Case study:Beam washlands: Difference between revisions
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Revision as of 12:53, 27 February 2025
Catchment and subcatchment
Site
| Name | Beam |
|---|---|
| WFD water body codes | GB106037028100 |
| WFD (national) typology | Rom/Beam |
| WFD water body name | |
| Pre-project morphology | |
| Reference morphology | |
| Desired post project morphology | |
| Heavily modified water body | No |
| National/international site designation | |
| Local/regional site designations | |
| Protected species present | No |
| Invasive species present | No |
| Species of interest | |
| Dominant hydrology | |
| Dominant substrate | |
| River corridor land use | silt, Urban, Parklands garden |
| Average bankfull channel width category | |
| Average bankfull channel width (m) | |
| Average bankfull channel depth category | |
| Average bankfull channel depth (m) | |
| Mean discharge category | |
| Mean annual discharge (m3/s) | |
| Average channel gradient category | |
| Average channel gradient | |
| Average unit stream power (W/m2) |
Project overview
| Status | Complete |
|---|---|
| Project web site | http://https://safag.org/wp-content/uploads/2020/07/19_Beam.pdf |
| Themes | Economic aspects, Flood risk management, Habitat and biodiversity, Hydromorphology, Monitoring, Social benefits |
| Country | England |
| Main contact forename | Becca |
| Main contact surname | O'Shea |
| Main contact user ID | |
| Contact organisation | Environment Agency |
| Contact organisation web site | http://www.gov.uk/government/organisations/environment-agency |
| Partner organisations | Arup, Design for London, Land Trust, London Borough of Barking and Dagenham, London Borough of Havering, Natural England |
| Parent multi-site project | |
| This is a parent project encompassing the following projects |
No |
Project summary
This multi-award winning partnership project built on a £4.5 million flood and coastal risk management (FCRM) scheme to improve the integrity and capacity of this flood storage washland, providing better protection to over 570 homes and businesses. The scheme provides a large, wildlife-rich, community parkland in one of east London's most deprived communities ((Map 1). This includes 12.6ha of Biodiversity Action Plan (BAP) habitat, 150m of remeandering on the Wantz Stream, 600m of reprofiling and 300m of in-channel features on the River Beam. The project was completed in 2012; maintenance is funded and delivered by partners.
Increasing the storage capacity of the existing washlands from 433,000m3 to 458,660m3 provides a standard of protection to downstream properties for (approximately) up to a 1 in 25 year flood event. The provision and operation of the pumping stations provides an enhanced standard of protection of up to 1 in 150 years. This reduces the risk of flooding to 570 homes and 90 businesses. The flood risk regulation benefits of undertaking this project provide a gross asset value of avoided flood damage benefits worth £591,000 per year compared with £193,000 per year before the scheme was constructed.
Socioeconomic/historic context Eftec (2015) states that: 'Beam Parklands is a multi-use community space and flood storage area situated in the south-east of the London Borough of Barking and Dagenham. The site lies on the borough boundary between Dagenham and South Hornchurch. Historically, the land has been used for a variety of different purposes. In the Victorian era, a smallpox isolation hospital was constructed on part of the site. However, for the majority of the 20th century, the site was open space and was eventually designated as part of the Green Belt to protect the openness of the corridor along the Beam River'. Before the recent flood risk management scheme discussed here, the majority of the land area (Beam Washlands) was owned and managed as a flood storage area by the Environment Agency. A smaller pocket of land was owned by the London Borough of Barking and Dagenham for use as park space. This was largely unmanaged with low levels of accessibility for some nearby communities, contributing to high levels of deprivation in the area, and subject to instances of antisocial behaviour.
Flood risk problem(s) The River Beam is a tributary of the River Thames, which flows through east London. The river starts in Essex and flows as the Bourne Brook and River Rom before its confluence with the Ravensbourne. From there, the River Beam flows south to the River Thames, joining the Thames at Dagenham. The River Beam forms the boundary between the London Borough of Barking and Dagenham and the London Borough of Havering.
