Australia’s Dr. Peter Coombes champions “Transitioning Drainage into Urban Water Cycle Management”

Note to Reader:

In May 2015, Dr. Peter Coombes was one of three Keynote Speakers at the Stormwater Victoria Conference. The conference theme was ‘Climate Change – Does it Matter Anymore?’. The conference focus was on the impacts of climate change and the mitigation measures that will be required to deal with those impacts. This presentation was the first in a series of presentations in 2015 by Dr. Coombes about Transitioning Drainage into Urban Water Cycle Management.


Towards Integration of Land and Water Planning

“Urban stormwater management is described in Australian Rainfall and Runoff (ARR) as the hydraulic design of urban drainage. The current approach to urban drainage is based on conveyance of stormwater runoff to meet minor and major design objectives to mitigate nuisance, and avoid damage to property and loss of life,” stated Dr. Peter Coombes.

“There have been many changes in our approach to urban water management in Australia since the establishment of the centralised and separate water supply, Peter Coombes_2015_original_trimmed2_500pstormwater and wastewater paradigm in the 1800s. Urban water management has especially evolved over the last two decades to include protection of waterways, mitigation of stormwater quality, Water Sensitive Urban Design (WSUD) and Integrated Water Cycle Management (IWCM) approaches. Although these approaches are relatively new, they have wide adoption and support in legislation and policies for water management throughout Australia.”

“This presentation discussed the need to integrate evolving approaches to urban water cycle management into guidelines for urban stormwater management.”

“There is a need to expand the guidance provided by ARR to accommodate contemporary and integrated approaches to urban water cycle management which starts with the integration of land and water planning across time horizons and spatial scales. This guidance must include advances in urban water cycle management, and be cognisant for the likely advances in science and professional practice over the next 30 years.”

“An appropriate policy framework is also required to integrate land and water management with design processes at all spatial scales from local to regional. This framework also needs to apply to urban renewal and asset renewal or replacement choices. Appropriate design methods for integrated solutions are likely to include variability of real rainfall events by using continuous simulation, Monte Carlo frameworks and techniques that consider complete storms, frequency of rainfall volumes and the spatial variability of events.”

Schematic of the connectivity of urban water networks

Schematic of the connectivity of urban water networks

What is Australian Rainfall and Runoff?

Australian Rainfall and Runoff (ARR) is a national guideline for the estimation of design flood characteristics in Australia. It is published by Engineers Australia. The 1987/1999 edition has reportedly served the industry well but is now being revised. The revision process includes 21 research projects, which have been designed to fill knowledge gaps that have arisen since the 1987 edition was published.

The research projects allow industry to comment on the technical direction before the new edition of the ARR guideline is released.

Keeping ARR up-to-date is an important component in the provision of reliable (robust) estimates of flood risk. This ensures that development does not occur in high risk areas and that infrastructure is appropriately designed.

To Learn More:

To download a copy of the paper presented by Dr. Peter Coombes in October 2015 at the WSUD Conference, click on Transitioning Drainage into Urban Water Cycle Management.

“The need to consider integrated approaches for future urban water management means that our current approaches of separate analyses of water quantity, water quality, potable water and wastewater systems are no longer the best approach. Integrated systems have the capacity to produce solutions that respond to multiple objectives including economic, social and environmental criteria,” cpncludes Dr. Coombes.

“ARR therefore needs to promote methods that bring these elements together in a combined analysis approach. This will require strong leadership from the water industry and a recognition of the need to collaborate across science, engineering, planning and sociological sectors in order to maximise the opportunities for implementing integrated solutions.”