Flood Risk Assessment – 10 Fulmar Road, Weston-Super-Mare

Our Ref: J-14088-01-HG 17th December 2020

Mr Hudson 10 Fulmar Road Mead Vale Weston-Super-Mare BS22 6YU

Re: Flood Risk Assessment – 10 Fulmar Road, Weston-Super-Mare

Introduction

Mr Hudson is proposing a new build dormer house at 10 Fulmar Road, Mead Vale, Weston-Super-Mare. As part of the planning process it has become apparent that the site is at risk of flooding.

According to the Environment Agency (EA) indicative flood map (Figure 2) the site appears to be located in Defended Flood Zone 3 and is therefore at a risk from flooding. As such, Mr Hudson has commissioned Nijhuis Industries Ltd to undertake a Flood Risk Assessment (FRA) for the site.

This report comprises the FRA for the proposed development, in line with The National Planning Policy Framework (NPPF) and Planning Practice Guidance (PPG).

Site Description

The approximate OSGR for the site is ST 35770 62196. The site location is shown in Figure 1 below. At present the site is occupied by the existing garage for 10 Fulmar Road. In a wider context the site is located in the centre of Weston-Super-Mare.

Figure 1. Site Location Plan

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Nijhuis Industries UK & Ireland | Nanjerrick Court - Allet - Truro - TR4 9DJ - United Kingdom | T +44 (0)333 7000 007 | www.nijhuisindustries.com/uk [email protected] Registered Office: Chy Nyverow - Newham Road - Truro - Cornwall - TR1 2DP | Registered in England No. 4785670

Figure 2. EA Flood Map Extract

Assessment of Flood Risks

The EA indicative flood map takes into account fluvial (river) and tidal flooding only, therefore an assessment of other potential flood risks is undertaken below.

Overland/Surface Water

The site is located in the heavily urbanised area of Weston-Super-Mare. As such it is considered that overland flows will be intercepted and diverted, generally into existing drainage features. In addition to this the Environment Agency risk of surface water flooding map (Figure 3 below) shows that the site itself is at very low risk of surface water flooding. There is a low risk of flooding to Fulmar Road located adjacent to the property, this flooding is anticipated to be no greater than 300mm and is limited to the highway. As such this mechanism of flooding will not be discussed further.

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Figure 3. EA Risk of Surface Water Flooding Map

Groundwater Flood Risk

The North Somerset District Council, Strategic Flood Risk Assessment (SFRA) highlights that the area is predominantly underlain by low permeability clayey soils and, therefore, is unlikely to be at significant risk from groundwater flooding. In addition to this, there is little evidence from historic flood data that there is a risk from groundwater flooding. Groundwater will not be considered further in this report.

Flooding as a result of Development

The proposal is the development of a dormer dwelling to replace the existing garage at 10 Fulmar Road. The footprint of the dwelling is anticipated to slightly larger than the existing garage. As such it is considered that there will be a slight increase to the impermeable area on the site. It is anticipated that the new dwelling with have a surface water drainage scheme implemented for the proposal. This mechanism of flooding will not be considered further in this report.

Fluvial (River Flooding)

As part of the FRA a flood information request was submitted to the Environment Agency (EA). The information obtained provided details on fluvial and tidal flooding. This information included within Annex B.

The information for fluvial flooding for the site gave levels for a series of nodes on the nearby watercourse. The closest node to the site has been considered. Based on this node the flood levels for the site are as follows:

1 in 100 year level: 5.28m AOD

1 in 100 year with 20% climate change: 5.29m AOD

1 in 1,000 year: 5.30m AOD

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It is noted that the EA did not provide an allowance for climate change in line with the current guidance of 40%. However, when examining the information given it is thought that when a 40% allowance for climate change is considered the flood level would not be greater than the 1 in 1,000 year level.

The proposed Finished Floor Level (FFL) of the dwelling is 5.80m AOD. The ground level surrounding the proposed dwelling is 5.52m AOD. As such it is deemed that the site is not deemed to be at risk from fluvial flooding.

Tidal Flood Risk

With regards to the tidal flood risk to the site the information from the EA included the highest recorded historic tidal level for Weston-Super-Mare (from 1981) which is to be considered as the tidal flood level they have given for the site. This flood level is 8.10m AOD.

The EA tidal flood levels do not include an allowance for climate change. An allowance for sea level rise due to climate change over the lifetime of the development should be considered. Information on climate change allowances has been outlined by the Environment Agency within the ‘Flood risk assessments: climate change allowances’ guidance shown online. According to Table 3 of this document it is estimated that the sea level rise for a residential property in South-West England is 1.21m over 100 years. Therefore, the tidal flood level with an allowance for climate change is 9.31m AOD.

Weston-Super-Mare is defended from tidal flooding. The Sea Wall in the North of the Bay was upgraded in 2010 to provide a defence standard of a 1 in 200 year return period. The minimum design level of the Weston-Super-Mare sea wall is 9.05m AOD, but has been designed to be raised to a level of 9.55m AOD.

It is anticipated that defences will be maintained for the lifetime of the development due to the high population density of Weston-Super-Mare which is being protected by the current defences.

Flood Risk Summary

Based on the information outlined above, the site is deemed to be free from fluvial flooding.

The site is currently defended from tidal flooding but is at residual risk from tidal flooding should the defences fail.

Mitigation Measures

The site is free from fluvial flooding and is currently protected from tidal flooding and is expected to be defended for the duration of its lifetime.

Nevertheless, the following mitigation measures are recommended as best practice.

- Any construction methods and techniques to be flood resilient/resistant where possible. Further advice is areas at risk of flooding is available from Improving Flood Resilience of New Buildings available at: http://www.planningportal.gov.uk/uploads/br/flood_performance.pdf

- It is recommended that the site should sign up for the Environment Agency’s flood warning system for the area. This will ensure prior warning of a possible flood event and allow adequate time to prepare for flooding. EA standing advice is given below:

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Figure 4. EA standing advice

Access and Egress

The nature of tidal flooding means that it is predictable in advance and as such, would allow time for residents to evacuate prior to a tidal flood event. The main access and egress for the site is via the existing route along Fulmar Road. The access road is also expected to be protected from tidal flooding for the lifetime of the development.

Figure 3 shows that parts of the access roads are at a low risk from surface water flooding. However, the risk is minimal and access should still be possible.

It is recommended that occupants of the site sign up to the Environment Agency flood warning service. However, in the unlikely event of inhabitants being unaware of an impending flood of sufficient magnitude to inundate the site, a refuge space is provide by the inclusion of a first floor levels included in the design of the dormer. This can act as a refuge space during the peak of the flood.

Due to the nature of tidal flooding, the maximum time that the site may be at risk from flooding is approximately 3.5 hours for an extreme tidal flood event with an allowance for climate change undefended event at peak tide, this is illustrated in Figure 5 using the rule of twelfths. Considering the scale of the development, a refuge of this nature is deemed appropriate.

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Figure 5. Rule of Twelfths Illustrating Maximum Time the Site is at Risk of Tidal Flooding

Policy

The proposed dormer dwelling has been shown to be located within Flood Zone 3 albeit defended. In accordance with the Planning Practice Guidance (PPG) Table 2, a development of this type “Buildings used for dwelling houses” is classified as ‘More Vulnerable’. Referring to Table 3 of PPG a ‘More Vulnerable’ development within Flood Zone 3 is deemed subject to the Sequential and Exception Tests (Figure 6).

