Wednesday, 14 March 2018

Beach Management Plan: meeting Thursday 15th March

Loads of questions still remain unanswered around Sidmouth's beach management plan:
Futures Forum: Beach Management Plan: and (again) failing to get answers to technical questions from the District Council
Futures Forum: Beach Management Plan: new FOI requests on coastal and cliff erosion in Sidmouth

One of them being - to what extent did the new 'protection' erected in the 1990s actually do more harm than good:
Futures Forum: Beach Management Plan: 'accelerated erosion' had occurred since 1996 - after the installation of rock groynes along the seafront in 1995

The next meeting of the BMP steering group will be tomorrow morning, Thursday 15th March, at Knowle.

It is understood that some of those present at the January meeting feel that the District Council's press release was misleading when it claimed that the meeting agreed that previous flood defence engineering works were definitely not responsible for the stripping away of the eastern beach and the escalating speed of cliff erosion.
15 January 2018 - Sidmouth BMP steering group receives progress update from East Devon’s consultants Royal HaskoningDHV - East Devon

The Coastal Processes Baseline report is here:

These are the controversial sections from the report:

6.3.3 Conclusions 

Based on the data and reports presented here, it is not possible to definitively state that beach depletion and accelerated cliff recession are a direct result of coastal engineering at Sidmouth. However, it is evident that defences along this frontage (dating back to the 1700s) have fundamentally changed the evolution of this shoreline and altered its ability to respond to erosion.

2.3 Characteristics of the cliffs 

2.3.1 Introduction 

The elevation of the beach acts as an important control of the ‘bottom‐up’ cliff recession process. When the beach is high it absorbs wave energy and protects the cliff toe from erosion; when the beach is low, waves can break at the cliff toe and cause erosion. The beach has no control over the ‘top‐down’ failure mechanism and therefore cliff top failures that are triggered by rainfall will occur even if the beach level is high. 

5.3.3 Results of cliff analysis GIS Based Analysis 

Taken as a whole, the historical data for East Cliff suggests the cliff experienced a phase of relatively more rapid recession from 1890s to 1950, limited change from 1950 to 2006, and more rapid recession thereafter.

However, this CBU‐wide average disguises a distinct spatial pattern that becomes particularly apparent from the 2006 image onwards from which point the western 250m part of the CBU has retreated markedly more rapidly than the eastern section. In the period 1946 to 2006, limited change is recorded in the whole CBU, with an average recession rate of 0.03m/year. However, from 2006 to 2015, the western 250m retreats at an average rate of 1.5m/year, while the eastern part retreats at 0.25m/year, which is equivalent to the long‐term average.

Coastal Processes Baseline - Sidmouth & East BeachManagement Plan 

Finally, there are fears that the notes of BMP meetings and the press releases and FAQs published by EDDC are so inaccurate, exaggerated or dissembling that they undermine any realistic chance of getting matched funding from agencies, or voluntary contributions from local residents and businesses. 

No comments: