Cain Bio-Engineering Case Studies

Below you will find numerous case studies of aquatic restoration project undertaken by Cain Bio-Engineering. Our case studies are broken up into river, canal and tidal studies.

River Case Study: Profits Wood

by Jake Dew on February 17, 2014

Project type:  Erosion Control
Location:  Chandler’s Ford, Hampshire
Length:  55m of new channel
River:  Chandler’s Ford stream
Client:  The Woodland Trust
Installation date:  2009

Project Brief

Erosion of this small headwater channel during high flows was increasing the risk of bank failure on the steep outside meanders and threatening to cause loss of land in nearby houses.

Cain Bio-Engineering designed and built a new channel through the adjacent ancient woodland, diverting the stream away from the housing.  The old channel course was in filled with excavated material from the new channel and the upstream and downstream extents protected using retained rock armor.  The new channel course was carefully selected to reduce the amount of mature trees removed. Imported gravel was used to create spawning habitat for Salmonids and LWD installed to provide additional habitat variation.

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River Case Study: Thames Valley Park

by Jake Dew on February 17, 2014

Project type:  Erosion Control
Location:  Thames Valley Park, Reading
Length: 60m
River:  Thames
Client:  GVA Grimley
Installation date: June 2012

Project Brief

The retained river bank fronting of the Wokingham Waterside Centre in Thames Valley Park, Reading had eroded and was de-constructing due to a combination of wave action, foot traffic and wildfowl.

Cain Bio Engineering designed and installed a new hard wearing bank front using timber sleepers and gravel.

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River Case Study: Kennet Wasing

by Paddy Staunton on December 10, 2013

Project type: Erosion Control
Location:  Wasing Estate, Berkshire
Length: 120m
River:  Kennet
Client:  Wasing Estate
Installation date:  May 2011

Project Brief

The river at this location runs between two lakes with just 8.5 metres between the banks of the river and the banks of the lake.

It was only a matter of time before the narrow track which separates the River Kennet from Oxlease Lake was breached. This would have had significant access, as well as environmental and financial implications if it was left unchecked.

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River Case Study: Ravensbury Park Weir Removal

by Jake Dew on December 19, 2012

Project type:  Weir removal and habitat restoration
Location:  Ravensbury Park, Morden, London
Length: 30m
River:  Wandle
Client:  The Wandle Trust
Installation date:  September 2012

Project Brief

A stepped concrete weir on a side channel of the River Wandle created a complete barrier to fish passage and a Water Framework Directive (WFD) failure. The weir also led to sluggish upstream river speeds and the silting up of the channel limiting its habitat diversity.

Cain Bio-Engineering reconnected the river by breaking out the concrete weir and stabilising the bed using sweet chestnut post flow attenuators and locally sourced large gravels.

 We also replaced the dilapidated oak boarding with a a geotextile revetment which is designed to fully vegetate.

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Project type:  Erosion control
Location:  Piddinghoe, Newhaven, East Sussex
Length:  50m brushwood bank protection
River:  Ouse
Client:  Environment Agency
Installation date:  April  2012

Project Brief

The River Ouse has large flood embankments on both banks for the majority of the tidal reach. This project focused on repairing a heavily eroded area of the chalk flood embankment.

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Tidal Case Study: Abbotsbury Swannery

by Jake Dew on October 12, 2012

Project type:  Erosion Control
Location:  Abbotsbury Swannery, Dorset
Length: 320m
River: Chesil Fleet
Client:  Strangways Enterprises
Installation date:  2012

Project Brief

The ancient dry stone wall which had once acted as a breakwater to protect the Swannery had fallen into disrepair. This resulted in frequent tidal inundation and loss of land behind the dilapidated wall. Consequently the bank margins of the decoy pond became heavily eroded which was exacerbated by the wildfowl population. High levels of siltation were recorded within in the decoy pond, and nationally important reed bed habitat was lost.

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River Case Study: A36 Southington Farm

by Jake Dew on July 27, 2012

Project type:  Erosion Control
Location:  Stapleford, Salisbury, Wiltshire
Length:  55m of geotextile revetment
River:  Wylye SSSI
Client:  Balfour Beatty, Mott MacDonald, Highways Agency
Installation date:  October 2011

Project Brief

This project is located on the River Wylye adjacent to the A36 west-bound carriageway.  River bank erosion was threatening the stability of the highway.

Cain Bio-Engineering Ltd designed and constructed a geotextile structure to re-claim and stabilise the entire length of affected left bank downstream of the bridge.

Winner of Chartered Institution of Highways and Transportation Award for Sustainability 2012

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Project type: Mill Leat Bypass
Location: Arborfield
Length: 200m of new bypass channel
River: Lodden
Client: Environment Agency
Installation date: 2011

Project Brief

On the River Lodden at Arborfield, historic mill and weir structures prevented fish passage, and had impounded the river for 4km upstream.

 A combination of civil engineering and soft engineering techniques were used to design and build a 200m weir bypass channel to reconnect 25km of the River Loddon.

Runner up prize in the Wild Trout Trust river restoration competition 2011 (professional category)

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River Case Study: Upper Itchen Mill Leat

by Jake Dew on July 27, 2012

Project type:  Mill leat and carrier restoration
Location:  Hampshire
Length: 500m
River:  Upper Itchen
Client:  Private landowner
Installation date:  2011

Project Brief

At this historic milling site, three off-take side carriers provided the opportunity to reconnect a perched mill leat with the main river Itchen. Because of a relatively steep fall from the mill leat down to the main river, the gradient had been previously stabilised using concrete weirs to create amenity impoundments with decorative waterfalls.

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Tidal Case Study: Erosion Control – Scots Float

by Cain Bio-Engineering on June 21, 2012

Project: Erosion Control
Project Location: Scots Float
River System: Rother Inter-Tidal Channel
Date of Installation: 2005

Project Brief

The project aims were to reinstate the failing flood embankment on a wide outside meander. Erosion was threatening significant areas of farming land and infrastructure in the tidal flood plain.

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