Ocean cities are a longstanding Utopian dream, but the majority of such schemes fail to address the immediate need of cramped urban centers, many of which around the world are bordered and constrained by large bodies of water.

Blue 21, a Dutch architecture and design group, aims to sustainably extend such cities into adjacent lakes and oceans, alleviating the stress on existing metropolitan areas and providing vital resources (like space to grow food) in close proximity to urban cores. The team has experience building floating homes in the Netherlands but wants to take their experience global and work at a larger scale.

These modular buoyant extensions can be added to over time and used to grow algae, veggies, crops and seafood, producing food and biofuels to support existing populations on land.

At the same time, they can serve to productively process and recycle city wastes and absorb emissions, becoming a productive rather than consumptive part of the regional ecosystem. “As an integrated concept it proposes floating development that can be ‘plugged in’ to existing cities and help them recycling waste nutrients and CO2 that often end up in the environment, polluting it.”

While Blue 21 may not be a solution on the immediate horizon as yet, it represents an approach that bridges the gap between fantastical floating cities and more realistic solutions that engage accessible stretches of ocean. “We are Blue21, starting a Blue Revolution. This is how: by building world’s first floating city with a positive impact on nature. Because we believe our future is on the water for seven reasons: 1. We are running out of land, 2. Cities on land are vulnerable, 3. Water will save us from our addiction to fossil fuels, 4. Water is the new oil, 5. Water is an innovation playground, 6. We can actually have a positive impact, 7. We can do this, now.”