Its hard not hearing what is going on in Ukraine due to OpSec and listening to all the speculation and rumours of Russia potentially pulling back to the left side of the Dnieper river (the closest shore on the photo above). I find it hard to believe they would give up the city easily.
At the same time there has been talk of Russia mining the dam at Nova Kakhovka, so as to flood the Kherson city region. That also seems weird as they would lose the fresh water supply to Crimea and possibly the water supply at the Zaporizhzhya nuclear plant up-river.
I also read that the Soviets blew the hydro dam farther up-river in Zaporizhzhya in WWII, to slow the Nazi advance, causing 20 to 100 thousand deaths due to surge flooding. www.rferl.org/… The dam at Nova Kakhovka wasn’t there then, so the water levels below that dam would have been lower, as there would have been no reservoir, so the differential would have been higher causing a bigger flood effect. Still, the reservoir that the dam at Nova Kakhovka has created holds an awful lot of water and the potential for a powerful flood is still there.
On the other hand, the dam at Nova Kakhovka, as a run-of-the-river dam, is much lower and smaller.
Kherson is very flat, so I was curious what the flooding would look like. How much damage to the city itself? How much spillage across the land? Some commenters on Mark Sumner’s article seemed to claim that Kherson city itself would be spared. So, here’s a quick and dirty look at it (I’m short on time as usual, so only the broad strokes on this one).
Assumptions:
- The dam is not wide, so any hole would be small enough that it would cause a long drain instead of a instantaneous tidal wave.
- The dam is not high, so again, the water force would not be a singular wall, but a long persistent flooding.
- There is a lot of water in that reservoir so I’ll simulate up to just below its level.
Here’s what it could look like:
Two meters of flooding: city loses some of the river bank. Airport safe and sound. Most of the water spreads to the left bank (toward us in this rendering).
Four meters of flooding. City loses low-lying spit. Everything else drains to the south (left) bank.
Ten meters of flooding. The large town of Oleshky (24,000 pre-war pop.), just across from Kherson is surrounded and only its higher center is above water.
Fourteen meters of flooding. This would be catastrophic levels, but isn’t really possible, because this is the level of the water in the reservoir, on the other side of the dam. Even then, Kherson is pretty safe. So is the airport.
Even at its worse, I don’t see the advantage for Russia. The flooding isn’t enough to push artillery out of range, so the damage would be to all the settlements on the south side (which are not minor, but are claimed by Russia) and to the nuclear plant up river that could loose cooling water. It would seem like more of an own goal, flooding the south side — the left bank — more than any damage to liberated Kherson.
Not that I understand the motivation or strategy. I just like playing with maps.
