Review on spring floods

In the middle part of river Daugava spring floods began in the middle of March with gradual rise of water level and melting of ice cover. Movement of ice caused more rapid rising of water level in Daugava near Vaikuļāni on March 23 and 24. Temporal decrease of water level followed the next days.  Rising of water level started once more on March 27 and continued till April 3, when lowest areas of Dviete floodplain started to overflow as well.  Maximal height of the first flood peak reached 88.2 m above the sea level in Daugava near Vaikuļāni and about 87.7 m above the sea level in Dviete floodplain at the Information center of Dviete floodplain – 'Gulbji' farm.  As a result most of the wells for monitoring of ground water level, arranged in winter, were under the water.

Due to colder weather and decreased intensity of snow melting, water level in Daugava near Vaikuļāni started to decrease on April 4 and during the next 10 days lowered for about 0.7-0.8 m, reaching minimum on April 13 and 14.

In the middle of April, when rapid snow melting started in upper parts of Daugava river basin (Valdai Hills) once more, water level in Daugava and Dviete floodplain rose again and reached the maximum of this spring on April 28. This peek was about 2 meters higher than the first, and its absolute height reached 90.4 m above the sea level on April 28 in Daugava near Vaikuļāni and about 89.8 m above the sea level in Dviete floodplain. That water level maintained for several days , and only in the very end of April considerable decrease of  flood level began both in Daugava  and in Dviete floodplain.

We can conclude that the course of spring floods in Daugava and Dviete floodplain had two expressed peaks this year, which followed one another after three weeks. Due to changing weather conditions, culmination of spring floods was two weeks later than usual, still the maximal flood level was close to the mean flood level in the area according to long-term data.

Dāvis Gruberts

11.05.2012.