Water Resource
In 2022, CEZ Group joined the UN CEO Water Mandate and committed to responsible water stewardship and regular reporting on water management. By endorsing the initiative, CEZ Group agrees to continuously improve in six core areas of water stewardship practice: Direct Operations, Supply Chain & Watershed Management, Collective Action, Public Policy, Community Engagement, and Transparency.
Surface water is an indispensable resource in the generation of electricity for CEZ Group facilities and an indispensable cooling medium used in generating processes. The water used for cooling is returned to the watercourses immediately downstream of the abstraction point.
Around two-quarters of the total surface water withdrawn is used for once-through cooling systems.
Water withdrawals do not pose a material environmental risk. The impact caused by mining and the disruption of the local water regime and ecosystems related to the MINING segment is considered material. This impact is addressed through decarbonization and the development of CEZ Group‘s business model and is also related to the topic of biodiversity, where additional mitigating measures are in place. More information is provided in the Sustainability Report, chapter Biodiversity and Ecosystems and/or in part Biodiversity and Ecosystems.
More information can be found in the Sustainability Report.
In order to achieve the commitments under the CEZ Group Environmental Policy and meet the set targets, actions are implemented that are primarily aimed at achieving climate neutrality and reducing pollution. The actions to increase the biodiversity of water resources are described in the the Sustainability Report, chapter Biodiversity and Ecosystems and/or in part Biodiversity and Ecosystems. In addition to these, other actions are being implemented to mitigate environmental impacts on water resources.
| Key actions | Site/company | Implementation |
|---|---|---|
| Certified environmental management system A certified EMS is implemented in all facilities with material water consumption. |
CEZ Group | In progress |
| Water recycling Recycling of used water is aimed at minimizing the amount of surface water withdrawn. |
Hydroelectric and nuclear power plants | In progress |
| Limiting the use of groundwater for technological purposes Groundwater is used in minimal quantities at CEZ Group. It is used for the production of drinking water, or in cases where the use of surface water is not suitable. |
CEZ Group | In progress |
| Harnessing the energy potential of water The energy potential of water is used in the cooling water channels of combustion plants and at wastewater discharge points of power plants through the operation of small hydroelectric power plants. |
Multiple locations | In progress |
| Modernization of hydroelectric power plants The modernization of the Vltava Cascade hydroelectric power plants and small hydroelectric power plants is currently being implemented. Already completed is the replacement of generators at the Dlouhé Stráně pumped-storage hydroelectric power plant. The modernization of the Dlouhé Stráně and Dalešice pumped-storage power plants, extensive modernization with increased efficiency of the Střekov hydroelectric power plant, and comprehensive modernization of the Orlík hydroelectric power plant are now being prepared. |
Hydroelectric power plants | In progress |
Withdrawals of surface water for CEZ Group‘s operations do not significantly impact the water volume of the watercourses involved. Maximum surface water withdrawal of plants with circulation cooling ranges from 0.1 to 7.12% of the natural flow capacity, and we can evaluate the withdrawal impacts as negligible or low. A material impact on the flow was caused by the maximum withdrawal during permitted surface water withdrawal for the Dukovany Nuclear Power Plant, which in 2025 amounted to no more than 31.5% of the natural flow. The surface water withdrawal is minimized by the use of the Dalešice water reservoir on the Jihlava River, which is also a wastewater recipient. Furthermore, the reservoir serves as a pumped-storage hydroelectric power plant for the generation of electricity, for long-term flow balancing, for reducing flood peaks in the lower reaches of the Jihlava River, and also for recreational use.
There was no recorded impact of surface water withdrawal on biodiversity in protected areas and on the presence of specially protected plant and animal species.
The indicator Water Intensity, i.e., total water consumption in m3/CZK million of operating revenues, is 245.8 m3/CZK million in 2025 (238 m3/CZK million in 2024).
Wastewater Recycling
After use, a part of the used water is recycled in the plants to minimize the amount of surface water withdrawn. In 2025, the volume of wastewater reused in power plant operations was 8.2% of process water consumption. Another way to utilize wastewater is to use it in small hydroelectric power plants. For example, used cooling water from the Temelín Nuclear Power Plant is reused to generate energy at the Kořensko II hydroelectric power plant. Another example of harnessing the potential of water to generate electricity is the use of the used cooling water discharge turbines in Ledvice and Prunéřov.
CEZ Group reuses wastewater from cooling tower blowdown, sand filter and gypsum washing, seepage water, and drainage water if the quality of the wastewater is sufficient for reuse.
Generating facilities withdraw surface and ground water and generally maintain small buffer reserves of both raw water and treated surface water for their own use. These reserves exceptionally range in volume from tens of thousands of cubic meters, with a total of approximately 128,000 m3 of surface water stored in heating and nuclear power plants.
A specific case of water storage is the reservoirs of pumped-storage hydroelectric plants. The total water supply reserved for energy accumulation during times of energy surplus is maintained in a volume of 19,385,000 m3. The retention of surface water and its storage in the reservoirs can generally be considered as an anthropogenic factor affecting water status and ecosystems by changing the morphology of watercourse channels. Simultaneously, however, reservoirs fulfill other essential complementary functions serving local communities. In order to protect against the effects of the increasingly significant climate change, reservoirs are used to buffer flood waves and to ensure minimum sanitary flows as laid down in the operational schedules approved by the local authorities. In times of drought, they provide the basic living conditions for aquatic plant and animal species in water streams. Water storage carried out by CEZ Group therefore has predominantly positive environmental impacts.