Creating a reed bed on an intertidal part of the Thames river is challenging - but Salix achieved a fantastic result as a consequence of their unique design approach.
Salix were approached for design support on an intertidal project on the Thames, just shy of the Thames Tidal Barrier.
The Salix Bioengineering solution of Rock Rolls /Pre-established Coir Rolls was adopted as the design.
This solution was able to address the technical concerns of the Environment Agency and has created an effective reedbed habitat. Two years after the installation the reed bed
The brief was
- The plants must cope with brackish water
- A level bed with alternating dry periods or sudden inundation
- Allow for a rush of water, and often wave energy that reflects back off the vertical walls, creating a zone of extra turbulence
- When emptying, the plants, the sediment accreted and the base growing medium must all be retained within the terrace
- Provide a long-term reed bed solution as a potential habitat
A novel solution to a terrace intertidal habitat
In August 2015 Common Reed, pre-established in Coir Rolls were installed alongside the Rock Roll component.
The Common Reed, Phragmites australis is tolerant of brackish water and frequent inundation. The reeds were established in a Coir Roll off site at our wetland nursery in Norfolk.
The reed plants will go on to establish further roots into the base material and also colonise the interstices of the adjacent Rock Rolls. By colonising the Rock Rolls the reed population now has an overall long-term stability against pulses of high energy turbulence created by the influx and retreat of the tidal waters.
The combination of permanent Rock Rolls and biodegradable Coir Rolls will provide a range of sediment traps that will benefit the biodiversity of the habitat in the future.
And the result two years on is one to be proud of, the reeds have filled the terrace and the habitat is firmly established for the benefit of a wide range of wildlife.
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 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
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
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
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
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