Thursday, 25 August 2016

Beach Management Plan: "More careful consideration is needed, starting with comparative modelling."

Earlier this month, the BMP's steering group met up to consider how to take its proposals forward:
Futures Forum: Beach Management Plan: steering group to meet tomorrow

It has agreed to consider both the cheapest and the 'technically preferred' options:
Futures Forum: Beach Management Plan: looking for funding for the 'technically preferred' option 4b
EDDC to look again at funding for £11million Sidmouth seafront option - News - Sidmouth Herald

Below are the personal reflections from the chair of the Futures Forum of the VGS (who is also a member of the BMP steering group), gathered from experts, stakeholders and concerned citizens following the meeting:

Personal reflections on the meeting

Ostensibly prudent advice from the consultants (CH2M) closes off any investigation into their own technically and environmentally preferred recommendation, although this appears to be the only one that can achieve the aims and objectives of the BMP.  More careful consideration is needed, starting with comparative modelling.

1.       The benefits of Option 1 seem to have been exaggerated.
1.1.     The “Economic Benefits” of the BMP have been crudely summarised as £85m for every option, based merely on the current value of properties that might be protected from the risk of erosion.
1.2.     Explicitly, the proposals aim to preserve existing amenities but exclude any consideration of adding to or enhancing amenities over the 100-year life of the project.
1.3.     For example, the tourism benefits from restoring the eastern beach as an accessible and sandy amenity have been ignored; and there has been no evaluation of the economic benefits from improving the main beach that can be achieved by removing the rock groynes to create large sandy tombolos similar to the western beach behind the existing rock islands.

2.       The costs of modelling and of maintaining Option 1 may have been miscalculated or misrepresented
2.1.     There is major discrepancy in the estimated costs of the mathematical modelling needed to provide reliable data, as revealed in conflicting advice reported from the Environment Agency (£25k to £50k to £120k).
2.2.     The added costs for maintaining and replacing the west wall of the Sid, as required for option one, have been deliberately omitted from the total cost analysis on the grounds that they will be borne exclusively by the Environment Agency (EA) although we will be looking to the EA for a major part of the partnership funding.
2.3.     There is an apparent discrepancy in the estimated maintenance costs. The report splits the £11m estimated cost of S1 into 78% capital and 22% maintenance, making a total of £2.42m for maintenance, an average of £24,200 pa over 100 years. The estimated £19.4m estimated cost of S4 is split as 86% capital and 14% maintenance, making a total of £2.716m for maintenance, an average of £27,160 pa over 100 years. Clarification is needed on how the maintenance costs can be more than 12% higher for a solution that does not require regular artificial recharging and recycling of beach materials.
2.4.     The cost of regular recharging of the beach within the context of a 1.2 m rise in sea-levels, and increasing storms resulting from climate change, and the inevitable financial crises over the 100 year lifetime of the project may well be unrealistic.
2.5.     An early investment in computer modelling should significantly reduce the uncertainty of long-term planning cost-predictions, which currently include a 60% optimism bias.

3.       The risks of Option 1 have been underestimated
3.1.     What is the risk that opposition from agencies such as Natural England, East Devon SAC, WHS, SSI could result in resources wasted on an unrealistic choice? Option 1 proposes a groyne or groynes that the National Trust anticipates will be orphaned in due course and which Natural England has repeatedly vetoed in the past.
3.2.     Could a rock groyne on the eastern beach attached to the toe of the cliffs present a hazardous obstacle to beach walkers, particularly those approaching from the east?
3.3.     Would not cliffs unprotected by a rock revetment or an adequate naturally replenished beach continue to pose a threat of rock-falls to beach walkers?
3.4.     Would not a growing reliance on the river wall west of the Sid as the major defence against both fluvial and tidal flooding not pose an unacceptable risk to Sidmouth Town in the context of the anticipated rise in sea-level and more extreme weather conditions during the life of the project?

