Poland, compared to other European countries, has relatively limited water resources. On average, there is approximately 60 billion m³ of renewable freshwater resources per year, and even less than 40 billion m³ during periods of drought. Water resources in Poland are highly variable both in time and space. This is particularly true for the south of the country, which is prone to both water shortages and periods of excess water caused by heavy rainfall and flooding.

According to the UN, annual renewable freshwater resources of at least 1,700 m³ per person are necessary to ensure water security. Since the beginning of the century, Poland has either been on the brink of water insecurity or actually experiencing it, especially during periods of drought. Between 2015 and 2023, renewable freshwater resources per Polish resident ranged from 1,100 to 1,600 m³, which is considered low, thus classifying Poland among those EU countries that are particularly susceptible to water shortages. Currently, it ranks third in the EU in terms of the least amount of fresh water per resident. Cyprus and Malta are the only countries with lower water resources than Poland.

Water stress is an important measure which shows how much pressure is on water resources. It illustrates the relation between the consumed amount of water and its actual supply. In Poland, the level of water stress has decreased from 19.2% to 15.0% since 2015, which indicates a moderate pressure on water resources and a relative stability of their consumption, although water supply remains limited. The reduction in water stress resulted partly from a decrease from 262 m³ in 2015 to 214 m³ in 2024 in annual water consumption per resident. Despite this improvement, Poland remains among those EU countries that face the highest levels of water stress.

Low water supply and a growing drinking water deficit show how important it is to manage this resource wisely. In Poland, water management is becoming increasingly more rational. The added value generated per m³ of consumed water steadily increased from EUR 38 in 2015 to almost EUR 65 in 2023. This proves that water is used more efficiently, bringing greater benefits to the economy.

At the same time, the capacity of small water retention facilities in Poland is increasing, which is of great importance given the variable flows and periodic water shortages. Between 2015 and 2024, the capacity of water storage grew from 830,000 dam³ to 881,000 dam³. Its systematic increase helps to mitigate the effects of both water shortages and heavy rainfall.

With water scarcity, it is important to closely monitor water consumption. The Water Exploitation Index plus (WEI+) is one of the indicators used to assess the extent of water resources consumption. It shows what percentage of renewable water resources is used in a given country or region. A value of over 20% indicates a potential risk and significant stress on the aquatic environment. In Poland, this index decreased from 7.7% in 2015 to 5.2% in 2023 (its value fluctuated in individual years). In 2023, Poland ranked 8th among EU countries in terms of the highest WEI+ values, with a score equal to the EU average. These data are averages and thus do not fully reflect seasonal and regional differences. Many regions in Poland, especially in the south, experience periodic water shortages, which are not visible in the aggregate data.

The quality of surface water is of great importance to human health, the environment and economic development. One of the measures used to assess water pollution by organic substances is biochemical oxygen demand (BOD). This indicator measures the amount of oxygen (in mg/l) that microorganisms need to decompose organic matter present in water. The higher its value, the greater the biological pollution. In Poland, between 2015 and 2022, an average of 2.80 mg of oxygen was needed to decompose organic matter in 1 litre of river water. This value increased slightly, from 2.76 mg in 2015 to 2.85 mg in 2022. Although these levels are not alarming, they indicate persistent moderate organic pollution. These results are lower than in EU countries with the worst water quality (e.g. in Spain, where the BOD index in river waters was 3.81 mg/l in 2022), but significantly higher than in countries with the best water quality such as Slovenia (0.78 mg/l) and Ireland (1.16 mg/l).

A more complete picture of the condition of surface waters in Poland is illustrated by the results of the assessment of the uniform surface water bodies (USWBs), i.e. basic water management units. The data show that the quality of water in Polish rivers and lakes is definitely unsatisfactory. Between 2019 and 2024, 3,200 SWBs including rivers and dam reservoirs were assessed, most of them located in the Vistula and Oder river basins. Only 49 units (i.e. merely 1.6%) were classified as in good condition. In terms of lakes, 1,100 units were assessed, out of which only 64 (i.e. 6%) were in a good state.

The assessment of the chemical condition of waters, conducted independently of the overall assessment of the USWBs, is also unfavourable. Between 2019 and 2024, only 14% of USWB rivers and dam reservoirs were in a good chemical condition, while as many as 86% did not meet the applicable norms. Transitional and coastal waters in the Vistula and the Oder river basins were also mostly assessed as being in poor condition, both chemically and ecologically. The unsatisfactory quality of water is also evidenced by the results of the tests carried out in Polish bathing waters, which tend to be conducted more frequently. In 2024, out of the 764 tested inland and coastal bathing waters, slightly more than a half (444) could boast excellent water quality. For comparison, in 2015, approximately 60% of the bathing waters tested (approximately 120 out of 197) received the same rating.