2. Water resources management in Thailand

The Kingdom of Thailand has made remarkable economic development visible through energy, transport and tourism sectors. Strong growth since the 1970s enabled the country to join the group of upper-middle-income economies in the early 2010s. Thailand aims to become high-income economy by 2037 enjoying “Security, Prosperity and Sustainability” according to its 2017 National Strategy Preparation Act. Therefore, Thailand is striving for enhancing its economic competitiveness and social advancement to become one of the leading countries in South East Asia (OECD, 2019[1]).

Effective water resources management - including flood control, irrigation and water supply - is a condition for economic success and the ambitious vision can be jeopardised by Thailand’s increasing water insecurity. Growing population, economic growth, rapid urbanization and the looming threats posed by climate change are expected to make sustainable water management significantly more difficult in the coming years. By 2030, Thailand’s population is projected to reach about 71–77 million, with an increasing proportion living in urban areas (The World Bank Group and the Asian Development Bank, 2021[2]). In 2020, the urbanisation rate reached 51.43% of the total population, showing a change of life pattern leading to an increase in water demand (Ta and Watershed, 2008[3]). Thailand’s economy is 90% based on the industrial and service sector, with the agricultural sector accounting for only 10%, but representing 33% of the workforce (The World Bank Group and the Asian Development Bank, 2021[2]). Water productivity is low in all sectors in Thailand, but in particular in agriculture (where it is almost nil); as comparison the industry sector reaches around 60 USD per m3 (Chokchai , and Sucharit, 2019[4]). The Eastern area is the second area with the highest water productivity for all sector 12.73 USD per m3, however being almost 5 time lower than Bangkok region (Chokchai , and Sucharit, 2019[4]). In addition, in the Eastern area, the industry sector has the highest water productivity rate of the country, namely 76.41 USD per m3.

Thailand is recognised as highly vulnerable to climate variability and change due to increasing natural hazards, such as heavy rainfall, floods, and droughts. In addition, sea level rise affects the country’s coasts. The country ranked in the 31th position in National Water Security Index among 49 Asian and Pacific countries mainly due to a low water urban security and high climatological risks (Asian Development Bank, 2020[5]). The Intergovernmental Panel on Climate Change reports that global sea level rise associated with climate change is expected to be between 8 - 16 mm/year in the 21st century. Due to global climate change, sea level in the inner part of the Gulf of Thailand is expected to increase in the future. The increase in wind speed, and especially of the monsoons that blow into the Gulf of Thailand, adds to the rising sea level. (The World Bank Group, 2021[6]).

Several water challenges coexist such as competitive increase in water demand in agriculture, industry and service sector, deterioration of water quality due to increasing pollutants, deepening damage from floods and droughts due to climate change, and management of rivers and aquifers shard across regions.

Floods are by far the greatest natural hazard facing Thailand in terms of economic and human impacts. Thailand is cited as one of the ten most flood-affected countries in the world. Drought and cyclone impacts also represent major hazards. All may intensify in future climate scenarios. The number of people affected by an extreme river flood could grow by over 2 million by 2035–2044, and coastal flooding could affect a further 2.4 million people by 2070–2100. Projections suggest that Thailand’s agriculture sector could be significantly affected by a changing climate, due to its location in the tropics where agricultural productivity is particularly vulnerable to temperature rises (The World Bank Group and the Asian Development Bank, 2021[2]).

The long-term forecast for the Eastern region indicates that the area is exposed and vulnerable to climate change. Rising sea levels can also introduce new, or exacerbate existing, saltwater intrusion into freshwater resources. Both groundwater and surface water sources are at risk (Petpongpan, Ekkawatpanit and Kositgittiwong, 2020[7])

Thailand is focusing its adaptation efforts in key sectors such as energy, water, transportation, agriculture, human settlements and public health, according to the submitted the Third National Communication to the United Nations Framework Convention on Climate Change in 2018, its Initial Nationally Determined Contribution in 2016 and its Updated Nationally Determined Contribution in 2020 (The World Bank Group and the Asian Development Bank, 2021[2]).

