Scanning: localiza evidencia sin releer todo el pasaje

In the late twentieth century, many industrial rivers were treated as drainage channels rather than living systems. The Westbrook River, for example, carried waste from textile workshops until new water rules were introduced in 1984. Although factories had closed by the 1990s, the riverbanks remained covered with concrete walls that made the area hot, noisy and difficult to access. In 2012, the city began a restoration project led by engineer Maya Chen and a small team of ecologists. Their first step was not planting trees, but removing sections of concrete so that the river could overflow safely during heavy rain. A 1.8-kilometre walking path was added later, after soil tests showed that most pollutants were concentrated near two former dye-storage buildings. The project did not satisfy everyone. Some business owners worried that construction would reduce foot traffic, while residents were concerned about mosquitoes. The design team responded by creating shallow wetland shelves that supported fish and dragonflies, both of which help control mosquito larvae. Within three years, summer surface temperatures near the restored banks had fallen by up to 4 degrees Celsius. Today, the Westbrook River is used in school science lessons and weekend walking tours. However, city planners warn that restoration is not a one-time event. Sediment must be tested every spring, invasive plants need regular removal, and flood gates upstream still require inspection before the rainy season.