4.       The contextual framework has been given limited consideration
4.1.     Analysis of Devon County Council's topographical survey at Pennington Point shows an erosion rate 3.8 times the rate in the baseline coastal process report for the same place and time period, upon which EDDC consultants CH2M base the entire project. Evidence to support the claim that this discrepancy will make no difference is needed.
4.2.     The range of risks from climate change, financial market movements, and other socio-economic developments in the 100-year life of the project should not be ignored.
4.3.     The report gives little weight to SMP2’s clear distinction between a policy of “Hold the Line” for the town and “Managed Retreat” for the eastern beach. The BMP needs to find a way to integrate these two objectives at the mouth of the Sid.
4.4.     The main recommendation of the 2011 Defra Pathfinder project emphasised the difficulty and the cruciality of inclusive community engagement in shoreline management planning.
4.5.     The on-going Neighbourhood Plan and Eastern Town scoping exercise may provide the Steering Group with a more comprehensive vision of the town’s economic potential and other priorities for the life of the project.

5.       Funding Options can be more fully explored
5.1.     A 7% increase in Council Tax across the District is of course unacceptable but this is not the only way of paying for option 4 or its variants. Historically, such major amenities as the Byes, Victoria Hospital, all the places of worship, the Museum, Town Council building, Peasland Knapp, Blackmore Gardens conservatory etc. have all been provided by “Voluntary Public Subscription”.
5.2.     The disappointingly low level of public response to the first round of consultation requires a more determined re-engagement that could include requests for and suggestions for funding contributions.

6.       Additional potentially cost-saving suggestions are worth considering:
6.1.     Would not appropriate planting and use of vegetation to stabilise cliffs and absorb ground water (as successfully done in parts of Cumbria) contribute to a long-term strategy of working with, rather than against, natural forces?
6.2.     Now that the cliff is not in the SAC and SSSI because it has eroded beyond their landward boundaries what might be the outcome of a fresh planning application for a rock revetment at the foot of the eastern cliffs?
6.3.     Has due consideration been given to the low-tech low-cost reintroduction of Victorian wooden groynes on the eastern beach?
6.4.     Similarly on the main beach, could not a few far less visually intrusive traditional wooden groynes replace the rock groynes to improve shingle retention, while the rock from these groynes is recycled (in option 4b) to create a third off-shore breakwater east of the existing ones, as tested by HR Wallingford ca. 1993, to duplicate the success of the western beach?

7.       Community Endorsement of the preferred proposal is very distant at present:
7.1.     The June 2016 attempt at consultation was disappointingly minimal. But there was striking consensus on certain issues.
7.2.     A total of 12 people voted for S1; 29 for S4 (or 4b which was added later), though some respondents appear not to have realised that the fourth options involved the removal of the rock groynes on the main beach.
7.3.     The priority reason for choosing any option was “defence from erosion”, on which only 2 respondents preferred S1, while 25 preferred S4 or 4b. It seems that lay people overwhelmingly believe that reefs rather than groynes offer the best protection against erosion.
7.4.     It was noted that respondents wish to see the inclusion of a jetty or harbour as part of the outline design for the preferred option.
7.5.     The public seem to have inadequate information on the effects of reefs or breakwaters as the survey revealed that some “beach users felt that additional breakwaters would detract from the visual amenity of the beach, and could create a hazard” despite the evidence from the western beach of the protection afforded by sandy tombolas popular with families and for water sports.
7.6.     See the main recommendation of the DEFRA Pathfinder Project of 2011 on the crucial importance and complex difficulty of full community engagement.

8.       Summary
I hope the Steering Group will agree to modelling the two main alternative solutions rather than opting for the least popular and least effective option simply on the grounds that it appears to be cheaper in the short term. It may of course turn out to be the only possibility, but we need to be more confident that it will work and that it will be acceptable to the regulatory and funding agencies.

