Headstone Manor Park Flood Alleviation Scheme

The Headstone critical drainage area was identified as one of the areas at highest risk of flooding in the London Borough of Harrow. Metis were engaged by the London Borough of Harrow to investigate options for addressing flood risk in the critical drainage area and have subsequently delivered the preferred option through to construction.

Our Approach:

• Hydraulic modelling of the critical drainage area to assess options for flood alleviation, determine flood storage size and quantify resulting flood and wider benefits.
• Economic analysis including the CIRIA Benefits Estimation Tool (B£ST) and the Environment Agency’s Partnership Funding (PF) calculator to secure project funding.
• Supporting Harrow Council with stakeholder engagement including preparation of visualisations and presentation of material at forums.
• Preparation of detailed design package including, engineering drawings, engineering specification, Civil 3D BIM model, pre-construction information package and bill of quantities.
• Ongoing support of the construction team, including work with Harrow Council, landscape architect, construction engineer and contractor.

Project Outcomes:

The Headstone Manor Flood Alleviation Scheme compliments the broader Headstone Manor Park rejuvenation works, and has been funded by the National Lottery and Heritage Fund, the Greater London Authority, the Environment Agency and Harrow Council. Together the works within Headstone Manor Park have included:

• De-culverting 100m of the Yeading Brook Channel between Headstone Lane and Headstone Manor Museum;
• Construction of a sedimentation pond and constructed wetland reed bed system in the space north and east of the Headstone Manor Museum;
• Construction of (approx.) 20,000 m³ flood storage in two basins at the southern end of the Recreation Ground.
• Improved access to the Yeading Brook channel throughout the park, including construction of 1.3 km of new pathways, upgrading 1.2 km of existing pathways, installation of 7 new bridges, and interpretation signs and wayfinding posts around the Recreation Ground;
• Restoration and future proofing the water filled historic 14th century moat in the scheduled monument;
• Delivery of apprenticeships; and
• Replanting of a historic orchard, playground upgrade and sporting field improvements.

The Flood Alleviation Scheme provides:

• Flood benefits to 225 properties in the North Harrow area by temporarily storing flood water in two dry basins during significant rainfall events.
• Numerous wider benefits to the surrounding environment and local communities, through creation of new habitats, improved park amenity, job creation and water quality benefits.
• Connectivity with an adjacent residential development to the north-east to provide continuity of green space and an ecological corridor throughout the area connecting to Wealdstone Town Centre and wider travel links.