Green Swales on Roadside - Salix Solutions

Soft engineered ‘Green Swale Grass Channel’ attenuates road run-off water, filters suspended solids, and traps hydro carbons and heavy metals, significantly improving water quality.

Pinning C125BN erosion control blanket over the HydraCX

Spraying HydraCX onto Type 1 fill

Light scattering of topsoil over Bionet C125BN

A11 drainage channels vegetating

Pinning C125BN erosion control blanket over the HydraCX

Spraying HydraCX onto Type 1 fill

Light scattering of topsoil over Bionet C125BN

A11 drainage channels vegetating

Green swales reduce pollution. Salix worked with Balfour Beatty and the Highways Agency to create a highly effective large scale SuDS project for 18 km along the side of the A11.

The new soft engineered ‘Green Swale Grass Channel’ attenuates road runoff water, filters suspended solids, and traps hydro carbons and heavy metals, significantly improving water quality.

Due to the presence of special protection aquifers in this area of the A11, the Highways Agency’s environmental statement required a green drainage solution to slow the flow of water and help cleanse hydrocarbons, salt and other road pollutants carried by the water before it reached the soakaways.

Robust scour proof erosion control

HydraCX and TerrAffix products, a hydraulic erosion control solution, was sprayed onto a Type 1 fill. This was used as it has been tested in extreme environments and ensured rapid vegetation of the drainage channels.

A tough grass selection was added to the straw, cotton, polymer and tackifier mix, these plants could withstand the level of pollution being washed off the road.

A surface erosion control blanket of biodegradable coir – Bionet C125BN – was installed over the top of the HydraCX to prevent scour erosion during storm events.

These erosion control blankets are designed to provide immediate erosion protection and vegetation establishment assistance, they then degrade after the root and stem systems of the vegetation are mature enough to be stable and withstand heavy flows of water.

Products Used

Spraying-TerrAffix-Hydrasoil-at-Frongoch

TerrAffix Soil Solutions

TerrAffix biochar stabilises & restores degraded soils, providing plants with nutrients whilst actively reducing pollutants in the soil & locking in carbon

Details

Client: Balfour Beatty and Highways Agency
Location: Norfolk
Green Infrastructure, SUDS & Drainage Channels, Soil Remediation

Atkins has worked with Salix on a number of projects, collaborating on design concept, trialling and implementation. We have found their experience valuable in delivering cost effective and environmentally functional solutions.

Atkins

We used HydraCX for the first time on a Network Rail project in Chipping Campden. We wanted to establish vegetation growth as quickly as possible on a slope with poor ground conditions without the need for importing topsoil due to possession time constraints. HydraCX provided an excellent growing medium for rapid germination.

Carillion Rail

HydraCX gave an immediate impression the embankment was grassed, making it more visually pleasing to our travelling customers. The rapidity of grass growth was exceptional and it added additional strength to the slope surface.

Network Rail

We invited Salix to re-landscape the watercourse through a design and build project. The works to the watercourse were completed within two weeks of starting on site and, despite a number of prolonged heavy rain events both during and after the works, the pre-established coir rolls and pallets all began putting on new growth within a matter of days providing the watercourse with instant channel vegetation and protection to the toe of the banks. The VMax reinforcement used to stabilise the slopes has also prevented any erosion to the sandy soil beneath and has allowed the rapid establishment of grass which wouldn’t have otherwise been possible.

South Ribble Council

Excellent overall performance – very approachable and offered a good sustainable solutions to rectify a significant erosion scour to the river foreshore without comprising the existing flood defence. Carried out work to agreed timescale and budget. Certainly would value their future input.

Environment Agency, Leeds

Your staff are always friendly, knowledgeable and helpful and we have always been pleased with the service and the quality of the wetland plants and planting services. Technical knowledge on erosion control is also excellent. Keep up the good work!

Living Water Ecosystems Ltd

We have worked with Salix on a number of projects throughout East Anglia over the last 6 years, and we have always found them to be highly professional and competent. We have used their services as suppliers of quality wetland plants, with a traceable provenance, and as contractors to both supply and plant the wetland plants. In addition we have always relied on the technical advice and knowledge of David Holland, in particular, to help answer queries from our clients regarding wetland planting schemes we have been involved in, this is an added value part of their service, for which we are grateful.

UPM Tilhill