Figure 6. Extract from PPG Table 3

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Further information relating to the Sequential and Exception Test are included within a separate document to be read in conjunction with this Flood Risk Assessment.

Conclusions

By using information from the EA, this investigation has shown that the proposed development at 10 Fulmar Road, is free from fluvial flooding and is currently protected from tidal flooding. It is anticipated that the site would be protected from tidal flooding for the lifetime of the development as the current defences protect the entire area and population of Weston-Super-Mare. The site is at residual risk of tidal flooding if defences were to fail.

Despite the site being protected from tidal flooding, mitigation measures have been recommended which include the use of flood resilient measures where appropriate.

The main access and egress route for the site is via Fulmar Road. It is anticipated that inhabitants would receive sufficient flood warning in order to undertake evacuation prior to a tidal flood event by following mitigation measures of being connected to the Environment Agency’s flood warning system for the area. If the residents have not evacuated then it is advised to stay on the first floor and above of the property until flooding at the access and egress subsides. It is anticipated that dry access to the building will be cut off for no greater than 3.5 hours.

According to PPG a residential dwelling is classified as “More Vulnerable”. Referring to PPG Table 3 if a “More Vulnerable” development is located in Flood Zone 3 then the Sequential and Exception Tests apply. This have been considered within the dedicated document to be read in conjunction with this report.

Based on the findings of this study, with regard to the criteria outlined in both the guidance outline by NPPF and PPG the development is deemed appropriate on this site from a flood risk perspective.

Yours sincerely For and on behalf of Nijhuis Industries Ltd

Hannah Graham Team Leader – Flood Water Management

Enc. Annex A Site Plans Annex B EA Flood Information

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ANNEX A – SITE PLANS

Location Plan 1:1250 0 50 100 150

Scale 1:1250

BLOCK PLAN 1:500

0 20 30 40 50 60

Project Design and Construction Management Ltd

5 Halswell Road Clevedon Somerset BS21 6LD

Date: Oct 2020 07710-063216 Proposed new dwelling at 01275-870781 Scale: 1:50 at A3 [email protected] LOCATION/BLOCK PLAN AS EXISTING 10 Fulmar Road, Mead Vale, W-s-M BS22 6YU Drg No: PDCM:581-01 www.peterbath.co.uk 5.52

5.46 5.55

5.52

FFL 5.80 5.55

5.47

5.50 5.48 FFL 5.80 5.52

5.50

5.46 5.55

5.52

FFL 5.80 5.55

c u p d

h a ll B e d r o o b m a t . 5.47 h 2 r o o m

c u p d

k L it c o h u e n n g / e 5.48 f 5.50 a m i ly

r FFL 5.80 o o m c u p d

B c u e p d d r o o m . 1

5.50

Location Plan 1:1250 0 50 100 150

Scale 1:1250

BLOCK PLAN 1:500

0 20 30 40 50 60

Project Design and Construction Management Ltd

5 Halswell Road Clevedon Somerset BS21 6LD

Date: Oct 2020 07710-063216 Proposed new dwelling at 01275-870781 Scale: 1:500 & 1:1250 at A3 [email protected] LOCATION/BLOCK PLAN AS PROPOSED 10 Fulmar Road, Mead Vale, W-s-M BS22 6YU Drg No: PDCM:581-06A www.peterbath.co.uk

ANNEX B – EA FLOOD INFORMATION

Abigail Gallacher Our ref: 193758-WX Nijhuis Industries UK & Ireland Your ref: [email protected] Date: 11 December 2020

Dear Abigail

Thank you for your enquiry which was received on 12 November 2020.

Abstract Name Product 4 Description Detailed Flood Risk Assessment Map for 10 Fulmar Road, Weston-super-Mare, BS22 6YU Information The mapping of features provided as a background in this product is © Ordnance Warnings Survey. It is provided to give context to this product. The Open Government Licence does not apply. Attribution Contains Environment Agency information © Environment Agency and/or database rights. Contains Ordnance Survey data © Crown copyright 2019 Ordnance Survey 100024198.

Flood Map for Planning The Flood Map for Planning is now classed as Open Data. It can be downloaded free of charge under an open data licence from the following link https://data.gov.uk/publisher/environment-agency

If you search for the ‘flood map for planning’ in the search box the following datasets will be available for you select and download the data:

 Flood Map for Planning (Rivers and the Sea) – Flood Zones 2 and 3  Flood Map for Planning (Rives and Sea) – Areas Benefiting from Defences  Flood Map for Planning (Rivers and Sea) Flood Storage Areas  Flood Map for Planning – Spatial Flood Defences (without Standard attributes)  Recorded Flood Outlines  Historic Flood Map  Risk of Flooding from Surface Water Extent for:  3 percent annual chance  1 percent annual chance  0.1 percent annual chance

If you have requested this information to help inform a development proposal, then you should also note the detail in the attached advisory text on the use of Environment Agency Information and Further Guidance for FRAs.

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

Flooding history We no longer produce pdf copies of the Historic Flood Map. This information is available to search select, and download free of charge as part of the Government’s ‘open data’ as  Recorded Flood Outlines  the Historic Flood Map

These are GIS layers and can be download from: https://data.gov.uk/publisher/environment-agency

Strategic Flood Risk Assessment (SFRA)

Planning If you have questions regarding the planning nature of your enquiry, or require advice on floor levels, please contact our Sustainable Places team on [email protected]. Please be aware that we now charge for planning advice when consulted on pre-application enquiries. This new approach provides advice to developers in two ways. Firstly there is the provision of ‘free’ advice available to everyone where we give a preliminary opinion on a proposed development. This sets out the environmental constraints together with any issues this raises for us. Should you wish us to review in detail any of these issues then we can do this through a chargeable scheme aimed at recovering our costs.

Flood Levels Fluvial flood levels and depths The attached map contains a set of modelled fluvial flood level node locations/unique identifiers, for the main river Cross Rhyne, taken from our Weston Villages Strategic Flood Solution (2012) NSC model. A sheet is also attached providing the associated flood levels, NGRs and further information for the river channel relating to each of these nodes. Please note that the labels annotated to the Node Location Map are unique node identifiers and not the associated flood levels. Please note there are no formal defences along this watercourse, therefore the fluvial flood levels are referred to as 'baseline'

Node type information:  1D_fluvial o In channel nodes, no 2D element to the modelling  2D_fluvial o In channel nodes, 2D data available from the modelling  Interpolated sections o Calculated weighted averages of the river or conduit section properties upstream and downstream to produce a hybrid section according to the location of the interpolated section. They are used to ensure a smooth gradation or transition between cross sections to avoid sudden variations which can cause instability in a model. This may be where the distance between surveyed cross sections is large and there is a steep gradient to the channel or other distinct changes between the two sections.  Replicate sections o Used to copy the preceding river or conduit section at a distance further along the reach and at a lower level. The Replicated Section is a quick method for adding a cross-section which has exactly the same dimensions as the cross-section immediately upstream.  Reservoir o Modelled measurements outside the boundary of the river channel

Interpolated and Replicate sections are not surveyed sections, however they are based on surveyed section data and the results from them can be used as long as their limitations are understood.

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

Please be aware that this data is from a fluvial in-channel (1D) model. We have no modelled data for the floodplain.

The Cross Rhyne data was taken from the Weston Villages Flood Solution 2D ISIS-Tuflow model that was produced in 2012. Please note this data is the property of North Somerset Council and is provided with their permission for the purpose of the flood risk assessment for the above named site. The data is subject to the terms and conditions within the enclosed Open Government Licence which we advise you read and note the conditions therein.

