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TRANSCRIPT
OVEREXPLOITATION OF GROUNDWATER AND
CONSEQUENCE IN
YANGON (Myanmar) AND BANGKOK (Thailand)
Prepared by: Myint Thein [Groundwater & Wells Consultant (Freelance) ] Advisory Group Member (Groundwater) NWRC, Myanmar [email protected] November 2018
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MAGNITUDE YANGON
Greater Yangon 4 Districts 33 Townships Population 7.6 million (2016) Métropolitain 10,170 km2 (City Area ) (3930 Sq mi)
Bangkok 50 Districts in Bangkok Metropolitain 7 Provinces Population 9.60 million(2018) Métropolitain 10,300 km2(2003)
(City Area) (3976 Sq mi)
BANGKOK
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SATELITE IMAGE YANGON BANGKOK
Gyobyu Reservoir
Ngamoeyeik Reservoir
Phugyi Reservoir
Hlawga Reservoir
Nyaungnapinwater treatment Plant
Inya Lake Kandawgyi Lake
Bay of Bangkok
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GEOLOGY YANGON
1 Alluvial deposit (Holocene age) (composed of gravel, sand, silt, clay and laterite)
2. Valley Filled Deposit (Pleistocene age) (includes the older alluvium of terrace of unconsolidated gravels, sands and silts)
3. Ayeyarwady Formation (the non-marine fluvial sediments) (Pliocene age)(composed of Arzanigon Sand-rock, Sand(fine o medium grain), fine grain gravel and Danyingon Clay)
4. Upper Pegu Group (miocene) (consist of (Thadugan Sandstone, Hlawga Shale, Besapat Alternations) and limited of Thadugan sandstone
NOTE: The rock type in Greater Yangon is mainly soft rock
BANGKOK 1 Bangkok Clay or Marine
clay(grey and greenish-grey clay) in the upper part soft to soft; stiff clay and hard in some deeper depth
2 Pleistocene sediment of tidal-dominated deposits (sediments consist of sand, silt, clay, and gravel.
3 The pre-Tertiary basement consists of sedimentary, igneous and metamorphic rocks
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GEOLOGICAL MAPS (BANGKOK AND YANGON)
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HYDROGEOLOGY (Groundwater Hydrology) YANGON
Greater Yangon Aquifer system is composed of Alluvial, Valley Filled, Irrawadan and Pegun aquifers.
Alluvial aquifer is unconfined with the thickness of 20 meters (250ft) yield (45 – 2200)m3/day
Valley Filled Aquifer, thickness is from 35 to 90 meter (120 to 300 feet), is principle aquifer with the high amount of yield (1000 – 4000)m3/day
Irrawaddy Aquifer thick is ranging from 250meters (800 feet to more) with the yield ranging from 70m3/day to 2270m3/day
Peguan Group is poor Aquifer discharge low yield with non-potable quality
Yangon is rich in groundwater resources
BANGKOK Hydrogeological Setting Occupied much of Lower Chao Phraya
Basin Underlain by thick inter-bedded alluvial
and marine sediment (~ 600 m depth) 8 semi-confined aquifers overlain by
Holocene Bangkok marine clay Bangkok Aquifer System composed of 8
confined aquifer Most of groundwater extraction from 3
aquifers at depths 100- 250 m (PD, NL, and NB Aquifers)
Nonthaburi (NB) Aquifer one of the most productive, yielding up to 200 m3/hr of excellent quality water
Deeper aquifers seldom used by domestic wells
Groundwater discharge are more discharge than Yangon
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Geological / Hydrogeological profiles of
Yangon and Bangkok are showing
in next two slides
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Geological Cross-Section showing the aquifers Bangkok
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Geological Cross-Section of showing the aquifers Greater Yangon
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GROUNDWATER MANAGEMENT & DEVELOPMENT YANGON BANGKOK
1950 Start groundwater development with over exploitation 1954 8360m3/day (discharged) 1969 Land subsidence give alert the authority and public 1976 937,000m3/day
(Discharged) 1977 An act of Groundwater 1978 Start action and license for groundwater activities
1842 (Myanmar King Era) 30 Wells
Private wells 1893 17 tube wells 1901 56 tube wells 1920 75 tube wells 8000m3/day 1924 139 tube wells 11000 m3/day 1930 400 tube-wells
31000 m3/day 1939 An act of Groundwater law: water wells Drilling licensed fee was10Kyats
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON 1958 450 tube-wells 35000m3/day 1972 900 tube wells 71000m3/day 1986 3000 tube-wells 237000m3/day After 1988 there are not drilling license fee and many private tube-wells (Domestic, Industries and others) are at 33 townships in Yangon City; (more than 200,000 tube-wells are discharging: predict 50% of population are relying on groundwater
BANGKOK 1980 Metropolitan waterworks Authority (MWA) discharged 500000 m3/day (132MGD) from 3 aquifers: (Phra Pradaeng, Nakhon Luang and Nonthaburi) caused land subsidence in center of Metropolitan area 1984 Defined Groundwater tariff: 1Bt/m3 in 6 provinces 1990s 2000000m3/day(2MCM) 1992 Amended the Groundwater Act 1994 Increased the tariff
up to 3.5Bt/m3 in 6 provinces 11
GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON 1992 YCDC start use
Groundwater20MGD (90910m3/day) 2003 74MGD(280148m3/day)
