Halil Önder Department of Civil Engineering METU Ankara, Turkey 24-Apr-17 Use of Underground Dams in the Sustainable Developement and Management of Groundwater Resources Halil Önder Department of Civil Engineering METU Ankara, Turkey Halil Önder 5. World Water Form Istanbul Halil Önder

Outline objective sustainability of groundwater, goals, strategies underground dams use of underground dams technical effectiveness and performance evaluation discussion and conclusion Halil Önder 5. World Water Form Istanbul

Objective To discuss and demonstrate the use of underground dams in the sustainable developement and management of groundwater resources in rural areas for small communities To draw a conclusion Halil Önder 5. World Water Form Istanbul

Groundwater Sustainability and Goals Definition The groundwater sustainability is defined as development and use of ground water in a manner that can be maintained for an indefinite time to meet both current and future beneficial purposes without causing unacceptable environmental, economic, or social consequences USGS (circular 1186) Goals sustainable long term yields from aquifers effective and efficient use of stored water in aquifers preservation of water quality preservation of water dependent ecosystems -aquatic environments maintenance of base flow integration of groundwater and surface water into a comprehensive natural resource management system Halil Önder 5. World Water Form Istanbul

Management strategies to ensure the sustainability: decrease discharge from groundwater system increase recharge to groundwater system change rates or spatial patterns of groundwater pumpage change the volume of groundwater in storage at different time scales USGS Intelligent tools and innovative approaches to enhance the sustainability of groundwater resources Groundwater Dam is an example Definition: Any structure designed to contain underground flow from a natural aquifer or from an artificial one, built with an impermeable barrier Types: Sub-Surface Dams Sand-Storage Dams Halil Önder 5. World Water Form Istanbul

Types of Sub-Surface Dams a) Clay dike, b) Concrete dam, c) Stone masonry dam, d) Reinforced concrete dam, e) Plastered brick wall, f) Plastic or tarred-felt sheets, g) Corrugated iron, steel, or PVC sheet, h) Injection screen (Nilsson, 1988) Halil Önder 5. World Water Form Istanbul

Types of Sand-Storage Dams a) Concrete sand-storage dam, b) Stone masonry sand-storage dam, c) Gabion sand-storage dam with clay cover, d) Gabion sand-storage dam with clay core, e) Stone-fill concrete sand-storage dam, f) Stone sand-storage dam (Nilsson, 1988) Halil Önder 5. World Water Form Istanbul

Examples Halil Önder 5. World Water Form Istanbul

Characteristics and Attractiveness of Underground Dams: low in capital cost an appropriate technology for the poorer communities requires essentially no external resources, use of local material is possible needs little expertise to run and maintain, can be understood, controlled and maintained by local people are relatively easy to make and very cheap to construct contributes to the decentralization of water management are able to store larger volume of water small enough in scale to be afforded by a small group of people Halil Önder 5. World Water Form Istanbul

Basic Utilizations of Underground Dams: basic water supply for domestic use, small-scale (manual) irrigation, industrial use livestock watering to prevent salt water intrusion in coastal aquifers combating or reversing the process of desertification treated waste water may be stored behind underground dam for non-potable purposes for artificial recharge to construct artificial wetland source of water for natural wetlands Halil Önder 5. World Water Form Istanbul

Utilisation of Underground Dams-1 reducing the impact of saltwater intrusion by construction or installation of an impermeable subsurface barrier paralleling the coast decreasing discharge from groundwater system into the sea (subsurface dam is recomended near the sea shore to prevent the subsurface flow from the aquifer to the sea) Halil Önder 5. World Water Form Istanbul

Utilisation of Underground Dams-2 combating or reversing the process of desertification Halil Önder 5. World Water Form Istanbul

Utilisation of Underground Dams-3 treated waste water may be stored behind underground dam for non-potable purposes an interesting method to achieve groundwater sustainability augmenting and enhancing the available groundwater resources treated waste water is: available for reuse at a relatively low cost provides a dependable source of water even in dought years eliminates the need for costly waste water disposal options Halil Önder 5. World Water Form Istanbul

Management of the groundwater resources management involves complete understanding of the cause and effect relationship that the human activities have on the groundwater resources and on the broader environment. in this context groundwater modeling constitutes an important task. performance evaluation is done by using numerical simulation numerical technique: finite difference method computer code: Visual MODFLOW Halil Önder 5. World Water Form Istanbul

Conclusions severe shortage of fresh water supply is being and will be experienced scarcity of water will result in insufficient food supply and undesirable health problems underground dams are environment friendly technology socially acceptable economically efficient hydro geologically sound ıntelligent tool and innovative approache to enhance the sustainability of groundwater resources positive impact on the wellfare of small communities Halil Önder 5. World Water Form Istanbul

Thank You for your patience Small is beautiful:a study of economics as if people mattered E. F. Schumacher. 1973 Make everything as simple as possible, but not simpler. Albert Einstein Halil Önder 5. World Water Form Istanbul