GDMS Surveys

(formerly DDMS & HADDMS)

Geospatial Drainage Management System

What is a GDMS Survey?

A GDMS survey (Geospatial Drainage Management System) is the current standard for high-spec drainage data capture and asset management across UK infrastructure projects.

Previously known as DDMS and HADDMS, GDMS surveys represent the latest evolution in compliant drainage inspection, reporting, and digital asset management.

GDMS surveys are typically carried out to assess the condition, performance, and structural integrity of drainage systems, identifying issues such as blockages, structural defects, flooding risks, capacity constraints, and asset connectivity.

Using advanced CCTV robotic crawler systems and Wincan software, our engineers capture high-resolution internal imagery of drainage networks.

All defects are coded in line with current Highways England compliance standards, including CD535 and CS551, ensuring accurate, structured, and auditable reporting.

What Does a GDMS Survey Deliver?

At NRC WWS, we deliver fully compliant GDMS surveys for complex, large-scale drainage networks.

Our surveys are designed to integrate seamlessly into asset management systems, supporting long-term infrastructure planning, maintenance, and compliance reporting.

Each survey provides a complete, data-rich picture of your drainage infrastructure, including:

Our Range of GDMS Services

We provide a full suite of GDMS-compliant drainage survey solutions.

All surveys are delivered using state-of-the-art equipment and fully trained in-house engineers, ensuring accuracy, consistency, and compliance at every stage.

GDMS Surveys for Drainage Asset Control & Compliance

For highways, infrastructure, and large-scale commercial environments, GDMS surveys provide the critical data needed to manage risk, maintain compliance, and protect asset performance at scale.

Network Visibility & Data Accuracy
Gain a complete view of drainage assets, with structured data aligned to CS551 and CD535 for consistent reporting across projects.
Proactive Risk Identification
Detect defects, blockages, and structural issues early, reducing the likelihood of failures, emergency works, and unplanned disruption.
Compliance with Current Standards
Meet the latest UK highways and infrastructure requirements, and transition seamlessly from legacy DDMS and HADDMS to fully compliant GDMS reporting.
Smarter Asset Management
Use reliable drainage data to prioritise maintenance, allocate budget effectively, and extend the lifecycle of critical infrastructure.
Better Commercial Decision-Making
Support stakeholders with clear, auditable data, enabling faster approvals, reduced uncertainty, and more confident project delivery.

Our Clients

Why Choose NRC for GDMS Surveys (DDMS / HADDMS)

When delivering GDMS-compliant drainage surveys, accuracy, consistency, and capability at scale are critical.

NRC provide a fully integrated service built around technical expertise, advanced equipment & nationwide delivery.

End-to-End Survey Capability
From initial inspection through to structured data delivery, we provide a complete GDMS survey solution tailored to complex drainage networks.
Advanced Survey Technology
We operate industry-leading CCTV systems, laser profiling equipment, and Wincan reporting software to capture high-resolution, fully compliant drainage data.
Specialist In-House Engineers
Our teams are fully trained in GDMS standards, including CS551 and CD535, ensuring consistent defect coding, reporting accuracy, and reliable outputs across all projects.
Proven Delivery at Scale
With a nationwide fleet and over 100+ drainage specialists, we deliver GDMS surveys across highways, infrastructure, and large commercial environments safely, efficiently, and with low disruption.

"We have worked with the team at NRC and before that Cleanline for many years now and find the service provided reliable, accurate, safe and competitive. NRC is our 1st port of call for all things CCTV, Sewer Cleaning and Lining, and intrusive and non-intrusive survey works."

"NRC have worked on our Highways contracts for last 3 years, they have always been professional, delivering a high standard of service using DDMS and I would highly recommend them."

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Drainage Services

NRC WWS - Nationwide Drainage Contractors

For over two decades, NRC has been a leader in providing commercial drainage services to the commercial, industrial, highways, civil, local authorities, and rail sectors.

We are recognised for our unmatched expertise across these sectors in the North West & Nationwide, including Wirral, Liverpool, Chester, Manchester, Warrington, Lancashire, North Wales, Wrexham, and support nationwide contracts on request.