(private wells) 2013 54.52MGD (206380m3/day) YCDC (645 Wells) 106.10MGD(401632 m3/day) Private 2015 198.3MGD (475000m3/day) Private wells 2017 52.2MGD(private wells) (YCDC distribute 205MGD to 60% of population)
BANGKOK 1995 Signify the 7 provinces as critical groundwater usage region 1997 Developed to pay the groundwater charges by user 2003 Increased groundwater use fee to 8.50 Bt/m3
2003 Amended the Groundwater Act 2004 200000m3/day (2.2MCM)Total 1800000m3/day (1.8MCM/day) (Private)
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON
BANGKOK 2004 Imposed the Groundwater preservation charge in Central Zone Bangkok 2004-2006 Groundwater conservation fee increased to 8.5Bt/m3
in 7 provinces and (industrial and commercial Groundwater users defined to pay total of t 17.0 /m3
2008 over 4000 licensed water wells for domestic extracted 1.6Mm3/day 58% 0f industries are licensed
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON
US$0.44/ m3 for households used and US$0.88/m3 for commercial used YCDC water supply
(Source: YCDC, 2006 Free Religious (temple,
mosque, church, pagoda),
BANGKOK 2011 Not more than 1.25Million m3/day 2011 Conservation fee was dropped 50% because land subsidence was improvement Today: Control groundwater The current groundwater abstraction is under 1 MCMD. The overall subsidence rate has been improved to less than 2-3 cm/year in central Bangkok and less than 1 cm/year in overall area.
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON BANGKOK Groundwater User Groundwater User
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued) YANGON BANGKOK
ORGANIZATION Ministry of National
Resources and Environment
Department of Groundwater Resources (2002)
Groundwater Control & Legislation
Groundwater Conservation & Restoration
Groundwater Potential Assessment
Groundwater Exploration & Mapping
Groundwater Drilling
Regional Groundwater Offices
Provincial Groundwater Control Office Inst
itutio
n
for
Ban
gkok
ORGANIZATION
There is not institution / organization
For Groundwater Management
& Development
to control groundwater Resources
up to the end 2018
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GROUNDWATER MANAGEMENT & DEVELOPMENT (Continued)
YANGON BANGKOK INSTITUTION OF GROUNDWATER
RESOURCES, THAILAND INSTITUTION OF GROUNDWATER
RESOURCES, MYANMAR
There is not institution /
organization for Groundwater
Management to control
the multi-users
up to the end 2018
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GROUNDWATER ACT YANGON
1939 British Governor act “ The Underground Water Act” Union of Burma (Burma Act IV,1930) (21st June 1930) Especially for Down Town Rangoon, Insein ) (Now Yangon City area) Drilling License fee was
10Kyats (10 Rupee in British Colony Time)(up to 1988)
BANGKOK 1977 Activate Groundwater
Act
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GROUNDWATER ACT YANGON
After 1988 Water Wells drilling license Fees are not paid
BANGKOK • 1992 Amendments: Groundwater Act, B.E. 2520 (1977)
Continued
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GROUNDWATER ACT YANGON
BANGKOK Continued
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GROUNDWATER LAW YANGON 2016-17 New Groundwater Act was prepared and submitted to Senate by Department of Urban and housing Department, Public Work Corporation, Ministry of Construction 2017 Processing at Cabinet
BANGKOK 1994 Groundwater use fee increased to 3.5 Bht/m3
1995 All provinces identified as groundwater use regions (must pay groundwater use fee) TODAY Number of groundwater users and resources management are under groundwater act (1977)
Continued
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CONSQUENCES
B . LAND SUBSIDENCE
A . GROUNDWATER LEVEL
C. GROUNDWATER QUALITY DETERIORATION
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A . GROUNDWATER LEVEL YANGON
1992 Groundwater Level was within 40 ft from ground in down town 9 townships Yangon city Other townships are also not beyond 40 ft below ground level Nowadays Groundwater Water levels are dropping ; compared with existing hydrogeological monitoring data from 1992 are nearly 100% drop, mostly in Downtowns Yangon City
BANGKOK
Before 1958 Water level was very shallow below ground level water level 4.5 meters 1968-69 groundwater level reached 25.30 meters 1978-1999 Groundwater level has declined 55 meters by pumping rate 2.5MCMD Groundwater level has been recovered 40 meter and above after pumping rate Under 1MCMD
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A. GROUNDWATER LEVEL BANGKOK
Continued
Source: Water level from three major aquifers and total land subsidence in Central Bangkok. Department of Groundwater Resources, Ministry of Natural Resources and Environment,Thailand.
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A. GROUNDWATER LEVEL Continued
YANGON
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B. LAND SUBSIDENCE YANGON BANGKOK
1960’s First noticed of Bangkok Land subsidence Early 1980s Land subsidence was critical state It’s highest rate was 12cm/year 1983 Land Subsidence rate (Centimeter / year) (10)> Central Zones ≥(5) Up to 1999 Total settlement was 100cm for 21Years with the structures’ load, traffic surcharge and groundwater exploitation in central area.
