Why is a Topographical Survey Crucial for Your Drainage Design?

As drainage design experts, there’s one question we’re asked frequently: “Why do we need a topographical survey for every project?”

Here’s why it’s non-negotiable 👇

1. Gravity is Your Best Friend

• Drainage systems rely on gravity for efficient water flow

• Accurate ground levels ensure proper pipe gradients

• Prevents costly design modifications during construction

2. Technical Precision Matters

• Water authorities require specific gradients:

 – 1:80 for foul drainage

 – 1:100 for surface water

• Connects seamlessly to existing infrastructure

• Ensures compliance with local regulations

3. What We Need in Your Survey

• DWG and PDF formats

• OS National Grid referenced

• Spot levels across the site

• Existing features and services

• Current drainage infrastructure

Pro Tip: A proper topographical survey isn’t an extra cost – it’s an investment that prevents expensive mistakes and delays during construction.