The earth embankment dam is believed to be over 100 years old. During this initial phase, Cognition will review the current condition of the structure and explore a range of potential improvement measures aimed at addressing long-term safety and performance of the dam. Subject to the outcomes of this preliminary stage, Cognition may be appointed to deliver the detailed design and implementation of the works.

Key areas currently being considered include:

• Investigating measures to significantly reduce dam leakage to safe and acceptable levels, mitigating the long-term risk of internal erosion and protecting the dam’s structural integrity.
• Assessing options to install a new impermeable lining system within the remaining section of culvert affected by fire damage to the previous 900 mm diameter corrugated GRP pipe, restoring reliable hydraulic performance and durability.
• Reviewing the potential provision of a purpose-designed auxiliary emergency spillway to safely convey flood flows beyond the capacity of the existing arrangements, appropriate to the catchment area and downstream risk profile.
• Considering suitable stilling structures to manage flows at the downstream toe of the dam.
• Exploring opportunities to improve access tracks to provide safe and reliable access for potential construction works and future maintenance.

We look forward to working closely with the City of London during this initial stage. Their vision is to enhance the Epping Forest area as a beautiful and accessible piece of countryside within the city, and Cognition is pleased to support the early stages of this important project.