The floating colonies did not begin as cities. They began as chemistry.

In the early 2100s, as GLMZ consolidated and the corponations tightened their grip on every square meter of land along the 88th meridian, a community of engineers, aquaculturists, and people who simply could not afford rent anymore turned to the one resource the corponations had not yet fully enclosed: the lake. Lake Michigan is freshwater, which presents a problem for the electrodeposition technique known historically as Seacrete or Biorock — a method developed in the late 20th century by Wolf Hilbertz, in which low-voltage DC current passed through submerged wire mesh causes dissolved minerals to precipitate out of seawater and deposit as a calcium carbonate structure. The ocean makes this easy: infinite mineral reservoir, natural conductivity, free material. Freshwater has none of these advantages.

The Water Collectives solved this. The early engineers — most of them Shelf refugees with fabrication skills and nothing to lose — adapted the process for Lake Michigan by supplementing the water with calcium chloride and magnesium chloride, both cheaply available from Ringo's road deicing supply chain (one of the few Ringo products the Collectives were willing to buy). They built recirculating mineral replenishment systems powered by offshore wind turbines — the lake has excellent wind resources — feeding both the colony's electrical needs and the electrodeposition rigs simultaneously. The process is slow. A structural reef takes months to accumulate meaningful mass. But the material is strong, self-repairing (cracks re-mineralize as long as current flows), and effectively free once the infrastructure is established.

The first Seacrete reef was grown in 2131 by a collective called the Foundation Circle, approximately four kilometers off the Kenosha shoreline. It was a wave break — a submerged wall of electrodeposited mineral designed to calm the water behind it for a cluster of anchored barges. Within three years, the reef had been expanded into a platform foundation. Within five, there were buildings on the platform — light structures at first, then heavier as the reef grew to support them. The Foundation Circle became the Kettle, the tech-abstainer commune that still exists today, its central platform now a solid mass of accumulated mineral deposit sixty years thick. The Kettle's elders say the platform is alive. They mean it metaphorically. The engineers are not sure it's metaphorical — the mineral structure has begun incorporating biological elements from the lake water, hosting algal colonies and freshwater invertebrates that appear to reinforce the structure in ways the original design did not anticipate.

Freeport, the largest colony, took a different approach. Rather than growing a single reef, Freeport's founders connected dozens of independent platforms — barges, decommissioned vessels, purpose-built pontoons — and grew Seacrete connective tissue between them. The result is an organic-looking structure that from the air resembles a coral reef more than a city: irregular, branching, dense at the center and sparse at the edges, with channels of open water running through it like streets. Freeport's infrastructure committee (they have committees, not executives) maintains the electrodeposition grid as a continuous process — the city is literally always growing, always mineralizing, always adding mass to its foundations. A Freeport engineer told me: "The city builds itself. We just tell it where."

The ice problem nearly killed the colonies twice. Lake Michigan freezes, and ice floes exert lateral forces that can crush a platform. The 2172 freeze destroyed two early colonies entirely. The solution came from a Shelf-trained engineer named Harada Osei who designed angled deflector structures — grown, naturally, from Seacrete — that channel ice around the colonies rather than into them. The deflectors work. They also produce a sound during freeze season that colony residents describe as singing. The mineral structures vibrate as ice slides against them, producing harmonics that carry across the water. On cold nights you can hear the colonies from the Old Harbor waterfront — a low, complex chord that changes with the wind.

Today the colonies represent an alternative economic model that the corponations cannot easily absorb. They generate their own power (wind and solar — pointedly not Ouroboros). They grow their own food (aquaculture in the channels between platforms, supplemented by trade with Old Harbor). They build their own structures from the lake itself. Their only dependencies on the mainland are calcium chloride, medical supplies, and — reluctantly — data connectivity, which Vantablack provides at rates the colonies consider extortionate and Vantablack considers charitable. The colonies exist because a group of people with fabrication skills and chemistry knowledge looked at a lake and saw a building material. They exist because the corponations looked at the same lake and saw only water.