Leading the way in integrated water management

Around the world, Integrated Water Management (IWM) is increasingly sought as a sustainable approach to long-term planning of water cycle services.

In recent years, we’ve seen water industry proponents collaborating on a number of planning studies to evaluate the benefits and costs of IWM compared to business-as-usual approaches. IWM planning offers a holistic and inclusive approach to water sector planning, embracing an integrated and collaborative planning process with the goal of ensuring a diversified, sustainable, and resilient water future, with a strong emphasis on water conservation.

In Australia, GHD is leading the way in IWM, particularly with respect to our innovative approaches to both local and city scale strategy development. This includes the use of geospatial analysis to identify, analyse, and assess alternative and decentralised options across large geographic areas, and our servicing strategies and concept designs for major greenfield, brownfield and infill developments.

From Australia to the USA

According to Ryan Brotchie, Service Line Leader – IWM for Australia, “A few years ago, we completed some iconic projects to help inform Sydney and Melbourne’s approach to integrated water planning.

“The success of these projects helped kick-start a broader interest in IWM and we are now working with a range of clients within Australia and overseas.

“For example, we’re now working with the City of Austin in Texas, USA, to provide inputs to its 100 year ‘Water Forward’ Integrated Water Resources Plan (IWRP) Plan, which will evaluate the city's water needs, and examine and make recommendations regarding future water planning. This includes the use of recycled wastewater, greywater, stormwater and rainwater implemented at both the building and community scale.”

Back in Australia, GHD has recently completed two IWM Servicing Strategies for major redevelopment sites in Melbourne – Fishermans Bend and the East Werribee Employment Precinct.

Ryan explains, “The strategy for Fishermans Bend Urban Renewal Area, next to Melbourne’s CBD, included a local sewer mining plant to enable delayed augmentations to the water transfer network, and multi-function rainwater tanks within buildings, which would provide internal dual water supply and a flood mitigation function. The concept design for the East Werribee Employment Precinct was for a ‘water neutral’ development, with a multi-purpose lake system and managed aquifer recharge for harvesting and reuse of stormwater (to dual supply in short term and potable supply in long term), as well as use of recycled water.”

Further to this, we have undertaken a review of 15 IWM planning studies for Melbourne Water where we explored and distilled the lessons learnt from a broad range of local, regional, and city-scale studies related to alternative water supply, wastewater management, stormwater management and drainage across Greater Melbourne, to a planning horizon of 2050.

Learnings from this project have been shared widely at industry conferences, including OzWater’16, the Australian Water Association’s annual conference, and WEFTEC16, the US-based Water Environment Federation’s Annual Technical Exhibition and Conference, together with the Water Environment Federation’s Great Water Cities Summit 2016.

“Building on our experience in Australia – one of the most arid regions in the world – GHD is stepping up our capabilities in IWM in California and other parts of the USA,” explains Ted Whiton, Service Line Leader – IWM for North America. “Projects that involve aquifer storage and recovery, indirect potable reuse, as well as a range of local and decentralised scale options, will become more common in the coming years as our clients look for ways to better address variability in water demand and supply.”

Planning for a deeply uncertain future

One of the emerging issues cities around the world face is how best to plan for the future given the deep uncertainties in not only climate change but also population growth, technological advancement and disruption, socio-economic conditions and community preferences.

Building on recommendations in the IWM Review, we explored best practice approaches to planning for uncertainty. Ryan says, “We found that a combination of scenario planning and adaptive pathway planning could be particularly useful in helping organisations develop their long term plans and strategies across the water sector. The adaptive pathways approach, first applied in the Thames Estuary 2100 Plan, can lead to strategies that are 'robust' because option pathways are tested against multiple plausible futures and 'flexible' because a diverse range of option pathways are considered to avoid 'lock-in' and maladaptation if the future unfolds differently than expected.

“The approach is valuable because it helps develop short and medium term actions in the context of a long-term strategic vision and can identify the potential need for transformational change.”