Thread by @gbrumfiel

The Kakhovka Dam appears to be gone. This is going to have far-reaching consequences for weeks and months to come.

Here are some very early thoughts. (video via Ukrhydroenergo Telegram)🧵

First, a little background on what had been going on. Water levels plummeted in February and then surged in May to record highs.

I think this is because Russia was not managing the dam. They left some sluice gates open on their side, which caused water levels to drop at the start of winter...

But after the spring rains, the gates weren't letting enough water through...

https://twitter.com/gbrumfiel/status/1663571076264108033?s=20

In early May, water levels were so high, that it started to overtop the dam. That means water was actually flowing over the sluicegates.

https://twitter.com/davidhelms570/status/1658447250450792448?s=20

The dam had already been damaged in two previous incidents.

❌ A possible Ukrainian strike in late Oct/Early Nov.

❌ A likely Russian explosive charge that blew up part of the roadway over the dam on 11 Nov.

(Sources: reuters.com/world/europe/u…
And reuters.com/world/europe/n…

The dam was already under enormous strain and damaged.

Then things got worse. On 2 June, it looks like a road over the dam failed. That could be indicative of a larger structural failure.

I made a short movie here using @planet imagery.

You can see that the road, which runs over the dam, was washed away between 2-3 June. That indicates to me that there were structural issues at the facility before whatever happened today.

It is obviously possible that the Russians destroyed the dam in the face of a new Ukrainian offensive.

But given the recent past events at the dam, I think a structural failure coincident to the offensive cannot be ruled out. Not yet anyway.

https://twitter.com/Osinttechnical/status/1665907948986458113?s=20

OK, so consequences--

The first one is catastrophic flooding on the lower Dnipro river. I don't know enough about the hydrology to know how it'll play out, but Kherson and Nova Kakhovka are the two biggest cities likely at risk.

The second is at the Zaporizhzhia Nuclear Plant. The plant relies on the Dnipro reservoir for its cooling water.

My previous reporting suggests if water levels fall below 13.2 m, it will cause cooling problems. (I'm not sure how hard that limit is).

npr.org/2023/02/10/115…

At the moment, the reactors at ZNPP are in cold shutdown. They still require cooling to move residual heat out of their cores, but it's at much lower levels than during normal operation...

So when the water levels drop below the critical limit (and they will in a matter of days or weeks, I suspect), it will not trigger an immediate nuclear crisis.

However, I have no idea how the plant will be able to maintain cooling in perpetuity.

Here's a little background on the plant's cooling pond. It appears to be separated from the reservoir, but I have no idea how good that separation once the reservoir drains completely.

https://twitter.com/davidhelms570/status/1618963523463430145?s=20

Bottom line-- This is really bad news for the Zaporizhzhia Nuclear Plant.

The plant has already endured:
❌shelling
❌ numerous blackouts
❌ A major exodus of staff
❌ Russian military occupation

Now it's going into the summer without its main source of cooling water.

And speaking of summer, that's the final consequence to think about:

The Kakhovka reservoir supplied irrigation and drinking water to the region--particularly Russian-held Kherson and Zaporizhzhia.

This is going to ruin the crop and leave many cities without water.

Final postscript (and then I'm going back to bed for a few hours anyway):

The canal that supplies water to Crimea has its intake just above the dam. However, as TASS reported last Nov, Russia has topped up Crimea's reservoirs. No immediate crisis there.

tass.com/russia/1535583