Lake Kleifarvatn, Iceland
US city invests millions of dollars in bluebelts to combat floods and clean the water. It is a nature-based solution.
new York is betting on a nature-based solution to face a problem that is likely to worsen in the coming decades: the increase in intense precipitation associated with climate change.
Context: US city sewers were not designed for the intensity of current rainfall.
Known as bluebeltsor “blue belts”, these drainage systems made up of wetlands and artificial lagoons are receiving significant investments from the municipality, which sees them as an effective way of prevent flooding, protect homes and return cleaner water to rivers and the ocean.
During light rains, the city’s extensive sewage network is generally able to cope. However, in episodes of intense and sudden precipitation — so-called cloudbursts — the system is quickly overloaded, causing water to accumulate in the streets and, in many cases, invade homes, especially basement apartments.
It was to respond to this type of situation that, around 30 years ago, New York began to develop the first bluebeltsespecially in Staten Island.
Explains it: bluebelts work like areas of natural rainwater retention.
Connected to the rainwater drainage network, these spaces slow down the flowreduce pressure on sewers and allow sediment and pollutants to settle before the water flows into waterways.
Native plants they help filter contaminants such as fertilizers, making the water that reaches the Hudson or ocean significantly cleaner.
Currently, there are almost 100 bluebelts in the city, most in Staten Island, where the availability of space facilitated its implementation in the 1990s and 2000s.
At the time, the island was facing accelerated urban growth, incomplete sewage networks and a heavy reliance on septic tanks.
Os bluebelts emerged as a more sustainable to the construction of extensive underground infrastructures.
In addition to protecting populations, these man-made wetlands have brought ecological benefits clear.
Where there were once invasive weeds and construction debris, habitats have emerged with native plants and wildlife, including waterfowl and species like the American eel.
Despite the success on Staten Island, the expansion of bluebelts in other neighborhoods it has been slower, mainly due to the lack of space and the predominance of combined sewage systems, which mix rainwater and domestic sewage.
Still, the city recently announced an investment of 68 million dollars (58 million euros) to build the first bluebelt de Brooklyn, no Prospect Park.
Municipal authorities argue that, although some projects may exceed 100 million dollars (85 million euros), the investment pays off by reducing material damage, insurance costs and risks to public health.
