Erosion control using placed stone and regrading the bank.
The riverbank had eroded over the previous few years – washing away a stand of willows & alders protecting the bank. The river was threatening to undercut the car parking area of the properties (apartments in a converted mill) and sections of a wall had fallen into the water.
We proposed to use placed stone to protect the toe of the embankment and re-grade the existing bank with clay and clean, locally sourced scalpings. We also installed coir netting over the bank regrading until the vegetation can become established (which will further hold the bank together).
The site access was limited, being a converted mill. In addition to the physical restraints, we had to conform to the Environment Agency licence. This meant keeping any impact on biodiversity and in particular, any sediment mobilisation, to a minimum. We obviously had to ensure that none of our activities increased the risk of the area flooding.
The works have been tested a few times since with high water levels and have stood up very well. The vegetation is now getting established and the site is safe from erosion.
It is often cheaper and more environmentally friendly to use natural methods (sometimes referred to as soft engineering or bioengineering) along rivers, streams and lakes.