On Monday 7th November a Catchment walk along the Toddington estate section of the River Isbourne took place, attended by representatives from the Toddington estate, the Isbourne Catchment Group (Annette Dawson, Sue Morris and Richard Wakeford), the University of Gloucestershire (lecturers Dr Lucy Clarke and Dr Chris Short and third year Geography students Jack Hackett, Kyle Conroy and Louise Wilson), the Environment Agency (Brian Smith) and the Farming & Wildlife Advisory Group (Jenny Phelps) and provide ideas to and discussion involving, reducing flood risk within the Catchment.
The University of Gloucestershire are helping to increase awareness of the Isbourne Catchment Group, as well as using geographical knowledge and techniques, such as GIS (Geographical Information Systems) to help provide ideas on flood management in the catchment. The students were recording the conversations that took place, recording the position of significant points along the route of the walk, and using alternative methods to log the catchment walk and its discussions.
As a group, we met outside the Toddington Manor at approximately 10:30am. The beginning of the walk saw us cross the river on a small brick bridge. This part of the river channel was filled with silt and other sediments and was very straight, and so looked to have been a man-made leat.
The first main point of interest was the ‘Old Victorian Pond’ area (Shown Left). This was originally proposed as a potential overflow pond for when flooding occurs. There is the possibility of using this as a water storage area. The University could map this area and calculate how much water it would hold in terms of overflow.
The next point of significance was a man-made Weir (Shown right). It was discussed that the Weir was a secondary entry point for water flow into the river, from an unknown original source. We believed the water comes underground from a sluice, but the exact path is currently unknown. Following on from the weir, a dent in the ground was found, suggesting a collapsed sluice? This was found in two different places. The university students are going to look into some historic maps of the area to try and figure out the path of these water flows and potential sluice positions.
The third significant discussion point was the original water channel for the river Isbourne before it was re-directed to flow along the leat (Shown right); the original channel was completely empty, unused, and full of debris. The debris included plant life, fallen trees and earth. It was suggested that this channel could potentially be used as an overflow during flooding. Backtracking along the dry channel, we noticed it to be blocked by a land slide, and so it was decided this is the point at which the overflow system could be used up too. Louise (one of the students from the University) is going to calculate the amount of water the dry channel can hold using GIS, allowing the team decide whether it is a worthy prospect.
Another issue highlighted was where the original channel met the leat (downstream of the first weir), there was a build-up of water. After investigation upstream it was noted that the channel was blocked from fallen trees and other various vegetation. Albeit an easily resolved problem, it is still a minor issue that was noted and will hopefully resolved soon.
The final stopping point was further upstream, where a second weir had been built. This was another potential area suitable for flood management; the river channel was wider here, and so could be filled with natural debris to reduce river flow in times of flooding to provide a feasible flood-management option.
To conclude, the walk was a great success in determining options for flood-management and discussing their possibilities. The main ideas involved the use of the dry channel as a water-overflow option, placing a check damn at the confluence of where the original channel meets the dry channel and placing debris by the second weir to reduce water flow. The ideas would need more consideration, such as the dry channels capacity, which is being calculated by the University students, and investigation into historic maps to learn more about previous water pathways, and so to test if they would be feasible, before being planned further.