Category: Innovation

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Innovation News

New flood gates and glass panel defences commissioned at New Passage

Commissioning of flood gates and glass panels at New Passage

We have taken another leap forward this month with the commissioning of the flood gate and glass panel defences at New Passage, South Gloucestershire. This is a vital process towards ensuring that the new defences will help protect communities from the threat of flooding and rising sea levels. 

Weighing over a tonne, the flood gates used on the project are a substantial part of the flood defence network. Unlike those found elsewhere, these gates can be mechanically and manually operated. This makes it much easier to open and close them for Environment Agency staff in a range of circumstances. The flood gate at New Passage is one of several being installed throughout the 17km project area, with others at Lamplighter’s Marsh and in Aust.  

To perform the test, two tonnes of water was pumped behind the gate with site staff observing carefully for any leakages. If any were spotted, the seals on the gate were adjusted and the test resumed. The same process was repeated on a section of the glass panel flood defences at New Passage. You can watch a short video of the test taking place to gain an idea of how the flood gate and glass panels withstand the levels of water that are possible in decades to come. 

Colin Taylor, Senior Flood & Coastal Risk Management Advisor at the Environment Agency, said: “We have installed a flood gate to allow access to the seaward side of the new raised flood defences at New Passage. The testing of the flood defences that have been installed this year is a crucial point for the project. We are now seeing how they stand up to the kind of real-world conditions that may occur if sea levels continue to rise in the decades ahead.” 

Cllr Toby Savage, Leader of South Gloucestershire Council and Cabinet Member with responsibility for Climate Change, said: “Seeing the flood gate and glass panel defences in action is a clear visual reminder of how far the ASEA project is has come. The rigorous testing happening now is incredibly important to give confidence to New Passage residents that the flood defences here will help provide protection from the effects of climate change and rising sea levels.” 

Cllr Nicola Beech, Cabinet Member with responsibility for Strategic Planning, Resilience and Floods, Bristol City Council, said: “I’m incredibly pleased with the progress being made on this ambitious project where we are now getting on with testing the flood defences that have been installed. The glass panel flood defences are one of several innovative solutions that will better protect residents and businesses from flooding in the future. They will also preserve views of the Severn Estuary which provides a home for internationally significant species of bird, such as curlew and shelduck.” 

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Innovation

New rock armour flood defence to protect water treatment infrastructure

New rock armour flood defence to protect water treatment infrastructure

This summer we continued our work creating and improving flood defences near the Bristol Port at Avonmouth, with the installation of huge boulders, known as rock armour at Holes Mouth Outfall.

You can watch a short video of the rock armour installation at the foot of this article.

Holes Mouth Outfall is operated and maintained by Wessex Water Services Limited and discharges water treated by its dedicated Water Recycling Centre. It is therefore critical that this infrastructure is protected from scour. Around 5,000 tonnes of ‘rock armour’ have been installed. The wider scheme will reduce the risk of tidal flooding across the Avonmouth and Severnside area.

Each of the boulders, weighing between one and three tonnes, have been transported from Cornwall. Skilled contractors ensure that each of the rocks interlock together to dissipate wave energy help to reduce erosion and flood risk. The project team has chosen rock armour at Holes Mouth because of its durability. The flood defences here will need almost no maintenance and will sit in place protecting the outfall culvert and adjacent flood defences for this century and beyond.

Colin Taylor, Senior Flood & Coastal Risk Management Advisor at the Environment Agency, said: “This section of the flood defence is the result of dialogue with Wessex Water, over how best to construct the flood defences without compromising the outfall structure”.

The rock armour is just one type of flood techniques being used for the project. Construction of earth embankments, sheet piling, flood walls and gates continues along the line of flood defences. The project is a partnership between South Gloucestershire Council, Bristol City Council and the Environment Agency.

The largest of its kind in the region, the £80m project will provide 17km new and improved flood defences, from Lamplighter’s Marsh in the south to Aust in the north, once complete in 2026/27. The defences will help reduce flood risk to around 2,500 homes and businesses over the scheme’s lifetime. It will also create a minimum of 80 hectares (the equivalent of around 112 football pitches) of new wetland habitats for the internationally important Severn Estuary’s bird species.

