Gipsy Hill Flood Alleviation Scheme
Update 12 August - please see construction update at bottom of the page
Please note - the below notification letter was sent to local residents on 4 August 2026.
Updated - November 2025
Due to the high frequency of highway flooding in the Gipsy Hill area Southwark Council is introducing a scheme in Long Meadow to address this issue.
Why is this happening?
The Thames Water (TW) surface water sewers serving Dulwich Wood Avenue and Gipsy Hill are separate. The factor restricting effective surface water management on Dulwich Wood Avenue is the hydraulic efficiency of the highway gullies, rather than the sewer network. The Dulwich Wood Avenue gullies, do not have the hydraulic capacity to capture the surface water runoff volumes during large storm events. Therefore, excess surface water bypasses the TW Dulwich Wood Avenue surface water sewer system and flows overland towards Gipsy Hill, exacerbating flooding in the lower lying area. As a result, surface water flows overland around the northern end of the park.
The proposed Sustainable Drainage System (SuDS) scheme aims to address the capacity issues of the highway gullies on Dulwich Wood Avenue. By utilising the natural topography, the proposed SuDS features intercept and manage surface water, reducing overland flows toward Gipsy Hill.
How will the SuDS scheme help?
The proposed SuDS scheme is designed to intercept and manage surface water on Dulwich Wood Avenue using the area’s natural topography. Key features include:
- Redirecting surface water flows at higher elevations before they reach Gipsy Hill.
- Reducing the volume of water bypassing the existing drainage system.
- Mitigating overland flooding in Long Meadow Park and Gipsy Hill.
The Environmental Agency (EA) Risk of Surface Water Flooding data (shown in the map below) demonstrates that the areas at risk in large storm events extends from Dulwich Wood Avenue, across Long Meadow Park, down to the northern end of Gipsy Hill.
Expected benefits
The SuDS scheme will significantly reduce surface water flooding risks in the area. It will capture runoff from:
- 200 m² of Dulwich Wood Park,
- 2,260 m² of Dulwich Wood Avenue, and
- 12,900 m² of Long Meadow Park.
By enhancing the capacity to manage surface water, the SuDS will not only improve flood resilience but also contribute to a more sustainable and environmentally friendly solution for the community.
Images of the revised design
Phases
Construction Update
Construction works are scheduled to commence week commencing 10 August 2026. Working hours will be 8:00am to 4:00pm, Monday to Friday.
The programme of works is set out below.
Mobilisation - 10 August 2026
Phase 1: Sewer Connection - 10-17 August 2026
Phase 2: Storm Basins - 13 August - 3 September 2026
Phase 3: Slipway Construction - 3-16 September 2026
Phase 4: Minor Swale - 16-22 September 2026
Phase 5: Major Swale - 16 September - 1 October 2026
Project Completion: 1-5 October 2026
Please note that construction dates are subject to change
Resident Engagement and Temporary Access Changes
A letter was delivered to neighbouring properties on 4 August 2026 to inform residents about the upcoming works and temporary changes to access within the park.
As shown on the map below, the entrance marked with a red cross will be temporarily closed for the duration of the construction works. Alternative access routes to the park will remain available.
While this temporary closure may cause some inconvenience, the works will provide a long-term improvement to accessibility by regrading and levelling the entrance. The existing entrance currently sits significantly below pavement level, creating a steep drop and making access more difficult. Once completed, the upgraded entrance will provide a safer and more accessible route for all park users.
We thank residents for their patience and understanding while these improvements are delivered.