Please be aware that this model did not include data for climate change allowances.

If you intend undertaking a FRA for a planning application using climate change flood level information supplied in this letter, you should consider whether it is appropriate in light of a range of potential allowances for fluvial flood flow now advised in curent planning guidance on 'Flood risk assessments: climate change allowances'. The relevant guidance is available at the following website address: https://www.gov.uk/guidance/flood-risk-assessments-climate-change-allowances

The modelled extent of the River Cross Rhyne is from upstream at ST 32334 58966 to downstream at ST 33588 59144.

Somerset and the Sea We attach a PDF copy of 'Somerset and the Sea'. This document contains the highest recorded historic tidal levels for Bridgwater, Weston-super-Mare and Avonmouth, which occurred during the tidal flood event of 13 December 1981.

Environmental Permit for Flood Risk Activities In addition to any other permission(s) that you may have already obtained e.g. planning permission, you may need an environmental permit for flood risk activities (formerly known as Flood Defence Consent prior to 06 April 2016) if you want to do work:  in, under, over or near a main river (including where the river is in a culvert)  on or near a flood defence on a main river  in the flood plain of a main river  on or near a sea defence

For further information and to check whether a permit is required please visit: https://www.gov.uk/guidance/flood-risk-activities-environmental-permits.

For any further advice, please contact your local Environment Agency Office, at [email protected].

Further Information We advise that you also contact the Flood Risk Department, [email protected] telephone 01275 888802, at North Somerset Council, Walliscote Grove Road, Weston-super-Mare, BS23 1UJ as they may be able to provide further advice with respect to localised flooding and drainage issues.

Further details about the Environment Agency information supplied can be found on our website: https://www.gov.uk/browse/environment-countryside/flooding-extreme-weather

If you have requested this information to help inform a development proposal, then you should note the information on GOV.UK on the use of Environment Agency Information for FRAs: https://www.gov.uk/planning-applications-assessing-flood-risk https://www.gov.uk/government/publications/pre-planning-application-enquiry-form-preliminary- opinion

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

We hope you find this information helpful and it is provided subject to the guidance below, which we strongly recommend you read.

Yours sincerely

Chris Doyle Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Email: [email protected] Telephone number: 03708 506 506

Enc: Use of Environment Agency Information for Flood Risk Assessments (below) 193758-WX Node Location Map 193758-WX Node Data Somerset and the Sea 193758-WX Defence Map 193758-WX Defence Data

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

Use of Environment Agency Information for Flood Risk Assessments (FRAs)

Important Use of Environment Agency data: you should note that

1. Information supplied by the Environment Agency may be used to assist in producing a Flood Risk Assessment (FRA) where one is required, but the use of Environment Agency information does not constitute such an assessment on its own.

2. As part of your data request, we have provided all of the modelled data we hold for your location. Please note that some of our modelled information may have been produced for purposes other than for flood zone generation. This may mean that some of the modelled data you have been provided with has a lower confidence level, and has not been used in producing our flood map, nor definitively reflects the predicted flood water level at the property/development site scale. To check the suitability of the use of this information in your FRA please contact your local Partnership & Strategic Overview (PSO) team.

3. This information covers flood risk from main rivers and the sea, and you will need to consider other potential sources of flooding, such as groundwater or surface water runoff. The information produced by the Local Planning Authority and the Lead Local Flood Authority (LLFA) may assist in assessing other sources of flood risk.

4. Where a planning application requires a FRA and this is not submitted or deficient, the Environment Agency may well raise an objection.

5. For more significant proposals in higher flood risk areas, we would be pleased to discuss details with you ahead of making any planning application, and you should also discuss the matter with your Local Planning Authority.

Pre-Planning Advice from the Environment Agency If you have requested this information to help inform a development proposal, then we recommend that you undertake a formal pre-application enquiry using the form available from our website:

Pre-application Preliminary Opinion: https://www.gov.uk/government/publications/pre-planning-application-enquiry-form-preliminary- opinion

Pre-application Charged Service: https://www.gov.uk/government/publications/planning-advice-environment-agency-standard-terms- and-conditions

Depending on the enquiry we may also provide advice on other issues related to our responsibilities, including flooding, waste, land contamination, water quality, biodiversity, navigation, pollution, water resources, foul drainage or Environmental Impact Assessment.

Flood Risk Assessment (FRA) Guidance You should refer to the Planning Practice Guidance of the National Planning Policy Framework (NPPF) and the Environment Agency’s Flood Risk Standing Advice for information about Flood Risk Assessment (FRA) for new development in the different Flood Zones. These documents can be accessed via:

National Planning Policy Framework Planning Practice Guidance: http://planningguidance.planningportal.gov.uk/

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

Environment Agency advice on FRAs: https://www.gov.uk/flood-risk-assessment-for-planning-applications#when-to-follow- standing-advice

https://www.gov.uk/government/publications/planning-applications-assessing-flood- risk

Customer & Engagement, Wessex Rivers House, East Quay, Bridgwater, Somerset, TA6 4YS Phone: 02030 250 376 Email: [email protected] www.environment-agency.gov.uk

193758-WX - AIMS data

Product 4 - AIMS Information 193758-WX Date: 18/11/2020

Actual fluvial Actual fluvial Actual fluvial Actual fluvial Actual fluvial Right Actual fluvial Map Approx length downstream downstream upstream upstream coastal crest Most recent Overall Asset ID Asset Type Asset Description or left coastal crest NGR Ref (m) crest level crest level crest level crest level level inspection condition bank level (mAOD) (mAOD) accuracy (mAOD) accuracy accuracy 10 173116 wall Flood wall 83.87 left 6.47 +/->5 to 15cm 6.47 +/->5 to 15cm DNR DNR ST3783263013 06/02/2020 3 11 173310 embankment Embankment 55.52 left 6.47 +/- 1 to 5cm 6.58 +/- 1 to 5cm DNR DNR ST3785162994 06/02/2020 2 12 173311 embankment Embankment 52.57 left 6.58 +/- 1 to 5cm 6.54 +/- 1 to 5cm DNR DNR ST3789662942 06/02/2020 2 51 1288 high_ground Natural Bank 349.35 left 6.38 +/->75cm 6.40 +/->75cm DNR DNR ST3706763952 06/02/2020 3 52 1289 high_ground Natural Bank 213.77 left 6.40 +/->75cm 5.72 +/->75cm DNR DNR ST3737463572 06/02/2020 3 53 1290 high_ground Natural Bank 868.31 right 5.75 +/->75cm 5.62 +/->75cm DNR DNR ST3727663720 06/02/2020 3 54 1291 high_ground Natural Bank 239.48 left 5.68 +/->75cm 5.51 +/->75cm DNR DNR ST3773463125 06/02/2020 3 88 12303 high_ground Natural bank 185.40 right DNR DNR DNR DNR DNR DNR ST3788062971 06/02/2020 3 110 41457 high_ground Natural Bank 259.72 right 5.62 +/->75cm 6.04 +/->75cm DNR DNR ST3772163165 06/02/2020 3 123 58526 high_ground Natural Bank 362.94 left 5.72 +/->75cm 5.68 +/->75cm DNR DNR ST3759163308 06/02/2020 3

Notes * Overall Condition has been taken from the most recent inspection * Inspections are of a purely visual nature and do not necessarily reflect the true condition of the asset * Condition 1 = very good, Condtion 2 = good, Condition 3 = fair, Condition 4 = poor, Condition 5 = very DNR = data not recorded

