Conventional water provisioning approaches relying on precipitation, river runoff and easily accessible groundwater are overexploited and insufficient to meet growing freshwater demand in water-scarce areas. Therefore the “world needs to enter a new era of water management where the barriers to efficient water management gradually fade and where unconventional water resources in all forms are monitored, digitized, accounted for”, the policy brief states.
What are unconventional water resources?
- Key unconventional water resources include, but are not limited to, the following:
- Atmospheric moisture harvesting such as cloud seeding and fog water collection;
- Micro-scale capture of rainwater where it could otherwise evaporate;
- Groundwater confined in onshore deep geological formations or in offshore aquifers;
- Water from urban areas including municipal wastewater and stormwater;
- Residual water from agriculture, such as agricultural drainage water;
- Ballast water held in tanks and cargo holds of ships to increase stability during transit;
- Icebergs collected from arctic regions and transported to water-scarce areas; and
- Desalinated seawater and brackish groundwater.
The volumes of some unconventional water resources such as municipal wastewater and desalinated water are known, for others broader estimates are available. However, using these different resources needs different technological approaches as well as political and social engagement – and concepts to finance them.
The UN Water Analytical Brief “Unconvential Water Resources” is here available.