Chandos Park is one of eight locations where various blue-green interventions were proposed as part of the wider Action for Silk Stream catchment-based approach. This was one of the 25 Flood and Coastal Resilience Innovation Program (FCRIP) projects awarded by the EA and DEFRA.

These climate resilience initiatives were designed to make more space for water, reduce flood risk, improve water quality, support community engagement initiatives, partner with river catchment hosts and the private sector across the Silk Stream catchment. Metis supported the delivery of this multi-funded, multi-benefit river restoration and flood resilience scheme at Chandos Park. The scheme transformed a constrained urban watercourse into a more naturalised, accessible and biodiverse blue/green corridor.

The river was moved away from the rear of properties in order to naturalise it. This involved removing timber revetment, modifying the straight channel to a more sinuous form, adjusting banks from near vertical to natural slopes, and laying gravel bars to improve water quality that will support diverse aquatic habitat.

Chandos Park has since become an instructive case for Metis in understanding contemporary Environment Agency requirements on future river restoration projects and Flood Risk Activity Permits (FRAPs).

The challenge

The Silk Stream is a major tributary of the River Brent, with tributaries including Burnt Oak Brook and Edgware Brook. Before the project, the Edgware Brook ran along the edge of Chandos Park, behind a fence and largely disconnected from the wider park environment. Many park users did not even know there was a river there.

The site presented several interconnected river restoration challenges:

• restoring a constrained section of the Edgware Brook within a live public park environment that abutted private homes
• re-aligning the brook to bring it further into the park while maintaining safe public access and construction controls
• creating flood storage and wetland features that could help alleviate flooding along park footpaths
• delivering ecological enhancements, including meanders, channel widening, gravel bars, sloped vegetated banks, new trees and meadow areas
• managing excavation, watercourse works, temporary fencing, public protection, environmental controls and construction sequencing in proximity to a watercourse
• designing and working around a live high voltage cable

Our approach to river restoration

Metis’s work at Chandos Park was aligned with the wider Action for Silk Stream objective: to restore rivers, create natural drainage features, improve water quality, build flood resilience and provide high-quality blue/green spaces for local communities. The project formed part of a broader programme of interventions across parks and open spaces in the Silk Stream catchment, including Watling Park, Lyndhurst Park and The Meads.

Design and technical support

The scheme re-aligned the brook further into the park and restored it to a more natural state.

It also introduced in-channel and bankside features to improve ecological value, slow the flow of water, and make the watercourse a more visible and integral part of the public open space. Specifically, the project modified the banks from the near vertical to provide a more natural gradient. This increased the river’s capacity, conveyancing and improved public safety on the site.

The project also delivered two new wetland areas in the centre of the park. These helped to alleviate flooding along footpaths, and contributed to wider habitat creation. Complementing the wetland areas were suitable aquatic and tree planting, meadow creation and landscape enhancement. These measures strengthened the park’s biodiversity and climate resilience.

Coordinating the construction phase

During delivery, the works included significant excavation to realign and reshape the Edgware Brook. Construction activities to protect the public and the environment were included in the construction logistics plan, method statement and risk assessment to work in the park itself and the river.

All these activities were reviewed and subsequently approved by the Council (as park owner) and the Environment Agency, in order to work on a main river. These requirements included working areas enclosed using fencing or temporary barriers, controlled access and egress, daily risk assessments and toolbox talks, permit-to-dig processes, environmental spill controls, sequencing plan and specific measures for works in and around the river environment – including working outside of the fish and bird breeding season.

Metis also had to re-design around the constraints of the site. Most notably, this included a high voltage cable found during the early phases of construction. The original ground penetrating survey had not picked this up.

The construction sequence included clearing vegetation, stripping and reusing topsoil, excavating and shaping the new river channel, introducing temporary bypass arrangements, forming the new intake and outtake of the new channel, and regrading the surrounding areas ready for seeding and landscape establishment.

Integrating park improvements into a river restoration scheme

Alongside the watercourse and wetland works, we:

• resurfaced paths
• upgraded the playground
• created a new picnic area
• completed car park improvements
• installed new entrance signage and three interpretation lecterns explaining the water cycle, at intervals parallel with the river
• established new storage modular buildings for the cricket team and the Chandos Park User Group

This integrated approach helped to improve everyday experience of the park for visitors, sports users and the wider community.

Outcomes and value delivered

The Chandos Park scheme delivered significant environmental, flood resilience and public realm benefits. The completed interventions included:

• 740m² storage footprint
• 290m³ of wetlands delivered
• 210m of watercourse improved and river habitat enhanced
• 12,013m² of landscape enhanced
• 123 trees planted
• 1.67 hectares of new habitat created

The realigned Edgware Brook is now more visible, more natural, and connected to the park. The project also improved the visitor experience at Chandos Park, with improved park infrastructure, deckboards crossing the swales that drain into the wetlands (which overspill into the river in winter), upgraded recreational facilities and enhanced planting. These changes support the wider programme ambition to create resilient, biodiverse and accessible green spaces. In turn, these benefit both people and wildlife – particularly in urban areas of high deprivation.

Metis brings deep experience in natural flood management, urban water engineering, river restoration and delivering programmes in line with Environment Agency requirements. At Chandos Park, this expertise helped to transform a constrained and hidden urban watercourse into a more resilient, attractive and ecologically valuable parkland feature.

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