Using ‘Flood risk assessments: climate change allowances’ following publication of new climate projections in UKCP18 Who are these messages for? These messages are for local planning authorities and developers preparing Strategic Flood Risk Assessments (SFRAs) and site specific flood risk assessments (FRAs). How to use these messages These messages advise developers who need to prepare site specific flood risk assessments and all local planning authorities how to use ‘Flood risk assessments: climate change allowances’ (published 2016) to account for the impact of climate change on flood risk now UKCP18 has been published. Main messages • UKCP18 was published on 26th November 2018. • UKCP18 is the official source of information on how the climate of the UK may change over the rest of this century. The UKCP18 projections replace the UKCP09 projections. • The allowances in ‘Flood risk assessments: climate change allowances’ (published Feb 2016) are still the best national representation of how climate change is likely to affect flood risk for: o peak river flow o peak rainfall intensity • Research that is due to be published in 2019 may result in changes to these allowances1. We will provide customers with more information regarding the need to update peak river flow and peak rainfall intensity allowances in due course. • The climate change allowances for sea level rise in ‘Flood risk assessments: climate change allowances’ will be updated and published as early as possible in 2019. Until then, it is reasonable to continue to use the sea level rise allowances in ‘Flood risk assessments: climate change allowances’ (published in 2016) for planning decision making, because the allowances that have been used to date represent the high end of the range of sea level rise projected by UKCP18.

1 High resolution mapping providing peak river flow allowances at 1km grid resolution due to be published Spring 2019. We do not expect the peak river flow allowances provided at a regional scale in ‘Flood risk assessments: climate change allowances’ to change as a result of this information, however, planners and developers may need to take account of this information where it shows a significant difference to the regional allowances. High resolution (daily and sub daily) rainfall projections is due to be published in the second half of 2019. These are used to understand the impact of climate change on peak rainfall. Following this, the peak rainfall allowances in ‘Flood risk assessments: climate change allowances’ may need to be updated, but this will not be until late 2019 at the earliest. customer service line 03706 506 506 floodline 03459 88 11 88 incident hotline 0800 80 70 60 Page 1 of 2

• However, in exceptional cases where developments are very sensitive to flood risk and have a lifetime of at least 100 years2, we recommend you assess the impact of both the current allowance in ‘Flood risk assessments: climate change allowances’ and the 95th percentile of UKCP18 ‘RCP 8.5’ scenario (high emissions scenario) standard method sea level rise projections of UKCP18, and plan according to this assessed risk. You will need to calculate sea level rise allowances beyond 2100 by extrapolating the UKCP18 dataset. The Environment Agency will check your extrapolation methodology and provide advice. • UKCP18 provides sea level rise projections for 2100 – 2300. The update of ‘Flood risk assessments: climate change allowances’ will include advice on using these projections. In the meantime, for development with a longer than 100 year lifetime e.g. large urban extensions, new settlements, major infrastructure, you should contact your local the Environment Agency office for advice on how to calculate such allowances. • Where it is appropriate to use the sea level rise information in UKCP18 as described in this briefing note, planning decisions should do so from now onwards, in order to ensure planning decisions are in line with policies in the National Planning Policy Framework. However, where local plans or development proposals and associated flood risk assessments are well advanced, it will usually be acceptable make decisions based on the allowances and advice in ‘Flood risk assessments: climate change allowances’ (published Feb 2016) in the following circumstances: o local plan has been submitted for examination (before or on the day UKCP18 is published); or o development proposals are well advanced or where a valid planning application has already been submitted to the local planning authority (before or on the day UKCP18 is published). • When the climate change allowances are updated, the supporting guidance will be updated at the same time to address user feedback collated since Feb 2016. • Once ‘Flood risk assessments: climate change allowances’ has been updated, over time we will update our flood risk modelling to reflect the revised climate change projections. This modelling work is principally done to inform our flood risk management activities, but we will continue to share this work with planners (for SFRAs) and developers (for site-specific FRAs) when it becomes available. Where the modelling needed by planners and developers has not yet been undertaken, we may be able to work together to do this work more quickly and to share the costs. Where this is not possible, the onus will be on planners and developers to undertake the necessary work at their own cost. Contact your local Environment Agency office to find out when they plan to update their flood risk modelling and to discuss working together.

2 Such as infrastructure projects or developments that significantly change existing settlement patterns including urban extensions and new settlements customer service line 03706 506 506 floodline 03459 88 11 88 incident hotline 0800 80 70 60 Page 2 of 2 193758-WX selected nodes data extract

TITLE Weston Villages Strategic Flood Solution - Haskoning 2012 MODEL DATE 01/09/2012 SOFTWARE ISIS

SCENARIO Baseline - Summer Penning Level at New Bow Sluice

NODE AA_to_Z Grum_N_0270 Grum_N_0413 Grum_S_0095 I_Cross_7000 lhb_2904 lhb_We2862 rhb_We3085 We_2464 We_2862d We_3085d We_3097 We_3421 Z_to_X Reservoir Grumblepill Grumblepill Grumblepill Reservoir Reservoir Reservoir West Wick Cross Cross Cross IDB Reservoir WATERCOURSE Unit Rhyne (N) Rhyne (N) Rhyne (S) Cross Rhyne Unit Unit Unit Rhyne Rhyne Rhyne Rhyne Rhyne Unit 2YR Level 5.01 5.05 5.05 5.04 5.00 4.99 4.40 4.40 5.08 5.08 5.08 5.08 5.08 5.03 2YR Flow 0.24 0.27 0.23 0.23 NMD 0.29 0.07 0.12 0.04 0.47 0.47 0.79 0.70 0.08 5YR Level 5.12 5.13 5.13 5.12 5.05 5.11 4.40 4.40 5.19 5.19 5.20 5.20 5.20 5.13 5YR Flow 0.27 0.34 0.30 0.30 NMD 0.37 0.07 0.12 0.05 0.64 0.64 0.98 0.72 0.08 10YR Level 5.16 5.16 5.16 5.15 5.07 5.16 4.40 4.65 5.24 5.24 5.24 5.24 5.24 5.17 10YR Flow 0.28 0.39 0.34 0.34 NMD 0.41 0.07 0.12 0.06 0.72 0.72 1.05 0.72 0.08 20YR Level 5.20 5.18 5.18 5.17 5.08 5.20 4.40 5.17 5.25 5.25 5.25 5.26 5.26 5.20 20YR Flow 0.27 0.45 0.43 0.43 NMD 0.40 0.07 0.13 0.06 0.77 0.77 1.10 0.72 0.08 20YR 20%CC Level 5.27 5.20 5.20 5.19 5.11 5.28 4.40 5.27 5.27 5.27 5.27 5.27 5.28 5.26 20YR 20%CC Flow 0.28 0.54 0.54 0.54 NMD 0.29 0.07 0.11 0.08 0.81 0.81 1.16 0.73 0.07 25YR Level 5.20 5.18 5.18 5.17 5.08 5.21 4.40 5.23 5.25 5.25 5.26 5.26 5.26 5.21 25YR Flow 0.26 0.47 0.45 0.45 NMD 0.37 0.07 0.13 0.07 0.78 0.78 1.11 0.72 0.08 30YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 30YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 50YR Level 5.24 5.20 5.20 5.19 5.09 5.24 4.40 5.26 5.26 5.26 5.26 5.27 5.27 5.24 50YR Flow 0.26 0.53 0.53 0.53 NMD 0.37 0.07 0.13 0.08 0.80 0.80 1.15 0.73 0.08 75YR Level 5.25 5.20 5.20 5.19 5.11 5.26 4.40 5.27 5.27 5.27 5.27 5.28 5.28 5.25 75YR Flow 0.27 0.57 0.56 0.56 NMD 0.35 0.07 0.13 0.08 0.80 0.80 1.17 0.73 0.08 100YR Level 5.27 5.21 5.21 5.20 5.12 5.28 4.40 5.28 5.28 5.28 5.28 5.28 5.28 5.26 100YR Flow 0.28 0.59 0.59 0.59 NMD 0.34 0.07 0.12 0.08 0.81 0.80 1.18 0.73 0.08 100YR 20%CC Level 5.33 5.25 5.25 5.24 5.18 5.37 4.40 5.29 5.29 5.29 5.29 5.29 5.29 5.31 100YR 20%CC Flow 0.29 0.71 0.71 0.71 NMD 0.18 0.11 0.16 0.08 0.91 0.91 1.18 0.72 0.10 100YR 30%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 30%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 40%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 40%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 85%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 85%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR 20%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR 20%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 500YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 500YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD

