1. Managing sub surface space –
opportunities and experience
Andrew Ross PhD
Senior Groundwater Specialist
UNESCO, Paris
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2. Benefits of managing sub surface
space
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Cost-effective water storage, reduced evaporative losses
Maintains aquifer levels, offsets depletion
Water quality can be improved, subject to good management
Helps communities adjust to climate variability, maintain food
production
• Can help synchronise environmental water with requirements
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3. Elements of managing sub-surface space: aquifer
storage and recharge
• Physical aspect
– Water to store in an aquifer
– Aquifer where water can be held until users want it
– Means to transfer water to the recharge site and the use site
• Institutional aspect
– People store water underground – a water bank
– They need to have guarantee that they can withdraw water less
proportion to cover leakage and management costs
• Water may be stored underground in two ways
– Infrastructure based: managed aquifer recharge
– Non-infrastructure based: natural recharge: reduction in groundwater
use, land and water management practices
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5. Managed aquifer recharge in the US and Australia
US - over 150 operations, many are commercial.
Examples:
Orange Co – stores 300 GL/yr enough for 2.3 m
people.
Semitropic water bank holds 860 GL, irrigation water
for 140000 acres, dry year reserve for 4.4 m
households.
Between 2007-2010 water banks in Kern Co and
Southern California Supplied 600 GL of dry year
supplies.
Australia – over 30 operations, mostly
experimental &/or small scale
Largest operation, Burdekin delta in Queensland,
average storage and recovery 45 GL/year
Source: Dillon et al 2009
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6. Questions for discussion
• What are the opportunities for managing sub
surface space and its water resources to
achieve better collective outcomes?
• What are the barriers against taking
advantage of these opportunities?
• How can collective action achieve better
management of subsurface resources?
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