Category Archives: Flood Risk

Flood Risk Assessment – Bristol

Flood Risk Assessment – Bristol 

Southwest Environmental Limited have recently been commissioned to prepare a flood risk assessment for a site in Bristol (Avonmouth). The site is subject to tidal flooding and, as if typical with the majority of the Avonmouth area, is low lying.

Avonmouth – Docks

Key factor explored in the flood risk assessment will be the anticipated flood depths from tidal, fluvial and pluvial (rain) flooding, and then design of mitigate measures.

In this instance the application is retrospective which will create further challenges. We will have to make sue of the current site lay out, existing outbuildings and other factor in order to present a positive proposal.

The report will include a Exception Test and Sequential Test

Image rights

English: The Royal Edward Dock at Avonmouth, 13 March 2014.
Source Own work
Author N. Johannes

Flood Risk Assessment – Enfield, London

Flood Risk Assessment – Enfield, London

Southwest Environmental Limited were approached by a firm of Architects, and were commissioned for producing a Flood Risk Assessment for  Residential Extension in Enfield.

In this case the report was required on a quick turnaround. We would normally recommend waiting for bespoke site data, takes around 20 workings days to be delivered. But in this case that was too long due to deadlines, and so the report was prepared based on commercially available data that is delivered same day.

The house is very close Immediately adjacent to a water course, and as such is at some risk of flooding the purpose of the flood risk assessment is to assess this risk, and provide quantitative commentary on the nature of the flooding.

Limited advice was also given of rainwater attenuation. An attenuation volume was calculated as part of a Surface Water Management Plan, although this does not constitute a Full Drainage Strategy.

Sequential Test Review – Rochford

Southwest Environmental Limited have been commissioned by Rochford District Council , to make an independent review of a Sequential Test document on their behalf.

The site is within a regeneration area and as such the the search area justification for the site has been restricted to the regeneration area.

We have considerable experience in all things Flood Risk, and have been writing reports for 10 years this June. Much has changed over that time, but the Sequential Test has away been a problematic elements of flood risk reporting.

If you would like any help with reviewing your sequential test prior to submitting it to the council we would be happy to assist, we could also do the whole thing if you prefer.

Flood Risk Assessment – Weston-Super-Mare

Flood Risk Assessment – Weston-Super-Mare

Based in Bristol Southwest Environmental Limited have recently carried out a Flood Risk Assessment for a Site in Weston Super Mare.

A large area of Weston Super Mare is low lying and is prone to flooding for tidal (sea) and fluvial (river) sources. In order to assess the risk, it is important to get hold of the best possible data which might indicate future flood depths on site.

Weston s Mare has good flood defences. 

Most of Weston Super Mare would flood in a serve tidal event, if the town did not have flood defences. But luckily it does! The problem is finding out how good these defences are. For example are the defences tall enough to keep flood waters out of the town.

Accurate Flood Risk Mapping can Help Produce a Good Report

The answer for the most part is yes. The flood defences in Weston Super Mare are tall enough to keep out a 1:1000 year tidal flood. But this depends on a few things:

  • Are the strong enough?
  • Have they been well maintained?
  • Will they be maintained in the future?
  • Will they be removed or changed at some point in the future?
The first two question above are fairly easily answered given access to the correct data. However, the the latter two will likley remain unanswered.

3 Flood Risk Assessments for DEFRA

3 Flood Risk Assessments for DEFRA

Commissioned via a 3rd Party Southwest Environmental have recently been working with DEFRA at one of their sites close to London. SWEL have produce 3 Flood Risk Assessments in support of 3 planning applications.

It should be noted that despite working for NGOs and Multi-Nationals we still accept commissions from individuals and companies of any size.

The reports were produced on a very quick turnaround and contained all required information plus design advice and surface water management information.

A Random Flood Map which is Not of the Study Site

The projects sites were within Zones 1 2 and 3, with varying levels of flood risk. The projects also carried various levels of vulnerability and this was taken into account when authoring the reports.

In one instance feedback was given at an early stage with regards to design requirements to mitigate against flood risk, this was provided within 48 hours of commissioning and the information was relayed to the design team ahead of draft plan issues.

Bespoke Flood Risk Activity Permit Application – Barnstaple

Bespoke Flood Risk Activity Permit Application – Barnstaple

Acting upon instruction from a client in Barnstaple, Devon, Southwest Environmental Limited have submitted a bespoke permit application for a flood risk activity permit.

The proposal was for a lowering of ground level within 9 meters of a main river. It was thought strange that lower of ground adjacent to a river require a permit, owing to likley positive flood storage benefits, but the Environment Agency are concerned with the disruption of the channel, and the potential for pollution to enter the river.

To that end the application forms etc. were filed and a number of supporting documents such as plannings and environmental management systems have been submitted, so the Environment agency can determine the application for this flood risk activity permit.

Flood risk activity permits are a relatively recent addition to the Environmental permitting regime, however they have been in forced under older regulatory regimes prior to being migrated to the EPR regs.

There are a number of standard flood risk activity permits available for an obscure set of activities, so for most operation a bespoke flood risk activity permit will be required.

Environmental Consultants London