There was a genuine openness to other ideas from the Chairman and the consultants on 17th August. We need to tap into local wisdom for additional tactics in dealing with this historic challenge. The next phase of public engagement should stimulate a socially inclusive conversation informing people better, soliciting funds and seeking insights into what can be achieved to improve the amenity quality and value of our beach for residents and visitors alike, as well as to defend the town from coastal erosion and flooding for generations to come.

Robert Crick, Chair of the Vision Group for Sidmouth Futures Forum, 24th August 2016


A             Relevant quotations from the report

“To inform a separate scheme for the River Sid that will be led by the Environment Agency (EA) at a later date.
To define how the beach management activities will contribute to the implementation of Shoreline Management Plan 2 (SMP2) policies of ‘Hold the Line’ and ‘Managed Realignment’.
To reduce the rate of beach and cliff erosion to the east of the River Sid (East Beach) in an integrated, justifiable and sustainable way.
Not to compromise or adversely impact the integrity of the environmental features of the Dorset and East Devon UNESCO World Heritage Site, Sidmouth to West Bay Special Area of Conservation or the Sidmouth to Beer Coast Site of Special Scientific Interest.”

“S4 - Remove existing beach structures and construct new offshore breakwaters
      - Construct new offshore breakwaters tapering towards the eastern end of the study areas.
The number, position, size and height of structures would only be known after modelling of the structures was undertaken as part of detailed design if this option was taken forward as the preferred option.”

Preferred option
“The technically preferred option that best achieves the project objectives is Option S4 and its variants. However, this is also the most expensive option with the worst economic case. Even under the ‘best case’ scenario (Sensitivity Test 8), more than £11m of funding contributions would be needed to unlock the government grant‐in‐aid funding accessed through the Environment Agency.” 

Coastal Processes 
“The impact of constructing the offshore breakwaters at a more oblique angle (consulted on as Option 4B) ... will be a more mobile beach, with much less stable salients behind the structures and the development of deeper troughs during southerly and south easterly storms than compared to more shore‐parallel structures. This greater beach volatility is due to the minimal protection that the oblique structures provide against waves from those directions.”
[This dire forecast on page 32 is then mitigated with the statement later in the same paragraph:]
 “... the relative difference in beach stability behind different offshore breakwater layouts is very much dependent upon the position, orientation, height, length and spacing of the structures, relative to the shoreline, and this would require further detailed investigation should offshore breakwaters (Option S4) be selected as the preferred option over the other Options S1, S2 and S3.”
[There is no reference to the successful development of a large sandy tombola behind the existing reefs or rock islands, but this again shows the necessity for modelling before this crucial decision is made and large sums of money are committed.]

B.            Tony Burch’s corrections to the minutes of June 23rd meeting

These were nodded through without discussion. Some points have important implications for the success or otherwise of bids for funding and for authorisation from the regulatory authorities in this highly sensitive area and internationally recognised asset. For example:

“Tony Burch wanted it put on record that the erosion rate at Pennington Point for 2012 to 2015, based on Devon County Council's topographical survey was 3.8 times the rate in the baseline coastal process report for the same place and time period. His concern was: if the measured erosion rates were out by this much at Pennington point, then by how much are they out for all the other cliff behavioural units, and what difference would this make to the findings and the conclusions in the baseline coastal process report upon which the whole project is based, including the economics of options which are dependent on erosion rates? He was also concerned because, if the impact of an option on the designated sites (SSSI, SAC or WHS) is dependent on the change in the erosion rate that it beings about, then the before and after rates are needed. In which case the 'before rates' need to be as good as possible, not least because they will form part of the evidence base in an Appropriate Assessment which will be scrutinised very carefully by the regulators and their statutory consultees. The chairman would take it up with EDDC.”

Vision group meets over beach management plan - View News
Futures Forum: Beach Management Plan: steering group to meet tomorrow

See also:
Streetlife | Scoping Study
Streetlife | Lifeboat
Streetlife | Beach Management Plan..cheapest option, or more effective long-term solution?

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