Dulwich Surface water drainage assessment

Lisa Davies

Project Background

A property owner contacted H Fraser Consulting Ltd following extensive renovations in a neighbouring garden. They were experiencing flooding and plant die-back in their own garden and wanted a professional assessment to determine the cause and potential solutions.

The goal was to provide a professional opinion on the source of flooding and waterlogging, and recommend effective hydrology and drainage solutions to prevent further damage.

Work Undertaken

  • Desk Study – Reviewing site data and local hydrology conditions.
  • Site Visit – Inspecting the affected garden and neighbouring property.
  • Assessment – Analysing flooding patterns and water movement.
  • Reporting – Providing detailed findings with recommended drainage interventions.

Findings

The investigation revealed that excess irrigation water from the neighbouring garden was causing flooding. Key observations included:

  • Video footage showed a strong morning flow under the shared fence, indicating automatic irrigation.
  • Flow rates were much higher than natural groundwater movement through the London Clay substrate.
  • The raised neighbouring garden caused water to percolate vertically, then move laterally into the affected garden.

Recommendations & Solutions

H Fraser Consulting proposed practical hydrology and drainage solutions:

  1. Reduce watering in the neighbouring garden and monitor the affected property to ensure flooding ceased.
  2. Install a boundary drain to manage excess water and direct it safely away from the property.

How H Fraser Consulting Can Help

H Fraser Consulting provides expert hydrology and drainage consultancy for both residential and commercial projects. Our services include:

  • Flood risk assessment and waterlogging analysis
  • Surface water and drainage solutions, including boundary drains and sustainable water management
  • Hydraulic modelling to predict water movement and prevent future flooding
  • Practical, site-specific recommendations to protect gardens, landscapes, and property

By combining technical expertise with practical solutions, H Fraser Consulting ensures that water management issues are effectively addressed, protecting your property from flooding and damage. Contact us today to speak with a flood and drainage consultant.