Strengths

  • Uses inexpensive and typically readily available materials.
  • Can act as a natural sediment accumulator, enhancing certain habitats.
  • Self-repairing.
  • Protects both the toe of slope and bank from the erosive force of water.
  • Lowers stream temperatures and decreases stream velocity.

Limitation

  • Incorporated vegetation must be planted at medium density to avoid excessive sediment deposition and projection into the stream.
  • It is extremely important to anchor each tree at the base or toe of the eroding bank
  • Should not be used near bridges or other structures where there is a potential for downstream damage if a revetment dislodges.
  • Protects both the toe of slope and bank from the erosive force of water.
  • If a revetment does not run the entire length of an eroding bank, the structure may be ineffective.

Vegetated revetment

Application: Canals, culverts and drains, dykes, embankments, floodgates, stormwater outfall.

Description: A vegetation revetment is an engineered slope with trees planted along banks, shorelines or cliffs to reduce slope erosion by absorbing energy and reducing water velocity, capturing soil, and creating a natural habitat enhancing conditions for planting or colonization of native species. It is constructed of trees (without root wads) that are cabled together and anchored along the structures by earth anchors, which are buried in the bank. The sediment trapped in and behind revetments provides a moist, fertile seedbed for vegetation establishment. The primary purpose of a revetment is to stabilize the eroded or undercut bank until trees and shrubs become established to provide permanent protection. Tree revetments decrease erosion and slow the nearshore current so that silt and sand can be deposited on the bank.

Contribution to climate resilience: Vegetated revetments prevent erosion by stabilizing the bank and slowing the near-shore current so that silt and sand can be deposited. This increases the resilience of streambanks to extreme climatic events. Because they are developed using local labour and locally available materials, they require less energy to produce, are far more sustainable, and can be applied in as quick a timeframe as traditional civil engineering works.

This resilience-building measure is sourced from the Water Resource Adaptation Guide (2019) published by the National Council for Sustainable Development at the Ministry of Environment in Cambodia. The full Guide is available to download at URL https://ncsd.moe.gov.kh/sites/default/files/2019-10/Water%20Resources%20Adaptation%20Guide_March%202019_En.pdf