15/03/2006 - The Environment Agency announced today (14 March 2006) that Bewdley’s Severnside South flood risk management scheme has been finished on time and on budget. Like its sister scheme along Severnside North, it is now ready and waiting to protect the local community from flooding from the River Severn. With the completion of Severnside South, well over half a kilometre of demountable defences (630 metres), along with 200 metres of brick-faced flood walls, now protect 174 properties on the west bank, at a total cost of more than £11 million.

In November 2000, Bewdley suffered serious flooding with 140 properties being affected. To solve the problem, we adopted an innovative demountable aluminium barrier system.

Bewdley (along with Shrewsbury) was the first use of demountable flood barriers in the UK. They are erected only when there is a danger of flooding and removed as soon as the danger has passed.

Flood walls and banks would have spoiled the quayside in this lovely Georgian town. The site includes 12 listed properties and more significantly a Thomas Telford Grade I bridge and a Grade II quay wall, but this new technology made it possible to protect the community from a flood with up to a 1% chance of happening in any one year.

The scheme was built in record time. Plans put forward after the disastrous floods of Autumn 2000 materialised into a £4 million working flood defence along Severnside North in just over two years. This defence was tested in a real flood in February 2004.

A month later (March 2004) we started to build the larger Severnside South section. Building a 21st century flood defence system, engineered in straight lines, along an eighteenth century listed quay with no straight lines, was a challenge. We finished the construction work in time for it to be tested when river levels rose in November 2005.

Our partners, Advantage West Midlands, contributed £0.5million landscape enhancements to the £7million flood defence project. The focal point of the scheme from the landscape and residents’ point of view is the creation of a new civic space, including steps, constructed as a circle of granite and York stone. Handrails, ramps and walkways were all designed to conceal the line of the flood defences, but give easy access during a flood.

The design also includes art. A system of steel lettering, referring to Bewdley’s historic significance as a Severn river port, can be seen set into the paving. They describe goods that were carried on the Severn and form a trail for people to follow along the quay.

Project Manager, Roger Prestwood, says: "Bewdley has always flooded, but the town suffered especially badly in Autumn 2000. We were determined to do something about it and everyone made a special effort to get this flood defence finished as quickly as possible.

"Any major construction scheme causes significant disruption and we thank the people of Bewdley for their patience and support while we carried out the work. We hope that they will now be able to enjoy the river without fear, knowing that they are well protected.

"But, they must not be complacent. We design our flood risk management schemes to high standards, but flooding is a natural event that can never be completely prevented. There is always a possibility of a greater flood than any of us could reasonably expect and people need to remain prepared."

Now that Severnside is finished, our focus moves across the River Severn to Beales Corner where, on Sunday 19 March 2006, we carry out a full test of the new temporary flood defences.

These defences will be used on a trial basis during the next flood to see if they will be effective in this location. On Sunday, we will be working in partnership with local authorities, Severn Trent Water, the Police and the Highways Department to erect the new temporary barriers so that we can ensure that they will provide the best possible protection for the local community.

More information:

Bewdley

Georgian market town on the banks of the River Severn in Worcestershire

Population 10,000

Once an important inland port

Grade 1 listed river bridge designed by Thomas Telford

Largest floods – 1947 - 5.8 metres above summer levels, 2000 – 5.6 metres above summer levels (3 floods in 6 weeks)

Number of properties affected by flooding – up to 175 on west bank will be protected by the flood alleviation scheme (some properties have flooded at least 50 times in last 100 years)

Long lead-time to flooding (i.e. time from rainfall to flooding) allows time for demountable defences to be erected

Severnside North

First use of demountable flood defences in UK - erected only when there is a danger of flooding and removed as soon as the danger has passed.

