The Warning

There are many catalysts that brought us here. The war, the discovery, the threat of starvation, and so on, and so forth. But the most important one, without which we would not even not be here, but nowhere at all, is the warning letter that the Ravenmight Institute sent out. If it wasn't for their timely warning, and people listening, the dam destruction would have led to thousands of deaths.
Such a tragedy might not have impacted the front logistically, as now we actually are a bigger drain that we would have been as corpses. Morally it might have actually helped, due to rage. In fact, that last bit may very well already have been proven right, as the front has made good progress after the news of the dam breach hits. So honestly, the enemy actually made their own lives harder through this failed mass-murder attempt.
There is one suspicious thing about the warning letter, though. They say the Ravenmight Institute realised the reservoir could be harnessed as a weapon, so they promptly arranged for a massive evacuation. But then you could ask, why did everyone go along? They made it sound not like a theory, but a fact. A dangerous move if they weren't sure.
And on that note, the scholars that signed the letter? Former nobles with a lot of political clout, whose names convinced knights and soldiers to provide their full support, no questions asked? In the chaos it was missed, but over time it became clear that not all of them could have signed the letter on that fateful night.
One could build some suspicious theories about that. Such as assuming they sabotaged the dam themselves, or were involved in the plot. Maybe as traitors, maybe in service of the king, to improve moral. But the most likely explanation is far less malicious. The scholars realised something felt weird about enemy movement, so they signed an empty document in advance, to serve as useful tool if impromptu authority was needed. If that is the case, their clever thinking helped save many lives.