Bid to tackle Rule sewage concerns

Action is to be taken after a river bank collapse led to fears of sewage entering the water stream near Hawick.

The River Rule at Bonchester Bridge.
The River Rule at Bonchester Bridge.

Scottish Borders Council this week endorsed a planning bid from Scottish Water to carry out river stabilisation works on the western river bank of the River Rule, which runs through Bonchester Bridge.

The company says that without intervention a sewer could collapse with the risk of a pollution incident into the watercourse, at approximately 55 metres south of the Bonchester Bridge, with the river containing such species as salmon and otter, in addition to lamprey.

The Scottish Water report says: “Due to river erosion there has been a collapse of the river bank close to the existing sewer line leaving the existing manhole and sewer exposed to the River Rule.

“Without intervention, there is a risk that the sewer will collapse and cause a pollution incident into the watercourse.

“The proposed development aims to address the situation and avoid collapse of the sewer. Within the scope of the work are the riverbank stabilisation works to protect the existing Scottish Water sewer from further damage due to increasing river bank erosion.”

The river bank enforcement works will include the creation of a 16-metre long vegetated retention wall.

The report adds: “At the outset, a temporary portadam system (comprising of sandbag walls lined with heavy gauge polythene) will be installed in close proximity to the proposed development in order to provide a dry working area.

“Pumps will be installed in order to remove water from the working area once the portadam is constructed. The existing river bed will then be cleared of all loose material and reduced to a specified formulation level. A compacted granular foundation will then be installed. Following the completion of the construction of the proposed development, all temporary materials and plant will be removed.

“The proposal is required to ensure the security of the public sewer network and prevent future waste pollution events downstream of the application site.”