A site manufacturing explosives was flooded following heavy rains. The products involved are not sensitive to water. A 15 hectare marshland located upstream to the site serves as an outfall for water overflowing from neighbouring lands. A 150 m³/h lift pump pumped out the excess water from the marshland via a pipeline to the CHAPELETTE marshland situated northeast. A non-stop and heavy downpour caused the water level to rise in the LANGLADE canal running southwards and adjacent to the plant. The gate valves that were shut for unknown reasons were unable to evacuate the excess water from the overflowing canal. Water swept into the site from the south west direction in form of a wave and drained into the 15 hectare marshland. The lift pump, completely submerged due to the rapidly rising water level could not prevent the flooding of the site where the water level reached 1.2 m. The operator installed four mobile pumps available on the site and requisitioned emergency pumps from neighbouring industries. A 2,000 m³/h capacity helped curb the rise in water level. After a week of pumping, the water level in the CHAPELETTE canal returned to normal. Despite the risk of exposure to water, a transformer suffered no damage. Even though the storage and production sites were not impacted, the two-week long production stoppage resulted in losses estimated at 105 K euros. The operator updated the internal contingency plan by adding the particulars of the companies capable of providing emergency pumps.