Musselburgh Coastal Flood Protection
FHSA Trustees have compiled this information so members and the community have visibility of the topics we have been discussing with the Musselburgh Flood Protection Scheme (MFPS) project team. It’s hoped that this will help members to become engaged in consultation events. Trustees have access to publicly available information, photographs and input from FHSA members and various comments from the local community.
Note that this relates only to coastal flood risk within the FHSA Area and does not discuss River Esk proposals by MFPS.
We are sharing what we know so far and our thoughts. If you have any questions or anything to add, please email flood-protection@fhsa.org.uk.
FHSA Trustees
03 February 2022
Thoughts from FHSA Trustees
Musselburgh has been protected from coastal flooding by the existing beaches, which have been in a period of growth for some time.
We need proportionate and carefully planned solutions to the coastal flood risk that we face now, and in the decades to come. We need a set of solutions to deal with acute storm events at high tide, in addition to protecting against predicted sea level rise and coastal changes. If more information is needed to plan these solutions, e.g. monitoring & active maintenance of our beaches, then this work should be part of the MFPS.
Unless they are very high, coastal sea walls, as a single defence, do not protect against overtopping waves at high tide during onshore winds, even at current sea levels.
Building a hard engineered defence would be an extremely disruptive infrastructure project and we need to first be sure that it's the right and only solution.
Any new infrastructure may need replacement/repair by the time sea level rise poses a more significant risk.
MFPS public meetings have so far been mostly devoted to sharing selected information about the pre-approved Preferred Scheme. It’s not clear how ongoing consultations influence design and what the future design decision stage gates are in the MFPS plan. The lack of opportunity to see other ideas flow through a consultation process and see evidence from the Options Appraisal Process (OAP), that was conducted by MFPS to arrive at the Preferred Scheme, is giving rise to serious objection. As a result, we’re concerned that the project will risk delay and go on to consume unnecessary resource and public money to address avoidable objections.
The people of Musselburgh need to be fully informed about the options available and the choices made to protect their town from flooding, so that they can confidently explain this to the future generations who will live with the consequences. To achieve this, the ongoing consultation needs to provide more information about the costs & benefits of all relevant options for our coastline, in enough detail for the people of Musselburgh to be informed and adequately address the questions being asked.
Information Gathered
Situated between the River Esk and Brunstane Burn, the Musselburgh coastline is predominantly a sandy shingle beach with patches of naturally occurring grass, except for the Harbour which is a solid stone and concrete structure.
East Lothian Council (ELC) have commissioned the Musselburgh Flood Protection Scheme (MFPS).
MFPS are following a Preferred Scheme that was approved by ELC Cabinet on 21st January 2021.
MFPS state that the Preferred Scheme follows an Options Appraisal Process (OAP). FHSA has asked for details of the OAP and MFPS have agreed to publish it. Trustees will share this on FHSA web site when available.
In public meetings, MFPS have referred to an underground sewage pipe, parallel to the Promenade, and the Nature Scotland Special Protection Area (SPA) as design constraints and that these constraints mean that, in places, a flood protection barrier will follow a very narrow line on the map. The structure can therefore only be assumed to be a wall in these places, a term that has been used interchangeably with barrier, while embankments have been mentioned as a potential solution where space allows.
Where the Preferred Scheme is a wall, MFPS have made reference to walls with wave returns. A schematic of such a wall in relation to Fisherrow beach is shown.
The Beach was much lower in the past. Doorways and streets were regularly awash with seawater during storms.
While folk would dance through breaking waves on the Promenade, it wasn’t always fun and games!
“In the 1940s during wartime blackout, a young girl was frightened during a Northerly gale and made for our house. A wave caught her on the pavement and she was swept off her feet, close to our front door. She hit the end wall of the Hamilton’s cottage front garden and then managed to bang on our front window.
