Ukraine: "Worst case modelling for Nova Kakhovka dam break"
Here's an analysis done last year after the dam was damaged. One current (!) theory is that because there are no videos of an attack in an area under 24/7 surveillance that the dam break was caused by the pressure of the water in the reservoir on the weakened structure, perhaps exacerbated by releases of water further up stream.
From Cornucopia, October 22, 2022:
IMPORTANT ADDENDUM 2023-06-06: The model have been further
developed and water should start rising at Cherson city after three
hours.The actual waterlevel in the dam is also higher
than in the model below. Media enquires about the modelling of a dam
breach at Nova Kakhovka should contact UNICEF in Ukraine who took over
the initial model from Dämningsverket. THE MODELLING BELOW SHOULD NOT BE
USED FOR DECISIONMAKING OR INFORMATION ON WHEN TO EVACUATE. THE
UKRAINIAN AUTHORITIES WILL HAVE CORRECT INFORMATION.
This blogger is not an expert on hydrology, dam
breaches or flooding. This blog just published a first prelminary
modelling of a dam breach at Nova Kakhovka. Any interview requests will be declined.
A worst case modelling for a russian demolition of the Nova Kakhovka
Dnipro river dam show that the worst flooding will take place on the
left (south east) side of the river bank. A 4 – 5 m wave will hit the
Antonovsky bridge east of Cherson city after 19 hours, and there will be
a backswell flooding up the Inhulets river, and after 4 – 5 days there
would be some flooding up the river Bug to Mykolaiv. The demolition of
the Nova Kakhovka dam is a war crime according to the Geneva Convention,
but Russia has already systematically broken the Geneva convention
during it’s illegal war in Ukraine.
Clarification: The worst case here is that all the floodgates are
blown, ie 200 meters. The entire dam is 3500 meters and in the event
that 400 m or 1 800 m would be torn down the modeled time for the water
to hit Cherson City would be almost halved. There would be some more
flooding.
Model of the flooding
First off, dams like the Dnipro dam in Nova Kahkovka are protected by
the laws of war and the Geneva convention. Destroying it would be
considered a weapon of mass destruction and an indiscriminate war crime.
Article 56 of the 1977 Additional Protocol I provides:
“Works and installations containing dangerous forces, namely dams, dykes and nuclear electrical generating stations, shall not be made the object of attack, even where these objects are military objectives, if such attack may cause the release of dangerous forces and consequent severe losses among the civilian population.
Other military objectives located at or in the vicinity of these works
or installations shall not be made the object of attack if such attack
may cause the release of dangerous forces from the works or
installations and consequent severe losses among the civilian
population.”
The following modelling of the worst-case dam break have been done by the Swedish hydrological engineering company Dämningsverket.
