Gradually the most efficient, or logical, or aesthetically pleasing plans began to emerge from the proposals, the best for each region being patched together, in a kind of mosaic. In the eastern quadrant of the deep south, streams would tend to run toward Hellas Basin and through a couple of gorges into the Hellas Sea, which was fine. Dorsa Brevia accepted a plan to have their town’s lava tunnel ridge become a kind of dam, crossing a watershed transversely so that there was a lake above it and a river below it, coursing down to Hellas. Around the south polar cap, snowfall would remain frozen, but most of the meteorologists predicted that when things stabilized there wouldn’t be much snowfall on the pole, that it would become a cold desert like Antarctica. Eventually of course they would end up with a largish ice cap, and then part of it would pool down into the huge depression under the Promethei Rupes, another partially erased old impact basin. If they didn’t want too large of a southern ice cap, they would have to melt and pump some of the water back north, into the Hellas Sea perhaps. They would have to do some similar pumping in Argyre Basin, if they decided to keep Argyre dry. A group of moderate Red lawyers was even now insisting on this before the GEC, arguing that one of the two great dune-filled impact basins on the planet ought to be preserved. It seemed certain this claim would receive a favorable judgment from the court, and so all the watersheds around Argyre had to take this into account.

Sax had designed his own southern watershed plan, which he sent to the conference from their rocket as it aerobraked into orbital insertion, to be considered with all the rest. It minimized surface water, emptied most craters, used tunnels extensively, and channelized almost all drained water into the fossil river canyons. In his plan vast areas of the south would stay arid desert, making for a hemisphere of dry tableland, cut deeply by a few narrow river-bottomed canyons. “Water is returned north,” he explained to Nadia in a call, “and if you stay up on the plateaus, it will look like it always did, almost.”

So that Ann would like it, he was saying.

“Good idea,” Nadia said.

And indeed Sax’s plan was not that much different than the consensus being hammered out by the conference. Wet north, dry south; one more dualism to add to the great dichotomy. And to have the old river canyons running with water again was satisfying. A good-looking plan, given the terrain.