May 30, 2017
Citizens pushing for rebirth project for Inokashira Ponds as Tokyo's oasis
The scenic Inokashira Ponds park has been loved by Tokyo citizens as a refreshing oasis in the big metropolis. The park, owned by the Tokyo metropolitan government, extends on an area of 380,000 square meters in Musashino and Mitaka in the western suburbs of Tokyo. In the center of the area are three ponds with a total area of 43,000 square meters, and in one of the bonds, people can enjoy riding small pleasure boats.
The Inokashira park turns 100 this year, overcoming hard years linked to environmental pollution. 
Until around the 1960s, an estimated 10,000 tons of pure spring water had been gushing out a day in the area. But the springs then almost dried up, because a lot of wells were dug around the park to draw underground water.
Park operators had to use underground water to keep water for the ponds. But this failed to maintain the ecology in the ponds in a proper condition and as a result, various introduced species began to dispel indigenous species.Toward the 100th anniversary, the park operators and a group of citizens got together to launch a rebirth campaign for the park. The operation features the "kaibori" dredging work from winter to early spring.
The first kaibori work was carried out in 2013, followed by the second one in 2015.
The third kaibori operation is scheduled to be held later this year. aimed at improving the quality of water in the ponds and getting rid of introduced aquatic species.
The operation has so far contributed to removing many harmful foreign species in the ponds, helping to get the ecology back to the original condition.
The dredging has also helped to restore the original life cycle from small aquatic creatures and waterweeds to indigenous fish and birds, such as a crucian carp and a dab-chick.The kaibori volunteer team includes 40 citizens registered as regular members.
The operation starts with catching aquatic creatures in the dredged ponds and dividing them into indigenous ones and foreign ones. After that, the pond bottom is exposed to the sun for several days to clean up the environment. Then, water is funneled back to the ponds, and only indigenous species are returned to the ponds.Unstable weather continued in spring this year in Tokyo and neighboring regions. But people are having difficulty adjusting themselves to unusually hot weather in recent days. This makes them feel the importance of the refreshing aquatic environment even more strongly in their daily life.