 

The project will boost the regional and national economy by enabling development within the 1,800 ha Avonmouth and Severnside Enterprise Area, helping to unlock 12,000 new jobs by 2026. Funding for the project has come from the West of England Local Enterprise Partnership, administered by the West of England Combined Authority. Other funding sources are Government’s Flood Defence Grant in Aid, and Local Levy raised by the Wessex Regional Flood and Coastal Committee. The contractor is BMMjv.

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Innovation News

Innovative new hybrid glass panel flood defence in place

Installed section of hybrid glass panel flood defence - February 2022

Innovative new hybrid glass panel flood defence in place

24 February 2022. We have achieved another milestone this month with an innovative hybrid glass flood defence at New Passage, South Gloucestershire. The glass panels, on a concrete base, were installed at New Passage because of its location as a popular viewpoint and birdwatching spot on the Severn Way footpath. 

You can watch a short video of the panels’ installation here.

The panels mean that residents and visitors will still be able to enjoy the breath-taking views of the Severn Estuary, while providing robust flood defence for years to come. Manufactured off-site, they were delivered directly to New Passage, minimising disruption to the public. Each panel has been fitted individually so that, if one were to be damaged, it could be repaired or replaced quickly without disrupting the rest of the flood defence.  

The glass panels are one of the innovative flood defence techniques being used along the project’s 17km stretch of coastline. Construction of earth embankments, sheet piling, flood walls and gates continues along the line of flood defences.  The project is a partnership between South Gloucestershire Council, Bristol City Council, and the Environment Agency.   

Colin Taylor, Senior Flood & Coastal Risk Management Advisor at the Environment Agency, said: “This section of flood defence is the result of long-term consultation and dialogue with the local community. The plans have evolved extensively to create a hybrid form of flood defence with a concrete base and glass panel installed above. Not only will this help significantly reduce flood risk to the community here at New Passage from flooding in the years ahead, but it will also preserve the stunning views of the Severn Estuary.”  

Cllr Toby Savage, Leader of South Gloucestershire Council and Cabinet Member with responsibility for Climate Change, said: “It is fantastic to see these glass panel flood defences installed at New Passage. Their innovative design was in direct response to feedback received from the community. This is a clear marker of the progress that we are making to help protect the Avonmouth and Severnside area from flooding for decades to come.” 

Cllr Nicola Beech, Cabinet lead for Climate, Ecology and Waste, Bristol City Council, said: “The completion of this part of the flood defence project is a great milestone for such an ambitious project, as well as a showcase of one of the innovative solutions that will better protect residents and businesses from flooding in the future, while preserving views of a landscape that is being improved to provide a better home for internationally significant species of bird, such as curlew and shelduck.” 

The largest of its kind in the region, the £80m project will provide 17km of new and improved flood defences, from Lamplighter’s Marsh in the south to Aust in the north, once complete in 2026/27. The defences will help reduce flood risk to the area from the increased risk of flooding from climate change and rising sea levels, reducing flood risk to around 2,500 homes and businesses over the scheme’s lifetime. It will also create a minimum of 80 hectares (the equivalent of around 112 football pitches) of new wetland habitats for the internationally important Severn Estuary’s bird species.  

The project will boost the regional and national economy by enabling development within the 1,800 ha Avonmouth and Severnside Enterprise Area, helping to unlock 12,000 new jobs by 2026.  

Funding for the project has come from the West of England Local Enterprise Partnership, administered by the West of England Combined Authority. Other funding sources are the Government’s Flood Defence Grant in Aid, and Local Levy raised by the Wessex Regional Flood and Coastal Committee. The contractor is BMMjv (BMMjv Explained – Avonmouth and Severnside Enterprise Area (asea-flood-ecology.co.uk).  

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Innovation News

Innovation in techniques: Creating natural refuges for wildlife

Work in progress to create hibernacula at Northwick

Innovation in techniques: Creating natural refuges for wildlife

17 December 2021. We are creating network of natural new refuges for local wildlife as part of our work on wetlands at Northwick, all part of the minimum of 80 hectares (the equivalent of around 112 football pitches) of new wetland habitat along the internationally important Severn Estuary.

