Most urban farming startups produce just a handful of foods–often greens and herbs–and most urban farmers would say that only a fraction of total food will ultimately be grown in cities. A new project in the Netherlands demonstrates how much more is possible. The Floating Farm will be home to 60 urban dairy cows that will produce local milk, cheese, cream, butter, and yogurt.

“Our idea is to create as much food as we can locally,” says Peter van Wingerden, director of Beladon, a building developer that specializes in floating structures and that envisions building fully floating cities in the future.

“The long-term idea is to create cities that are completely self-sufficient on essential elements like clean water, energy, food, and waste–to create this inside these cities on oceans,” he says.

The company was inspired in part after Hurricane Sandy, when New Yorkers were reminded how quickly food can disappear. After a disaster, if routes are blocked or delivery trucks can’t refuel–and if consumers empty out shelves in grocery stores–food in the city might only last for three days.

Beladon sees the water as an ideal place to produce more urban food. “If you want to produce food near consumers, then you look at the major cities, and there is not so much space in these cities,” says van Wingerden. “One of the spaces we do have is the water and the ports. The ports and rivers were always used in the past as logistics hubs–we say now rivers are becoming life essentials.”

To grow the same amount on land would take 30 to 50 times more space.

The new Floating Farm, which is expected to be completed in January 2017, will grow food for the cows on board. Over the last nine months, the designers have been working with a local university and Philips, the lighting manufacturer, to test different seeds and LED lights to grow the most grass possible. In an experiment, they produced about 15% of the food the cows will eat, and plan to get to 20%. To grow the same amount on land would take 30 to 50 times more space; modern vertical farming technology shrinks the area needed.

The grass is also better for the cows than what they would eat in a rural field. “The type of grass we are producing year-round is very healthy and vitamin-rich,” he says. “So we’re also producing a healthier milk.”