Overhead shot of a construction site highlighting newly laid asphalt

Sprowston

Furlong Heath

Sprowston

Tilia Homes, Furlong Heath
Sprowston

Bulk Earthworks
Foundations
Highways & Infrastructure
Wet Well Pumping Station
SUDS
Lagoons
Attenuation
Mains Services
Street Lighting
S278 Works

Scope of works

This ambitious project involves the development of 251 housing plots over a 6-year timeframe, paired with extensive infrastructure and a Sustainable Urban Drainage System (SUDS). To meet the site’s complex engineering requirements, this project includes gabion walls, impermeable lagoons, offsite swales, independent deep bore soakaway systems, and traditional roads and sewers. This substantial infrastructure is integral to delivering a high-quality residential community.

We are continually impressed by our team’s ability to navigate complex challenges. Managing a high water table and integrating substantial infrastructure components crucial for this large-scale residential community has been no small feat. Through our strategic use of wellpoint systems and Sustainable Urban Drainage Systems (SUDS), we have maintained strict adherence to environmental and safety standards.

Our approach

Given the exceptionally high water table, a professionally installed well point system was critical to safely lowering the water level below the planned invert level of the adoptable drainage. This wellpoint system allowed our team to manage water levels effectively, enabling safe and efficient drainage installation.

The groundwater would have posed significant safety and quality risks without this system. Our site teams coordinated precisely to maintain quality and safety, using this well-pointing approach as a foundation for the rest of the project’s drainage and infrastructure.

Key stats

Surplus Material Removed: Over 20,000m³ of surplus material was removed.

Impermeable Basins: Three basins, totalling 15,000m³, each fitted with a living salix liner for enhanced water quality and ecosystem integration.

Bore Soakaways: Eight soakaway manholes, each drilled to a depth of 14m to accommodate site drainage needs.

Wellpoint Systems: Over 1,200m of professionally installed well-pointing systems.

Gabion Walls: Approximately 800m³ of gabion walls, providing essential structural stability.

Challenges faced and overcome

Groundwater Management

High groundwater levels initially presented a challenge for installing adoptable drainage. This was managed with the wellpoint system, ensuring that water was removed effectively, creating a safer work environment.

Low Existing Formation

The site’s initial low formation level required a significant amount of imported material to reach the planned development levels. Starting the project in November also brought challenges with the wet winter conditions, requiring protective measures and increased coordination to manage site formation effectively.

Groundwater Pressure

Beyond initial drainage, groundwater continued to impact the site. We assisted the client with controlled and licensed over-pumping to manage this ongoing issue, protecting site integrity and maintaining progress.

Controlled groundwater pressure through licensed over-pumping ensured the stability of the construction site, allowing us to proceed with foundational and infrastructural developments without delay.

Successfully installed impermeable basins with environmentally integrated liners provide enhanced water quality control, ensuring compliance with environmental standards while fostering local biodiversity.

Efficient use of wellpoint systems allowed for timely and safe completion of drainage, significantly reducing the risk of water-related issues and enabling continuous progress across all construction phases.