Ohori Park is a water park with a pond of two-kilometer per lap and three islands in the middle. It is in the vicinity of the city center and a famous tourist spot representing Fukuoka City as well as a recreation spot for the residents. Jogging and cycling around the park is very popular because of the lush scenery and waterside landscape. You can also contemplate the flowers and birds flying while walking along the park, enjoy fishing or riding a boat. In the springtime, visitors flock for cherry blossom viewing. To keep the status of being the most loved park in Fukuoka City, clean water has always been a requirement, and flexible approaches were applied to this park to solve the problem.
Initially, the location of the park was an inlet of Hakata Bay. Nagamasa Kuroda, the first feudal lord of Fukuoka of Edo Period, built his castle in this area, and use the inlet as a part of the moat of the castle. When the feudal era ended and turned to the Meiji Era, a part of the moat connected to the river was reclaimed and turned into a street. The environment of this area soon worsened due to the blockage of the water circulation path by this reclamation. Then complete reclamation of the moat was planned. However, the intellectuals in the era protested against this plan. Finally, Fukuoka Prefectural Government decided to reclaim the half of its 23-hectare moat and keep the rest as a pond. And it used as a site for the East Asia Industrial Exposition in 1927 and opened as a park to the public in March 1929. Since then, the park had been very popular by the public; however, the environment conditions deteriorated in 50 or more years.
During the 1980s, the park suffered from an outbreak of blue-green algae, high fish mortality, and odor. In 1985, 100 thousand people petitioned for the purification. The experts and engineers of the Fukuoka Prefectural Government examined and studied the problems such as budget costs and sullage processing. They finally came up with solutions to these problems in 1992. First, the water was taken out of the pond, and the layer of the sullage switched with that of sand underneath, so no need to take the sullage out of the park for secondary processing. And a filtering plant was built in order to rotate the water of the pond and keep the water quality to the target level.
Sustainable nature conservation has become increasingly apparent, and this park provides a thought-provoking case. This park plays a vital role in the ongoing joint project by Fukuoka City and Prefectural Governments, Central Parks Project, and as a disaster prevention and evacuation site in disaster. To stay as the most loved park in Fukuoka, it has to remain well-maintained and keep evolving toward the future.