The River Beam catchment is a relatively small area and the river has a ‘flashy’ (quick) response to heavy rainfall events. The river level will rise relatively quickly, but will also fall quickly if floodwater can drain into the River Thames freely. However, if water levels in the River Thames are high, there is a ‘tide-lock’ effect on the River Beam, meaning that water is not discharged and the volume of water in the river channel increases. The lower reaches of the River Beam are heavily urbanised in the south Dagenham and Dagenham Dock areas. The land use is mixed including residential, education, leisure and recreation, retail and industrial property. Beam Parklands (the washlands) provides an upstream flood storage area which protects the south Dagenham and Dagenham Dock areas from fluvial (river) flooding from the River Beam. Downstream of the confluence, the River Beam and Wantz Stream sluices along the A1306 road can be closed during periods of high tide in the River Thames (which prevents discharge from the River Beam via the tide-lock effect). This causes water to spill into the washlands from the River Beam. When the washlands are full, water is returned to the river via a spillway. If the fluvial flow were to top the washlands, pumps are operated at the Beam Tidal and Gores Brook pumping stations
Monitoring surveys and results
Increasing the storage capacity of the existing washlands from 433,000m3 to 458,660m3 provides a standard of protection to downstream properties for (approximately) up to a 1 in 25 year flood event. The
provision and operation of the pumping stations provides an enhanced standard of protection of up to 1 in 150 years. This reduces the risk of flooding to 570 homes and 90 businesses. The flood risk regulation benefits of undertaking this project provide a gross asset value of avoided flood damage benefits worth £591,000 per year compared with £193,000 per year before the scheme was constructed.
What was the design rationale? This project complements a £4.5 million capital scheme to make space for water and reduce the risk of flooding to 570 homes, 90 businesses (including the Ford Dagenham plant), major infrastructure (including Barking power station) and strategic development sites. The project was developed in partnership with Barking and Dagenham Council and the Land (Restoration) Trust, and provides BAP habitat within 53ha of regenerated open space. The local community were consulted on the design and investment came from the European Regional Development Fund, the Thames Gateway Parkland Fund and the Landfill Tax Credit Scheme. Between 2009 and 2011, the 2 plots of land were redeveloped (see Photo 1) – packaged as a green infrastructure investment – into a single award-winning multi-use parkland and placed under the management of the Land Trust. The management costs are primarily paid for by interest received from the deposit of an endowment (in the region of £2 million) from the East London Green Grid to be used solely for the purpose of maintaining the parkland in perpetuity. Beam Parklands still acts as a flood storage area, with an increased storage capacity, but also provides additional benefits to the local community with a well managed park, a variety of different habitats and increased interconnectivity to nearby residential areas.
Before the project began, Beam Parklands was already an ecological haven for a number of protected species such as water voles, great crested newts (the site was once recorded as having the largest population of great crested newts in London) and a wide variety of wetland birds. A successful design approach was needed to integrate these valuable species and their habitats, so it was critical that in�house experts in environmental design at the Environment Agency worked effectively with the project team, project partners and framework consultants.
The early production of a well-developed concept plan for the site was an essential tool for communicating the vision and facilitating engagement. So as to achieve the necessary improvements to floodwater management, and therefore best value for money, the project focused on the floodplain.
- 750m length of river benefitting from project
- Improvements to the pumping station
- 12ha BAP habitat created (ponds, reedbeds, lowland fen and wet woodland)
- 150m of Wantz Stream realigned, reprofiling around 600m of the River Beam banks and installation of in-channel features along a 300m stretch
- 25,660m3 additional flood storage created.
- The washlands provide a 1 in 25 year standard of protection.
- The provision and operation of the pumping stations (physical capital) provides an enhanced standard of protection of up to 1 in 150 years.
- 570 homes, 90 businesses (including the Ford Dagenham plant), major infrastructure (including Barking power station) and strategic development sites
Lessons learnt
How effective has the project been?
The original storage capacity of the washlands was approximately 433,000m3
. The redevelopment of the site between 2009 and 2011 increased this capacity by 25,660m3
. The process of containing the
fluvial flow within the washlands provides a standard of protection to downstream properties for
approximately) up to a 1 in 25 year flood event. The provision and operation of the pumping stations
(physical capital) provides an enhanced standard of protection of up to 1 in 150 years.
Annual avoided damages are calculated based on the 1 in 25 year standard of protection attributed to
the washlands. Annual benefits are calculated by estimating the number of properties at risk of a 1 in
25 year flood event and the associated damages. An assessment by Eftec (2015) estimated the flood
risk regulation benefits (avoided flood damages) of undertaking this project to provide a gross asset
value of avoided flood damage benefits worth £591,000 per year compared with £193,000 per year
before the scheme was constructed.
Image gallery
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Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
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