Remember that the sluice gates are seized. Obviously they should still drain it but it's not as simple as making the call.
1. I didn't make a claim. I asked a question.
2. According to the experts, the clock is currently ticking down on a million lives with no idea of how much time is left, so your implied suggestion of doing nothing (which is the implied suggestion when you summarily dismiss a line of thought while providing nothing in its place) is... well, how exactly would you describe the suggestion of just letting a million people die, had it come from someone else?
Second, one would normally expect the force required to break the dam to be orders of magnitude larger than that required to open a sluice gate. Obviously this isn't a normal situation, but then, what are the figures? If a stick of dynamite isn't the appropriate tool, exactly what would it take to open the gates?
Third, if you could say 'we are going to try this at such and such a time, everyone be prepared' that would be far better than having it fail at an unknown time.
Fourth, now that I think of it, even deliberately blowing up the dam at a known time would be better than letting it fail at an unknown time.
Fifth, I'm sure there is some relevant idea or consideration I haven't thought of, that someone else could think of if they put their mind to doing so.
The main fear here is that if the dam reaches its design head, the water will tunnel underneath and around the dam through the water soluble rocks. The dam can't exceed the design head because of the spillway that is visible to the south east of the dam.
So explosives could well be used to force open the sluice gates.
This would make for a great Michael Bay movie, but real life doesn't work that way.
The article says only one of two gates has problems, but they cannot open only one because of the asymmetry that would introduce. So, to solve the problem with dynamite, it would be necessary to make very good calculations to be sure you make exactly the hole you want, then actually do it with a very high precision (for an explosion).
I do not think opening that gate is as much a technical problem as a problem of initiative and responsibility.
The spillway of the Mosul dam is made of concrete the problem with it appears to be that it allows too high a water level for the dam in its current shape even when fully open.
http://www.physicscentral.com/experiment/askaphysicist/physi...
Also what you're describing is literally how all siphons must work--you can't siphon to a higher elevation.
"Here we report an experiment of a siphon operating at sea level at a height of 15 m, well above 10 m. Prior degassing of the water prevented cavitation. This experiment provides conclusive evidence that siphons operate through gravity and molecular cohesion."
"""Extrapolating these results from even the most conservative experimental measurements of the tension under which cavitation occurs it is possible that the cohesive strength of fully degassed water is able to support a continuous vertical column greater than several hundred meters. While the experiment performed here did not reach anywhere near the absolute limit predicted it does shed light on the stability of flowing water under tensile stress and the possibility of constructing apparatus of suitable dimensions to test such a limit. (...) In view of the many anomalies of bulk water, it would be interesting to explore the physical properties of water in the negative pressure regime of a siphon above 10 m."""
So, as long as we don't break the water column by bubbles (or other impurities in the water that will lead to formations of bubbles on their surface) we could empty the Mosul dam via a siphon.
That's a fascinating result! We only have to remove the rocks, the fish and put the dam under high-vacuum for outgassing for a few weeks ;-). If we don't do that, the old atmospheric pressure model holds, and the siphon will be limited to 10 metres, 30 ft.
As long as you are below the limit, you can still claim that the "two sides" of your siphon are held together by the pressure extorted on both sides by our atmosphere. And only as you exceed this limit you'll require the water to resist actively to be "pulled apart".
Unfortunately this interesting property is pretty irrelevant in real-life situations where water you'd like to siphon contains dirt, rocks, crockodiles... And these impurities will make your "water cable" break as soon as (or probably just a little later when...) you reach vacuum on the top, at 10m.
https://www.wolframalpha.com/input/?i=(1+atmospheres)+%2F+(d...