The Emergency Group has been considering the practicalities of implementing a community wide flood mitigation scheme. This consists of identifying particular points along the river frontage and assessing what impact flood barriers would have? This work is of course complex. There are so many points between Riversmeet and the Topsham Rec where inundation could occur that it is simply not practical or economic to consider defending everywhere. However we have identified a number of points along Ferry Rd and The Strand where we consider that the use of de-mountable barriers would mitigate the flood risk.
We have considered the use of two types of barrier: firstly, barriers consisting of sections of rigid triangular plastic, around 1m high, that join together to form a flood barrier. There are holes in the bottom to allow water in, which the gives the structure stability, and holes at the top to allow the escape of air. Sections joined together are then placed across the point to be defended, usually there is no need for a securing mechanism at an adjacent wall or house. These barriers are relatively ‘cheap and cheerful’, are available from local DIY stores, but would not keep out 100% of flood water.
Secondly, we have considered slatted aluminium barriers which are the barrier of choice for many Topsham residents. These barriers require securing points on walls on each side of the defended area, any space wider than approx. 2m would require additional post(s) sunk into the ground to ensure a rigid defence. They are significantly more water tight than the first type of barrier and relatively easy to deploy.
The barriers would be stored close to deployment point, would only be put in place when the threat of a flood is severe. Work to put in place and take down would be undertaken by community volunteers – Topsham already has a number of trained flood wardens, we see this as an extension of their work. Suggested barrier points along the Strand and Ferry Rd are given in the appendix (not attached).
However there are community-wide considerations that have to be taken into account, including:
- impact of closing the public highway during times of potential flooding (eg through a barrier on the Strand at Hannaford’s Quay)
- similarly, the impact of restricting foot access along the river front (eg through the barrier at Wixels on Ferry Rd)
- who makes the ‘stand-up’ and ‘stand-down’ decision?
- ensuring volunteers are trained and available when needed
- storage – actually finding the physical space to do this(see above)
- impact on properties with low wall heights from the deployment of community barriers (ie the ‘displacement effect’)
As at April 2019, work is underway to identify the best option and consider financial implications.
