Stormwater Retention & Detention Systems — Compliant, Site-Specific Solutions

Stormwater management is a non-negotiable part of modern building development. DMB Plumbing Group designs and installs retention and detention systems that comply with council requirements, protect downstream infrastructure and are built to last beneath your slab or landscaping — correctly, the first time.

Timeline-aligned installation

Reliable project delivery

Compliance-Focused Work

What Are Retention & Detention Systems?

As Melbourne's urban footprint grows and rainfall events become more intense, councils across Greater Melbourne, Macedon Ranges and Bendigo have introduced strict stormwater management requirements for new developments. Most residential and commercial new builds are now required to install either a detention tank, a retention tank, or both — designed to limit peak stormwater discharge from your site into the public drainage network.

Detention Systems

Detention systems temporarily hold stormwater on-site during heavy rainfall events, then release it slowly into the drainage network at a controlled rate. This reduces peak flows that can cause downstream flooding and infrastructure damage. Detention tanks are typically required by council as a condition of planning permit for new developments — particularly multi-unit sites.

Retention Systems

Retention systems permanently store a specified volume of stormwater on-site — reducing the total volume discharged into the drainage network. Retained water can often be plumbed for reuse in toilet flushing, garden irrigation or other non-potable applications, contributing to your project's WSUD (Water Sensitive Urban Design) compliance.

How DMB Plumbing Approaches Stormwater Compliance

Every council has slightly different requirements — tank sizing, outlet control specifications and documentation formats all vary. DMB Plumbing Group works directly from your drainage engineer's report and the relevant council WSUD guidelines to ensure your system is sized correctly and installed to comply. We coordinate with your civil and drainage engineer, excavation contractor and building surveyor to ensure sign-off is straightforward.

Underground retention and detention tank installation

Tank sizing based on engineer specifications

Outlet control device installation and calibration

Sump and overflow connection

Inspection point installation for council sign-off

Connection to existing drainage network

Rainwater reuse plumbing (toilet flushing / irrigation connections)

5 stars Reviews

Trusted by Builders & Developers Across Victoria

Professional plumbing solutions delivered on time, on scope, and without site delays.

Reliable plumbing partner delivering projects on time, every time.

Michael Carter

Director, Carter Developments

“DMB Plumbing Group handled the full plumbing scope for our multi-unit development in Bendigo. Their coordination with other trades was seamless, and the project stayed on schedule from rough-in through to final fit-off.”

Project Manager

Residential Development

“Reliable, organised and easy to work with. DMB provided clear quoting upfront and delivered exactly as agreed. No delays, no surprises.”

Commercial Builder

Melbourne

“We’ve worked with several plumbing contractors over the years. DMB stands out for communication, compliance documentation and structured project delivery.”

Site Supervisor

Luxury Home Build

“Reliable, organised and easy to work with. DMB provided clear quoting upfront and delivered exactly as agreed. No delays, no surprises.”

Commercial Builder

Melbourne

Precision Plumbing for Luxury Homes

Getting stormwater management wrong is expensive — particularly if the system needs to be excavated and reinstalled after concrete has been poured. DMB Plumbing Group's approach to retention and detention is meticulous: we confirm the engineer's design against site conditions, we check every dimension before backfill, and we document every stage for your building surveyor and council inspector.

We regularly handle stormwater systems on sites across Melbourne's inner east — where existing drainage infrastructure is often undersized and council scrutiny of new development is high — as well as across the Macedon Ranges and Bendigo, where local planning schemes may have specific rural and peri-urban drainage requirements.