Mr B Whitcombe
Barn Conversion at Burtle Farm, Bridgwater,
TA7 8NT
Flood Risk Assessment
3rd February 2015 – V2
15003 – Burtle Farm, Burtle – Flood Risk Assessment
Contents
1
2
3
4
5
6
7
8
9
Introduction
Site Location and Setting
Existing Development and Ground Conditions
Proposed Development
Predicted Flooding Mechanism
Flood Policy
Surface Water Drainage
Means of Escape
Conclusions and Recommendations
Appendix
1
Email from Sedgemoor District Council with regards to flood
map
This report is based on the instructions given by our client. It is not intended for use by a
third party, and no responsibility will be given to any third party.
The consultant has followed accepted procedure in providing the services, but
given the residual risk associated with any prediction and the variability which
can be experienced in flood conditions, the consultant takes no liability for and
gives no warranty against actual flooding of any property (client’s or third party)
or the consequences of flooding in relation to the performance of the services.
Report prepared by Amy Jefferies – BSc, MA
Report approved by Clive Onions - BSc CEng FICE FCIWEM MIStructE MCIHT
Version history
Version
Date
Prepared by
Approved by
Comment
V1
03.02.15
AJ
CO
Issued to accompany planning application
V2
03.02.15
CO
Minor amendments
Issue history
Version
Date
Issued to
Method
V1
03.02.15
David James & Partners
Email pdf
V2
03.02.15
Ditto
Ditto
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
1. Introduction
Mr B Whitcombe, the Client, wishes to convert an existing barn into a dwelling. The site is
located within Flood Zone 1, at low risk of flooding, as defined by the Environment Agency
(EA). However, it is on an island, surrounded by land vulnerable to flooding.
The SFRA shows the site in Flood Zone 3, but consultations with Sedgemoor District Council
and the Environment Agency (EA) have confirmed that the site is in Flood Zone 1, and the EA
Flood Map for Planning takes priority.
Clive Onions Ltd has been requested to prepare this Flood Risk Assessment to accompany a
planning application for the barn conversion at Burtle Farm.
2. Site Location and Setting
The site is located in Burtle, on raised land within the Somerset Levels. Glastonbury is
situated roughly 8km to the south-east, Wells further to the east, and Bridgwater is to the
south-west. The coast lies roughly 8km to the north-west, the River Brue flows east-west to
the north of the site, and a large drain is approximately 600m to the south of the barn. The
site is located on a small area of raised ground, above the floodplain.
The area is predominantly open farmland, transected by the A39 in the south and the M5
motorway in the west (Fig. 1.). There is a minor road close to the site (Fig. 2.). The site is
adjacent to a road and neighbouring buildings are to the immediate south and west.
Fig. 1
The site within a wider locational context. (Google, 2015)
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
Fig. 2
The site within Burtle, Somerset (Streetmap, 2015)
3. Existing Development
The existing barn building is located within a large rectangular property, with 180mx190m
dimensions. To the east of the site is a road (Fig. 3.). There are no waterways impeding
access.
Barn
Fig. 3
Situation of barn within site (David James Surveyors)
The site lies at an elevation of approximately 6 to 7m. Fig. 4 shows the barn from a groundlevel perspective. The barn appears to be connected to utilities services.
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
Fig. 4
Ground level perspective of the barn with nearby bungalow.
4. Proposed Development
The proposal is to convert an existing agricultural barn to a residential building.
The floor level of the barn will be raised approximately 150mm above the surrounding
ground level. Access to the site will be along the existing gravel track, and any new external
parking areas will be formed in permeable paving, allowing infiltration into the ground
below. The rainwater system from the roof of the existing barn will be directed to a
soakaway/swale for infiltration into the garden.
5. Predicted Flooding Mechanism
The Environment Agency Flood Risk Map for Planning shows the site to be on an island within
Flood Zone 1, at low risk of flooding (Fig. 5).
The recent flooding in the Somerset Levels has been caused by prolonged rainfall being
unable to escape fast enough, and therefore storing on the Somerset levels.
