Background Information
The River Yare that runs through Earlham Park and the University of East Anglia is a popular site for public river access.The site suffered from increased bank erosion due to dogs and members of the public entering the water. This was causing over widening of the channel and increase sediment entering the river.
Scope of the Project
Norfolk Rivers Trust in partnership with the Environment Agency commissioned Aquamaintain Ltd to carrying out a range of habitat improvement works along this stretch of the River Yare. The works aimed to reconnect the river with its floodplain to allow water to be held in the surrounding grazing meadows, improving morphological diversity with the placement of in-channel woody debris, repair and protect eroded riverbanks while providing formal dog access points to further prevent erosion and reduce the amount of sediment entering the river. A new wetland was also created to store water and filter surface run-off, thus improving the quality of the water before it flows into the river.
Our Solution
A bund was installed in the adjacent water meadow joining drainage ditches to create a new wetland. A standpipe was fitted through the bund so that water levels in the meadow could be controlled. More water can now be stored in the ditch network, increasing habitat and ecological diversity. In areas where banks had been badly eroded hazel faggots were installed and fixed with hazel stakes. Steep banks were then graded down to the newly formed edge pinching the channel in, and creating a gentle gradient down to the water. Large brash berms were installed using site won material in areas of over widening. The se berms will gradually collect sediment and become colonised by plants. These works help to increase marginal habitat within the river and help to keep gravels clean by increasing water velocity. Formal dog access points were created using site won timber to help prevent bank erosion. Finally, large woody debris was installed along the stretch to increase flow diversity and provide food and habitat for inverts and fish.
