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Hanna Williamson Kingston University April 2010

Project Key Brentford

Floating Habitat


Habitat Cladding


Nesting Basket

Hard Edge


Soft Edge



Introduction to

Brentford London River & Canal Navigation Map Brentford is located by the Grand Union Canal just where it meets the Thames. This is an unique position in London and the canal is a great resource for Brentford as a town.

Lee Valley Park

River Lee Navigation Birmingham

River Silkstream

Hackney Marsh

River Brent Victoria Park Regent’s Park

Regent’s Canal


Grand Union Canal Hyde Park

Osterley Park

Grand Union Canal & Syon River Brent Park

Kew Garden

Duke’s Meadows

Richmond Park

Bushy Park

Barnes Wetland Centre

Greenwich Park

Heritage of the Canal The surrounding area of Brentford grew as direct result of the development of the Grand Union Canal. The canal opened in 1794 and River Brent was converted into the British canal network in 1805. Strong trade and a thriving marketplace was established. The canal helped to transport goods in and out of Brentford.

The market place was the centre of Brentford. View from Kew Gardens towards the docks in the 1960.

Basket weaving was one of the trades that were strong in Brentford during the 19th century,

Introduction to

Brentford Brentford Regeneration Brentford is identified as one of the target growth areas in Hounslow’s UDP. 1. Commerce Road - being developed by ISIS in partnership with British Waterways. 2. South of the High Street - developed by Ballymore. 3. Derelict church - no current plans. 4. High Street - regeneration plans are being researched by Brentford High Street Steering Group. No planning approval has been granted yet and most sites are currenlty under going public consultations.


4 3

N 25 m






Introduction to


Proposal Aim Today the canal has lost its strong identity and focus in Brentford. The high street has turned its back on the canal. Future developments have a unique opportunity to bring the canal back into Brentford. Aim: • This proposal aims to make use of the great open space of the canal. • To highlight it and to give it a new focus and identity.



Green Open Space Brentford has got a range of open spaces in the surroundings. The tidal meadows at Syon Park is protected as a SSSI and Boston Manor Park has been awarded green flag status. There are not many spaces direct adjacent to the canal that are green. The canal has got a great opportunity to act as a green corridor between these spaces and link them. Allotment ‘Wild Open Space’ -not accessible Derelict Overgrown Space -not accessible

Public Open Space (excl. large parks) Parks-Boston Manor Park, Syon Park & Kew Garden

Grand Union Canal The Thames

Boston Manor Park Kew Garden Syon Park

Tidal Meadows

Habitat Survey

N 25 m

Emergent Plants

N 50 m

Marginal Plants

Wet Wet Woodland Grassland

Reed bed

Wildflower Meadows

Amenity Grassland


Mature Trees



Grand Union Canal River Brent Catchment Area River Brent is a minor tributary to the Thames. The river gets most of its flow from run-off from the urbanised areas with some additional sources from groundwater aquifers. River Brent is a lowland clay river. The clay beds are mixed with sand and silt. These beds are in hydraulic continuity with the chalk that lies underneath and this is the reason that the Brent also receives some water from the groundwater. The Grand Union Canal is joined with the River Brent from Osterley Park to Brentford and therefore shares water supply.

River Silkstream


River Brent

Regent’s Park

Regent’s Canal


Grand Union Canal Hyde Park

Osterley Park

Grand Union Canal & Syon River Brent Park

Kew Garden

Duke’s Meadows

Richmond Park

Barnes Wetland Centre

Canal Biodiversity What is Canal Biodiversity? Towpath verge


Banks / Edges

Marginal vegetation

Emergent Plants

Canals create great opportunities for: • Wildlife corridors • Linking to adjacent habitats • Allowing nature in built up ares

Waterside Birds

Built structures

Invertebrates Reptiles

Fish & Amphibians


Canal Biodiversity What affects Canal Biodiversity?

Recreational Activity

Navigation Towpath use

Water Quality

Disturbance Pollution from catchment area Low Levels of oxygen

Water Resource Management

Increased Flow Weirs & Locks

Invasive Species

Japanese Knotweed Giant Pondweed

Canal Management

Dredging Bank protection Towpath Management

Edges How important are the edges to the biodiversity opportunities along a canal?

Urban Canal - Grand Union Canal Brentford


Rural Canal - Wey & Arun Canal Surrey


A soft and gradual edge has larger opportunity to support a diverse plant and wildlife community. Also Important are the conditions of the towpath and the adjacent space.


Existing Edges 2.



N 25 m

1. Sheet piling edge adjacent to derelict land Opportunities for: • Increasing the biodiversity value of the edge • Softening of banks

2. Double level towpath Opportunities for: • Increasing the biodiversity value of the edge • Habitat cladding

3. Concrete & sheet piling edge next to residential area Opportunity for: • Increasing the biodiversity value of the edge

0.5 m


Existing Edges 5.



