IN-RIVER WORKS - TIMBERLAKE ALLOTMENTS
Timberlake Allotments is an open space designated as a Local Wildlife Site 84/014 for flowing waters (rivers and streams); species. The site provides a mosaic of different habitats, including river corridor, pond, reed bed, woodland and scrub and is a popular walking route for local people. The backwater site is owned by Affinity Water.
This site also provides peaceful refuge for residents to relax and enjoy the green and blue spaces in the shade.
Current site issues:
Siltation and domination of reed bed
Backwater not connected with river in all flows
A lack of sunshine which negatively impacts floral biodiversity
The unique aspect of this site is the backwater feature, which hosts a reed bed, a rarity in Hertfordshire and extremely important habitat for wetland species. The backwater feature is currently disconnected from the main river, due to the accumulation of organic debris, silt and plants in the pond area and outlet channel. This is preventing aquatic species using it a refuge area. In addition, due to a lack of management, reeds are encroaching on the centre of the pond, reducing the area of open water and further raising bed of the backwater.
Creation of a series of berms, flow deflectors and hinged trees to improve habitat diversity and species which can thrive in the river. In addition, small tree works will occur to ensure there is a 60:40 ratio of sunshine and shade, maximising blue and green habitat quality.
To address the disconnection of the backwater issue, the bed level of the pond and outlet channel is to be lowered to match the bed level of the adjacent river channel, so as to provide a constant connection between the two features. The reed bed will be reduced to create a larger area of open water, and to prevent the outlet channel from blocking. It managed on a rotation, annually, to maintain the balance between vegetated areas and open water.