Editing Selenga (section)

=== Floods ===
Periodic floods are characteristic of the Selenga River, with small flooding events observed annually.<ref name=":3" /> There have been four periods of high-flooding: 1902-1908, 1932-1942, 1971-1977 and 1990-1998. The floods of the Selenga River can be classified based on the degree of impact. "Catastrophic" floods refer to floods that cover the majority of the river basin and cause flooding of whole settlements. These floods included the possibility of human casualties, and are estimated to occur 3-4 times per century. Twenty-six floods occurred between 1730 and 1900, and of these 26, three floods were "catastrophic".<ref name=":10">{{Cite journal|last1=Kadetova|first1=Alena V.|last2=Radziminovich|first2=Yan B.|date=2020-05-11|title=Historical floods within the Selenga river basin: chronology and extreme events|url=http://dx.doi.org/10.1007/s11069-020-04001-z|journal=Natural Hazards|volume=103|issue=1|pages=579–598|doi=10.1007/s11069-020-04001-z|s2cid=218592869 |issn=0921-030X|url-access=subscription}}</ref>

The flood of 1830 in the Selenga River is the first flood that was recorded in some detail. On August 1, 1830, the Selenga River and its tributaries, the Chikoy, Dzhida, Khilok and Temnik Rivers, burst their banks. The flood plains and the islands in the Selenga River were completely flooded. On August 16, Verkhneudinsk, the city now known as Ulan-Ude, was flooded and the water level in the city reached {{convert|420|cm|in}}. The flood destroyed fifty-four buildings in Selenginsk. After the flood, the town was moved to higher ground on the left bank of the Selenga River. There were also heavy losses in agriculture, with the flood making some pastures and hayfields unusable for an extended period after the flood. The river retreated to its banks by September 27.<ref name=":10" />

Water levels began to rise on July 24, 1869, but slowly decreased from August 5, 1869 The water level began to rise again on August 22, only beginning to decline from September 3. In Verkhneudinsk, the water level reached {{convert|386|cm|in}}, and in Lake Baikal, the water level rose by more than {{convert|2|m|ft}}. The water level in the Angara River also rose and did not return to its pre-flood levels by January 1870.<ref name=":10" />

The flood of 1897 began on August 11, when water levels started to rise in the middle and lower reaches of the Selenga River and reached its peak on August 14. The water level then proceeded to decrease gradually over ten days. On the first day of the flood, the water level rose by {{convert|4|m|ft}} in three hours. The water level in the Selenga River was over {{convert|350|cm|in}} near Verkhneundinsk. The flood did not heavily impact settlements on the banks of the Selenga River, but there were reports of bridge and telegraph pole destruction between the towns of Selenginsk and Verkhneundinsk. The volume of water inflow into Lake Baikal during the 1897 flood is estimated to have been approximately {{convert|22.2|km3|mi3}}. Flooding from the Selenge River can affect the environment of Lake Baikal. It can also cause an increase in runoff from the Angara River.<ref name=":10" />