How do you manage the problems of riverbank erosion and flooding?

Environmental equilibrium needs careful planning

We know that the environment has a delicate equilibrium that cannot be altered without consequences.

Both the welfare and development of our society and mankind, are strictly related not only to the exploitation of water resources, but also to the environmental equilibrium.

IT IS NECESSARY TO CARRY OUT RESTORATION WORKS TO PROTECT THE ENVIRONMENT AND MANKIND.

At African Gabions, our main objective is to achieve the maximum results with a minimum amount of energy loss by joining hands with nature and not competing with it.

Gabions are frequently used in the management of rivers and their relation to erosion.

 

Example: African Gabions used to help control river bank erosion

The problem – erosion of riverbank

The engineered solution – install African Gabions

How did it work out? The riverbank is retained and vegetation has naturally integrated with the gabions.

Before
After

Here we see the effect of time on the bio-engineered riverbank at Silvermine in South Africa.

The hydraulic restoration of water courses

The nature of the hydraulic problem to be solved will differ according to the location of the surrounding watercourse.

What is hydraulic restoration?

This is the modification of a water course, which has had its equilibrium altered, i.e. Limiting its natural trend to change direction, flow and profile to safeguard infrastructures and urban areas.

Any restoration work which alters the natural course affects both water course and basin. The restoration work carried out today might give rise to future damage.

Environmentally compatible design criteria for modern hydraulic restoration works

  1. Effectiveness of technical solutions
  2. Minimum environmental impact
  3. Rapid recovery of the fluvial in of the fluvial habitat
  4. Protection of biodiversity
  5. Evaluation of both biological and hydraulic parameters
  6. Maximum safety for the surroundings

It is not environmentally responsible to consider a natural water course as an artificial canal, because the ecological and biological parameters can now be considered in the mathematical calculations and engineering design.

Concrete lining impoverishes the watercourse’s natural equilibrium because:

  • The use of concrete elements destroys any link between the watercourse and its surroundings
  • Wide concrete revetments prevent plants from growing and animals from settling in
  • The use of natural rock and artificial concrete hinders access to the riverbank, therefore preventing proper maintenance
  • The equilibrium required to allow a water course to survive, may easily be achieved with a soft solution carried out with gabions

Natural is anything that favours the environmental equilibrium

Natural is synonymous with continuity between the environment in terms of flora and fauna, the riverbed, the riverbanks, the subsurface water, and a perfect integration without interruption.

The ability to maintain a high level of biodiversity means to create or maintain differences, which allow the development or sustainment of different micro-habitats related to one another. The fluvial habitat is based on a vital coexistence between flora and fauna, which must be protected. A natural transition between eroded and silted areas, between banks, pebbles and vegetation represents the natural aspect of a water course. Natural does not only mean regreening. Vegetation by itself is not always able to solve problems related to erosion.

On the other hand, the watercourse equilibrium depends upon different factors. Rocks, minerals and metals, with different morphologies, are an integral part of the river habitat.

These elements are fundamental design components for the use of all African Gabions products.

African gabions restoration design methods use a complete analysis of the water flow to find the best solution based on a total holistic solution rather than on “ temporary” solutions along the damaged area.

One of the main criterion is to carry out minimal protection, pursuing the minimum entropy to employ the most cost effective solution.

What problems are all river training works aimed at solving?

  1. Control of solid transport and riverbed erosion
  2. Control of bank erosion
  3. Reduction of flooding
  4. Protection of infrastructure and urban areas
  5. Protection against desertification

Gabion solutions for river training

  1. Longitudinal gabion gravity protection
  2. Channel linings
  3. Gabion weirs
  4. Gabion groynes
  5. Bridge protection

Can we assist you with with one of these solutions using gabions on an upcoming project?

Contact us for advice on the placement of African Gabions.