The project I’m currently working on is set on a pair of planets, arranged like Pluto and Charon. Typically (I’m certainly not original, that’s for sure) one planet is very wet (like, super wet) and one planet is very dry (like, super dry). The plot follows the establishment of a small colony on the dry planet. It’s full of xenophobia, mystery and sabotage. There is a struggle to collect and store water from underground and because I’m a sucker for geology, I want to make sure that the dry planet makes sense; that it could actually be possible (at least vaguely!) to have a planet where 95% of the water is trapped underground.
I asked some of my geologist friends (because I’m cool) and one of them suggested I investigate karst systems. These systems are made through the dissolution of rocks (like limestone and gypsum) and create landscapes with underground drainage systems, sinkholes and caves. If you’ve ever been potholing then it was probably through limestone caves. The whole idea is that the dissolution of the rock forms joints and dykes, causing the surface water to sink. Perfect!
But there would probably still be rain in that scenario, right? I want water-acquirement to be difficult, since that will be the main ‘antagonist’ of the novel, so the rain has to be very limited. I want the world to be flat apart from one mountain range. Could it rain in the mountains and sink there, only to reappear later? I researched it, and yes! That’s called a ‘blind-valley’ – where a river suddenly disappears at high-ground and becomes part of the groundwater system.
This is double-perfect, because I recently discovered that underground dams exist! So this is the perfect way to harness water in that environment. Feels like the plan is certainly coming together!