The new refuges at the Northwick wetlands are made from grass, mud and other natural materials. Also known as hibernacula, they make a warm, moist and safe habitat for Great Crested Newts, other amphibians, reptiles and insects. Hibernacula also act as a well-stocked larder, with earthworms, slugs and spiders on offer, and provide protection from predators too.

During winter, the hibernaculum offers a safe place for reptiles and amphibians to hibernate. This is particularly important for Great Crested Newts who are largely inactive in winter.

Hibernacula are useful at many other times of year too. They offer shelter for breeding and from hot weather. The network at Northwick will give animals safe passage from the refuges to other areas. The hibernacula are an important part of our work to create and provide locations for wildlife to thrive. You can find out more about the project’s ecological mitigation work here. 

Work in progress to create hibernacula at Northwick

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Innovation News

Innovation in techniques: A new flood defence wall with special features- stone render-effect finish and built-in habitats for plants

Innovation in techniques: New flood defence wall with special features - stone render-effect finish and built-in habitats

22 November 2021. A section of our recently completed flood defence wall at Aust Wharf Road has some special and unusual features. 

The section is part of a stretch of reinforced concrete wall at the most northern part of our project. It has a stone render-effect finish on one side and, on the other, facing onto the Severn Estuary, built-in habitat shelves for plants. The shelves are made from oak. Natural materials make a better and more sustainable habitat for many reasons. They suit small amounts of natural planting which flourishes; invertebrates prefer them; and they are also renewable, durable and strong. 

The stone render-effect finish was a design response to comments from local residents, as well as South Gloucestershire Council’s technical officers, and the requirements of the planning application. The location of the wall is a rural area, overlooked by homes. Officers and neighbours wanted a structure that fitted with these surroundings. 

In response, we devised a design for a stone render-effect finish that would look natural. We then sent this to a form liner manufacturer. Form liners are the liners, or moulds, used in the preparation of designs of concrete walls. As they are available in many different shapes, the manufacturer was able to recreate our design. The resulting finish has a stone and masonry texture with a horizontally running pattern of ‘rocks’ of different sizes. 

The render-effect finish also has considerable environmental benefits. It has meant we have avoided importing stone material, reducing CO2 emissions in the construction process. The finish makes the wall much easier to maintain compared to stone which would have needed repairing over its lifetime. 

As we pride ourselves on being good neighbours, we are delighted that the design fits well with its surroundings, offers a habitat for plants, and is environmentally friendly.

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Innovation News

Innovation: Precast Flood Defence Units

Concrete finishing to installed precast concrete flood defence units

Innovation: Precast Flood Defence Units

18 October 2021. We are using precast concrete units to form the new flood barriers in several areas, including around Severn Beach. Thames Valley Construction produces and builds these units off-site in Newport, Wales. They are then transported directly to site and lowered into position. 

This method minimizes disruption for local residents and the environment, compared with pouring the concrete directly on site. Its benefits include:  

  • Quicker construction, all pre-cast were constructed on site and were ready ahead of the programmed installation date. On average we can install 26 pre-cast units per day. This is a significant time saving compared with cast in-situ where we would have only been able to install 8 to 10 units a week.
  • Long and variable alignment: 374 identical pre-cast units were installed (south of Severn Beach,) each 2.3m in length with only 3 in situ stiches required over the entire length of 860.2m
  • Fewer staff needed on-site
  • Safer
  • Reduction in traffic movements to and from site
  • Less noise and ground vibration.
  • A higher standard of quality control, in particular the surface finish of the pre-cast units.

We expect to install a total of around two kilometres of precast concrete units by the time we complete the works.

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Innovation

Chestle Pill Outfall Design

Chestle Pill Outfall Design

There are a number of existing outfalls throughout the ASEA project area. We need to raise the height of the outfalls, in-line with the new flood defences. In many cases, in order to support the increased height, we need to widen the outfalls, to support the extra load.

At Chestle Pill Outfall, the existing outfall structure would not have supported the additional load from the increased height. To overcome this, we looked at ways of reducing the weight of the existing earth over the outfall. We identified the best way to do this was to replace some of the existing earth over the structure with lightweight high strength modular cells. This network of cells has a 95% void ratio – being much lighter in weight than the ground they will replace but still robust enough to support the same load. It is also recyclable at the end of its service life.