Aim of the study:
The purpose of the work is to find solutions among those offered by the Room for the River program acceptable for nature, durable and long-lasting. We addressed whether the evaluated solution provides positive synergy, attenuates flood waves to mitigate flow rates, and offers an alternative to storage reservoirs. Furthermore, we examined whether any of the proposed measures produce adverse effects, such as the levee/embankment paradox.

Material and methods:
The methodology adapts eco-engineering interventions from the Dutch 'Room for the River' program (initiated 2001–2002 on the Rhine and Meuse) to the Vistula River. Using computational analysis, we focused on non-traditional measures, formulating hypotheses to define expected hydrological outcomes. Finally, a proof-of-concept verification validated the technical feasibility and efficacy of the proposed measures: main channel horizontal and floodplain vertical expansions, embankment shifting, and side channel activation.

Results and conclusions:
This paper defines the scope of effectiveness of the solutions measures. We present verifications of project effectiveness across alternative solutions and verify which project elements can be applied under specific conditions. The evaluation criteria for hydraulic effects consist of the acceleration or deceleration of flood wave propagation, the reduction in the water surface level (WSL), and the enhancement of channel conveyance capacity. We use the results of 1D modeling to create our own computational analysis; without time-consuming and computationally expensive 2D modeling, we obtain numerous comparative results to facilitate the selection of measures.