ross managing sub surface spacev2
TRANSCRIPT
Managing sub surface space – opportunities and experience
Andrew Ross PhDSenior Groundwater Specialist
UNESCO, Paris
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Benefits of managing sub surface space
• 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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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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Examples of managed aquifer recharge
Managed aquifer recharge in the US and Australia
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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
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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