Total cost £3 million (Environment Agency), £1million (Severn Trent Water)

Length of defences – 180 metres demountable defences plus 60 metres permanent flood walls

Degree of protection – flood with a 1 in 100 chance of happening in any year

Construction time: 9 months (plus surveys, exploratory work and consultation)

Completion: autumn 2002

Flood defence components:

permanent reinforced concrete flood defence wall from Tolley’s Corner to high ground near the entrance to Dog Lane car park, faced with brick to match traditional walls in Bewdley

underground waterproof wall along the quayside, comprising a continuous line of vertical concrete piles (7 metres deep), braced by a series of inclined 'raking piles'

aluminium demountable posts and barriers bolted onto stainless steel base plates that have been cast into a re-inforced concrete ground beam along quayside

one main pumping station at the bottom of Dog Lane and associated monitoring equipment and drainage to control groundwater behind the defences.

Other construction details:

resurfaced using original block paving

new Victorian-style pedestrian guardrail along the quayside

widened footpath

landscaping near to Dog Lane car park

Design and build – Birse Construction Ltd

Demountable defences – DEMFLOOD by Bauer Inner City

Severnside South

Cost - £7 million

Length of defences – 450 metres of demountable flood defence and 140 metres of permanent brick faced wall

Extends from Bewdley Bridge to the cricket ground

Flood defence components:

permanent reinforced concrete flood defence wall at cricket ground, faced with brick to match traditional walls in Bewdley

underground waterproof wall along the quayside, comprising a continuous line of vertical concrete piles (7 metres deep), braced by a series of inclined 'raking piles'

aluminium demountable posts and barriers bolted onto stainless steel base plates that have been cast into a re-inforced concrete ground beam along quayside

one main pumping station and associated monitoring equipment and drainage to control groundwater behind the defences.

Other construction details:

approximate cost of hard landscaping £1/2million

resurfaced using combinations of tarmac, block paving and York stone slabbing

a new walkway along the lower quay, with disabled access

new civic space with high quality paving near Bewdley Bridge and

new lighting along Severnside South.

Height of demountables varies from 1 to 2.25 metres

Construction time – approx 2 years, plus surveys, exploratory work, and public consultation

Degree of protection – 1 in 100 year flood

Design by W. S. Atkins Consultants Ltd

Contractor is Volker Stevin Ltd.

Demountable defences – DEMFLOOD by Bauer IBS

Programme:

Outline design –December 2002/January 2003

Planning application - May 2003

Start on site (enabling works by Transco) – 28 July 2003

Construction of an underground pumping station and sewers by Severn Trent Water – September 2003

Flood defence construction began – spring 2004

Completion March 2006

The flood alleviation scheme is designed to provide protection for about 175 properties on the west bank in a flood with a 1 in 100 chance of happening in any one year. A more extreme flood (which has never been recorded) could overtop the new defences.

Beales Corner temporary defences:

Recent developments have made temporary defences, such as the Geodesign barriers being used at Wribbenhall, more effective. These 21stcentury alternatives to the humble sandbag should not be confused with the demountable barriers used along Severnside North and South, which provide a higher level of protection.

The Swedish designed Geodesign barriers are designed to be erected along the ground. Made up from metal frames covered by a waterproof membrane, they are supported by pumps behind the defences to deal with surface water and seepage.

These temporary barriers protect against a flood with approximately a 10% chance of happening in any one year, but are not intended to protect against major flooding.

At Worcester, in February 2004, 24 properties were protected from flooding for the first time by the temporary defences on Hylton Road. The defences also kept the main Hylton Road at Worcester open for 30 hours longer than it would have been without them. When the road eventually did have to close, it was due to drainage problems, not a failure of the defences.

At Ironbridge, also in February 2004, more than 20 properties were saved by this innovative new approach to flood defence, which was the first to receive the Kitemark and was being used in these two towns for the first time as part of a successful national trial.

We purchased 300m of the Geodesign barrier last year for Wribbenhall, at a cost of £130,000 (not including equipment, e.g. pumps, and construction work). The barriers are specific to Bewdley. They will be stored with the Severnside demountable barriers at Mance House, Kidderminster and erected if there is a flood warning. This is made possible by the long lead time to flooding on the River Severn.

Severn Trent Water has carried out civil engineering work to seal the sewer system in readiness for the new flood defences.