Continued
Distinguish land subsidence are no noticed and evidence
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B. LAND SUBSIDENCE
YANGON No evidence are recorded
but it could be happened along riversides and soft soil area
High rise buildings are huge numbers and because of structure’ load, weak foundation, less Geotechnical Instrumentation and groundwater decline
BANGKOK
Land subsidence
continued
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B. LAND SUBSIDENCE YANGON
There are not Marine Clay as distinguished layer Citywide in Yangon reference to Tube wells logs
BANGKOK The upper clay layer, Marine Clay (better known as Bangkok Clay 10-30 meters thickness is key to land subside because of over groundwater xploitation TODAY land subsidence is controlled (1-2cm/year) under Groundwater management by Law
Continued
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B. LAND SUBSIDENCE
YANGON BANGKOK
Continued
MARINE CLAY
Central Bangkok Lower Kyimyintaing
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B. LAND SUBSIDENCE YANGON
Abandon well head is effected by land subsidence. The difference between a recent road level and a previous road level. Land subsidence rate is about 1.25 meter(during 1980-2003).
BANGKOK Continued
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C. GROUNDWATER QUALITY DETERIORATION YANGON BANGKOK
The major cause of inferiority of the groundwater water quality in Bangkok City is NaCl, Hardness, Fe & Mn. Chloride > 1500mg/l ,
Hardness > 920ppm, Fe/Mn > 2.0ppm Depression of pizometric surfaces raised concerns about aquifer sea-water intrusion but the rate of movement of salt water is relatively lower than fresh water movement toward cones of depression.
• the ground water from tube wells are expected to have water quality problems, especially high concentrations of saline (Cl+), iron (Fe+2, Fe+3) and acidity (pH). Because Yangon City is located near the Andaman Sea and Bay of Bangle, saline intrusion has reached well into the inland area especially in southern part of Yangon City. Chloride (Cl+ ion) content is between 1,000–10,000mg per liter somewhere in Yangon City.
Continued
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C. GROUNDWATER QUALITY DETERIORATION
YANGON
BANGKOK
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CONCLUSION Study Groundwater in Bangkok and Groundwater in Yangon get clear vision on eventuality Finding: Geology , Hydrogeology and host rocks are different Groundwater Management and Act Fee for water well drilling, groundwater use and conservation
charges in Bangkok are perfected but not in Yangon City Groundwater discharge in Bangkok are more than discharge in
Yangon. Control the water wells drilling and discharge water from individual
well in Bangkok Groundwater qualities are not so different in Chloride / Chlorite in
both Bangkok and Yangon Salt water intrusion townships / area in Yangon is more than in
Bangkok
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CONCLUSION continued
Number of tube wells ( 100mm and above) are more in Bangkok than Yangon.
The great difference is “Groundwater Act” Groundwater Act is active and ruling the groundwater
management in Bangkok as well as Thailand countrywide
There are “ No Groundwater Act “ not only in Yangon but Countrywide also (It say under processing)
Groundwater management in Yangon is 42 years behind
Groundwater management in Bangkok
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CONCLUSION (continued) • In Bangkok, Marine clay are distinctive to land subsidence
from the points of geotechnical engineering and groundwater engineering.
• Groundwater & wells are under controlled , nowadays • Subsidence has been happen but less and get stability in
Bangkok • In Yangon, There are no outstanding of Marine Clay as like
Bangkok; especially in city downtown (metropolitan) area. • Description of land subsidence are not reported in Greater
Yangon • Water wells drilling and discharge from wells are own
decision • Groundwater Act is not in Groundwater Industries and action
may be active after Law is approved in Yangon
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Suggestion for Yangon Groundwater
11 Points are suggested as below: 1.Restriction of groundwater extraction by Law 2.Natural and artificial recharge and discharge of aquifers 3.Development of alternative water supply (instead of groundwater) 4.Integrated (Urban) flood water management 5.Improving governance and decision-making by Groundwater Act 6.Decision support models and tools by technical management 7.Appropriate monitoring and database system 8.Integrating geotechnical aspects in planning and design of buildings and infrastructure 9.Asset management, financing and public-private-partnerships(PPP) 10.Exchange of knowledge and best practices 11.View and review the existing groundwater discharging
CONCLUSION (Continued)
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CONCLUSION (Continue) Special thanks to U Myo Aung (Hydrogeologist / Bangkok) and Ma Pwint Pyu Aye PhD (AIT, Bangkok) for their provision of valuable information of Bangkok Groundwater / Hydrogeology. U Wanna Pho (Director PGE) and U Hsan Wynn( GE /RE) for his valuable information of Geotechnical Engineering works including piles foundation in Yangon City area. U Hsan Wynn (Professional Geotechnical Engineer /RE) U Aung Kyaw Swar Drilling Master (Private Water Wells driller Contractor) in Yangon.
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Be aware of Groundwater in Myanmar
Myint Thein, Consultant (Groundwater & Wells), [email protected]
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November 2018