How Sidmouth seafront has changed to try and stop flooding and erosion
By The Editor
1st May 2020 | Local News
The rock armour installed in the 1990s to help protect Sidmouth's fragile coastline was exposed last week.
Easterly storm conditions over the Winter led to a drop in beach levels and saw shingle moved from the beach to completely cover the slipway at the York Steps, blocking access to the beach. The large boulders, installed in the 1990's to help protect the sea wall, had subsequently become exposed.
Following storms in the early 1990s which washed away much of the shingle beach protecting the sea wall, the rock armour was part of a package of measures to protect the town from flooding and erosion, with two rock breakwaters, three rock groynes, and tons of pebbles were trucked in to replace the beach.
But the winter storms that caused the bizarre phenomenon and frequent cliff falls which have seen large chunks of the cliff at Pennington Point on the town's East Beach give way have highlighted the need for more protection.
Plans are being developed to try and protect the cliffs and the town, with the preferred beach management scheme consisting of adding a new rock groyne on East Beach and importing new shingle onto Sidmouth Beach, as well as increasing the height of the splash wall on the seafront.
However, a £1m funding gap has still not been met – and if the funds cannot be found by August 2020 – or December 2020 at the very latest – a cheaper, and perhaps inferior scheme will have to be worked up instead.
The Local Democracy Reporting Service takes a look at what work has already been carried out to protect Sidmouth and what the future plans include.
The history of flood events and erosion on Sidmouth dates all the way back to the 1820s, with literature reviewed as part of the Devon Tidal Flood Warning Report showing Sidmouth was affected by the "great gale" that affected large parts of the south coast of England in November 1824; with both coastal erosion and flooding of properties reported at Sidmouth.
As a result, between 1825-1826, timber groynes and breastwork were built, and in 1835, the first seawall followed. Further work took place in 1917 where the seawall was repaired and extended, and the following year, the River Sid training wall was replaced with a structure that acted as terminal groyne, and in 1957, a seawall and promenade built to protect Connaught Gardens.
But in addition to wave overtopping impacts and associated flooding, coastal erosion has been a regular occurrence over the years, and along the Sidmouth town frontage, this resulted in the seawall failing at various times; including incidents over the winter 1989/90 which precipitated the construction of the 1990s current coastal defence scheme
Phase 1, in 1991, saw work on the Sidmouth Coast Protection Scheme begin, with the encasing of the old seawall, the building of a low level rock apron and removal of the timber groynes.
A rock revetment was placed along the frontage as emergency works in 1993, while 1994 saw the rock revetment placed in front of the 1957 Connaught Gardens seawall.
Then, in 1995, Phase 2 of the work began. This included the two offshore breakwaters, two rock groynes (York and East), and the Beach recharge which buried the rock revetment built in 1993 – the revetment that this week was revealed again.
The Clifton Walkway built which connects the main beach with Jacobs Ladder was built in 1999, and in 2000, Phase 3 was completed with the Bedford groyne and some beach sediment recycling along the frontage. More beach recycling took place in 2015 to re-distribute beach sediment along the Sidmouth Town beach.
But while, bar occasional instances of wave overtopping, the frontage of the town has been mainly been protected, the erosion at Pennington Point has continued apace with cliff falls aplenty.
A pair of massive landslips in the space of a few weeks in 2013 decimated around 15 metres of gardens along Cliff Road, while storms of February 2017 saw a garden shed fall off the cliff and smash onto the beach during a devastating landslip.
April 2018 saw five cliff falls in a week, while 2020 has seen 'frequent and unprecedented' amounts, according to Cllr Stuart Hughes.
Resident Paul Griew, of the Cliff Road Action Group, had previously said: "If Pennington Point goes another four or five metres, the River Sid will become the sea.
"If we then have a high tide and a south-easterly gale, water will rush over the river wall and flood across the Ham – and Sidmouth will be under water.
"It is estimated that such a flood will cause £72million of damage to people's homes and businesses which won't be able to run.
"Something needs to be done or Sidmouth is going to be flooded."
WHAT IS INCLUDED IN THE BEACH MANAGEMENT PLAN?
Along the East Beach part of the frontage, there are no existing defences, and as the erosion is now posing a risk to the eastern side of Sidmouth, the Sidmouth and East Beach Management Plan was developed.
It has three aims – to maintain the 1990's Sidmouth Coastal Defence Scheme Standard of Service, to reduce the rate of beach and cliff erosion to the east of the River Sid (East Beach), and carry out them in an integrated, justifiable and sustainable way.
The plans would not stop cliff falls but would reduce the erosion from the toe of the cliffs, which would reduce the erosion rates.