Environment Agency 08/12/2020 Page 1 of 4 193758-WX selected nodes data extract

1000YR Level 5.40 5.28 5.28 5.27 5.25 5.47 4.40 5.30 5.30 5.30 5.30 5.30 5.30 5.34 1000YR Flow 0.32 0.88 0.84 0.84 NMD 0.14 0.15 0.19 0.09 0.90 0.90 1.19 0.72 0.12 1000YR 20%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 1000YR 20%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD TIDE 200YR NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD TIDE 1000YR NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD Eastings 336889 336919 336839 337079 336427 336948 336794 336585 336809 336532 336352 336337 336064 336910 Northings 162675 161440 161530 161115 161133 163112 161781 161485 161568 161682 161549 161541 161368 162404

Environment Agency 08/12/2020 Page 2 of 4 193758-WX selected nodes data extract

SCENARIO Baseline - Winter Penning Level at New Bow Sluice

NODE AA_to_Z Grum_N_0270 Grum_N_0413 Grum_S_0095 I_Cross_7000 lhb_2904 lhb_We2862 rhb_We3085 We_2464 We_2862d We_3085d We_3097 We_3421 Z_to_X Reservoir Grumblepill Grumblepill Grumblepill Reservoir Reservoir Reservoir West Wick Cross Cross Cross IDB Reservoir WATERCOURSE Unit Rhyne (N) Rhyne (N) Rhyne (S) Cross Rhyne Unit Unit Unit Rhyne Rhyne Rhyne Rhyne Rhyne Unit 2YR Level 4.99 5.04 5.04 5.03 5.00 4.98 4.40 4.40 5.07 5.07 5.07 5.07 5.07 5.02 2YR Flow 0.24 0.26 0.22 0.22 NMD 0.29 0.07 0.14 0.04 0.43 0.43 0.77 0.70 0.08 5YR Level 5.11 5.13 5.13 5.12 5.05 5.10 4.40 4.40 5.19 5.19 5.19 5.19 5.19 5.12 5YR Flow 0.27 0.34 0.30 0.30 NMD 0.37 0.07 0.15 0.05 0.63 0.63 0.97 0.72 0.08 10YR Level 5.16 5.15 5.15 5.14 5.06 5.15 4.40 4.59 5.23 5.23 5.24 5.24 5.24 5.16 10YR Flow 0.28 0.39 0.34 0.34 NMD 0.41 0.07 0.15 0.06 0.71 0.71 1.05 0.72 0.08 20YR Level 5.19 5.18 5.18 5.17 5.08 5.20 4.40 5.16 5.25 5.25 5.25 5.25 5.26 5.20 20YR Flow 0.27 0.45 0.43 0.43 NMD 0.40 0.07 0.15 0.06 0.77 0.77 1.10 0.72 0.08 20YR 20%CC Level 5.27 5.20 5.20 5.19 5.11 5.28 4.40 5.27 5.27 5.27 5.27 5.27 5.27 5.26 20YR 20%CC Flow 0.29 0.54 0.54 0.54 NMD 0.29 0.07 0.11 0.08 0.81 0.81 1.16 0.73 0.07 25YR Level 5.20 5.18 5.18 5.17 5.08 5.21 4.40 5.22 5.25 5.25 5.25 5.26 5.26 5.20 25YR Flow 0.27 0.47 0.45 0.45 NMD 0.38 0.07 0.15 0.07 0.78 0.78 1.11 0.72 0.08 30YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 30YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 50YR Level 5.23 5.20 5.20 5.19 5.09 5.24 4.40 5.26 5.26 5.26 5.26 5.26 5.27 5.23 50YR Flow 0.26 0.53 0.53 0.53 NMD 0.37 0.07 0.15 0.08 0.80 0.80 1.15 0.72 0.08 75YR Level 5.25 5.20 5.20 5.19 5.11 5.26 4.40 5.27 5.27 5.27 5.27 5.27 5.28 5.25 75YR Flow 0.27 0.57 0.56 0.56 NMD 0.35 0.07 0.15 0.08 0.80 0.80 1.17 0.72 0.08 100YR Level 5.27 5.21 5.21 5.20 5.12 5.27 4.40 5.28 5.28 5.28 5.28 5.28 5.28 5.26 100YR Flow 0.28 0.59 0.59 0.59 NMD 0.34 0.07 0.15 0.08 0.80 0.80 1.18 0.72 0.08 100YR 20%CC Level 5.33 5.25 5.25 5.24 5.18 5.36 4.40 5.29 5.29 5.29 5.29 5.29 5.29 5.31 100YR 20%CC Flow 0.29 0.71 0.71 0.71 NMD 0.20 0.10 0.15 0.08 0.91 0.91 1.19 0.72 0.09 100YR 30%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 30%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 40%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 40%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 85%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 100YR 85%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR 20%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 200YR 20%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 500YR Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 500YR Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD

Environment Agency 08/12/2020 Page 3 of 4 193758-WX selected nodes data extract

1000YR Level 5.40 5.28 5.28 5.27 5.25 5.47 4.40 5.30 5.30 5.30 5.30 5.30 5.30 5.34 1000YR Flow 0.32 0.88 0.85 0.85 NMD 0.12 0.14 0.18 0.09 0.90 0.90 1.20 0.72 0.10 1000YR 20%CC Level NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD 1000YR 20%CC Flow NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD TIDE 200YR NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD TIDE 1000YR NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD NMD Eastings 336889 336919 336839 337079 336427 336948 336794 336585 336809 336532 336352 336337 336064 336910 Northings 162675 161440 161530 161115 161133 163112 161781 161485 161568 161682 161549 161541 161368 162404

The model was produced to assess our flood risk management assets and the results are fit for this purpose. We have MODERATE confidence in its input data, and subsequently its results. The reason Moderate Level of confidence that we have MODERATE confidence in the model and its results is because the model requires verification against a known flood event. You will need to contact our Partnership and Strategic Overview Team to discuss whether the flood levels from this model are suitable for your FRA or whether they require you to carry out further work to update the modelling.

NMD No Modelled Data UNITS LEVELS: mAOD FLOW: cumecs

Environment Agency 08/12/2020 Page 4 of 4 Node location map centred on ST 35774 62190 - created 08/12/2020 [Ref: 193758-WX]

lhb_2904 (!

