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Use of Underground Dams in the Sustainable Developement and Management of Groundwater

Resources

Halil ÖnderDepartment of Civil Engineering METUAnkara, Turkey

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Outline

objective sustainability of groundwater, goals,

strategies underground dams use of underground dams technical effectiveness and performance

evaluation discussion and conclusion

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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

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Groundwater Sustainability and GoalsDefinition 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

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Management strategies to ensure the sustainability:Strategies 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

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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)

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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)

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Examples

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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

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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

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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)

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Utilisation of Underground Dams-2

combating or reversing the process of desertification

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Utilisation of Underground Dams-3

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

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

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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

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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

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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

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