A foreign firm. A utopian vision. A mythical terrain. Is this the stuff of science fiction or of an engineering master plan? Turkish writer Orhan Duru is credited with bringing the concept of science fiction and its Turkish term, bilim kurgu, into the language in the 1950s, at roughly the same time as another genre, the engineering master plan, became a necessary factor in accomplishing massive infrastructure works on Turkish rivers. Since that time, the two types of world-making—one literary and one infrastructural—have evolved in tandem. Writers have expanded the scope of science fiction in the Turkish language. Engineers have expanded the scope of master plans (the Southeast Anatolia Project [GAP] Master Plan runs to four volumes and nearly 600 pages). Both genres conjure on a fantastical scale. Both evoke imagined pasts, presents, and futures. Both authorize, justify, and legitimate imaginative constructions, though one has generally been more successful in bringing about material manifestations. This research connects the production of master plans and other engineering documents with the cultural production of science fiction narratives in a Turkish context, illuminating how each genre expresses the boundaries of its world-making endeavors, imagines environmental change and human-nonhuman relations, and reflects social and historical processes.