Scale:1:12,000 at A3

AA_to_Z (! ¬ Z_to_X Legend (! NODE_TYPE ^_ 1D_RiverSection

^_ 2D_RiverSection

^_ Interpolate

^_ Replicate

lhb_We2862 (! Reservoir

(! 193758-WX_site_boundary We_2862d We_2464 ^_ Main Rivers We_3085d ^_ We_3097 ^_^_ ^_ (! Modelled Flood Level Nodes rhb_We3085 ^_ We_3421 A table that references the node locations/unique ^_ Grum_N_0413 identifiers is also attached, giving associated flood levels, NGRs and further information for the Grum_N_0270 river channel and model.

I_Cross_7000 Grum_S_0095 ^_ ^_

© Environment Agency copyright and / or database rights 2019. All rights reserved. © Crown Copyright and database right 2019. All rights reserved. Ordnance Survey licence number 100026380. Current Flood Defences centred on NGR ST 3577362192, created 18/11/2020 Ref: 193758-WX

51 53

52 110

123 Scale: 1:20,000 88 54 /

72 Legend 65 10 Defences bridge_abutment 11 12 73 barrier_beach cliff demountable embankment (!(! flood_gate high_ground promenade quay wall ØØ beach ØØ dunes Channels open_channel 69 71 simple_culvert

This data has been extracted from the Asset Information Management System (AIMS) which was created to draw various data sources into one database and has been populated with information of varying quality.

© Environment Agency copyright and / or database rights 2019. All rights reserved. © Crown Copyright and database right 2019. Ordnance Survey licence number 100024198. Contact Us: National Customer Contact Centre, PO Box 544, Rotherham, S60 1BY. Tel: 03708 506 506 (Mon-Fri 8-6). Email: [email protected] Somerset and the sea

The 1981 storm - 25 years on Foreword We are the Environment Agency. It’s our job to look after your environment and make it a better place – for you, and for future generations. Your environment is the air you breathe, the water you drink Coastal defences play a vital role in the future of our area. and the ground you walk on. Working with business, The 1981 storm that hit Avon and Somerset caused significant damage and Government and society as a whole, we are making your demonstrated how vulnerable our coastline can be. environment cleaner and healthier. More than £60 million has been spent over the last 25 years improving the condition The Environment Agency. Out there, making your environment of our coastal defences, and protecting over 37,000 homes. At today’s prices this would be approximately £100 million. This investment has averted major damage in a better place. similar surge tide events that have occurred since 1981.

Here in the south west sea levels could rise by up to 86 cm by 2080, putting our coastal communities under greater risk of flooding. Extreme weather events causing serious flooding will be more common.

Continuing to reduce flood risk and adapting to climate change is a major part of our corporate strategy and is the challenge for now and the future.

Published by: Environment Agency Manley House Kestrel Way Exeter, Devon EX2 7LQ Tel: 08708 506 506 Richard Symonds Email: [email protected] Area Flood Risk Manager - Wessex (North) www.environment-agency.gov.uk

Environment Agency Somerset and the sea The 1981 storm - 25 years on 01 Flooding from the sea - Huntspill area, 1981

The big storm of Sunday 13 December 1981

The highest tidal levels in the last century were recorded on 13 December 1981 along the Somerset and Avon coastline. A high spring tide of 7.95m AOD (above Ordnance datum) was recorded at Bridgwater with a 1.45m surge. The predicted tide had been 6.5m AOD with a 0.38m surge. At Weston-super-Mare and Avonmouth, the predicted tides were 7.2m AOD. The actual tides recorded were 8.10m AOD at Weston-super-Mare and 8.83m AOD at Avonmouth, with a 1.7m surge. The tides combined with storm force westerly winds - gale force 8 to 10, up to 50 knots.

Sea defence damage and flooding It is recorded that 12,500 acres of land were inundated with floodwater and 1,072 houses and commercial properties suffered flooding, with floodwater reaching the M5 motorway. The National Farmers Union reported 2,500 sheep, cattle and pigs and 22,000 chickens drowned. Fortunately there was no loss of human life.

SeaWessex Defence Water Damage Authority, and predecessor Flooding to the Environment Agency, estimated in excess of £6 million damageIt is recorded to the that Somerset 12,500 coastline acres of landbetween were Clevedon inundated with floodwater and approx. 1072 houses and and Porlock, necessitating an initial three-year Meteorological conditions on 13 December 1981 programmecommercial ofproperties sea defence suffered repair flooding. work. 22 The locations National of seaFarmers defences Union were reported overtopped that livestock or damaged to the - valuesome of Meteorological conditions resulted in a very intense extensively£150,000 (sheep, - over an lambs, 11 kilometre cattle, pigs, (7 mile) poultry stretch and of1 secondary low-pressure area moving rapidly through coast.hive of bees recorded) were drowned, together with the western approaches to the Bristol Channel. The feed/grain to the value of £50,000 were destroyed. rapid movement - about 40 knots - with pressure Fortunately there was no loss of human life. Aerial view of Clevedon after the storm dropping from 1012 to 962 mb in the Bristol Channel between 0000 hours and 1800 hours, caused a large Wessex Water Authority, the predecessor authority of rising surge in sea level. the Environment Agency, estimated £6m damages to the Somerset coastline between Clevedon and Porlock, The maximum surge level at Hinkley Point on the necessitating a 3-year programme of sea defence repair Somerset coast occurred 11 minutes after predicted work. 22 locations of sea defences were overtopped or high water. The surge of 1.3m elevated the tidal level to damaged, some extensively, a total of 11 km (7 miles) 7.4m Ordnance Datum (OD) at 2025 hours. At Flood damage - Pawlett, Somerset of coast. Avonmouth the surge was 1.7m. Wind that had been Overtopping of the sea defences began at this time with blowing from the south in the afternoon at 30 to 40 peak tidal level occurring at 2025 hours and staying knots dropped to 25 knots at 1630 hours and to 20 near that level until about 2130 hours. The westerly knots by 1845 hours. It then swung west and gradually wind steadily increased up to 50 knots by 2300 hours, increased. Suddenly, at 1940 hours wind speed leapt by which time the tide had dropped away from the sea from 25 to 40 knots. defences. Burnham-on-Sea promenade after the storm Stolford sea defence damage 15 December 1981

02 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 03 What we have achieved so far

The North Somerset coastline has 87 kilometres of tidal rivers with raised embankments and 38 kilometres of sea defences. Its 114 kilometre coastline along the length of the Severn Estuary has the second highest tidal range in the world. Approximately one-fifth of the area is low lying (635km2 at or below sea level) and therefore at risk of flooding. Some 18 rivers and streams drain into the Bristol Channel between Portbury Dock, Bristol and Foreland Point near Lynmouth, Devon.

Since the Big Storm of 1981 we have made a lot of improvements to our coastal defences, all aimed at reducing flood risk and adapting to climate change.

