Sunday, May 01, 2016

The Roding Faggots

We do like to report on matters nature from time to time and we are grateful to Cllr Bond for pointing out the works on the River Roding downstream by the flood defence barrier at Barking Creek.

We are also delighted to read in the Ilford Recorder letters page that the extension to Roding Valley Way (see Sustrans map here) has been completed, although we have not seen any official statement from Redbridge Council.

This southern extension takes it from the A12, just west of Redbridge roundabout, along the eastern edge of Wanstead Park and down to Ilford, Romford Road, just west of the A406 flyover. One day it might go all the way down to Old Father Thames.

Anyway, the faggots are located about 100m upstream from the little known Barking barrier (see Youtube Video here) and are part of an Environment Agency project with aims of both flood defence and nature conservation.

Basically inter-tidal rivers, such as this one, are subject to two daily inundations, which leave the riverbanks saturated reducing the shear strength of the soil. The banks are then subject to failure/slide and the soil gets washed away with the tide.

However, where there are mature strands of vegetation cover, the roots and rhizomes appear to create drainage paths that reduce water pressure thus decreasing the bulk weight of the bank and increasing shear strength and stability.

So the faggots (or brushwood fascines) create sediment traps, which includes seeds, that encourage growth of vegetation and native plants to establish, which in turn is good for insects and wildlife and ultimately us.

The technical details are here at the Salix site with more photographs.

And here’s the letter in last week’s Recorder, there’s no internet link I can find.

No comments:

Post a Comment