluvial flood defence scheme.
one was applicable

Perhaps an SDC, Town or county councillor reading this might decide to ask some serious questions about this project, one can only hope.

29/12/201819/01/2019

Flood protection, wildlife & environment is always a one sided view.

The impact of wildlife organisations on locally managed flood projects is a concern. They seem to be free to make unsubstantiated statements whilst pursuing their objectives with little public visibility, criticism or professional oversight and it is a growing problem. It is a situation becoming increasingly familiar and yet another example of our growing democratic deficit where minorities impose their ambitions on the majority. The Somerset Levels, the Parrett Estuary and Bridgwater’s need for a flood defence from the sea has brought many of these parties with their own agenda to one location each focusing on what they consider to be important. Bridgwater seems to be well down the list of importance despite the planned construction of the Bridgwater Tidal Barrier. The purpose of this article is to provide an explanation as to how this is happening.

Context

Bridgwater currently builds around 500 houses a year and if that rate continues at even half that rate for the next 100 years we could expect to see the number of houses in Bridgwater rise by 25,000 taking another 700Ha (1,700 acres) of land for housing and a further 300Ha needed for employment. This 1,000Ha’s will see Bridgwater’s existing footprint grow by at least 50%, The 25,000 houses and associated economic development will generate perhaps 300,000m³ of clays and soil waste.

With flat and level land needed for employment land at the old BAE site and at Horsey offer the only other viable employment options to Bridgwater and they are to the northwest. New housing will be forced onto good quality farmland south along the A38 swallowing up North Petherton and eventually meeting Taunton coming the other way and to the west developing the land between Bridgwater and Cannington. Bridgwater will consume its high value agricultural land on the hills as it, like the rest of the country, continues to build our outdated ideas of housing.

Bridgwater will therefore become an even more difficult place to live and work as the gap between residential development and employment continue to grow. Every day a large part of Bridgwater’s population will get up and drive along the A38 and A39 to get to work. Bridgwater will not even start considering a bypass until 2040.

Apart from the normal lack of imagination by planners and developer’s Sedgemoor’s (Bridgwater) greatest problem now appears to be the wildlife and flood pressure groups that seem to take an extreme view in the pursuit of what they consider to be in their interest. They show little tolerance or understanding that people also live on the Levels and in Bridgwater and ignor the EU directives that accept people must come first. The true impact of their objectives is concealed and never addressed.

These organisations also seem immune from any need to consider facts in their statements whilst criticising property developers for the smallest omission. The irony that is they now ape those same commercial organisations in assembling land and changing its use without considering its long term impact on the wider local population and it should be lost on no one.

Some typical examples

Steart Peninsula

The local economic benefits alluded to as part of the original Steart Peninsula planning application remain unproven and therefore represent little tangible benefit to the local population yet quoted as fact by The Severn Vision statements.

The Severn Vision

This plan will expand the existing saltmarsh by 833% around the Severn Estuary and in Bridgwater’s case large areas of agricultural land removed from food production and converted from a freshwater environment to a saltwater one (intertidal habitat). To date two phases have been completed; The Steart Peninsula and the RSPB reserve (funnded by Bristol Ports) both of which remove economic activity and destroy an existing habitat to create another. A process little different from modern housing development. Whilst an argument might be made on the basis of geography for these two areas to be returned to the sea no such argument exists for the destruction of Pawlett Hams and Chilton Trinity including areas of the SSI.

This is a process promoted by the following organisations

Wildlife and Wetlands
The Wildlife Trusts
RSPB
National Trust
Campaign for Rural England (CPRE)
Severn Rivers Trust

With regard to Bridgwater it makes claims regarding carbon savings whilst ignoring the collateral effect of moving Bridgwater’s housing developments onto higher quality agricultural land and increasing commuting distances. Also ignored is the loss of food production on 5,000 acres of land and the transfer of that food production overseas. It is particularly misleading in its statements with regard to Bridgwater providing no supporting evidence as to the negative benefit that it has considered in any balanced and holistic way. It is completely one sided yet already two key elements have been delivered, Steart Peninsula and RSPB reserve. The Bridgwater Tidal Barrier will deliver the southern land at Chilton Trinity and Pawlett Hams .

Bridgwater Tidal Barrier

The Environment Agency and Sedgemoor District Council’s Dec 2018 public consultation made a claim with regard to the lack of any environmental impact of this scheme. The EA and SDC have not considered environmental impacts beyond the immediate area of the scheme despite this scheme imposing restrictions on economic development forcing residential development to the south and west of Bridgwater and employment to the northwest of the town.

It is worth noting that HPC looked at issues far beyond the immediate area of the power plant when it did its enviromental impact assessment.

Environmental Impact Statement

This statement above cannot be true as

Seawater is shown overtopping the river banks onto the existing farmland, the fact that it is seawater is misleading.
The farmland at Chilton Trinity and Pawlett Hams will be poisoned for agriculture through the introduction of saltwater
The existing wildlife that requires a freshwater environment will be destroyed.
The location of the borrow pits, which side of the secondary flood defence, was not shown. The plan to excavate 100,000m3 of material will create a lake of nearly 13 acres that will act as a reservoir for saltwater.
1,400 acres of high quality farmland suitable will be unnecessarily developed invariable towards North Petherton and Cannington as this scheme will convert 1,400 acres of low quality farmland that could have been used to saltmarsh.
100 years of lost food production on 2400 acres of farmland.
100,000m3 of clay will be unnecessarily excavated from the land being protected whilst during the same period 300,000m3 will be produced as waste through normal housing and industrial construction activities. (the secondary flood defences do not need to be completed to the full height during intial construction
Denying economic development in the north-west will increase commuting efforts in the local community generating avoidable C02; the scheme ensures the increased separation of employment areas from housing.

The claims regarding this scheme are questionable at best and the lack of information misleading at worse. The extract from the EA/SDC public display indicates a plan to create a stepping-stones for species that are not identified.

Campaign for Rural England (CPRE)

The CPRE’s support for The Severn Vision that results in the wholesale destruction of a large area of our existing productive landscape and the equivalent of 10 500 acre farms is not what we imagined their core mission to be that says

“We campaign for a beautiful and living countryside. We work to protect, promote and enhance our towns and countryside to make them better places to live, work and enjoy, and to ensure the countryside is protected for now and future generations.”

How allowing saltwater (seawater) onto productive farmland that has taken 500 years to remove the salt from seems a strange way of protecting our countryside.

Somerset’s Wild Trust (SWT)

Another supporter of The Severn Vision.

Somerset’s Wild Trust’s website says

Since the 2013-14 flooding events, the dominant narrative in the floodplains has focussed on hard engineering schemes and dredging to reduce flood risk, overlooking flood risk reduction techniques that work with nature and provide a range of benefits to society. A future is developing where more public money will be spent on fossil fuel intensive dredging and pumping, to further drain the peat soils of the Levels, thus releasing more carbon and exacerbating climate change. As peat is drained, it shrinks, lowering land height and making the area ever more vulnerable to extreme weather. Well-informed debate on the future of Somerset’s low-lying areas in the face of rising sea level is limited, so a further vital part of our work on the Levels is to communicate a more optimistic narrative which gives nature its proper value.

This statement ignores that the Somerset Level’s is an artificial environment that needs regular maintenance and seems to conflate the need to dredge Somerset’s rivers and the need to get pluvial flows from the upper Parrett catchment areas to the sea bypassing the levels storage with an idea that somehow this process is designed to shrink the peat. “A future is developing where more public money will be spent on fossil fuel intensive dredging and pumping, to further drain the peat soils of the Levels, thus releasing more carbon and exacerbating climate change” is a particularly spurious and misleading statement. It sounds like people are secretly pumping water off the levels as some sort of conspiracy.

Anyone with any knowledge of the Levels would know that retaining water levels is just as important to the Levels as draining them. No one is going to drain the peat. Well informed debate requires informed knowledge and that is clearly not the case with this statement by the SWT.

FLAG Flooding on the Levels Action Group

FLAG reflects its single issue origins seemingly taking its position on Somerset’s farming industry geographically from the lands relationship to Moorland and what is best for Moorland.

A post (Nov 2018) supporting Somerset’ s farming industry on the Levels was made by FLAG making Brexit the largest threat to farmers in anticipation of a nonexistent trade deal with the US; no doubt the cause of the 2014 flood and global warming will in time also be subscribed to Brexit.

FLAG’s postion downstream of Moorland at Chilton Trinity and Pawlett Hams is quite different. Flag is altogther less compasionate regarding the farmers there having their land flooded with saltwater to alleviate upstream flooding. Concern is simply dismissed by a statement worthy of Marie Antoinette “let them raise salt beef or lamb”. It completely ignores that the Bridgwater Tidal Barrier has already destroyed land values for 2,400 acres of land and food production we might have gained. Reverse nimbyism seems to apply; as long the flooding is on someone else’s land FLAG appears to be happy whilst refuses even the smallest tacit support for or willingness to consider alternatives tht might have a better outcome for the wider community.