Avonmouth Legend Kilometres P Tidal structures 0 1.5 3 9 12 1 Sea defences Portishead Pill N Portbury Tidal structures 1 Portbury Ditch Outfall O 2 Land Yeo Outfall and N 2 Marshall’s Bank 3 Clevedon 3 Blind Yeo Sluice M 4 Hurditch’s Flapped Outfall 4 5 Mill Leaze Sluice L 6 Tutshill Sluice 5 8 6 7 Sampsons Sluice 7 8 New Bow Sluice Bristol Channel K 9 Uphill Sluice 10 Brean Farm flood gates Weston-super-Mare 11 Brean Cross sluice 12 Maddock’s Slade flood gates J (Burnham) 13 Pier Street flood gates 3 9 (Burnham) 10 14 Brue Pill flood gates 11 (Burnham) I 15 Highbridge Clyce Brean 16 Huntspill Sluice Cheddar 17 Dunball Sluice 18 Pill Outfall 1 Burnham-on-Sea M5 19 Warren Point flood gates and Highbridge (Minehead) 12 20 Quay Street flood gates H 13 (Minehead) A 14 20 E F 15 Sea defences 19 D Wedmore A Minehead sea wall B 16 B Dunster Beach earth bank Minehead C Watchet G Wells C Blue Anchor sea wall 18 Steart D Lilstock rock armour Huntspill E Stolford sea wall and rock armour F Steart peninsula shingle ridge 17 G Huntspill coastal embankment Wilton Glastonbury H Burnham sea wall I Brean sea defences J Weston-super-Mare sea wall K Sandy Bay nourishment scheme Bridgwater L Wick St. Lawrence rock armour Street M Blakes sea wall Aerial view of Clevedon showing: N Kingston Seymour bank defence O Clevedon sea wall P Portbury Wharf earth bank 1. Land Yeo outfall

© Crown copyright. All rights reserved. Somerton Environment Agency, 100026380, 2006. 2. Marshall’s Bank Langport This map is based on Ordnance Survey Landline data and produced for the Environment Agency with the permission of Ordnance Survey. Aerial imagery is copyright Getmapping plc, 3. Blind Yeo sluice all rights reserved. Licence number 22047.

Somerset sea defences

04 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 05 1. Land Yeo outfall 2006 2. Clevedon sea wall 3. Kingston Seymour sea defences

Clevedon to St Thomas Head (North Somerset) 2 3 4 4. Tidal banks looking south from Clevedon to St Thomas Head

Clevedon

Clevedon Town (West Leaze) sea wall - Responsibility Clevedon sea wall - The sea wall lies along a section of In 1983/1984 improvements were carried out to the 1980’s. Emergency piling work on the tidal banks of the for this defence is split between North Somerset the Bristol Channel coast, south of Clevedon, running sea wall. A feature of the scheme was the formation of a Congresbury Yeo was carried out in autumn 2006 due to Council and us. In 1986-1988 the sea wall and from Kingston Seymour sea wall to the outfall of the large borrow pit on land near the southern end of the the risk of bank failure during high spring tides. promenade were raised by one metre. The original wall Blind Yeo river. It forms part of our chain of defences wall. The pit, known as a pool, was created by was demolished and rebuilt in masonry-faced protecting large, low-lying areas of Somerset from tidal excavation to provide spoil for the sea defence works. Wick St Lawrence reinforced concrete to achieve this. flooding. The flooding caused by the 1981 storm The pool was designed to form a nature reserve once extended as far as the M5 motorway. The sea wall was flooded on completion of the project. Avon Wildlife Wick St Lawrence sea defence (Wick Warth) - In Land Yeo outfall and Marshall’s Bank, Clevedon - In replaced by an efficient set-back clay bank and front Trust took over management of the site that includes 1989/1990 a rock armour strengthening scheme was 2005/2006 major improvement work to the outfall and revetment system. two smaller pools built later. The pools cover several carried out on the existing wall, north of Weston-super- bank was carried out. The £3.2 million scheme reduces acres in total. The reserve is known as Blakes Pool and Mare. This was followed in 1990 by bank strengthening the risk of flooding to 3,000 low-lying properties in Kingston Seymour has proved to be a valuable environmental to the Commission Bank and raising works in 1991. Clevedon. enhancement to the area. Kingston Seymour - A scheme was carried out at River Banwell Blind Yeo sluice, Clevedon - In 2004/2005 major Kingston Seymour, two miles south of Clevedon, to Congresbury refurbishment of the sluice was carried out. The Blind improve and strengthen the tidal defences following New Bow sluice - A tidal exclusion barrier and outfall for Yeo sluice lies at the tidal outlet of the Blind Yeo damage caused by the 1981 storm. A new 1.4km length Congresbury Yeo tidal banks - Improvement works to the River Banwell - originally built in 1790 - was watercourse, where it meets the Clevedon Pill and of earth bank was built and a line of rock armour was the right bank of the River Yeo adjacent to Blakes Pool replaced by a new structure in 1990. Severn Estuary. The Blind Yeo, a man-made river built in added during the early 1990’s. borrow pit were carried out in 1986 and 1988 and also 1952, takes flows from the Land Yeo, River Kenn and on the Mill Leaze outfall (Congresbury Yeo) in the Nailsea, Tickenham and Kenn rhynes and provides Blakes Expenditure flooding relief for 2,100 acres of land and approximately 1,700 residential properties, together Blakes sea wall - The sea wall runs north-easterly from Clevedon to St Thomas Head - with camping and caravan sites and farms. The cost of the Congresbury Yeo and joins the defences at the scheme was £1 million. Hurditch’s Wharf. It is a section of sea defence that Total cost of improvements since together with the sea walls at Kingston Seymour and Clevedon, provides protection against tidal inundation 1981 = £20.5 million for a large part of North Somerset.

06 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 07 5. Brean Cross sluice 6. Sand Bay

Sand Bay to Brean

Sand Bay Axe Estuary/Tidal River Axe Sand Bay - Sand Bay is located immediately north of Axe tidal banks - The River Axe discharges into the Weston-super-Mare. It runs north-south between high Bristol Channel (Severn Estuary) at Uphill. The banks ground at Middle Hope/Sand Point in the north and are a vital tidal defence for a large area of Weston Woods/Worlebury Hill in the south, approximately predominantly agricultural land. In the 1990’s a 3,000 metres in length. The sea defence protects the number of schemes were carried out to improve both villages of Kewstoke and Sand Bay. A beach nourishment banks protecting the Brean Peninsula where there are scheme was carried out in 1983/1984. This was one of many static caravan parks, residential and commercial the first beach nourishment schemes of this scale carried properties. out in Britain. Over 600,000 tonnes of sand were dredged from the Severn Estuary and pumped onto the beach, Brean Cross sluice - Originally built in the early 1970’s, raising it by approximately three metres at the sea wall. this is the tidal limit of the River Axe and protects 15,000 acres of agricultural land as well as farms and Uphill residential properties. Refurbishment works were carried out in 1985 and 1995. Uphill sea defence - In 1981 properties in the village of Uphill suffered some of the most dramatic flood damage when large volumes of sea water poured over the sea defences. In 1982 the masonry wall was supplemented by a second line of defence - a low earth bank and wall which runs adjacent to the most seaward houses. Expenditure In 2003/2004 a new state-of-the-art sluice gate, Uphill Sand Bay to Brean - Total cost of sluice, was installed to reduce the risk of flooding to approximately 1,000 properties in Uphill and the south improvements since 1981 = of Weston-super-Mare. At high tide the sluice gate closes to keep out tides from the Bristol Channel and at £5.5 million low tide the sluice lets out river water from upstream. The cost of the scheme was £1.8 million. 6

08 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 09 7. Burnham-on-Sea sea wall 8. Brean 9. Highbridge Clyce 10. Construction of the Burnham-on-Sea defences 1983 4. Clevedon to St Thomas Head Tidal Banks

