Flood Risk Assessment – Bristol

SWEL were recently commissioned to undertake a flood risk assessment in Bristol. This site is an interesting one in terms of settings. As is resides within some characterful gardens walls, which have a curved to match the site boundary.

A Pub near the Site

The key as always with a good flood risk assessment is collecting a wide selection of data to characterize flood risk at the site. 3rd party data reveled flooding of significant depth on site, whilst the Environment Agency data from neighboring sites showed details that will aid in the design of the building.

The report also includes exceptions test, sequential test and surface water recommendations.

Flood Risk Assessment Kent

SWEL were instructed to undertake a Flood Risk Assessment for a proposed development in Romney Marsh, Kent. For a Residential Development.

The scheme saw the construction of 2 homes, on a site occupied by a dilapidated bungalow.

A Wider Variety of Flood Risk Data was Used to form an Opinion

Key the flood risk assessment was establishing the level of protection afforded by the coastal defenses in the area, we arranged to have data supplied on the sea defenses which showed they were in good condition and that they were gave an applicable protection level.

Advise was included on required attenuation volumes, and any special construction techniques.

The sequential test was a key part of the report. We include a sequential test in our flood risk assessment as standard. . .if it is required.

Flood Risk Assessment – Catford SE6

Southwest Environmental Limited were commissioned by a client to undertake a Flood Risk Assessment at a site in South East London.

The project was for conversion of a basement to living quarters. This is usually one of the more difficult situation to get passed off with the Environment Agency (as consultees in planning) as a flooded basement is not a very good thing / situation:

• It is hard to dry out.
• It is hard to get flood data (most relates to ground level).
• Hard to prove people will be safe.

Flood Risk Assessment – Harrow

Southwest Environmental Limited have recently prepared a Flood Risk Assessment for a site in London.

The site was in flood zone 1, and was under the area (1 hectare) that would ordinarily trigger the requirement for a Flood Risk Assessment.

It was our opinion that the Flood Risk Assessment was requested because the site is:

• A risk from surface water flooding.
• Includes a basement. 

Surface Water Flow Velocity

Surface Water Depth

The report recommended that as long as a few simple measures were adopted such as:

There is surface water flooding highlighted as close to site of the extension and basement. Careful consideration will have to give to the avoidance of flow path creation. For example: the ground level at the rear of the building should be maintained so as to prevent surface water flowing towards the rear of the house. This would include depressions created for external stairways. An up an over stair crest may be required to maintain this level.

Removable flood boards should be fitted in all external doorways, up to a height a 50cm above threshold. Levels (front threshold + 50cm) should be matched at rear of property for stair crest.

Flood resilient construction should be used in basement level (see below table). Clear access should maintain from basement to ground floor level. New External and Internal Doors should hinge inwards.

Centralised service nodes such as boilers and consumer units should be situated on the ground floor level. 

3 x Flood Risk Assessment  – Bridgwater & Highbridge

Southwest Environmental Limited were commissioned for a “job lot” of 3 Flood Risk Assessment within Sedgemoor District Council Administrative Area.

The flood risk assessments were prepared on a rapid turnaround, provided with practical advice for the design response and resilience measures.

A good report needs good data.

Flood Defenses in the Area are not great.

Flood depths exceed flood defences.

The three projects were conversions of existing buildings and parts of buildings fro use as residential dwellings. These conversion add a constraint to the design in that often one can not extend outside the envelope of the existing building.

This becomes problematic when flood water depth is much above 50cm, as raising of floor level beyond this height is often impractcial and so other solutions have to be offered up.

Flood Risk

Flood Risk Assessment  – Exeter

Southwest Environmental Limited have recently carried out a flood risk assessment for a site in Exeter, Devon. The site was very close to the river exe flood relief channel and as such it was important to establish whether it was indeed possible to build a dwelling at the location that would:

1. Mitigate Against Flood Risk 
2. Remain in Keeping with Surrounding Buildings

Topography Indicates a Level Area

The Site is Well Within Flood Zone 3

Flood Depths were Fairly Deep on Site

Flood Risk Assessment – Dorset

Acting on instruction from an architects in dorset, SWEL have been commissioned to carry a flood risk assessment, for a barn conversion.

Flood Risk to Barn Conversion

The flood risk assessment will be based on third party data, which will indicate flood depths in the area, and these flood depths will be used to inform decisions relating to finished floor level and safety of occupants.The flood risk assessment will be submitted to North Dorset District Council, who will be required to present the report to the Environment Agency as statutory consultees.

All being well, the EA will agree with the content of the report, and they will not raise an objection. The project will not be subject to the sequential test as it is a conversion.

Flood Risk Assessment

Flood Risk Assessment for Hotel – Bristol

Acting on instructions from Global Client Southwest Environment have undertaken a Flood Risk Assessment for a development site in Bristol, UK.

The project encompassese the retention of a sporting facility and the extension of the facility to include a 55 bedroom hotel and several eateries.

A mixed use development like this is ideal for a site within a high risk flood zone as it allows for low vulnerability uses on ground floors and and high vulnerability uses on the upper floors.

This site however, although surrounded by high risk areas, was at low risk of flooding and also had a convenient escape route in the form of a raised flyover, so as to provide an evacuation route in case of a flood.

Flood Risk Assessment Bristol