Sheetflow Erosion Control Erosion Control for CESCL's

September 8, 2020

Biodegradable Wattles

I wrote this biodegradable wattles specification for a riverbank habitat restoration project. This can be modified to make it specific for other types of projects. The reference to WSDOT works for Washington state only. The last three sentences are written for this particular project which has a 2:1 slope above the river. We will be placing 12 inches of compost before native plants are installed 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.

January 10, 2020

Plastic Netting

I saw this plastic netting today while looking at site we will be working on this summer. The straw wattle was left over from a previous project, completed almost six years ago. The straw filler is almost completely degraded. The netting is partially degraded, but in places is too strong to tear apart with my fingers. We need more 100% biodegradable best management practices and less plastic netting.

Six year old straw wattle. Photo: David Jenkins
Close up of plastic netting. Photo: David Jenkins

July 2, 2019

Biofence Specification

I am trying to get to 100% biodegradable, recycled, reusable, recyclable, low impact best management practices.  I have used burlap fabric fence several times.  I use it whenever I can leave it in place to degrade, like on habitat or wetland work. 

Biofence Specification

Materials
BIOFENCE
A. Biofence shall consist of 7 ounce or heavier uncoated burlap fabric at least 36 inches wide and 100 feet long. Wood stakes dimensions shall be a minimum 1 1/8 x 11/8 inches by 42 inches high.

Construction Requirements
 BIOFENCE
a. Stakes shall be driven into the ground a minimum of 12 inches and be spaced no more than 6 feet apart.
b. Fence ends shall be joined by wrapping ends together around a post 3 times and driven into the ground.
c. Burlap fabric shall be attached to the post in at least 3 places using staples or other method approved by the Engineer.
d. When used as a barrier fence, fabric shall not be trenched into the ground. When used as a silt fence, a minimum 8 inch flap shall be left at the bottom and held in place with straw wattles staked in as detailed in item 9 above.

Payment
C. Payment for “TESC – Biofence” will be made at the contract unit price per linear foot as stated in the Schedule of Unit Prices and shall be full compensation for furnishing all labor, equipment, materials and tools necessary to complete the installation of the biofence as detailed on the drawings or as directed by the Engineer and specified herein. The unit price shall include all maintenance, the removal of biofence, and restoration of the area at the completion of the work

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