N 25 m

4. Brick and timber edge adjacent to Syon Park Opportunities for: • Increasing the biodiversity value of the edge • Softening of banks

5. Traditional towpath’ Some biodiversity value in the edge Opportunities for: • Nesting baskets and habitat cladding

6. Tidal sheet piling next to the Thames Valuable existing tidal habitat. • No interventions suitable here

0.5 m



Biodiversity Precedents Biodiversity Trends 2010 is the International Year of Biodiversity by the UN. The biodiversity is life website shows interesting biodiversity projects from all over the world and also has got a section about how you can get involved.

Natura 2000 Network is a website dedicated to raising awareness of Natura 2000 the Europe-wide network of sites tasked with the preservation of natural heritage. On here you can advertise your green day and also see other event and workshops that goes on around Europe.

The Future Nature garden was designed by Nigel Dunnett, Adrian Hallam and Chris Arrowsmith for the Chelsea flower show in 2009. It shows a garden using found and re used materials with planting for wildlife and people. It got a great response at Chelsea, showing that gardens designed for biodiversity can be successful and meet aesthetic requirements by the public.

Habitat Interventions

The images above are showing two different kinds of walls which have been designed to incorporate habitats. The concrete wall (top right) is called animal wall and is designed by Gitta Gschwendtner. It is contains integrated bird and bat nesting boxes and was designed for a housing estate in Cardiff.

When looking at the floating habitat that exists today, most are islands are made with geotextile and planting. These can be quite expensive, but have proved to work well.


Concept Summary Increasing the biodiversity value whilst encouraging community involvement Creation of Micro Habitats 1. A series of low cost interventions for increasing the biodiversity along the edge of the canal that can be created without removing the hard flood defence wall. The creation of the habitats will carried out in workshop days along the canal involving the community.

Supporting Strategies 2. To support the construction of the micro habitats and further softening of banks - a nursery for marginal planting will be introduced along the abandoned canal basin. 3. Identification of strategies and methods for softening the banks and areas identified where this could be considered.


Design Considerations Technical Considerations • Ability to float with the deck just above the water line • Ability to fall and rise easily with the water over the maximum flood range • Nest areas needs to be dry and secured and not attract attention of crows or other avian predators • The nest must be above the storm water level • Appearance that looks natural and beautiful • Consideration into materials that won’t hurt wildlife or pollute the water Dry Habitat cladding

Floating habitat

10 m clear water for boats

Ability to fall and rise easily with the water over the maximum flood range Ability to float with the deck just above the water line

Space for boats

Nesting basket

Storm water level

High tide level

Low tide level

Wet Habitat cladding

Nest needs to be well above the storm water level and secure and dry


Palette Materials Palette Use of natural and biodegradable materials are safest for the wildlife and less likely to contribute to the pollution of the water. A materials palette of natural, reclaimed and recycled materials has been developed for use in the habitat creation. Logs are ideal for using in the creation of habitat cladding on the towpath and on the hard canal banks. Encouraging vegetation and wildlife to live amongst the nooks and crannies.

Tree logs float low in water without help. These can be used in the floating habitats

Used telegraph poles will also float without help and can also be used for the floating habitats. The poles can also be used to add vertical structure to the canal edge.

Reclaimed rocks and stones from the different developments around Brentford can be used to make the habitat cladding for the towpath.

Planting Palette Plants have been chosen for their suitability to a navigable canal. Qualities like tolerance to pollution, disturbance, fluctuating water levels and summer drying have been prirotised. Important is also that the plants already exists locally and that they support a large range of wildlife. These plants provide the starting planting palette and will be increased as the project proceeds. * Nuphar lutea

Ranunculus aquatilis

Potamogeton natans

Myriophyllum spicatum Polygonum amphibium

This water lily is tolerant of disturbance and bears small yellow flowers in June to August.

This water crowfoot provides cover for most aquatic life including water spider and the larvae of dragonflies and damselflies.

This floating plant produces both floating and submerged leaves and is a good oxygenator. It also tolerates some disturbance.

The emergent stems provide places on which dragonflies and damselflies can land and up which their larvae can crawl before their transformation into adults. It has attractive leaves and casts little shadow.

*Big thanks to Topher Martyn, head gardener at Syon Park for providing advice and plants.

Can grow either as a submerged or emergent plant and tolerates fluctuating water levels well.

Woven willow will be used for the nesting baskets. It is important to leave enough space between weaves to make sure the birds can see out.

Woven willow will also be used to provide a natural platform for the growing medium to sit on for the floating habitats.

Coir will be used as the growing medium. It is made from fibrous outer shell of a coconut.

Hessian is made from a vegetable fibre called jute. It is biodegradable and natural material.

Straw together with mud will be used as fill on the rafts, in the nesting baskets and in nooks and crannies on the habitat walls.

Typha latifolia

Butomus umbellatus

Caltha palustris

Iris pseudacorus

Menyanthes trifoliata

Blue tits are often attracted to the large flower head, which also can harbour the larvae of moths. Several species of bug and beetle overwinter in the dead leaf sheaths. It is also tolerant of pollution.

A magnificent aquatic plant with pink flowers in Summer. It attracts the green leaf-hopper and can grow in depth up to 0.5 m.

