Water Management
Water is an important and limited resource. EGAT therefore establishes efficient water management practices to ensure balanced resource utilization and to minimize any impacts that EGAT’s operations may have on society and the environment.
| 2025 Target | Performance |
| ● The quality of effluent discharged from power plants must not exceed the standard limits as prescribed in the Notification of the Ministry of Natural Resources and Environment: Prescribing Effluent Standards for Power Plants B.E. 2565 (2022) | ● The quality of effluent discharged from power plants remained within the prescribed standards under the Notification of the Ministry of Natural Resources and Environment: Prescribing Effluent Standards for Power Plants B.E. 2565 (2022) |
Management Approach
EGAT adopts an approach to maximize the beneficial use of water resources in electricity generation processes as well as for internal consumption within the organization, while taking into consideration the impacts that its activities may have on society and the environment at every stage of operation. Water is managed comprehensively, covering water withdrawal, water use, and water discharge, with strict compliance with all relevant laws and measures.
Management of Water as a Shared Resource
Most of EGAT’s water use is for electricity generation purposes, particularly at its eight thermal and combined-cycle power plants, which withdraw water from nearby water sources. These sources include both man-made and natural water sources. The man-made sources are Mae Kham Dam and Mae Chang Dam, which supply water to the Mae Moh Power Plant. Natural water sources include Raphiphat Canal, which supplies the Wang Noi Power Plant; the Nam Phong River, which supplies the Nam Phong Power Plant; the Chao Phraya River, which supplies the North Bangkok Power Plant and the South Bangkok Power Plant; the Bang Pakong River, which supplies the Bang Pakong Power Plant; Pakasai Canal, which supplies the Krabi Power Plant; and Phoma Canal, which supplies the Chana Power Plant. None of these eight water sources are classified as conservation areas or protected areas at either the national or international level, and no protected or conserved species have been identified in these areas.
Before project implementation, EGAT assesses the environmental impacts of water use from power plant water sources, including Environmental Impact Assessments (EIA) and Environmental and Health Impact Assessments (EHIA). Details of water use from each water source are specified in the environmental impact assessment reports for each power plant. During project operation, every EGAT power plant must obtain water use permits from the relevant local permitting authorities. In addition, water quantity and quality are closely monitored and controlled. Some power plants have established working committees to monitor water withdrawal from water sources in order to consider approvals before water is pumped into the plants. Based on past operations, all water sources have been found capable of supporting power plant water use during both the dry and rainy seasons without causing adverse impacts or conflict over water use with surrounding communities.
EGAT also implements measures to prevent potential impacts on water resources and to restore them, both physical and biological. These include the installation of screens at power plant water intake points to prevent aquatic animals and juvenile aquatic species from entering the system, as well as the annual aquatic species release activities. Measures are also in place to regularly monitor any impacts that may occur in nearby water sources.
For hydropower generation, water simply passes through turbines to generate electricity with no loss. Electricity generation is a secondary outcome of water releases for agricultural irrigation. Nevertheless, EGAT places importance on caring for communities both upstream and downstream of reservoirs by studying the impacts of water storage and water release, as well as promoting stakeholder engagement to identify concerns, discuss issues, and monitor solutions for any potential impacts that may arise.
With regard to water use in coal mining operations, mine pits are designed to include rainwater retention ponds within the pit area. Water is pumped down to a controlled level and stored for use. Part of the water is reused in mining activities, such as water spraying during the dry season to suppress dust from roads and conveyor systems, extinguishing coal fires, and mine rehabilitation. Another portion is pumped out of the mine. EGAT has also conducted studies and prepared Environmental Impact Assessment (EIA) reports for mining projects in accordance with the criteria, methods, and procedures of the Ministry of Natural Resources and Environment in order to strictly manage any impacts that may arise from project activities on environmental quality, natural resources, and health.
Management of Water Discharge Impacts
EGAT controls the quality of water discharged from its power plants by installing treatment systems to ensure compliance with legally prescribed standards, after which the water is stored in holding ponds within plant premises and discharged to nearby authorized receiving water sources, such as Pakasai Canal and Canal 26, which receive discharged water from the Krabi Power Plant and the Wang Noi Power Plant, respectively. Many power plants reuse treated water stored in holding ponds for watering lawns and trees throughout the plant area, without discharging wastewater to external water sources. Only water from the cooling system is discharged after its temperature has been reduced before being returned to the water source. The temperature of such discharged water is controlled to remain within a range that does not affect aquatic life and complies with legal standards.