Brean to Highbridge 8 9

Brean Brean sea defence - The coastline between Burnham- length of sea defence wall. The £7 million scheme was on-Sea and Brean Down protects 330 hectares of land, carried out in four phases and took five years, being some 17 houses, 27 hectares of holiday parks and completed in 1988. several businesses. Improvement works were carried out in 1984/1985 and in 1996. A 1.4km line of Highbridge Clyce - Refurbishment works to the limestone rock was set against the existing sea wall. structure were carried out in 1984/1985 and in 122,000 tonnes of rock and stone were used. In 1997 1999/2000 the tidal mitre doors were replaced. new floodgates were installed to replace stop-boards at both slipways on Brean sea front. The cost of the Brue Pill tidal banks - The Pill extends from Highbridge scheme was £2.15 million. Clyce to its outfall into the Parrett Estuary. The defences protect large areas of Burnham-on-Sea and Highbridge Burnham-on-Sea defence - The storm of 1981 caused from tidal flooding. A programme of improvement work flooding to 400 properties in Burnham and surrounding began in 1995 and was completed in 1998. area. The storm ripped up pavements, tore stone and concrete from the sea wall, promenade and steps - damage totalled £1.5 million. Emergency repairs were carried out and plans commenced to build Burnham’s new sea defences. In 1983 work started on the construction of a new sea Expenditure wall and promenade, the levels of both being raised by up to one metre. A flight of concrete steps stretches Brean to Highbridge - Total cost along Burnham’s sea front - it absorbs wave energy of improvements since 1981 = whilst providing a public amenity. At the time of construction it was Britain’s biggest wave return wall - a £10.3 million curve of concrete 3.2 metres high and a 1.6 kilometre

10 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 11 11. Parrett tidal banks improvement works - Moorland, near Bridgwater 14. Tidal defences at Stolford looking towards 12. Hydraulic piling machine pushing in the piles Hinkley Point power station 13. Piling frame on tidal banks at Northmoor pumping station, Moorland 15. Combwich flood wall and outfall 16. Combwich Pill tidal defence

11 14

Highbridge to Bridgwater to Bridgwater 12 13 Hinkley Point 15 16

Highbridge Parrett tidal banks Bridgwater to Hinkley Point Huntspill sluice - A major refurbishment of this tidal In the 1980s and 1990s a comprehensive programme Bridgwater to Combwich tidal defence - Bank sluice at the confluence of the River Parrett and River of improvements to tidal embankments of the tidal strengthening works were carried out on the left bank of Huntspill, near West Huntspill was carried out in River Parrett from Huntspill to Bridgwater and the River Parrett estuary between 1993 and 1995. 1992/1993 and 2002. Bridgwater to Burrowbridge, including the River Sowy, was completed. Steart to Combwich - During the 1980s and 1990s Huntspill sea defence - This is the sea wall between the improvements to strengthen the tidal flood banks In 2000 another programme of works to the Parrett tidal Huntspill River to the south and the River Brue to the between Steart Point on the Parrett estuary and North banks from Bridgwater to Langport began. These north. The extent of the damage in 1981 to properties Clyce on the River Parrett were carried out. protected by this defence, gave particular urgency to improvements are due to be completed in 2007 at an estimated cost of £2.7 million. the reconstruction of the defences. Within a year of the Combwich tidal defence - Between 1985 and 1987 an event, a new upgraded defence had been constructed earthbank was built, north of Peel Cottages and a stone to give a high standard of protection to the retaining wall behind the Cottages. New road drains, communities. outfalls and a masonry flood wall were also built.

Dunball sluice - Tidal sluice and outlet of King’s Sedgemoor Drain to the estuary. Works completed in 1997.

Expenditure Expenditure Highbridge to Bridgwater - Total Bridgwater to Hinkley Point - cost of improvements since Total cost of improvements since 1981 = £8.8 million 1981 = £2.8 million

12 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 13 17 and 18. Minehead during construction 1997/1998 19. Minehead sea wall - viewing platforms 20. Aerial view of completed Minehead sea defences

Hinkley Point to Porlock (West Somerset) 18 19

Hinkley Point to Porlock Lilstock - The sea defence at the village of Lilstock, west In 1999 Phase 2 saw the replenishment of the of Hinkley Point power station, bridges a natural gap foreshore using 320,000 tonnes of sand and shingle between two lengths of cliff and protects a small dredged from the seabed near Holm Sands. The beach number of properties, 10 agricultural buildings and 45 was raised by approximately two metres. hectares of land. The natural shingle ridge is reinforced by approximately 350 metres of gabion baskets. Over Porlock the last 15 years a number of minor improvement schemes have been carried out. We maintained the natural shingle ridge throughout the 1980s and 1990s until such time that it became Blue Anchor uneconomical to continue to do so and the ridge was allowed to breach by the tide. Pill River outfall - A tidal outfall was constructed in 2003. Expenditure Minehead Hinkley Point to Porlock - Total Minehead sea defences - The Environment Agency promoted a £12.7 million project to reduce the risk of cost of improvements since tidal flooding and generally improve the amenity of the 1981 = £13.1 million seafront. Phase 1 - 1997-1999 - involved the construction of a new, raised sea wall. The promenade was also raised Total expenditure on the North and three viewing platforms installed to retain views of the bay. Somerset coast since 1981 = £61 million

14 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 15 The future Major urban locations and their properties at risk along our coastline: Location Total properties Properties in flood zone 3*

Weston-super-Mare 30,965 12,209

Bridgwater 15,742 8,558 Irrespective of the uncertainties ahead of us with Clevedon 9,298 6,498 climate change, the Environment Agency is Burnham-on-Sea and Highbridge 7,618 7,775 Portishead 6,317 1,766 committed to reducing flood risk to people, property Minehead 5,044 867 and to the environment. *In the case of flooding from the sea the flood zone indicates the event of a flood with a 0.5 per cent (1 in 200) chance of happening in any year

Climate change Climate change and sea level rise will increase the risk We have set ourselves priorities for making our area a of flooding in our area. Sea levels rose by about 150mm better and safer place. We aim to: in the 20th century and are predicted to rise by about ● 86cm by around the year 2080. This will threaten sea build new flood defences and improve what we defences and block rivers’ flow even more than now. already have, such as flood banks and walls, pumping stations and sluices Floods in 1994, 1997, 1998, 1999 and 2000 have ● improve flood risk mapping to show people the risk shown that extreme weather is becoming more to their homes and businesses. This will ensure we frequent. Climate change is becoming universally target our work at places most at risk accepted but its impact is difficult to predict. ● issue timely flood warnings to 70 per cent of people at risk by 2010, so they can prepare for flooding Tackling flood risk and climate change ● work closely with planning authorities to prevent the wrong sort of development in areas prone to floods The Environment Agency faces twin challenges in ● ensure that economic development and regeneration managing flood risk and adapting to climate change. take account of the need for flood defences We have a new five year strategy to help us. ● make people more aware of the need to change their Two of our main goals will help fight flooding by: lifestyles to take account of climate change ● take account of the predicted effects of climate ● reducing flood risk change when we design flood defences and require ● limiting and adapting to climate change developers to do the same ● respond to floods quickly and efficiently so we can lessen their effects.

Map showing Somerset if unprotected by coastal defences

16 Environment Agency Somerset and the sea The 1981 storm - 25 years on Environment Agency Somerset and the sea The 1981 storm - 25 years on 17 Would you like to find out more about us, or about your environment?

Then call us on 08708 506 506 (Mon-Fri 8-6) email [email protected] or visit our website www.environment-agency.gov.uk incident hotline 0800 80 70 60 (24hrs) floodline 0845 988 1188

Environment first: This publication is printed on paper made from 100 per cent previously used waste. By-products from making the pulp and paper are used for composting and fertiliser, for making cement and for generating energy.

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