The other memory is of the seawater flooding our front lobby. I think this happened more than once but I only remember one occasion; the long carpet/rug in the lobby was soaking!”
[These are the recollections of a Promenade Resident]
Over the years, the beach has slowly grown, especially to the East of the Harbour. It appears that the beach has been growing more rapidly after the Musselburgh Lagoons were built in the 1960s, with a theory being that a sheltered bay is allowing sediment to collect.
Comparing a recent satellite view, to a map from 1938, helps to confirm this.
During a storm on 30 March 2010, waves crashed onto the beach. Most of the wave energy was dissipated by the beach. While seawater and driftwood did wash up onto the Promenade, properties remained dry.
By comparison, the same waves hit the Harbour walls and massive overtopping occurred.
This video was taken approximately 2 hrs after high tide.
The beach was mechanically reshaped after the 2010 storm. The Firth of Forth was designated as a Special Protection Area in 2020 and there may now be restrictions on activities which affect this area. FHSA have asked for more details on the advice given from NatureScot to the MFPS, on what is permitted and the relative impact & cost of the options which have been considered / rejected, but this has not yet been provided by MFPS to FHSA.
In 2016, the top section of the beach would regularly be flooded, even during calm conditions
Then, by around 2020, flooding on the top section stopped. The beach had grown! It appears that, after mechanical raking stopped, naturally occurring grass has accumulated. This grass is collecting sand. The height of the beach is increasing more rapidly and is now higher than the level of normal spring tides. A dune system has started.
The growing beach is playing a more and more significant role as a flood protection barrier. The beach dissipates storm wave energy, before waves reach the Promenade or properties.
We saw this during Storm Arwen. The Prom and properties remained completely dry. [Video from Friday 26th Nov 19:01]
Meanwhile, at The Lagoons, where there’s a hard sea wall, the area was flooded.
This Sea Wall at the Lagoons is significantly higher than the proposed barrier at Fisherrow, to the extent that the Lagoons are being left untouched by MFPS and these walls will form part of the Preferred Scheme.
Wave Overtopping
The site of the former Cockenzie Power Station is also bounded by a hard sea wall...
...and was flooded during Storm Arwen...
...and again during Storm Malik [Saturday 29th January 2022]
In Musselburgh, should the beach ever become a victim of coastal erosion, a barrier (such as a wall with a wave return) may certainly help to protect against the highest of high tides, but only if the sea is relatively calm and there is no strong onshore wind to blow crashing waves over the top. There is however a new concern here, resulting from expert advice that hard sea walls increase coastal erosion, either locally or to neighbouring coastlines.
In October 2023, for the first time in several years, accumulated grass on the beach was affected by high tides and storm waves, crashing on the beach.
Without a beach, or other solution like an offshore reef to reduce wave energy, a hard barrier is apparently ineffective and may indeed create a new flood risk by holding seawater and other flood water on the ‘dry side’. This is a concern, given that some parts of Fisherrow are particularly low lying and also at risk from river flooding.
The approved Preferred Scheme states a “minimum 2.2m high defence would be required” and there’s a “second option, which involves a much lower height defence with a minimum height above ground level of 1.4m, which is designed to be overtopped, [and] was preferred. This lower height option would also require an enhanced drainage network and series of pumping stations to be provided to ensure the overtopping flows do not cause property flooding.”
In recent public meetings, a defence of 1.4m was proposed by MFPS, without pumps. MFPS explained that this is because refreshed data shows higher sea level predictions. FHSA remain unclear how such a barrier could prevent overtopping of waves in a Northerly storm during a high tide at current sea levels. We’re now more concerned about flood risk from raised sea levels in future, if a barrier is the only solution. FHSA continue to seek clarity from MFPS on this topic.
There’s a moderate risk of between a 15cm and 60cm sea level rise in the next 80 years, according to the Met Office UKCP18 data used by MFPS.
