A Ukrainian defense consultant has come up with an innovative solution to slow down Russia’s advance on Kyiv. Oleksandr Dmitriev knew that by blowing a hole in the dam controlling the Irpin River, he could flood the surrounding boggy terrain and make it impassable for Russian war machinery. With his knowledge of the area, having previously organized off-road races there, he convinced the commander to allow him to execute the plan. The strategy proved effective, rendering the Russian troops unable to move forward.
Source: https://www.politico.eu/article/russia-defense-kyiv-ukraine-nato-eu-bogs-poland-war-germany