1. Son, Young Chul (K-water, Korea) World conference for Public Administration

2. Water Resources in Islands 1 1 Water Supply Model 2 2 Groundwater Dam 3 3

3. 1 Water Resources in Islands

4. Islands in Korea ProvinceIsland Inhabited Island Uninhabited Island 계 3,1074832,624 Incheon14542103 Geonggi411130 Chungnam25537218 Jeonbuk1032677 Jeonnam1,9642801,684 Kyeongnam53780457 Busan45342 Ulsan--- Kyeongbuk46442 Kangwon34- 4

5. Drought in Islands 5

6. Water Problems in Islands 6 - Drought vulnerability : irregular precipitation, little water resource from small area - Surface water shortage : weak of stream development, difficulty in reservoir construction, sedimentation in reservoir - Groundwater shortage : poor alluvium development, little groundwater recharge - Seawater Intrusion : surplus water intake in coastal area - Contamination of water source : disposal of agricultural pesticides or domestic sewage, turbidity rise as reservoir sedimentation, eutrophication as birds’ secretion etc. Water Quality Degradation Lack of Quantity

7. Water Problems in Islands 7 - Increase of water demand and pollution risk in densely populated and touristy island - Difficulty in Basic data acquisition and water resources evaluation - High operating costs and lack of specialized operating personnel for seawater desalination facility - lack of municipalities finances, adverse accessibility, seawater intrusion etc. Others

8. Water Supply in Islands - Nationwide including islands : 95.1% - Islands : 67.6% Water Supply Rate

9. Water source 9

10. Water sources 10

11. 2 Water Supply Model

12. Flow chart for water supply model Regional water supply system well Planned for regional water supply system? Seawater desalination well+ Rain harvest well reservoir Seawater desalination well YES NO

13. Water Supply Model Well including rain harvest composed most of water supply model for island Rate(%)reservoirwell seawater desalination well + rain harvest regional water supply system 1009.551.120.317.21.9

14. 3 Groundwater Dam

15. Facility that stores groundwater in the pores of strata to enable sustainable use through rise of groundwater level by installation of cutoff wall underground 지하수댐이란  Definition 15

16. Groundwater Dam

17. Merits of Groundwater dam `` Land is not submerged to store water No danger of breaching due to natural or manmade disasters Surface area can be used in the same way both before and after construction of groundwater dam No loss of water by evaporation Generally water quality is good and safe

18. Classification of Groundwater dam overflowretentionPrevent seawater intrusion subsurface semi-subsurface Surface/subsurface convertible By cutoff wall type By storage type

19. 19 Groundwater dam in Korea NameLocationUse Dam Length(m) Sustainable Yield ( ㎥ /day) Year of Completion Yian Sangju, Kyungbuk provinceIrrigation23024,0001983 Namsong Youngil, Kyungbuk provinceIrrigation8923,6001986 Okseong Gongju, Chungcheong provinceIrrigation48227,9001986 Gocheon Jeongeup, Jeonbuk provinceIrrigation19225,1101986 Wooil Jeongeup, Jeonbuk provinceIrrigation77816,2001986 Ssangcheon Sokcho, Kangwon provinceWater supply80033,0001998 Ssangcheon damYian dam 19

20. More than 9 countries, 1,000 groundwater dams Groundwater dam in the world Japan (1973~recent) : 18 Korea (1983~2000) : 6 China ( (?)1987~2004) : 7 Ethiopia (?~1981) : 2 Burkina Faso (1997~1998) : 1 USA (1800s(?)~1988) : 1(?) India (1962~1987) : 4 Kenya (?) : about 450 Brazil (1990s) : about 500 Namibia(?) : (?) Sardinia Island in Roman Age Turkey (2004 ?) : ? Thailand (Planning, 2010) (Collected by TC on Groundwater Dam, ICOLD)

21. Hukuzato dam, Okinawa, Japan Sand Storage Dam, Kenya Groundwater dam in the world

22. Basic Studies Coastal areas :72 Islands : 483 Pre- candidate sites (64ea) Water Condition Candidate sites (15ea) Seawater Intrusion Selection of project sites (10ea) Basic Survey (water demand, geographical conditions) Analysis of sites conditions Detailed Survey (drilling, pumping test) Groundwater Dam Project in Korea Coastal areas 72 Manned islands 483 Proposed sites 15 Project sites 10

23. Depth of alluvium and fractured zone Depth to water Constant pumping rate, Time and drawdown Hydraulic conductivity Composition of strata Analysis of aquifer materials Depth of alluvium and fractured zone Depth to water Well Installation Pumping test, sampling of groundwater Soil texture, grain size Porosity and conductivity of soil Reference measurement Vertical and crossing survey Drinking water standard Analysis of chloride Detailed Survey

24. Feasibility Study Items Daeyizak island Gaya islandAnma islandChengsan island Water demand ( ㎥ /day) * By 2025 -109-129-93-323 Water Supply ( ㎥ /day) 110130100330 Cutoff wall methodOpen Cut Grouting (3 layers) Grouting (3 layers Grouting (3 layers Length/Height(m)80/11.3271/23480/31400/25 Pumping facilities3 wells5 wells6 wells10 wells Cost (million USD)2.53.58.66.5 B/C1.6651.2711.5431.023

25. Pilot site (Anma Island) 25

26. Pilot site (DaeYizak Island) 26

27. Gaeya Island

28. Cheongsan Island

29. Project Schedule 2013(4 sites) 2014 (Pilot 2 sites) 2015~2016 Feasibility study 29 DesignConstruction Project expansion to other sites 2017~2020 Daeyizak Island Anma Island Gaeya Island Cheongsan Island Other 8 sites Pilot 2 sites (Daeyizak Island Anma Island)

30. Thank you for your attention