1 / 17

The Importance of Surface Water- Groundwater Interaction in Australia by Dr Richard Evans May 2010

The Importance of Surface Water- Groundwater Interaction in Australia by Dr Richard Evans May 2010. i/wcms/110/01/papers/LWA GW SW Interaction 17052010. Groundwater- The Major Water Resource of the World. Approximate Use 50% Groundwater 50% Surface water

regis
Download Presentation

The Importance of Surface Water- Groundwater Interaction in Australia by Dr Richard Evans May 2010

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Importance of Surface Water- Groundwater Interaction in Australia by Dr Richard Evans May 2010 i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  2. Groundwater-The Major Water Resource of the World Approximate Use • 50% Groundwater • 50% Surface water But about half of surface water is actually Groundwater i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  3. The World’s Fresh Water i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  4. LWRRDC- GroundwaterProgram What has the LWRRDC/LWA Groundwater Program Achieved? • A very small investment • Dryland salinity • Impact of grassed leguminous pastures on groundwater quality • Diffuse sources on groundwater quality • Introduced GDE’s • Raised profile of SW-GW interaction • Groundwater balances of Australia • Vegetation water use • Initial investment in the Centre for Groundwater Studies i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  5. Types of GDEs i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  6. i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  7. Response of Ecosystem Health to Water Regime i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  8. Groundwater-Surface Water Interaction i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  9. General Principles of SW-GW Interaction • Groundwater and surface water are usually interconnected and interchangeable • GW becomes SW, and SW becomes GW • Not recognised • Results in double accounting and double allocation • Not recognised because of long time lag • Commonly decades 4. In some parts of Australia we have capped SW, but still drill a bore near a river and call it GW and get it licensed i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  10. i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  11. Significance of Double Accounting in Australia 08/09: • Estimated use is 10,000 GL/yr (2,000 GL in MDB) • Double accounting is estimated at 25 to 50% of this use i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  12. When is Double Accounting Important? • Relative to mean annual stream flow, double accounting is usually very small • However double accounting is often important during the flow times of the year and during drought • Hence it is important for low flow planning- ie. environmental flow, drought water supply and security of supply to surface water users i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  13. Surface Water/ Ground Water Interaction-Where is Australia at? • Fundamental concepts still not grasped by key people eg. general denial • Drought has disguised effects of groundwater pumping on stream flow • Virtual complete absence of integral surface water and groundwater management across Australia • National Water Plan (announced January 2007) proposes groundwater to be included in new MDB Cap -silence, and a surge in new licence applications i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  14. Impact of the Fellowship Influential in: • National Policy- NWC Second Bi Annual Assessment • MDB SDL • State Water Resource Assessments • Local licensing approvals and conditions But • Still challenged by many farmers, politicians • Sceptics alive and fighting i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  15. The Future Big Questions in GroundwaterR&D in Australia Energy/Water Nexus in groundwater – honest economies of groundwater compared to the alternatives Aquitard Behaviour- Kv and storage- focus not on aquifers, but more on the limiting factor, the aquitards Recharge change due to climate change– complex and counter intuitive Managed aquifer recharge i/wcms/110/01/papers/LWA GW SW Interaction 17052010

  16. Urban Groundwater Ignored Broad Range of Issues:- • Excessive recharge • Flooding basements • Brackish groundwater intrusion into sewers • Managed aquifer recharge • Urban stormwater harvesting – no allocation ? Or prioritise • Lack of Bank storage schemes • Honest economies – including externalities • S & D use ignored • Over exploited coastal systems and sea water intrusion i/wcms/110/01/papers/LWA GW SW Interaction 17025010

  17. The Overriding Process is Evapotranspiration • Controls GDE, SW-GW Interactions, recharge and discharge change • Ultimately water management in the world will become ET management (Consumption based, not supply based) i/wcms/110/01/papers/LWA GW SW Interaction 17052010

More Related