Essential Pre-Design Requirements for Successful Drainage Projects: A Detailed Guide

Let's dive deep into what you need before starting your drainage design project. Understanding these requirements can save time, prevent costly issues, and ensure project success.

📋 Topographical Survey

A comprehensive topographical survey in DWG format is crucial. This should include:

- Accurate ground levels and contours

- Location of existing drainage features

- Position of trees and structures

- Underground services mapping

- Site boundaries and constraints

- All details referenced to OS National Grid

🔬 Ground Investigation

A thorough ground investigation report reveals:

- Detailed soil composition analysis

- Groundwater level measurements

- Potential contamination assessment

- Soil permeability characteristics

- Subsoil conditions

- Foundation implications

💧 Soakaway Testing

Soakaway testing results provide essential infiltration data:

- Site-specific infiltration rates

- Groundwater monitoring data

- Soil percolation values

- Testing locations and depths

- Seasonal variation considerations

- SuDS feasibility assessment

📐 Site Levels Planning

Proposed levels are critical for effective drainage:

- Finished floor levels

- External ground levels

- Access and pathway gradients

- Threshold details

- Cut and fill requirements

- Surface water flow paths

🏗️ Architecture Plans

Fixed architecture and landscape plans in DWG format should show:

- Building footprints and dimensions

- Hardstanding areas

- Landscaping proposals

- Access routes

- Service corridors

- Future development zones

👷 Foundation Details

Foundation design details and sections must include:

- Foundation types and depths

- Structural loading information

- Below-ground structures

- Service corridor locations

- Construction sequence

- Ground improvement requirements