Sheet Flow Construction Erosion Control

September 8, 2020

Biodegradable Wattles

I wrote this biodegradable wattles specification for a riverbank habitat restoration project.

I wrote the last three sentences for this particular project, which has a 2:1 slope above an intertidal river. We will place 12 inches of compost before installing native plants this winter; without the wattles, wet compost will slide to the base of the slope.

BIODEGRADABLE WATTLES

  1. Wattles shall consist of 100% biodegradable straw, coir, excelsior or compost encased in 100% biodegradable fabric or mesh.
  2.  Wattles shall be a minimum of 8 inches in diameter free of cuts tears and damage.
  3. The installation of straw wattles shall be per WSDOT Standard Plan I-30.30-00 “Wattle Installation on Slope”.
  4. Wattles shall be staked in place using wooden stakes a minimum of 16 inches long.  The stakes shall be cut flush with the top of the wattles.
  5. Wattles shall be installed on the Site 25 slope above +12 elevation.
  6. Wattles shall be installed in two rows across the slope parallel to the 12 + elevation. 
  7. Rows shall be approximately 7 feet above the +12 elevation and 7 feet below the top of the slope.

July 27, 2020

BMP Graveyard-Straw Wattle

Photo: David Jenkins

Another ten year old straw wattle and the plastic is partly degraded but mostly too strong to pull apart.

July 10, 2020

BMP Graveyard-Straw Wattle

Photo: David Jenkins

This used to be a straw wattle 10 years ago. Now it is just plastic mesh BMP graveyard.

June 16, 2020

BMP Graveyard-Straw Wattle

Photo: David Jenkins

Here is another BMP graveyard. Ten year old straw wattle. The straw is long gone but the plastic mesh just as strong as ever.

June 9, 2020

Old Excelsior Wattle

photo: David Jenkins

I don’t know how old this excelsior wattle is but old enough to grow moss. The straw is well degraded but the plastic mesh is still too strong to pull apart.

March 31, 2020

Straw Wattle on Slope Stops Rills

Video: David Jenkins

This straw wattle on a slope stops rills before they can completely form.

February 15, 2018

Straw Wattles Reduce Erosion

Straw wattles reduce erosion when placed on a slope, on contours and at regular intervals.  They will intercept flowing water, reducing its velocity and reduce erosion. Straw Wattle Installation Drawing


Video: David Jenkins

November 24, 2014

Inspecting Straw Wattle

Video: David Jenkins

This video discusses inspecting a straw wattle installed on a slope contour.

April 1, 2014

Straw Wattle Installation Guide

strawwattle_install

This is a great straw wattle installation guide from ACF West.

July 4, 2013

Straw Wattles at Bryce Canyon National Park in Utah

Straw wattles installed on roadside slopes at Bryce Canyon National Park in 2004 still function to hold back erosion and allow vegetation to establish in a harsh, high altitude environment.

Straw Wattle Installation Guide

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