The preferred plan for Sidmouth would involve beach replenishment, periodic beach recycling, a new rock groyne on East Beach, raising the height of the splash wall, and repairs to the River Sid training wall.
The groyne will help keep shingle from being moved eastwards away from the vulnerable cliffs and the higher splash wall will capture water coming over the sea wall to prevent flooding in the town centre.
The splash wall would have to be raised by around 1m, but local residents had called the initial stone wall design 'hideous' and 'an eyesore that would mean the picturesque view of the Esplanade would disappear'.
As a result East Devon District Council had been exploring the possible use of a 'glass sea wall'. The temporary glass panel was installed on Sidmouth seafront in February and survived both Storm Ciara and Storm Dennis, but failed to survive 'Storm Vandal' when it was smashed with a sledgehammer.
A council spokesman said that the new act of vandalism jeopardises the trial and has implications for the installation of a glass panel along the entire seafront to help protect Sidmouth from coastal flooding.
They added: "The damage has been reported and we will work with the Police and seek a prosecution if possible.
"The trial of the panel is due to finish at the end of April and the glass appeared to be holding up well, having weathered the impact of three major storms. In light of its robustness to date it is therefore disappointing and immensely frustrating that it has succumbed to this malicious and destructive act.
"This new act of vandalism jeopardises an important part of the Sidmouth Beach Management Scheme, and sadly has implications for the installation of a glass panel along the entire seafront to help protect Sidmouth from coastal flooding.
"If a glass panel is going to be subject to repeated damage by vandals, then it will not be sustainable. We will now have to consider very carefully, whether the use of glass panels to minimise the visual impact of the splash defence is a material option that the council can take forward."
Cllr Geoff Jung, portfolio holder for the environment at East Devon, added: "The test panel of glass may have provided a possible solution to the required protection for the Sidmouth and East Beach management plan that would have protected residents and properties from serious overtopping along the seafront.
"It is clear the panel was up to the task of resisting shingle and storms, but sadly failed to withstand vandalism. The vandalism of the panel now casts doubt on its use in the final scheme."
WHAT HAPPENED THIS WEEK?
Constant Easterly storms over the winter, rather than the usual South-Westerly storms, had led to the breakwaters and rock groynes being less effective than planned and saw the shingle transported along the beach and up the slipway.
Over the weekend East Devon District Council officers had taped off the slipway, but access to the beach has since been restored following the StreetScene team clearing away shingle.
An East Devon District Council spokesman said what happened was as a result of a 'natural process' which had exposed the rock armour, but that they expected to see the shingle re-established on the beach.
Explaining what had caused the shingle to cover the slipway, the council spokesman said: "The shingle on the slipway was brought in during storms, which moved the shingle off the beach and up on to the concrete slipway.
"This natural process has exposed the rock armour, which acts as a secondary defence to protect the sea wall. Our StreetScene team moved the shingle this morning, so bar some stormy weather, we're hoping the slipway should stay clear now.
"Over the winter shingle has been drawn down off the beach due to easterly storm conditions, which has resulted in a drop in beach levels. Now that the prevailing wind direction is returning to the normal south westerly direction, we expect to see shingle re-established on the beach.
"We urge people to take care when using the slipway to access the beach, as the shingle cover is still lower than normal and the rock armour is clearly in evidence.
"The long standing Sidmouth BMP is seeking to establish improved protection in the longer term Including some beach recharge."
WHAT HAPPENS NEXT?
The draft outline business case has already been prepared, but needs full funding information before it can be submitted, and a deadline of August 2020 was agreed by the Steering Group in which to source the outstanding finance.
After which time an alternative plan, involving only the town frontage, would be worked up and submitted for funding approval.
Costs for construction of the scheme are estimated at £8.9million, with around £1 million still needed to be found.
If the funding cannot be raised after December 2020, the council will have to review the project aims and possible management scheme options.
WHAT OTHER OPTIONS HAVE BEEN DISCUSSED?
Additional offshore breakwaters had been discussed as part of the project and although the breakwaters they may present a more robust solution technically, they would come at almost double the cost.
Two previous attempts for a rock revetment on East Beach had also been proposed but planning applications were subsequently withdrawn following recommendation for refusal.
Objections from multiple agencies, including Natural England, the Environment Agency, the Jurassic Coast Team and the East Devon Area of Outstanding Natural Beauty, had been registered, as the BMP has been undertaken to consider theoptions which are more likely to receive planning and marine consents.
Rock armouring had been considered and while the design itself of the rock armour may be simpler, it's unlikely to significantly reduce the programme going forwards and there is the additional risk for a rock armouring scheme because the Outline Business Case may not be approved, as the Environment Agency may have insufficient confidence that the scheme would get planning (and marine planning) consent.