Sustainable Water Resources Strategy in Taiwan Island Shen-Hsien Chen Director General, WRA Water Resources Agency, MOEA Nov 4, 2004

-2- Contents  The status quo of Water Resources in Taiwan  Challenge  Present Stage of Sustainable Strategy  Conclusions

-3- Characteristics of Rainfall Uneven distribution.(Seasonal and Regional) Rainfall intensity. Concentrated rainfall. Abundant typhoons and cloudburst. The Status quo of Water Resources in Taiwan

-4- Rainfall Uneven distribution over Space 2,510 mm of annual rainfall - Mountain Area: > 4,000mm - Plain: < 1,200mm Uneven distribution over Time - Dry Season : Rainy Season 23% ： 77% ( 10% : 90% in South) - Difference of annual rainfall between rainy year and dry year is 1,500mm. 6 The Status quo of Water Resources in Taiwan

-5- Rainfall Rainfall intensity - Annual average rainfall of Taiwan is 2,510 mm, annual average rainfall of the world is 973 mm. -Maximum rainfall per hour is 300 mm. -Maximum rainfall per day is 1,748 mm. (Her-bo typhoon, 1996) 6 The Status quo of Water Resources in Taiwan Globe Taiwan Japan

-6- Rainfall Abundant typhoons and cloudburst -Northeast monsoon occurs during Winter, southwest monsoon does in Spring Typhoons per year bring in abundant rainfall during summer season. -Flood causes 12.8 billion of property damage per year % 49 14% % 48 13% 22 6% 21 6% 15 4% Typhoon Routes and No. of Occurrences(1897 to 1997) The Status quo of Water Resources in Taiwan

-7- Rainfall -- Major Countries of Annual Precipitation and Amount of Water Share Per Capita CountryPrecipitation (mm/yr) Amount of Water Distribution (m 3 /yr/person) Ratio of each country’s amount of water distribution to global average Australia460264,93010 Russia50240, USA76029, Philippines2,36012,7381/2 France7507,4741/3.6 Japan1,7145,1601/5 Taiwan2,5104,1841/7 Global Average 97326,871 The Status quo of Water Resources in Taiwan

-8- Characteristics of River  Relatively short, only 6 rivers > 100 km.  Relatively small drainage area, only 9 rivers >100 km 2  Relatively steep slope, upstream reaches > l/100, downstream reaches 1/200~ l/500, only 5 rivers with slope milder than l/1000. The Status quo of Water Resources in Taiwan

-9- River  Run-off Distribution The Status quo of Water Resources in Taiwan Ratio of discharge in rainy/dry is 9 : 1 Uneven distribution in year highest/lowest is 7 : 1

-10- River  Rapid rising and descend of peak flow The Status quo of Water Resources in Taiwan

-11-  Utilization rate of water resource from rivers in Taiwan The Status quo of Water Resources in Taiwan

-12- Catchment  Poor geologic conditions in watershed, sediment concentration is huge, also exists some special geologic structures such as mudstone which can easily cause mudflow. Reservoir Height （ m ） Capacity （ billion ton ） China Three-Gorge Dam US Shasta Dam Taiwan Der-Kee Dam Region Annual Erosion (mm) US Tennessee River 0.25 Taiwan North2-7 Central10-30 The Status quo of Water Resources in Taiwan

-13- Water Pollution in Taiwan  unpolluted 62.4 % (2002) ( %)  mild polluted 12.0 % ( %)  Moderate polluted 11.5 % ( %)  Serious polluted 14.0 % (1996 年 10.4 %) Challenge

-14- Challenge Insufficient Capability of Drought Control  Total amount of reservoirs and weirs are 110 sites with total storage of 2.2 billion ton, less than U.S. Shasta Dam of 5.54 billion ton and China Three-Gorge Dam of 39.3 billion ton.  Total storage of reservoirs and weirs is under water demand.

-15- Groundwater Over Pumping  Land-subsidence problem Region - Southwest coastal region - LanYang plain coastal region Area (Subsidence Rate > 3cm/year) Km 2, before regulation control (before 1996) Km 2, after regulation control (to 2003) 2.24/0 說明：累積下陷量（公尺） / 年下陷量（公分） 0.35/ / / / / /2.40 Challenge

-16- Annual river run-off 64.5 Annual rainfall 90.5 Annual evaporation loss 22.0 groundwater pumping (31.82%) river drawing (40.09%) reservoir water supply (28.09%) 71%5% Over-pumping Total water demand %10.5%69.13% Flow into ocean Annual groundwater infiltration % 24% Domestic water Industrial water 1.869Agricultural water % Water Demand Increasing Unit:10 9 m 3  Industrial water: 1.63 (1991) → 1.74 (2001) Domestic water: 2.49 → 3.73 Water Allocation (2000) Challenge

