Borders flood warning service to be upgraded

by OUR ENVIRONMENT EDITOR

A succession of serious flooding events across the River Tweed catchment over the last ten years has prompted Scotland's environment watchdog to commission a wide-ranging analysis of the region's flood warning systems in a bid to improve the current arrangements and examine the potential for extending the service into new areas of the Borders.

A significant number of locations are classified as being vulnerable to flooding, with 4,600 homes and other properties at risk from rising rivers and streams. The annual damage from flooding across the catchment is put at £10.5 million.  

Statistics provided by the Scottish Environment Protection Agency [SEPA] include a breakdown of the financial impact as follows: 45% residential properties (£4.8 million); 37% non-residential properties (£3.9 million); 7% emergency services (£710,000); 6% roads (£610,000); 3% agriculture (£300,000); and 3% vehicles (£290,000). 

According to SEPA: "Within the catchment it is estimated that 104 cultural heritage sites are at risk of river flooding. These sites include scheduled monuments, gardens and designed landscapes, battlefield sites and listed buildings. Approximately 42 protected environmental sites are at risk of river flooding. These include three Special Areas of Conservation, two Special Protection Areas and 37 Sites of Special Scientific Interest".

Now, the Agency has engaged leading environmental, engineering and risk management consultants Jeremy Benn Associates to oversee a project titled Recalibration of Flood Warning Models - Catchments in Scottish Borders. The £125,000 contract covers many aspects of flood monitoring as well as the provision of specialist training for SEPA staff.

Recalibration involves correcting or adjusting the settings on precision equipment used for measuring. In this case the network of river gauging stations already operating on the main Tweed and its tributaries will be checked for accuracy.

In 2022 SEPA published its Flood Warning Development Framework (FWDF), making several strategic commitments for improving flood forecasting and warning with the aim of reducing the impact of flooding through the provision of reliable and timely flood warnings. One of the key areas for improvement is the Scottish Borders area which includes the River Tweed and various sub-catchments, as well as the Liddel Water, close to the village of Newcastleton, and Eye Water in Berwickshire.

Paperwork produced by SEPA in connection with the Borders project explains: "Several significant changes have occurred since the flood forecasting system was originally developed. This includes the construction of new flood defences, channel changes and updated hydrometric information (including a significant number of years of records, and rating changes).

"Several large floods have been recorded in the area, including Storm Desmond and Storm Frank in December 2015, which caused considerable damage and affected a large number of communities.  More recently, in February 2020, Storm Ciara and Storm Dennis affected large parts of the Tweed catchment, causing flooding to homes, business and transport infrastructure."

It is hoped the main outcome of the project - due to be finalised next April - will be an improved flood warning service in the Scottish Borders. 

SEPA states: "This project is being commissioned with the following high level objectives:

• To review and improve the flood forecasting approach in the Scottish Borders. 

• To identify the main catchment challenge(s) and develop a flood forecasting solution that acknowledges and addresses these. This will include snowmelt.

• To review flood warning areas and thresholds, taking into account new data including observed flood information, flood studies and schemes.

• To revise forecast locations based on new information or channel changes (such as flood protection schemes).

• To report on model calibration and performance, and recommendations for future improvements.

• To assess the feasibility to extend the warning service to new areas, such as Bowmont Valley and Bonchester Bridge. 

• To train flood warning duty officers and participate in a knowledge exchange programme."

Scottish Borders Council has completed a number of flood protection schemes in the area with varying standards of protection which include: Galashiels Flood Prevention Scheme - completed 2014; Jedburgh 1987 (Jed Water) and 2016 (Skiprunning Burn); Selkirk Flood Protection Scheme: completed 2016; Hawick Flood Protection Scheme: ongoing construction programmed 2020-24; Romanno Bridge Flood Protection Scheme 2023. 

The council has also erected a small earth embankment within Newcastleton to help reduce the risk of flooding. Another informal flood defence wall has been erected in Jedburgh at Malestriot Court which includes a gate that can be closed.

*Note: Flood modelling - A flood model is an important part of developing projects to manage flood risk. A model helps interpret how a river system behaves during flood conditions. It assists in the identification areas that may be affected by flooding. It also enables SEPA and other agencies to assess the impact of both natural and man-made features upon flood risk.