For water discharge from hydropower generation, EGAT applies technology to forecast and plan for water situations. It also integrates data from both the public and private sectors under the supervision of the Office of National Water Resources to ensure that its operations do not adversely affect stakeholders’ access to and use of water resources, while remaining aligned with applicable laws and operational guidelines under Thailand’s National Strategy-based Water Resources Management Master Plan. During the dry season, EGAT releases sufficient water to meet the needs of the Royal Irrigation Department and local communities. During the flood season, EGAT manages water jointly with government agencies and local administrative authorities to minimize impacts in upstream and downstream areas of dams. In cases where unavoidable impacts occur, EGAT supports communities by providing machinery, equipment, and essential supplies.
For water management in coal mining operations, drainage systems are used to separate natural water from water potentially contaminated by mining activities. In addition, water retention areas and treatment systems are provided to manage such water. Water pumped from the mine pit is conveyed to sedimentation ponds outside the mining area for sediment removal. It is then treated through a constructed wetland system located near the ponds before being discharged into natural waterways. In addition, wastewater quality is monitored quarterly within the project area and surrounding areas. Samples are collected from 14 monitoring stations during both the dry and rainy seasons to ensure compliance with industrial factory and industrial estate effluent standards.
EGAT also publishes water quality management results on its website and through environmental information boards located in nearby communities. Furthermore, annual surveys are conducted to assess community trust in EGAT’s environmental management, evaluate operational performance, and gather feedback for continuous improvement. The Mae Moh Basin contains limestone layers interspersed among soil and coal seams. Water quality monitoring has consistently shown pH levels ranging from neutral to slightly alkaline, and no acidic conditions have been identified in the mine.
Water withdrawal, discharge and consumption
| Item | 2025 | 2024 | 2023 | |||
| All areas (megaliter) | Water-stressed areas (megaliter) | All areas (megaliter) | Water-stressed areas (megaliter) | All areas (megaliter) | Water-stressed areas (megaliter) | |
| Water withdrawal | ||||||
| Total water withdrawn | 234,194.81 | 214,959.69 | 245,272.63 | 224,120.38 | 213,129.71 | 194,593.94 |
| Surface water (including rainwater) | 233,035.08 | 213,929.17 | 244,115.14 | 223,169.95 | 211,670.85 | 193,239.78 |
| – Fresh water | 143,021.37 | 140,315.12 | 139,161.03 | 136,526.74 | 123,139.27 | 121,014.16 |
| – Other water | 90,013.71 | 73,614.05 | 104,954.11 | 86,643.20 | 88,531.58 | 72,225.62 |
| Groundwater | 91.82 | 31.14 | 82.52 | 38.58 | 102.00 | 58.81 |
| – Fresh water | 91.82 | 31.14 | 82.52 | 38.58 | 102.00 | 58.81 |
| – Other water | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Water from other organizations | 1,067.90 | 999.38 | 1,074.96 | 911.85 | 1,356.86 | 1,295.34 |
| – Fresh water | 1,067.90 | 999.38 | 1,074.96 | 911.85 | 1,356.86 | 1,295.34 |
| – Other water | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Water discharge | ||||||
| Total water discharged | 131,821.07 | 106,181.35 | 180,974.33 | 169,222.05 | 134,061.94 | 123,818.27 |
| – Discharge to surface water | 130,020.82 | 104,381.10 | 179,218.25 | 167,465.98 | 131,860.21 | 121,616.54 |
| – Discharge to groundwater | 1,800.25 | 1,800.25 | 1,756.08 | 1,756.08 | 2,201.73 | 2,201.73 |
| – Discharge to the sea | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| – Discharge to other organizations | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| – Fresh water discharged | 63,307.60 | 49,350.35 | 73,929.04 | 73,924.31 | 55,626.43 | 55,625.14 |
| – Other water discharged | 68,513.47 | 56,831.00 | 107,045.29 | 95,297.74 | 78,435.51 | 68,193.13 |
| Water consumption | ||||||
| Total water consumption | 102,373.74 | 108,778.34 | 64,298.30 | 54,898.32 | 79,067.76 | 70,775.67 |
Notes
– Fresh water refers to water with total dissolved solids (TDS) of no more than 1,000 mg/L.
– Other water refers to water with total dissolved solids (TDS) exceeding 1,000 mg/L.
– Water consumption refers to water withdrawn from external sources less water discharged.