The CIREG Guide to Managing Flood Risk during Construction – an overview, from risk assessment to practical response and mitigation recommendations

Abstract Flooding is a major cause of physical loss or damage during civil engineering and infrastructure construction, and a key risk for tunnels and underground works. Damage to partially or fully completed projects can lead to high reinstatement and cleanup costs, delays, budget overruns, lost revenue, penalties, and DSU insurance expenses. These impacts affect all stakeholders — clients, designers, consultants, contractors, insurers, and third parties. Where flood risk exists, exposures must be identified, responsibilities defined in contracts, and mitigation measures costed into project delivery. Climate change is making weather patterns more unpredictable, with heavy rain and floods causing significant damage and delays. It also undermines the reliability of historical hydrological data. This guide, compiled by the Construction Insurance Risk Engineers Group (CIREG), focuses on flood risk during construction, shares lessons learned, and provides a reference protocol for risk management. It aims to raise awareness, prompt action, and support the creation of Flood Risk Management Plans, Baseline Reports, and Hazard Maps.