Although VMU professor hydrologist Steponas Kolupaila predicted such a flood, they were not prepared for it. The flood started on April 13. in the evening, as the ice moved, the water began to rise. It was most intense on the night of April 14. During the flood, about 30 streets and 204 houses were flooded in Kaunas, 700 families and 3,326 residents were affected.
April 15 In Kaunas, the water rose as much as 6.78 meters. The largest ice floes, which caused the high water level that year, formed near the settlement of Pypliai. The flood lasted for several days, on April 17. the press reported that the danger had already passed. But when the water receded, there was a second flood, only much smaller.
April 21 Neris and Vilnelė overflowed from the banks and flooded the lower streets of Vilnius. April 26 the recorded maximum discharge of the Neries in Vilnius was 1690 cubic meters. m/s, when nowadays it is 5-6 times lower during a normal flood. The incredibly high water covered the Cathedral Square, several streets, Antakalnis and Žvērynos districts.
Why was this flood so exceptional? 1930 in autumn, 13% of precipitation fell in the Neris basin. more than normal, which made the water level 114 cm higher than the perennial one before freezing. At the beginning of winter, the ground froze very wet, and in 1930-1931 winter was deep and long. The snow began to melt only in mid-April, and when the weather warmed up to +19 °C, all the rapidly melting water on the surface of the ground (due to freezing) quickly flowed into the river.
LHMT inf.
