Percolation Testing
Get in touchThe Flood Protection Associates provides Percolation Testing to assess how quickly water drains through the ground. The service supports soakaway design, surface water drainage strategies and development planning with accurate site-specific infiltration data.
What Is Percolation Testing?
Percolation Testing is the process of measuring the rate at which water infiltrates into the ground. The Flood Protection Associates carries out testing to determine whether the soil is suitable for soakaways and sustainable drainage systems, providing data for drainage calculations and engineering designs.
Testing helps engineers design drainage systems that perform effectively while reducing surface water flooding.
What Types of Percolation Testing Are Available?
The Flood Protection Associates provides Percolation Testing for residential, commercial and development projects. Testing methods are selected according to the drainage proposal and site conditions.
Soakaway infiltration testing – Measures soil permeability for soakaway design.
Surface water drainage testing – Supports sustainable drainage strategies.
Development site testing – Provides infiltration data for planning applications.
Commercial drainage testing – Assesses larger development sites with greater runoff volumes.
Replacement drainage assessments – Evaluates existing sites requiring improved drainage.
Each assessment is carried out using recognised testing procedures appropriate for the proposed drainage system.
When Is Percolation Testing Needed?
Percolation Testing is needed before designing infiltration-based drainage systems or where planning authorities require evidence of ground permeability. The Flood Protection Associates provides testing that supports informed drainage design decisions.
Common situations include:
New housing developments
Home extensions
Commercial developments
Soakaway design projects
Sustainable drainage system proposals
Surface water management strategies
Testing at an early project stage can help reduce planning and construction delays.
How Does Percolation Testing Work?
Percolation Testing follows a structured site investigation process. The Flood Protection Associates gathers field data that engineers use when designing drainage systems.
Site inspection – Ground conditions and drainage constraints are reviewed.
Test pit excavation – One or more pits are excavated to the required depth.
Water infiltration testing – Water is introduced and infiltration rates are recorded.
Data analysis – Results are used to calculate soil permeability.
Reporting – Findings support drainage design and planning documentation.
Most percolation testing projects can be completed within 1 day, with reports commonly issued within 3 to 10 working days.
Who Needs Percolation Testing?
Percolation Testing is suitable for anyone planning a development that relies on infiltration drainage. The Flood Protection Associates supports projects across multiple sectors.
Typical clients include:
Homeowners
Property developers
Architects
Civil engineers
Planning consultants
Commercial property owners
Local authorities
Each assessment is tailored to the site's proposed drainage requirements.
How Much Does Percolation Testing Cost?
Percolation Testing typically costs from around £400 to £1,500 depending on site size, the number of test pits and reporting requirements. The Flood Protection Associates provides quotations based on individual project needs.
Typical cost ranges include:
Single residential test – around £400 to £700.
Multiple test locations – around £700 to £1,200.
Large commercial developments – from approximately £1,200 to £1,500+.
Final costs depend on site access, testing requirements and project complexity.
What Are the Benefits of Percolation Testing?
Percolation Testing provides reliable information for effective drainage design. The Flood Protection Associates supplies accurate infiltration data that supports planning applications and sustainable drainage solutions.
Benefits include:
Accurate soil infiltration measurements
Better drainage system design
Support for planning submissions
Reduced risk of drainage failure
Improved flood risk management
Compliance with drainage design requirements
Reliable testing helps ensure drainage systems are designed using measured site conditions rather than assumptions.
What Regulations Apply to Percolation Testing?
Percolation Testing is commonly undertaken in accordance with recognised UK drainage guidance. The Flood Protection Associates carries out testing that supports planning and drainage requirements where applicable.
Relevant guidance may include:
Building Regulations Approved Document H
BRE Digest 365 for soakaway design
CIRIA SuDS Manual (C753)
National Planning Policy Framework flood risk guidance
Local Planning Authority and Lead Local Flood Authority drainage requirements
Specific requirements vary according to the site and proposed development.
Percolation Testing: Frequently Asked Questions
How Long Does Percolation Testing Take?
Percolation Testing is usually completed within 1 day. Testing on larger sites or projects requiring multiple test pits may take up to 2 days depending on ground conditions.
How Much Does Percolation Testing Cost?
Percolation Testing generally costs between £400 and £1,500 depending on the number of tests, site access and reporting requirements. A project-specific quotation provides the final cost.
Why Is Percolation Testing Important?
Percolation Testing provides measured infiltration rates that engineers use to design soakaways and sustainable drainage systems. Accurate results help reduce the risk of drainage failure and surface water flooding.
Is Percolation Testing Required for Planning Applications?
Many planning authorities require Percolation Testing where soakaways or infiltration drainage systems are proposed. The results demonstrate whether the ground can effectively manage surface water.
How Long Are Percolation Test Results Valid?
Percolation test results are generally suitable while site conditions remain unchanged. If significant excavation, development or changes to ground conditions occur, additional testing may be required.
Get a Free Quote for Percolation Testing
The Flood Protection Associates provides Percolation Testing for residential, commercial and development projects. Contact the team to discuss your project and receive a tailored quotation.
Related Percolation Testing Services
Percolation testing provides the ground infiltration data required for soakaway design, ensuring infiltration systems are designed to suit site conditions.
The results also support SuDS design, helping engineers select the most effective sustainable drainage solution.
Drainage proposals are typically documented within drainage strategy and drainage statements for planning submissions.
Where infiltration alone is insufficient, attenuation tank and storage design can provide additional surface water storage capacity.
Surface water performance is assessed through surface water drainage assessments, ensuring drainage systems perform as intended.
Long-term drainage performance is maintained with SuDS maintenance and management plans, keeping systems operating efficiently.