runnel

pieni joki A small stream, a rivulet.
1998, A. S. Byatt, Elementals: Stories of Fire and Ice, Chatto & Windus

...great chambers in the rock where all sorts of plants were growing, under windows which had been cut to let in the sun, and glazed to adjust his warmth, and where runnels of water ran between fruit trees and seedlings, pumpkin plants and herbs.

The people who settled here weren’t farmers. They hunted. Yet they built a large amphitheater of mud, a platform carefully runneled to carry liquid—possibly blood.