The prevailing institutional organisation for water management in Thailand is complex and may lead to overlaps and inconsistencies, as presented in Table 2.1. . This is detrimental to effective policy making and cost-effective investments, as it can hinder policy coherence across jurisdictions (across policy areas and across levels of governments). Based on Thai authorities’ priorities, this Dialogue will not review the arrangements in detail. This could be the focus of a subsequent project, should there be an interest.

According to the Water Resources Act 2018, the National Water Resources Commission is in charge of water resources regulation1. Since the creation of the ONWR, Thailand has 22 major rivers basins Committees and 353 small and medium river basins.

Water and sanitation services are provided by public utilities across the countries (Table 2.2.), with few exceptions such as Eastwater a private entity operating in the EEC region. Currently, no agency is in charge of regulating water and sanitation service providers.

Thai government has set water security as a top priority in the political agenda and has undertaken a major policy reform. The government reviewed the current framework through four main pillars, to set the direction in improving water management resources:

  1. 1. The 20 year Master Plan on Water Resources Management (2018 – 2037);

  2. 2. The creation of Office National Water Resources (ONWR);

  3. 3. Water Resources Act 2018; and

  4. 4. Developing a water management system.

The Thailand 4.0 economic model aims to become high-income country. The four pillars of this strategy are economic prosperity, social well-being, raising human values and environmental protection. In order to achieve these objectives, the government is developing new growth hubs, starting with the Eastern Economic Corridor (EEC). The government is also set to accelerate the area’s readiness to support all aspects of investment and economic growth, and expects that the EEC will be an important centre for trade, investment, regional transportation, and a strategic gateway to Asia. Thailand’s government masterplan aims to develop the EEC region as the main hub of high-tech industries of the country. Developing new economic growth hubs including EEC needs stable and resilient social infrastructures to underpin well-functioning city mechanism such as sufficient and reliable energy, water and other public goods supply networks (EEC Office, 2019[8]).

The EEC covers three provinces (Chachoengsao, Chonburi and Rayong) with very different socio-economic and climatic conditions (Figure 2.1. ). In the north area of the EEC, Chachoengsau main economic sector is agriculture, producing mainly rice and aquaculture. According to ONWR, current water demand equals the supply, and water supply is ensured by numerous dams in the watershed. Rayong and Chonburi provinces contain the industrial and touristic development following the coastline, as well as the new cities. These two regions have limited water resources, and the current water demand is already higher than supply. Supply is ensured by small reservoirs in the area. Due to the climatic-topographic conditions, it is not possible to develop larger in-situ water storage.

Water supply in the EEC is ensured through a complex system of reservoirs and distribution lines across the region and neighbourhood provinces. Current and future sources of water in the EEC are reservoirs, as illustrated in Figure 2.2. .

Source: Presentation during the ONWR interviews, 2022.

The Royal Irrigation Department is the main authority undertaking water allocation from reservoirs in the EEC, based on water availability in the reservoir and demands from all sectors. During normal runoff years, the current demands are met. However, during dry years, supply is insufficient to satisfy demand. Therefore, special measures have been put in place across sectors, such as reduction of rice land during the dry season and imposing water conservation measures. However, as forecast by Thai authorities demand will overpass supply in the future. During some periods of the year, this is already the case and restrictions need to be imposed on some users, mainly farmers.

The water development plan for the EEC was approved in 2020 (Figure 2.2. and Box 2.1) which covers quality and quantity management elements aiming to ensure water security in the region.

The EEC water management plan sets a short-term plan to prevent drought and a long-term plan to ensure “environmentally friendly and sustainable water management”. The short-term plan focuses mainly on increasing water supply through reservoirs and water diversions. Only one activity targets water demand management by aiming to reduce water usage from the industry sector by 10 percent (EEC Policy Committee, 2020[9]).

The long-term plan focuses on supply through reservoirs and diversions systems, reaching 50 thousand million Baht (1.5 thousand million USD). It considers as well desalination as potential additional source. The budget for demand management is almost 50 times lower (19 thousand million bath, 58 million USD) aiming to reduce losses through agriculture water usage plan, groundwater database and reinforcing the collaboration with the Provincial Waterworks Authority. In addition, it includes reservoir construction and water diversion system under the water management component (EEC Policy Committee, 2020[9]).