Is this risk a good justification to build a solid structure now? While recent communications from MFPS have included more references to nature-based solutions, the early focus on the necessity of an engineered barrier solution raised significant concerns. MFPS presentations explained how a more environmentally friendly concrete could be used and this level of detail appears to indicate that concrete will form a significant component of a barrier.
There are plenty local examples of concrete sea walls and we can see how they age. The potential, far reaching negative impact of creating such a barrier in a residential area, used for recreation and outdoor pursuits should not be underestimated.
FHSA Submissions
Since initial meetings in March 2020, FHSA members have submitted a range of ideas and questions to Trustees, who have in turn shared them with MFPS to understand feasibility, or rationale for excluding these. MFPS mentioned that some ideas were ruled out during the Options Appraisal Process but, as yet, this has not been published or a full response received.
Trial Dunes
Help the beach to continue growing by planting grass to collect wind blown sand.
Raised Dune / Boardwalk
Enhance the John Muir Way from the Brunstane Burn to the Esk. Enclose the Harbour in the scheme to protect it too. (Map View)
Dyke
Can we build a Lagoon, like Cardiff Bay? As well as protecting from coastal flooding, a dyked lagoon could be drained at low tide to hold river flood water, potentially reducing the height of the river defences.
Multi Region Investment
Could the previously mentioned dyke be extended with investment from Edinburgh Council and be linked to protect Portobello and Edinburgh/Leith? This could open up a potential transport link.
Offshore Reef
Can an offshore reef, even underwater, be used to reduce wave energy and reduce the required height of onshore barriers?
National/European Schemes
As wild as some ideas may appear, the questions are out there. What consideration has been given to ideas like this by MFPS and were they factored into the OAP?
MFPS Response
The above ideas were assessed by the MFPS Project team but rejected in March 2022.
FHSA Options Analysis.pdfBeaches play a huge part as a costal defence. In certain circumstances they do suffer from erosion over many years, so need maintenance and sometimes replenishment, especially if they are to remain effective as sea levels rise.
Nature-Based Solutions
Many local people have raised concerns during the 2021 consultation process about the absence of consideration being given to nature-based solutions. Some have started experimenting with actions that have been successful in other coastal locations and that might help to replenish or boost Fisherrow beach. It’s hoped that the MFPS will provide evidence to show that these kinds of approaches have been taken into account.
Scientific Predictions
It's well documented that future sea level rise will depend on previous and future emissions and resulting global warming. In a worst case scenario of 4°C warming, predicted sea level rise is between 30cm - 90cm in the Edinburgh area by 2100 according to Met Office UKCP18 data. Less extreme 2°C warming leads to a prediction of 15cm – 60cm by 2100. MFPS are using 124cm sea level rise in 2025 as design input.
Storm Surges can significantly add to the height of a tide over a number of hours or days. UKCP18 finds "no evidence for significant changes in future storm surges, although you may wish to carry out sensitivity tests with our scenarios."
FHSA would welcome more information from experts in coastal flooding around all of this data and the most appropriate way to incorporate this into protecting Musselburgh.
Modelling
We do not underestimate how complex the MFPS project is, however clear and informative analysis & dynamic modelling around flood risk and coastal management is possible, and we would welcome this in relation to the Musselburgh coastline, in order to evaluate the risks and benefits linked to designed solutions which are put forward. A practical demonstration as seen in this video would be very helpful to increase understanding within the community.
Correspondence with MFPS
02 December 2021
Response from Musselburgh Flood Protection Scheme
MFPS-LO-0037 - FH&SA - Formal Response to October 2021 Letter - Rev 0.1.pdf01 October 2021
After attending com public meetings, FHSA Trustees wrote to the MFPS.
Letter FHSA MFPS Questions 2021-10-01.pdf01 February 2021
FHSA hosted a meeting with MFPS to raise various points submitted by members of FHSA. Here are the points raised.
MFPS FHSA Meeting Agenda - 1 Feb 2021.pdf