Skip to main content

EOFY SALE! Get up to 50% off New DRAINS Subscriptions, Licences, Upgrades & Training!  

End of Financial Year Sale Background




Up to 50% off new drains subscriptions,
Up to 50% off new drains subscriptions, licences, upgrades and training!
licences, upgrades & training!


with DRAINS Training Workshops

Earn 40% credit towards a new or upgraded DRAINS licence when you attend any DRAINS In-Person Workshop.


Sydney: 6-8 Aug 2024
Brisbane: 3-5 Sep 2024
Melbourne: 22-24 Oct 2024
Sydney: 26-28 Nov 2024
Adelaide: Feb/March 2025
Perth: Feb/March 2025

Model Consultations


Book an online

DRAINS Model Consultation

Monitor icon

One-on-one DRAINS Modelling Support

Person icon

Work with a qualified specialist engineer

Cursor Mouse icon

Instant online bookings for ultimate flexibility



We design, develop and support Australia's leading modelling and analysis software for stormwater and drainage systems.

Australian-owned and operated since 1998.

previous arrow
next arrow

DRAINS: Australia's leading Stormwater Drainage System design and analysis software.

Developed and supported locally, DRAINS is Australia’s most trusted and widely-accepted modelling and analysis software for stormwater and drainage systems.

Celebrating its 25th year, DRAINS allows users to design and analyse stormwater drainage systems, produce summary graphs and tables, and create pipe long-section drawings.

DRAINS also incorporates the latest Australian Rainfall and Runoff (AR&R) guidelines.

  • Draw drainage system components such as sub-catchments, pits, pipes, detention basins, channels and overflow routes.
  • Use several available hydrological models recommended by the AR&R guidelines.
  • Solve the full unsteady flow equations in pipes, channels and overflow routes.

First software to incorporate AR&R Design Procedures & BOM 2016 IFDs (January 2017)


AR&R Compliant

First software to incorporate the new Australian Rainfall and Runoff (AR&R) design procedures.


Use IL-CL (the AR&R preferred model), Horton ILSAX, Rational & Extended Rational Method models, and a Storage Network Routing Module that includes RORB, RAFTS and WBNM.


Solve the full unsteady flow equations, which is useful for analysing complex surface flooding situations where storage or backwater effects occur in overflow routes, or when splitting surface flows in multiple directions.

DRAINS Versions

We offer multiple versions of DRAINS.

DRAINS Demo, DRAINS and DRAINS Viewer all include the Australian Rainfall and Runoffs’ (AR&R) Initial Loss – Continuing Loss (IL-CL), Horton (ILSAX) and Rational & Extended Rational Method hydrological models, and are capable of analysing AR&R temporal patterns and design procedures.

The Full Unsteady Hydraulic Model, Storage Network Routing Models (RORB, RAFTS & WBNM hydrological models) and the GIS Module are also included.

DRAINS Licensing

DRAINS is available in various licences and options.

Here are some things to consider when planning to purchase a new licence.

Explore LicensingView FAQs

Number of Links

Most licences are available in 5, 20, 50 or Unlimited Links.


Simple recurring payments. Select 30-Day or Annual Terms.

Perpetual Softlock

Access DRAINS without a USB on a single registered device.

Perpetual USB

Pay upfront once, then pay yearly Maintenance thereafter.


Shared access between PCs via Subscription or Perpetual Licence.

All Features

All new licences include the full suite of current DRAINS functionality.

Included Modules

Three additional modules are included with new DRAINS licences.

Storage Network Routing Module

The Storage Network Routing Module adds the RORB, RAFTS and WBNM storage routing hydrological models, useful when modelling large urban or rural sub-catchment areas where estimating the time of concentration with time area routing might be difficult.

DRAINS RAFTS does not rely on XP Rafts and is not affected by the discontinuation of XP Rafts by Innovyze.

Request a Quote

GIS Module

The GIS Module is useful where you need to interface with GIS systems that support ESRI shapefiles or Mapinfo MID/MIF files. This module allows transfer of data and results between DRAINS and GIS.

Request a Quote

Rational + Extended Rational Method Hydrological Module

The Rational + Extended Rational Method Hydrological Module adds the ability to model the rational method procedures with ARR87, ARR2019 and AS3500.3.

The Extended Rational Method allows users to produce hydrographs to improve detention basin analysis and utilise the full unsteady hydraulic model. This is achieved by including temporal patterns as part of the analysis and including the ability to model ensembles of storms from ARR2019.

Request a Quote

Maintenance & Support

Request a QuoteLicensing

In-Person & Online Training

In-Person WorkshopsOnline Training

Recent News

March 24, 2024 in DRAINS, News

Message from the CEO

This month marks two years for me as CEO of Watercom, and I am enthusiastic about our accomplishments and the solid groundwork we have established. Dr Benjamin Kus, CEO of Watercom Since 2022, we have strengthened our capabilities by integrating new…
Read More
January 15, 2024 in News

Draft Updates to ARR Guidelines

Draft updates to the 'Climate Change Considerations' chapter in Australian Rainfall & Runoff (ARR) Guidelines are now available for review. Feedback is being sought on the draft guiding principles and key considerations to update the Climate Change Considerations chapter of…
Read More
January 11, 2024 in News

Welcome to the team, Jonathan Klaric!

We're excited to welcome Jonathan Klaric into the team as our Senior Software Solutions Developer! Welcome to the team, Jonathan Klaric! Jon brings over 10 years of experience to Watercom, specialising in mathematical & statistical modelling, and hydrologic & hydraulic…
Read More
November 16, 2023 in News

Hydrology & Water Resources Symposium (HWRS) 2023

We had a fantastic time at the Hydrology & Water Resources Symposium (HWRS 2023) – a great opportunity to meet so many DRAINS users in person! Across three packed days from 13-15 November 2023, the Engineers Australia event covered a…
Read More

For further information on our products, licensing options, updates, support and/or training, please get in touch.