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.

Royal Wharf intertidal reed bed solution
Sediment accretion in Rock Rolls which ensures they are no longer visible
Royal Wharf intertidal reed bed solution - 2 years after installation
Sediment accretion in Rock Rolls which ensures they are no longer visible

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
is flourishing.

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
Royal Wharf Rock Roll Coir Roll sandwich
Royal Wharf Rock Roll Coir Roll sandwich

Reedbeds established in Rock Roll and Coir Roll sandwich
Reedbeds established in Rock Roll and Coir Roll sandwich

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.

Royal Wharf reed bed looking up the Thames
Royal Wharf reed bed just installed

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.

inundated reed bed at high tide
Inundated reed bed at high tide

Products Used

Coir Rolls

Coir Rolls are an organic living revetment that provide erosion control and rapid vegetation establishment. Salix have developed a range of specific species mixes for use in all types of water bodies.

Pre-filled Rock Roll

Rock Rolls are a robust and permanent revetment for use around reservoirs, shorelines, lake edges, streams and river banks. They are cost-effective revetments that are suitable alternatives to rock rip rap and gabions in many scour applications.


Client: Oxley Developments
Location: Royal Wharf, North Woolwich Rd, London
Reedbeds & Wetlands, Rivers & Water Courses, Salt Marshes & Intertidal Rivers, Urban Rivers