There is a risk of tidal flooding, but because of the ebb and flow of the tide over the
defences, this is a very low risk and this has not occurred for centuries, other than in localised
areas on the coast..
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
Site
Fig. 5
Flood Risk Map for Planning (Environment Agency, 2015)
It is recognised that the SFRA for Sedgemoor District Council (SDC) shows the site to be
within Flood Zone 3. The Environment Agency )EA) and Sedgemoor District Council have been
contacted and both have agreed that the EA map takes priority and the site is at low risk of
flooding (see Appendix 1).
Fig 6
SFRA map extract with site located in small black circle.
The extreme weather and flooding of spring 2014 has shown that the flood risk to the
Somerset Levels arises from fluvial flooding and this area was not affected by flooding.
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
6. Flood Policy
Flood Policy relates to the protection of people and property. The National Planning Policy
Framework (NPPF) and its Technical Guidance note (TG-NPPF) give guidance on flood risk and
steer development away from areas at risk of flooding.
The development is all within Environment Agency (EA) Flood Zone 1. In accordance with the
NPPF Technical Guidance (NPPFTG), Table 1, Residential Development is appropriate within
this zone.
The proposal is conversion of a barn building to a residential building. It is recommended that
the property owners are advised to prepare a Flood Plan and register with the Environment
Agency’s Floodline Direct. This is to warn them of potential flooding on surrounding land,
which might affect their freedom of movement and departure from the ‘island’.
7. Surface Water Drainage
The report cover photo shows that the barn has no managed roof drainage system. The
renovation will include rainwater goods to drains which will be taken to soakaway within the
soft landscape.
8. Means of Escape
The principal hazard to escape is from flooding of the Somerset Levels. This will take some
time to rise, and the event will be widely broadcast as in the case of the spring 2014 flooding.
The owner should be registered with Floodline Warnings Direct, monitor the weather, and
prepare a Flood Plan which includes a route which is least likely (or the last) to flood.
The property owner should consider evacuation if the surrounding land begins to flood. The
closest area of safety is Wedmore. The map below shows several available routes to dry land
to the north or south, and they would not flood all at the same time, giving options for
managing access in times of flood.
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
Fig. 6
Location of escape routes to Wedmore. (Environment Agency, 2015)
9. Conclusions and Recommendations
The proposal is for the conversion of an existing barn building to a residential building.
Burtle Farm lies within EA-defined Flood Zone 1, at low risk of flooding, in an isolated area of
elevated land within an area defined as Flood Zone 3. (A ‘dry island’). The development is
therefore appropriate development a this location.
There are three completely separate potential access routes to the main dry land, two to the
north and one to the south, which will have different flood characteristics.
The Householder should be registered with Floodline Warnings Direct, and produce a Flood
Plan in accordance with Environment Agency guidance so that he monitors the weather and
flood risk, and leaves the area if access is likely to be seriously flooded.
The Flood Plan should therefore include escape routes towards Wedmore.
If flooding does occur, it will occur slowly over a period of weeks, and will be widely
broadcast, as was the winter/spring flooding of 2014. So the risk of becoming trapped is very
very low.
The proposal therefore complies with the NPPF and there is no reason on grounds of flooding
to refuse the application.
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15003 – Burtle Farm, Burtle – Flood Risk Assessment
Appendix 1 – Email confirming acceptance of EA flood map standards over SFRA.
From: Nick Tait [mailto:[email protected]]
Sent: 22 December 2014 11:01
To: Clive Onions
Subject: RE: [OFFICIAL] - RE: Barn conversion to residential consideration - Burtle - TA7 8NT
Hi Clive,
Just to confirm what Rebecca has said below, the SFRA was only a snap shot in time
and has in some instances been superseded by the more up to date EA mapping. My
advice would be to always be guided by the EA data in the first instance as this will be
the most accurate.
We will be updating our SFRA during the course of next year making use of the
recent flood modelling work that has been developed as part of the 20 year flood
action plan. I also have the advantage of a new senior planning officer starting in
January who previously worked at the EA.
Have a good Christmas,
Nick
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