Impermeable Area Studies

Impermeable Area Studies assess the extent of surfaces that prevent rainwater from naturally infiltrating into the ground. These surfaces typically include roofs, roads, car parks, pavements and other hardstanding areas.

As development increases the amount of impermeable surface within a site, the volume and rate of surface water runoff can significantly increase. Understanding this impact is essential for effective drainage design, flood risk management and compliance with planning requirements.

At Such Salinger Peters, we undertake detailed impermeable area assessments to support drainage strategies, flood risk assessments and sustainable drainage (SuDS) design for developments of all sizes.

When rain falls on natural ground, much of the water infiltrates into the soil. However, impermeable surfaces prevent this natural process, causing water to flow directly into drainage systems.

Without proper assessment and management, this can lead to:

• Increased surface water runoff
• Overloading of drainage networks
• Localised flooding
• Increased flood risk downstream
• Planning and regulatory challenges

An accurate understanding of impermeable areas helps ensure developments are designed sustainably and responsibly.

Our engineers utilise site layouts, topographical information and development proposals to accurately calculate existing and proposed impermeable areas.

Assessments typically include:

• Identification of current impermeable surfaces 
• Baseline runoff calculations 
• Assessment of drainage constraints 

• Calculation of proposed impermeable areas 
• Comparison against existing site conditions 
• Identification of runoff increases 

• Surface water management recommendations 
• SuDS opportunities 
• Attenuation requirements 
• Planning support documentation

Impermeable Area Studies are commonly undertaken for:

🏡  Residential developments

🏢  Commercial and industrial schemes

🛣️  Infrastructure projects

🚗  Car parks and hardstanding areas

🏫  Schools and public sector developments

🌿  Regeneration and redevelopment sites

At Such Salinger Peters, our multi-disciplinary expertise allows us to seamlessly integrate impermeable area assessments with:

• Drainage Consultancy & Design
• Sustainable Drainage Systems (SuDS)
• Flood Risk Assessments
• Civil Engineering Design
• Planning Support

By bringing these services together, we provide a coordinated and efficient approach that helps clients progress projects with confidence.

Our impermeable area assessment services support a wide range of clients across both public and private sectors.

• Property Developers
• Commercial Developers
• Architects & Planning Consultants
• Contractors
• Local Authorities
• Educational, Healthcare & Community Organisations

Regardless of project size or complexity, our team delivers practical and reliable engineering solutions tailored to each client's requirements.

Understanding impermeable surfaces is a fundamental part of creating sustainable developments.

By accurately assessing surface water runoff and integrating appropriate drainage measures, developments can minimise flood risk, protect local infrastructure and support environmental objectives.

At Such Salinger Peters, we provide practical, evidence-based assessments that help clients deliver compliant, sustainable and resilient developments.

Contact Such Salinger Peters today to discuss your project.