Blue Silk River
The Blue Silk River is a major waterway on the Medial 1A floodplain - the ancestral home of almost all humans now living beneath the Manifold Sky. While the mighty Blue Silk now lies entirely within Voxelian territory, the river has had a great impact on both the New Voxelian and Elovisian descendants of those early human tribes.
The Blue Silk River has its headwaters in streams in the corner mountain range around the aptly-named town of Vianne Tributaries. These streams are fed through a combination of snowmelt year-round and the monsoon rains around Rainmaas in the late summer. The Vianne Reservoir at the foot of the corner mountain range features a dam to provide better flood control, as flash floods on the Blue Silk would historically wash away villages that were built too close. The Blue Silk continues clockwise from the Vianne Reservoir to wind its way almost all the way around Medial A1 - its long, sinuous route goverend primarily by the hilly terrain - before finally flowing towards the commissure at the center of what is now Silkenvault. Another small reservoir at the edge of the commissure provides Silkenvault with drinking water. Overflows from this reservoir cascade over the edge of the commissure as falls, where the falling water atomizes, evaporates, and returns to the hydrological cycle provided that the weather is warm enough. During heavy rains or cool weather, some water accumulates in the micro-gravity region of the commissure at Medial A1. Weatherproofed transit stations and a network of scavenger pumps can keep the commissure navigable in these circumstances. However, if the Coalition of Breakaway Colonies is making advances in Medial H and there is a potential threat of air raids against the A side of Silkenvault, the Grand Army of Voxelia may instead order that the commissure be allowed to fill for a time. Doing so effectively interdicts all air travel through the commissure, but it also helps prevent air raids against the Voxelian heartlands.
Medial Tesseract - and especially in other tesseracts beyond Medial - were not quite as forgiving, leading to the collapse of possible competitor civilizations in early antiquity. The development of irrigation techniques later allowed the Old Voxelians and proto-Elovisian peoples to expand beyond the salubrious reach of the Blue Silk's rejuvenating flood cycles.
The Blue Silk River once played host to abundant fish populations. The explosive growth of the Voxelian civilization saw these populations fished almost to extinction. Now, while fishing continues all along the Blue Silk, the catch is regulated with the advice of the Voxelia Academy of Sciences to ensure sustainability.
It's a common misconception that the Blue Silk River was named for the silk being shipped along it from the outlying kingdoms in antiquity. While the river was used this way for a time, the 'Silk' part of the river's name actually comes from the presence of a fine, glittering silt that sometimes washes down the river during the dry season, lending the water a silken sheen in direct sunlight. The upper reaches of the river are known to hide veins of gold and copper - enhancing this sheen when bits of them wash downstream - but none large enough to warrant dredging.
Extensive trade was once conducted along the Blue Silk River, with traders, fishermen, loggers, and stonemasons using flat-bottomed boats to ride the current downstream with their wares. The boats would make a full circuit of the river before being carried overland where it diverted towards the commissure. In more modern times, where trains and other dieseltech vehicles are much faster modes of transportation and provide easy access to other cube faces, boat rides on the Blue Silk are mostly undertaken for recreational purposes. White water rafting from Vianne Tributaries is a popular extreme sport, but the lower extent of the river is more gentle and better suited for taking in scenery. The Vianne Reservoir remains a popular recreational fishing spot. The reservoir in Silkenvault is uncommonly used for watersports due to the pollution that accumulates there, but Silkenvault has installed tree-shaded boardwalks around it and zoned it for light commercial use, making the area popular with pedestrians and tourists.