This marsh marigold is an early pollen source for a variety of insects, and provides good shelter for frogs and other waterside creatures. It is also tolerant of shade.

This iris is a useful plant for emergent damselflies and dragonflies. It is host to the bright blue flea beetle, Aphthona nonstriata, and may also attract bees.

This marginal plant has beautiful floating stems and white spectacular flowers which attracts bees and other insects.




Test Raft A test raft was built using natural and recycled materials. Syon Park generously provided local marginal planting.


The materials chosen for the test raft was chosen for the suitability for a low cost intervention and to be able to trial in the canal next to a residential barge. Without attaching anything to the bottom of the canal or side of canal.


Plastic bottles


+ Coir mat

+ Marginal planting






Constructed Raft


Test in Water


Biodiversity Raft Test

Benefits of a floating habitat CO2 oxygen seeds



The plants and logs above water provides shelter, resting and feeding habitat for birds, frogs and aquatic invertebrates.

The bottom of the raft gives fish and reptiles shelter. Roots uptake pollution from the water and improves the water quality.

oxygen pollution

The roots also provide a food source and a habitat.


Log Habitats Floating Log Habitat

1.5 m


2.2 m 1.5 m

The floating log habitat float up and down with the water level - but is kept in place by the telegraph pole. Sections


Dutch Nesting Basket

Telegraph pole Coir mat

0.2 m

Woven willow Tree log

Close up Section 5m

0.75 m Opening 0.15m opening 1.5 m

1.5 m

Woven Willow basket Telegraph poles



The nesting baskets sit safely above the storm water level of the water on 5 m stilts. The shape of the baskets are very sculptural and provide interesting vertical elements to the canal edge as well providing important nesting habitat for birds.

Habitat Cladding Dry Habitat Cladding

1.9 m


1.6 m

1.7 m

Existing fence line




Water Habitat Cladding

Habitat walls are created to provide space for wildlife on the towpath - but also to green the towpath. The walls will be created from logs, branches, stones and any other natural waste materials. The walls will attract invertebrates and small mammals.

Silt and gravel build up

Cladding the hard edges with timber or logs will increase the opportunity for wildlife and planting. Preferably recycled timber should be used, as this will allow wildlife and plants to occupy the nooks, crannies and ledges created by years of weathering. It also allow silt to get in which will help further. Perspective of timber cladding edge


Supporting Strategies Canal Nursery The location of the nursery is at the abandoned canal basin. This is part of the site that will be developed by Ballymore. The nursery could be temporary and would be run by the community. This creates a communal feeling and interest to this unique area by the canal and could be important for future development.

Softening of hard edges 1. This site is overgrown with shrubs, tall grass and wildflowers. This section has got sheet piling in front of a soft edge and is ideal for softening. It is important to dig into the site and not out into the canal as this would increase the flood risk. 2. The other ideal section for breaking up the hard edge is where Syon Park faces onto the canal. This creates a opportunity for a more visual link and relationship between the park and the canal - but also between the park and the town. It will also add additional important marginal habitat for Syon Park. 2.


Gabion mats are used for river bank protection, channel linings for erosion control, and embankment stability. They are filled with rock to form flexible and permeable structures to promote rapid growth of natural vegetation.

The voids in the rockfill become progressively filled with silt, promoting vegetation growth which is essential to increase the biodiversity value of the bank.

Coir mats are used as erosion control materials for surface protection and structural stability of soils.

The mat can be germinated with seeds which quickly grow and help to naturalise the canal bank.


Community Involvement

Local materials & plants + Low scale interventions + Community involvement

Local businesses



Hounslow Council








= Syon Park


4 months later...

References Books Gilbert, O.L The Ecology of Urban Habitats. London: Chapham and Hall, 1989 Emery, M. Promoting Nature in Cities and Towns. London: Croom Helm, 1986 Hough, M. Cities and Natural Processes. London: Routledge, 1995 Dunnett, N. & J. Hitchmough. The Dynamic Landscape. London, Taylor & Francis, 2008

Documents Brentford Area Action Plan. [pdf] Available at: [Accessed October 2009] Urbed, 2004. Biodiversity by design – a guide for sustainable communities. [pdf] London: TCPA. Available at: [Accessed 3 November 2009] Canals Action Plan. [pdf] Available at: [Accessed January 2010] Defra, 2007. Securing a healthy natural environment. [pdf] Available at: [Accessed January 2010] Thames Landscape Strategy. The Local Landscape. [pdf] Available at: [Accessed November 2010] Environment Agency. Hounslow borough: Environmental summary Available at: [Accessed March 2010]

Websites [Accessed January 2010] [Accessed January 2010] [Accessed March 2010] [Accessed January 2010]

Canal Biodiveristy for Brentford  

A proposal for increasing the biodiversity along the Grand Union Canal whilst encouraging community involvement.

Canal Biodiveristy for Brentford  

A proposal for increasing the biodiversity along the Grand Union Canal whilst encouraging community involvement.