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Unconventional Water Resources: From The Fringes To The Mainstream

EBENSBURG PA, United States

OOSKAnews Voices is a series of guest columns written by senior participants in different parts of the international water community. In this article, Renee Martin-Nagle examines unconventional water resources (UWR). Martin-Nagle is President and CEO of A Ripple Effect plc, Treasurer of the International Water Resources Association and a Visiting Scholar at the Environmental Law Institute. She holds two undergraduate degrees and three law degrees, including a PhD in Law from the University of Strathclyde in Glasgow, Scotland. Her book Governance of Offshore Freshwater Resources was published by Brill Nijhoff in early 2020.

With predictions of dire consequences for humans and other species due to an impending global freshwater scarcity, attention is turning to sources of freshwater that have until now been viewed as unconventional. On 5 June 2020, UN-Water published an Analytical Brief that examines in detail several types of unconventional water resources (UWR), some of which have been utilised for years while others await catalysing circumstances:

Produced by seventeen cross-disciplinary collaborators from across the globe, the brief also explores non-technical issues such as linkages to the Sustainable Development Goals, governance, policies, financial issues, environmental and ecosystem impacts, education, capacity building, community involvement and gender mainstreaming. The concluding discussion includes key barriers and response options as well as suggestions for creating an enabling environment to move forward with development and utilization of UWR. This article lists the types of UWR presented in the brief and summarize some of the findings. 
 
The only common factor linking the various forms of UWR is the fact that they all contain freshwater, for UWR can be found underground, on the surface and in the atmosphere and can be found as liquid, ice and vapor. In the deep underground are fossil aquifers sheltering freshwater that was emplaced thousands to millions of years ago. While land-based fossil aquifers currently support domestic and agricultural needs in northern Africa, Brazil, China and the US, seabed fossil aquifers have only recently attracted scientific attention and have not been utilized for any purpose. The enormous volumes of freshwater in seabed fossil aquifers can sate many human needs, but their development is impeded by the significant capital expenditures required to access, extract and transport their liquid treasures. Some fossil aquifers, such as the Nubian Sandstone Aquifer System, hold pristinely fresh water, but others, particularly those in seabeds further from the shoreline, produce slightly brackish water that must be treated prior to use.
 
UWR on the surface of the land include recycled municipal wastewater and agricultural drainage water, while the atmosphere yields additional UWR, such as fog harvesting, micro-scale rainwater harvesting, and rain enhancement through cloud seeding. Finally, the oceans can provide several forms of UWR: desalinated seawater, ballast water from ships and icebergs that are towed from polar regions to water scarce areas in warmer climates. These unconventional sources of freshwater do not provide the volumes found in deep fossil aquifers, but in many cases they are more accessible and thus less expensive to develop. However, some forms of UWR may produce surprising co-benefits -- recycling municipal wastewater not only reduces the need for conventional water resource, it can also be a source of freshwater, nutrients, precious metals, and energy.

In calling for international, regional, transboundary and country-level collaboration, the brief recommends an eight-point approach to development of UWR:

  • Determine whether UWR have the potential to supplement current water supplies in water-scarce areas;
  • Encourage policymakers and water management agencies in nations and river basins experiencing water scarcity to prioritize UWR in their agendas and policies and develop supportive action plans;
  • Support integrated approaches by strengthening institutions, promoting collaboration and clarifying roles and responsibilities of water professionals and institutions;
  • Facilitate data-driven economic decisions that weigh the consequences of action and inaction by investigating innovative financing mechanisms, alternative options, and economic and social costs;
  • Engage in capacity building to enhance understanding of the practical implications of utilizing UWR, including the environmental, ecosystem, and economic tradeoffs;
  • Promote private sector investment in UWR projects;
  • Involve communities in community-based projects while integrating gender mainstreaming objectives and processes;
  • Support increased scientific funding for UWR, especially in water-scarce regions.

Since utilisation of many of the UWR is in its infancy, varying issues need to be explored and analyzed, and, given that the forms of UWR are so different, defining a single set of guidelines may be impossible. For example, use of recycled municipal wastewater is purely a local matter, fog harvesting may have local and transboundary impacts, and towing an iceberg through areas beyond national jurisdiction may have no transboundary impacts at all. Thus, a one-size-fits-all approach to adjudging impacts would not be appropriate or practical. Questions will also arise about which governing regimes should apply – domestic, regional or international – and the answer will probably depend on the type and location of the UWR. Cultural issues must also be considered; in some countries recycled wastewater is considered unappealing, and fog harvesting raises apprehensions in some parts of the world. The role of international water law principles must be investigated to decide whether principles such as equitable and reasonable utilisation and no significant transboundary harm apply to all UWR, to some or to none.

Some UWR will have greater environmental impacts than others. For example, desalination contributes to carbon emissions through energy requirements and to coastal degradation through brine deposits and entrapment of marine organisms in the intake pipes. Rain and fog harvesting and cloud seeding could impact precipitation patterns, causing local and regional freshwater imbalances. Ballast water can carry hidden organisms and microorganisms that could become invasive species in their new locations.

Perhaps more fundamentally, policymakers must determine the balance to be struck between conventional water resources and UWR. Should conventional water resources always be utilized first, with UWR considered as reserves? Or should utilization of UWR be primary whenever possible so that conventional water resources may serve ecosystems? Where UWR are non-renewable, as with fossil aquifers, should they be left in place for future generations? How would decisions be made that meeting current needs is more urgent than providing for the needs of future generations?

As freshwater scarcity tightens its grip on the biome, UWR will move from the fringes to the mainstream of water resources, especially in water-scarce areas that have access to UWR. In preparation for that eventuality, policymakers and scientists alike would be wise to invest time, attention and financial resources to understand and evaluate the contribution that UWR can make to meeting future water demands.

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