Water quality of the Odra and Baltic after the flood. We have an answer from GIOŚ

The September flood on the Odra not only left destruction in infrastructure but also raised questions about the condition of surface and marine waters. The Chief Inspectorate of Environmental Protection (GIOŚ) has responded to our questions regarding the water quality in the affected regions. What are the monitoring results? Were additional studies initiated, and how did the flood affect the ecological state of rivers and the Baltic Sea?

Water quality of the Odra and the Baltic

• What were the water quality monitoring results for the water bodies in September, October, and November 2024? Were there significant changes in water quality parameters compared to earlier periods?

GIOŚ: The Central Research Laboratory of GIOŚ continuously conducts tests on samples collected as part of the National Environmental Monitoring program. Current results obtained in terms of surface water monitoring are posted as they are received on the portal.

• Has GIOŚ initiated additional monitoring on watercourses affected by the floodwater, including the Szczecin Lagoon, to assess the type and concentrations of pollutants? If so, what were the results of these studies?

GIOŚ: As part of the emergency monitoring, the CLB GIOŚ is currently conducting tests/measurements on water samples from the Odra River according to the document approved by the Minister of Climate and Environment, GIOŚ’s internal document: Procedure for Emergency Monitoring of Prymnesium parvum (golden algae). The procedure specifies how to conduct emergency monitoring to detect potential risk of blooms.

Following the flood situation, according to the recommendations of the Inter-ministerial Team for Crisis Situations and Environmental Threats on the Odra River from September 19, 2024, the performance of golden algae studies within the Odra River emergency monitoring was limited. From September 23, 2024, CLB conducted emergency monitoring at 4 measurement and control points located on the Gliwice Canal.

However, routine studies were carried out after the threat associated with the passage of the flood wave had ceased, and current results are available on the website. Those significantly deviating from the norm are forwarded to the appropriate provincial environmental protection inspectorates (WIOŚ) and regional water management authorities PGW WP to take potential control actions.

From October 21, 2024, emergency monitoring of the Odra River, Gliwice Canal, old river beds, reservoirs, and lakes was resumed. Results of studies and measurements carried out as part of emergency monitoring are presented on the GIOŚ website.

• Assessments of the flood’s impact on water quality: does GIOŚ plan to conduct a comprehensive assessment of the flood’s impact on water quality, including the Baltic Sea? If so, when can we expect the results of such an assessment?

GIOŚ: GIOŚ performs water condition assessments according to current regulations, i.e., the regulation of the Minister of Infrastructure from June 25, 2021, on the classification of ecological status, ecological potential, and chemical status, and the method of classification of the status of uniform parts of surface waters, as well as environmental quality standards for priority substances (Official Journal of Laws 2021, item 1475).

The next assessment will be conducted by the end of September 2025 and will include the results of studies obtained as part of the national environmental monitoring for the period 2019-2024.

It is worth noting that according to the aforementioned regulation, the classification and assessment of the status of uniform parts of surface waters (JCWP) do not include exceedances resulting from natural disasters, including floods. Including such results would be inconsistent with the provisions of RDW, whose purpose is to determine the general state of JCWP without the influence of extraordinary conditions, such as a flood.