Conclusion

Whilst our wildlife organisations may have started with good intentions what is clear is that many people associated with these organisations simply don’t understand the mechanisms of the Somerset Levels, the impact of what they propose (The Severn Vision) and in most cases don’t care if it doesn’t suit their agenda. They fail to consider that ultimately the economy pays for everything and destroying local economies will ultimately call into question the viability of protecting our environment; the ratepayer maintains the roads used to get to our wildlife sites and will pay or make a significant financial contribution to the cost to the current planned defences and the their subsequent replacements. A case of shooting the goose that lays the Golden Egg of in this case chasing away industry and people.

It is clear that many organisations support the existing proposals to turn the Parrett Estuary into a saltmarsh. The decision by SDC and the EA not to commission an economic impact assessment has allowed those organisations and the Environment Agency to create the worst possible long term economic future as there is no assessment mechanism other than the government investment rules to measure the value of this scheme. Allowing the undermining Somerset’s agricultural industry, wasteful development and not working towards an integrated low energy society is not what we should be doing.

08/10/201809/10/2018

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.

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.

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

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.
The Thames Barrier is upstream of what were active docks that had navigation rights in the Thames Estuary.
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.
All the Thames Barrier replacement options move the replacement barrier downstream perhaps as far as Tilbury. (July 2016 update)
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.
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;

How will the proposed Bridgwater Tidal Barrier be replaced?”
What becomes of Bridgwater after sea level rise exceeds the design basis of the Bridgwater Tidal Barrier?
Why is there no long-term plan or vision for what comes next?
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?
Why is not improving fluvial flow in the river system part of the scheme?
Why did the cost of the scheme almost double after the location was decided on?

23/08/201830/08/2018

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

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

05/03/201816/08/2018

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

01/07/201711/03/2018

Bridgwater Tidal Barrier Drop in Session 10th July 2017

On the 10^th 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 10^th 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

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?
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.
Why does the barrier only do TIDAL and not FLUVIAL (2014 rainfall) with equal importance?
What is the extra cost of building a barrier with a bridge on it?

Steve Trowbridge CEng MICE MIStructE

05/06/201726/09/2018

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.

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.

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

03/05/201707/08/2018

Bridgwater Tidal Barrier a Fatal Flaw

The existing Bridgwater Tidal Barrier scheme has a flaw.

Water can go around it.

Any system including a flood defence system is only as good as its weakest link. The banks of the River Parrett is the Achilles heal of the EA’s scheme.

The ground along the river is simply too weak to support the continued raising of the river banks and from the EA’s point of view too expensive to maintain. The Parrett’s highest tides hidden behind the raised banks are already at the top of the doors of Bridgwater’s houses along the A38.

Even before it’s been built and the complete scheme revealed to the public the EA is working on adding secondary flood banks (dashed red lines) on the premise of a bank failure or a future decision not to maintain the existing flood defences. The drawing below is a scheme the EA has to fix the flaw. The red arrow is the open back door at Walpol where a breach to the north could circumvent all the defences. When the Dutch build a dyke they don’t build another one a few hundred metres behind it; clearly the EA expects a failure to occur or the river to over top.

The line in green is an option never considered by the EA but one that would offer much better protection than what is being proposed.

EA Secondary Flood Barrier, Downstream Bank Modifications and Alternative Barrier Route

This is information never presented to the public in any of the consultations in 2016.

To my knowledge Bridgwater will have the UK’s only tidal surge barrier not located at the mouth of the river it’s meant to control. At Bridgwater’s present rate of expansion the proposed barrier will in 100 years time not be just near the centre of Bridgwater but within the centre of its developed area. Only in Somerset would anyone come up with the plan we have and think its acceptable to have a scheme that has such an obvious flaw. Let’s also not forget that the EA’s other wider site downstream is being reserved for a road bridge to land that the EA is not protecting in the same way as existing housing. What happens when that is to be developed? Start again?

The ratepayer should have had real options presented rather than the EA’s version of the Henry Ford motto “any colour you like as long as its black”, ie anywhere in the river as long as its at the narrowest part of the river we can persuade people to accept.

The letter below confirms that the barrier can be circumvented.

EA Letter to Chilton Trinity landowner