In mid-January 2022, the team from MGGP S.A. in Krakow completed the implementation of the project "Development of flood hazard maps and flood risk maps for areas vulnerable to flooding in case of destruction or damage to dam structures." The project was carried out at the request of PGW WP KZGW in two parts – from 2019 to 2020 for 7 dams (part 1), and from 2020 to 2022 for another 19 dams (part 2), for a total amount close to 2.8 million PLN.
These works were carried out as part of the broader project "Review and update of flood hazard maps and flood risk maps," financed under the Operational Program Infrastructure and Environment, Priority Axis II: Environmental Protection, including climate change adaptation, Action 2.1 Climate change adaptation with securing and increasing resilience to natural disasters, especially natural disasters, and environmental monitoring. The review and update of flood hazard maps (MZP) and flood risk maps (MRP) in 6-year cycles is an obligation resulting from Article 171(8) of the Water Law Act of July 20, 2017 (Journal of Laws of 2018, item 2268, as amended), necessary for the implementation of the provisions of Article 14 of Directive 2007/60/EC of the European Parliament and of the Council of October 23, 2007, on the assessment and management of flood risks (Floods Directive).
Flood hazard and risk maps were developed for the following flood scenarios:
1) Scenario I - areas where the probability of flooding is low, at 0.2%;
2) Scenario II - areas where the probability of flooding is moderate, at 1%;
3) Scenario III - areas where the probability of flooding is high, at 10%;
4) Scenario IV - destruction or damage to flood embankments for flow with a moderate probability of occurrence p=1% (scenario of total embankment destruction).
5) Scenario BP - destruction or damage to the dam structure for controlled flow at the dam and for flow in the watershed below with a low probability of occurrence of 0.2%.
The team's task was to prepare a database and cartographic versions of Flood Hazard Maps (MZP) and Flood Risk Maps (MRP) for the last of these scenarios - scenario BP. Part 1 of the project was carried out based on spatial layers or raster files provided by the Ordering Party, containing flood hazard areas developed by other contractors. Part 2 was implemented based on hydraulic models provided by the Ordering Party, made for scenarios I - IV, and independently generated as a result of modeling flood hazard areas for dam failure scenarios. In the next step, MZP and MRP projects underwent internal and external control, followed by alignment with 11 voivodeships. Accepted spatial layers (in shp files) and cartographic versions (in geotiff and pdf files) were provided to the Ordering Party for publication on the hydroportal and to contractors preparing the final report for the European Union.
Additionally, during the project, based on the methodological development prepared in 2011 by RZGW Kraków, a methodology for developing MZP and MRP for the case of destruction or damage to dam structures was developed and continuously updated. This methodology includes indications regarding the scope of required geodetic and hydrological data, construction of disaster scenarios for earth and concrete dams, located separately or in a cascade, principles of hydraulic modeling, scope, and method of preparation of spatial layers and cartographic versions of maps. This document will be used in subsequent planning cycles for updating MZP and MRP.
Currently, since October 22, 2020, Flood Hazard Maps (MZP) and Flood Risk Maps (MRP) for part 1 of our project are available on the website https://isok.gov.pl/hydroportal.html.
Maps from part 2 of the project are planned to be published in June 2022.