From legacy to load: how pumped hydro is redefining asset closure

Across the globe, industries are facing mounting pressure to responsibly retire aging infrastructure - from mines and smelters to manufacturing plants and power stations. The complexity is increasing: regulatory scrutiny is tightening, communities are demanding long-term accountability, and investors are linking closure performance to environmental, social and governance (ESG) outcomes.

Yet with the right strategy, closure can become more than risk mitigation. It can be an enabler of transformation, especially when integrated early in the asset lifecycle. GHD’s Asset Transition Framework helps organisations embed closure thinking from the outset, aligning with long-term goals such as emissions reduction, community revitalisation, and sustainable land use.

This is where pumped hydro comes in.

Applying this framework through a hydropower lens reveals several key considerations:

1. Strategy

• Align closure with long-term business, sustainability, and decarbonisation goals
• Define a forward-looking vision for the site beyond its operational life
• Identify pathways for redevelopment, reuse, or regeneration
• At the planning and pre-approval level, GHD has supported clients by embedding PHES as a strategic element of closure planning for a number of coal and hard rock sites

2. Market and customer relevance

• Assess future demand for industrial land, clean energy, and logistics hubs
• Avoid stranded value by positioning assets for market-aligned transformation
• Leverage closure as an entry point into new sectors or business models

3. Technology and partnerships

• Integrate advanced monitoring, remediation, and reuse technologies
• Form cross-sector alliances with governments, NGOs, Indigenous groups, and private partners
• Accelerate scale and capability through collaboration

4. Community and stakeholder engagement

• Conduct early and ongoing consultation with local communities and Indigenous custodians, address social impact, cultural values, and land use preferences
• Workforce planning and timing with mine closure, retaining local skilled labour, retraining
• Build trust through transparent, place-based planning that includes ambitious habitat restoration - aiming, where possible, to return sites to pre-mining or even pre-settlement ecological conditions

5. Future workforce planning

• Design for local reskilling, retraining, and job creation opportunities
• Support economic continuity in regions affected by asset closure
• Embed social equity and employment transition into project delivery

As the clean energy transition accelerates, energy storage is emerging as a cornerstone of grid reliability. Pumped hydro - using water to store and dispatch electricity - is one of the most proven, long-duration storage technologies available. It balances intermittent renewable generation, supports frequency control, and offers inertia for stable power systems.

But the real breakthrough lies in its synergy with asset closure. Many legacy mining and industrial sites are ideal for pumped hydro redevelopment. They already possess the physical characteristics - elevation changes, reservoirs, and transmission access - that pumped hydro requires. By repurposing these sites, developers can reduce costs, minimise environmental disturbance, and accelerate timelines.

GHD’s work on the Kidston Clean Energy Hub in Queensland exemplifies this transition in action. In partnership with Mott MacDonald and led by Genex Power, the project is transforming a decommissioned gold mine into Australia’s first new pumped hydro scheme in over 40 years.

The project reuses two existing mine pits as upper and lower reservoirs, avoiding major dam construction and associated impacts. Solar energy is used to pump water uphill during daylight hours, which is then released through turbines to provide dispatchable electricity at peak times. When completed, Kidston will offer 250 MW of generation capacity and 2,000 MWh of storage, forming a key element in Queensland’s clean energy plan.

GHD led the design and construction supervision, including tunnels, shafts, a 6 km dam wall, and a 132kV substation. The project also delivered regional benefits by creating jobs, attracting investment, and helping a remote community chart a path beyond mining.

In New South Wales, Yancoal’s Stratford Renewable Energy Hub offers another blueprint for closure-led energy transformation. As the Stratford Mining Complex nears its end-of-life, GHD is helping Yancoal redevelop the site into a clean energy facility that integrates pumped hydro (3,600 MWh) and a 320 MW solar farm.

This initiative aligns closure and rehabilitation timelines with the development of new infrastructure. GHD’s involvement spans site identification, pre-feasibility and feasibility stages, geotechnical studies, environmental assessments, and grid connection design. By leveraging disturbed land and existing reservoirs, the project avoids greenfield development and ensures continuity of regional employment.

It’s a model of how energy, environment, and economics can intersect through strategic closure planning.

Further afield in Alberta, Canada, the Tent Mountain Renewable Energy Complex is redefining what’s possible for legacy coal sites. Spearheaded by Evolve Power, with GHD as technical advisor, the project combines pumped hydro, wind power, and green hydrogen production on a single repurposed site.

Here, the natural topography is used to enable pumped storage, while adjacent wind generation powers a proposed 100 MW hydrogen facility. GHD’s integrated feasibility and design work helped establish a compelling business case and regulatory pathway. The result is a scalable, multi-technology solution that supports Alberta’s energy diversification and positions Tent Mountain as a hub for clean exports.

While pumped hydro solves engineering challenges, it also addresses social and economic needs. Legacy sites are often located in resource-dependent regions, where closure can pose serious disruption to local livelihoods. Projects like Kidston and Stratford offer more than megawatts - they offer continuity.

This means actively involving local populations in shaping their future by providing clear pathways for employment in new or revamped hydro industries, tailoring retraining programs to meet community needs, and ensuring local voices are central to long-term land use and resource planning. Early and sustained engagement with Indigenous groups, stakeholders, and regional and local governments ensures that new developments respect cultural heritage and deliver lasting social value.

Governments are increasingly recognising the value of PHES on legacy land. In Australia, closure planning is now integrating into permitting processes, with financial provisioning and monitoring required from project inception. In Canada and the US, incentives for storage and repurposing brownfield land are gaining traction, aligned with broader decarbonisation and energy justice goals.

In some jurisdictions, PHES is also emerging as a viable alternative to traditional dam infrastructure, particularly in regions where Indigenous groups have called for dam removal. With significantly smaller reservoirs, PHES can offer strong investment returns while supporting full fish passage and ecological restoration, making it a more culturally and environmentally acceptable option.

GHD is working alongside clients to navigate these evolving regulatory environments, ensuring pumped hydro projects align with both closure obligations and emerging clean energy mandates.

Pumped hydro is helping redefine what it means to close an asset. No longer the end of a story, closure becomes a platform for resilience - technically, environmentally, and socially. As more legacy sites reach the end of their operational life, the opportunity to turn them into clean energy infrastructure has never been greater.

With deep expertise across hydropower, closure planning, and environmental stewardship, GHD is uniquely positioned to lead this transformation. By collaborating early, thinking holistically, and designing with purpose, we can help clients and communities close well - and build better.