My guess is all the energy that was being diverted from the rain aspect, according to the graph, suddenly flowed into whatever controlled the water control systems
Maybe that amount of energy was conducted by Climatrol (aka Automated Meteorological Data Acquisition System or "Rainmaker") for other things more important than its main functions (production of rain and irrigation)... and no rain = more temperature.
Maybe they needed to concentrate all energy to provoke a new "great flood" (perhaps an earthman's idea since they came in that "noah ship"). Maybe their first plan was "purifying" Motavia and then establish there (like it happened on the great flood of noah), that's why they didn't wanted Parma at all (every thing was settled in Mota, they just have to close the dams again to finish the job).
I have to wonder where all that water came from. It doesn't seem like all of it could have been stored in one building or underground.
I think climatrol is also a "straw", like it could suck the water underground "main land" (or should I call it "big island" instead?). It can be also seen like an ordinary (but colossal) dam controlling the water from the bottom to top (and not from a side to another, like blue, red, green mini-dams). That’s why they needed so much energy (or all of it).