The key aim for this location is to provide additional storage to capture and slow the flow of surface water into the Prittle Brook, to reduce the risk of flooding downstream.
We’re helping slow the flow of the Brook with the introduction of leaky dams at various points to hold back the flow and release it slowly. The leaky dams are a natural barrier which hold back water at times of heavy flow, such as in flood conditions, releasing it at a slower rate over a longer period of time.
In order to increase the storage capacity of the Brook areas of wet woodland are being created adjacent to the Brook.
In addition, we will explore embedding mycelium (a fine network of living fungal threads) into the leaky dams. The mycelium would act as a natural filter and improve water quality at the same time! High flow rates in the water course do create some challenges here. We will likely put the mycelium in special bags and stuff them into the gaps in the dams.
Computer simulation modelling software has helped us determine where to put the dams. Stage monitors are recording how effective the dams are and their impact on storing flood water. A weather station is also in place here collecting live data to support data collection and we’re planning to have stage height boards at the leaky dam sites.
We’ve used natural material from on-site, such as coppiced timber.
We have been informed by an ecological survey that the change in hydrology in Belfairs Wood would have a negative impact on surrounding trees. This doesn’t mean we won’t use wet woodlands here, but it does mean we are going to have to rethink locations and how we use this measure.
We have finalised designs for our proposed leaky dams and are obtaining the relevant permits from the Environment Agency and Natural England for the installation to start. As well as traditional leaky dams made from logs, we are planning to build dams made of mycelium-filled bags to trial the use of mycelium to improve water quality.
