Drainage

30% of drainage maintenance expenditure will be spent on reactive maintenance. Such as responding to incidents or asset failures.

70% of drainage maintenance expenditure will be spent on planned maintenance. This includes routine, cyclical and risk-based activities.

We use a digital drainage management system that includes:

• asset inventories
•  inspection history
• sensor data
• risk scoring

We also maintain records of locations where drainage issues are known to cause or contribute to:

• road deterioration
• surface water ponding

Evidence summary

We use Kaarbon Tech's Gully SMART drainage management system to help manage and maintain highway drainage assets across the network.

The system records:

• drainage asset information
• inspection and maintenance records
• known flooding and drainage issues
• risk and performance data

We use information from inspections, drainage surveys, customer reports and local knowledge to:

• identify drainage issues
• assess risk
• prioritise investment
• plan maintenance programmes

Evidence used to support drainage management includes planned cleansing and inspection programmes, reactive maintenance records, CCTV drainage surveys, asset mapping and flooding hotspot data.

This information helps us take a proactive approach to drainage maintenance, improve network resilience and reduce the risk of flooding and drainage-related damage.

More information about drainage asset management

We take a risk-based approach to managing highway drainage, using asset condition data, inspection results, local knowledge and information about flooding issues to identify where maintenance is needed most.

To support this work, we:

• carry out planned drainage inspections and cleansing 
• use condition data and survey results to inform maintenance programmes 
• identify and prioritise known flooding hotspots 
• review maintenance priorities and investment programmes regularly

Our in-house CCTV drainage inspection team carries out targeted investigations to identify blockages, defects and drainage issues, helping us diagnose problems and plan the most appropriate repairs.

We are continually improving our drainage asset mapping to strengthen our understanding of the network and support better decision-making.

This approach helps us target resources effectively, reduce flood risk, improve network resilience and protect highways from drainage-related deterioration.