As illustrated in Figure 2.1. , according to Thai’s government plan, Chanthaburi neighbouring province, with abundant water resources and agricultural sector producing high value crops, will be providing water to Prasae, the main reservoir in the EEC.

In relation to water quality, the Pollution Control Department monitors inland and coastal water quality of Chonburi and Rayong provinces. Water quality is poor due to water pollution from domestic and industrial uses. Some point sources discharge wastewater, which is not compliant with the standard.

To manage industrial wastewater quality, the reduction of wastewater at point sources, establishment of a permit system to control industrial loading, and installation of online monitoring equipment at point sources are priorities set in the region plan. Moreover, Pollution Control Department is revising effluent standards in order to control and prevent pollution discharged from various point sources more effectively and efficiently.

With regard to domestic wastewater management, a municipal action plan consists of four key measures including wastewater control and minimization at point sources, public participation, effective law enforcement, and rehabilitation and construction of wastewater treatment facilities. Currently, there are nine and three wastewater treatment plants in Chonburi and Rayong provinces, respectively. All of these will be rehabilitated in the near future. A total of 25 wastewater treatment facilities will be constructed in both provinces in order to manage the increasing amount of wastewater. All of the new wastewater treatment plants are to be constructed by 2036 in the priority area to treat all the wastewater generated from point sources (OIC, 2019[10]).

The following sections address the issues identified as a priority by the ONWR within the main two topics, water demand management in the ECC and water and sanitation financing, and provide recommendations based on other countries experience.

It is important to highlight that no quantitative analysis was carried out for the analysis, due to lack of access to the required quantitative data. Therefore, the recommendations provided aim to guide the direction that Thai’s authorities might wish to explore to increase water security. However, all recommendations provided in this document should be fine-tuned, reviewed and implemented under an action plan based on more robust data.


[5] Asian Development Bank (2020), Asian Water Development Outlook 2020, Asian Development Bank, https://doi.org/10.22617/SGP200412-2.

[4] Chokchai ,, S. and K. Sucharit (2019), “Evaluation of Water Productivity of Thailand and Improvement Measure Proposals”, https://www.koreascience.or.kr/article/CFKO201936062693853.pdf.

[8] EEC Office (2019), “EEC Brochure 2019 (EN)”.

[9] EEC Policy Committee (2020), EEC Water Management Plan, https://www.eeco.or.th/en/news-release-pr/NO-1-2020-The-Eastern-Economic-Corridor-Policy-Committee-1st-issue (accessed on  2022).

[1] OECD (2019), Multi-dimensional Review of Thailand (Volume 2): In-depth Analysis and Recommendations, OECD Development Pathways, OECD Publishing, Paris, https://doi.org/10.1787/9789264307674-en.

[10] OIC (2019), “WasteWater Management in EEC”.

[7] Petpongpan, C., C. Ekkawatpanit and D. Kositgittiwong (2020), “Climate change impact on surface water and groundwater recharge in northern Thailand”, Water (Switzerland), Vol. 12/4, https://doi.org/10.3390/W12041029.

[3] Ta, L. and K. Watershed (2008), IMPACT OF URBAN EXPANSION ON WATER DEMAND : The case study of Nakhonrachasima city.

[6] The World Bank Group (2021), THAILAND CLIMATE RISK COUNTRY PROFILE, http://www.worldbank.org.

[2] The World Bank Group and the Asian Development Bank (2021), Climate Risk Country Profile: Thailand, https://reliefweb.int/sites/reliefweb.int/files/resources/climate-risk-country-profile-thailand.pdf.


← 1. Resolving problems from the performance of work of State agencies and local government organisations which take action in accordance with the laws, Regulations or Rules binding them insofar as they are concerned with the use, development, management, maintenance, rehabilitation and conservation of water resources, with a view to generating integration as well as public participation (Water Resources Act, 2018).

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