-17- Agricultural water < 12.0 (60%) 1.5 (7.5%) Industrial water ≦ 3.0(15%) Agricultural demand < 10.9 Paddy infiltration Groundwater recharge Domestic water ≦ 3.5 (17.5%) Total demand < 20.0 (100%) Water reuse Groundwater ≦ 4.0 (20%) Reservoir 5.0 (25%) River 11.0 (55%) Ordinary Ordinary and emergency Emergency and flexible using Sea water Desalination Water Supply and Demand in Taiwan, 2021 Conservation water Unit:10 9 m 3 Challenge

-18- Effect of Global Climate Change  Greenhouse effect The average temperature increased by 2 ℃ and mean sea level raised by 20~40 cm in the past hundred years in Taiwan.  Rainfall type change Rainy day is decreasing yearly. Take Taipei rainfall gauge station as an example of that decrease of 27.8 rainy days but amount of rainfall increases to 268 mm Taipei rainfall gaugeMudanrainfall gauge Challenge

-19- Sustainable water development Equal Weight of Water Saving and Development Equal Concerns of Conservation and Development of Ecosystem Carry Out Principle of User Pay, Promote Feedback Mechanism of Landuse Limitation Combination of Methods of Engineering and Non-Engineering Present Stage of Sustainable Strategy Innovation and Reorganization of Institutes and Capacity Building

-20- Sustainable water resources Cope with the water shortage Improvement and renovation of reservoir Remove deposit of silt and construct off-stream reservoir Carry out watershed conservation Agricultural water transfer to domestic and industrial water use Promote artificial rainfall Equal weight of saving and development Management demand orientation substitute for development supply orientation Multi-target artificial lakes and ponds Present Stage of Sustainable Strategy

-21- Diversifying water resources Reasonable water utilization Conservation, recharge and recycle of groundwater Seawater desalination Recycling of waste water Strengthen mechanism of water distribution Enterprization and multi-operation of Irrigation Associations and Water Supply Department Promote rainfall harvesting system Carry out total quantity control institution of district water resources demand Continue the water saving plant Present Stage of Sustainable Strategy Equal weight of saving and development

-22- Equal Concerns of Conservation and Development of Ecosystem Master planning of comprehensive watershed management Promote Quasi- ecological engineering method Overall planning in mitigating soil and water disaster Enhance measures of marsh recovery and environment maintenance management Combine community construction with characteristic of history culture to redevelop river and coast environment Process investigation and plan of water environment and ecological conservation Intensify conservation of forestland and sloped land, and water preservation in plain Enhance land-subsidence mitigation measures Establish integrated management system of water quality, water quantity, and soil and water conservation in catchment Present Stage of Sustainable Strategy

-23- Carry Out Principle of User Pay, Promote Feedback Mechanism of Landuse Limitation Reasonable Water Price Compensation mechanism of water resources limited Setup of committee of rational water price Regulate basic fee of domestic water supply Mechanism of water price variation by season Mechanism of compensation for limited development Promote public participation mechanism Ecological measures in limited area with comprehensive community construction Fair, efficient, simple, flexible, and transparent water price regulation mechanism Present Stage of Sustainable Strategy

-24- Establish control system on flood and drought and Early-Warning system for unusual climate Combine with technology of meteorology and hydrology to setup decision making system on flood and drought Establish mechanism of flood insurance Strengthen regulations of flood plain management Setup of detention pond Promotion of Green Building and using pervious pavement in urban area Combination of Engineering andNon-Engineering Methods Establish Disaster Control and Early- Warning System Promote Non- Engineering of Flood Control Measures Enhance Concept of Water Preservation Reward construction of flood-proof building and high standard of embankment Present Stage of Sustainable Strategy Propagate concept of disaster prevention and water preservation

-25- Integrate authorities in charge of affairs related to water, land, forest, ocean and setup Ministry sector Setup of Basin Management Authority Promote water industry and carry out education and instruction Integrate Institutions and Authorities Revitalize Water Industry Water Authority of local government Raise the capability of self-reimbursement and participation incentive, promote private sector to participate hydraulic construction Innovation and Reorganization of Institutes and Capacity Building Present Stage of Sustainable Strategy

-26- Enhance integrated observation system and transmission system Enhance ecological engineering method and development of constructive material Modification of Water Law Modification of Water Supply Law Develop Hydraulic Technology Modification of laws Integrate bio-environmental technique and river recovery technique Regulation of Hot Springs Law Promote middle/long-term project of water resources technique and international exchange Present Stage of Sustainable Strategy Innovation and Reorganization of Institutes and Capacity Building

-27- The average rainfall per capita in Taiwan is less than one eighth of the world average, which is due to special hydrology, topography, and geology. A more effective and constructive action is required. The conventional water development has reached its bottleneck. New water development, such as seawater desalination, wastewater treatment and reuse, rainwater harvesting, artificial lake, etc., will be an important strategy to cope with water shortage. Conclusions

-28- Water conservation should be participated by all citizens. Water price should be reflected its cost and be independent from political influence. The rational water price will help promoting water conservation. International cooperation and experience exchange are helpful solutions and unavoidable trend to tackle similar water problems around the world. Conclusions

-29-