Get Started
NHRR Source Protection Zone

NHRR Source Protection Zone

Groundwater Protection & Drainage Strategy in SPZ

Location

Lincolnshire

Project

North Hykeham Relief Road – Catchment 10

Focus

Groundwater Protection in SPZ2

Status
  • Completed

Challenges & Approach

The Challenge

A section of the NHRR falls within a Source Protection Zone 2 (SPZ2), where infiltration drainage posed a risk to public water supplies. The goal was to allow sustainable drainage without compromising groundwater quality.

Our Approach

Courous Ltd developed a multi-layered pollution mitigation strategy aligned with HEWRAT, LA113, and CIRIA SuDS guidance.

Key Measures:

  • 🌀 Vortex separators for removing hydrocarbons and metals

  • 🌱 Sediment forebay and grass channels for natural filtration

  • 🛑 Penstock valves for emergency shut-off during spills

  • 📊 HEWRAT and spillage risk assessments demonstrating compliance

  • 🧪 Ground investigation confirming low permeability and no groundwater within 10m

Outcome

  • Infiltration drainage approved within SPZ2
  • Pollution risks mitigated to “acceptably low” levels
  • Fully compliant with EA and groundwater protection policies
  • Sustainable, maintainable, and resilient design

This project highlights Courous Ltd’s capability to deliver compliant drainage solutions in sensitive groundwater zones, balancing environmental protection with practical design.