To resolve persistent flooding caused by insufficient drainage and rapid runoff on a sloped pedestrian area by designing a terraced rain garden that improves water absorption, prevents soil erosion, and increases biodiversity in an urban residential setting.

• Manage runoff from approximately 450 sqm of paved surfaces draining into a sloped grass border.
• Expand and reshape the border by 8 sqm, creating a 96 sqm terraced rain garden.
• Reduce slope gradient with a wooden sleeper terrace to slow water flow and boost infiltration.
• Replace compacted soil with a shingle drainage layer and SuDS planting medium for better permeability.
• Introduce diverse, drought- and wet-tolerant plants suited for partial shade under mature trees.
• Protect existing trees and infrastructure while preventing vehicle access to avoid further soil compaction.

A range of strategic design measures were implemented to address flooding, improve drainage, and enhance biodiversity within the rain garden. These included terracing the slope, improving soil permeability, expanding the catchment area, and introducing SuDS-appropriate planting.

Flood Mitigation and Soil Stabilisation

The terraced rain garden effectively captures and slows surface runoff, preventing puddling and erosion that previously damaged footways and caused soil displacement. This leads to a more stable, safer pedestrian environment.

Enhanced Urban Biodiversity

The diverse planting scheme creates a dynamic habitat for pollinators and insects, encouraging a new ecosystem to develop in an area previously dominated by grass and bare soil. Log piles and seasonal living walls further enrich this microhabitat.

Community Engagement and Wellbeing

By transforming a problematic flood-prone area into an attractive green space, the project offers residents a place to reconnect with nature and observe seasonal changes, improving local quality of life and fostering environmental awareness.

Long-Term Resilience

The rain garden’s design addresses current drainage deficiencies while adapting to future weather extremes through increased soil permeability, retention, and vegetative water uptake – supporting sustainable urban water management on the Lancaster West Estate.