The need to proceed immediately with new anti-flood planning with an emphasis on resilience, taking into account the new climate data that emerged from the bad weather Daniel, was expressed by the Minister of Environment and Energy, Mr. Thodoros Skylakakis.

As Mr. Skylakakis points out based on the available data, 8 billion tons of water fell in Thessaly. However, “the coming, however, of a flood that occurs once in 1,000 years, which was not foreseen, changes the hydrological data of the country and requires a comprehensive revision of the anti-flood planning” he points out.

In particular, according to the announcement of the Minister:

1. During the “Daniel” flood based on available data, 8 billion tons of water fell in Thessaly. In the extreme scenario of the existing flood risk management plans, which would occur once in 1,000 years, the rainfall would reach about 6-8 billion tons (the corresponding maps are drawn with the average scenario predicting about 6 billion tons). Flood control projects in Greece, according to Law 4258/2014 and Ministerial Decision TT660/2017 (B’ 428), are designed for floods that occur once in 50 years. In the “Daniel” flood the water was 3 times more than a 50 year flood. Therefore, objectively (regardless of any individual weaknesses, local or national, which obviously need to be thoroughly scrutinized) there was no way that flood defenses designed for a 50-year flood could contain a 1,000-year flood.

2. The country’s anti-flood planning is based on the most recent (as of 2018) Flood Risk Management Plans (FRMs) including Hazard Maps and Flood Risk Maps, which only give an indication of where floods will occur.

The indication is useful, but its usefulness is limited, as the maps are based on the unrealistic assumption that water falls evenly over all areas and at a constant rate throughout the day, and also does not include the all-important dimension of the materials carried.

These static maps instead of dynamic prediction models, the lack of preventive measures for the resilience of productive activities against large flood phenomena and the lack of coherence so that the network of anti-flood works works as a single whole, were the objective weaknesses of those plans.

In relation to coherence, it must be realized that a flood protection system, comprising an entire catchment or several connected catchments, is only as strong as its weakest point in terms of flood protection provided by the network of flood works.

Flood protection is not about a single project, but requires a multitude of individual flood protection projects, working as a single unit to cover the watershed, and their implementation has taken decades and been done at great cost. Therefore, the change of level of flood control planning, regardless of which level should be done, leaves the flood control planning in the interim until the completion of all projects concerning a catchment, to a large extent, closer to the previous than to the next level, in terms of protection it offers.

3. The multi-division of responsibilities and bodies overseeing the implementation of flood control planning is a structural weakness of Greek flood control planning, as the bodies have different capacities and levels of effectiveness. Therefore, the implementation of flood control planning is only as good as its weakest agent.

4. The climate crisis has two characteristics: First, for the next 30 years at least it is irreversible and possibly worsening, with phenomena that did not exist in previous centuries. Second, there is very significant uncertainty about the magnitude of these phenomena, as climate models are still imperfect. Therefore, our planning should be done under the assumption of an adverse, realistic scenario.

The government, to deal with the new reality regarding flood phenomena moved in the previous four years in two directions: First, it invested in important anti-flooding projects, after Janos, which are in various stages of implementation, while at the same time it started the unification of the policy regarding the monitoring of water issues, despite the strong reaction of the opposition, with the institutionalization of the Waste, Energy and Water Regulatory Authority (RAAEF) and the planning of the reform in the matters of water service providers such as DEYA and GOEB/TOEB.

However, the arrival of a flood that occurs once in 1,000 years, which was not foreseen, changes the hydrological data of the country and requires a comprehensive revision of the anti-flood planning, which will take into account that:

A) You have to to improve climate models, to obtain a safer – if possible – forecast for the frequency of “super-floods” in the coming decades. At the same time, we must (in parallel with the completion of the updating of hazard maps, which is also our legal obligation) move from static flood maps to dynamic flood forecasting and monitoring models, with priority in the most dangerous areas.

B) Whatever level of flood protection is decided (e.g. floods that occur every 50 years, based on the new climate data), must be ensured – by flood protection projects and plans – that it exists everywhere, works effectively and is implemented in the context of strict planning (schedules, quality of execution and holistic treatment of flood phenomena).

C) It should be entered into our design, as a priority, the concept of durability and be supported with very significant resources. And resilience is both about the length of time it takes to raise the level of flood protection and to manage events that may be larger than flood planning in the environment of uncertainty we have entered. First of all, our design should protect human life as an absolute priority. Moreover, the concept of resilience is inherent in the new European strategy for the climate crisis (Green Paper on the European Program for the Protection of Critical Infrastructures and Directive 2022/2557) and includes resilience of critical infrastructures, which may need to have a much higher level of resilience , from the flood resistance level. This means that these infrastructures should withstand floods, e.g. 1,000 years, even if the general level of flood protection planning is lower. Furthermore, the planning must also concern productive infrastructures and activities of the private sector.

The implementation of this design requires time for study. At the same time, however, it should be started and implemented with great speed, because we simply do not know how much time we have.