Like Lae and other parts of the highlands region, the city of Yokohama, located south of Tokyo in the Kanagawa area, experiences a lot of rainfall and had drainage problems. However, that was addressed through multi-purpose reservoir storage areas.
Port Moresby does not have a river flowing in the city, but the roads turn into fast flowing rivers whenever it rains.
In Japan, the Tsurumi River runs through Toyko and has a river basin of 235 square kilometres that extends to Kanagawa and Yokohama city.
The river’s amount of outflow has been greatly influenced by urbanisation since 1958 and floods caused by typhoons. Control measures had to be introduced by the Yokohama city authorities for flood control.
Outflow measures are used to control excess rain water as well as sewerage.
1982 saw the commencement of construction of the main multi-purpose reservoir in the city to cater for flood storage or adjust and store flood water in an area. This came into use in 2003 and covers an area of 84 hectares.
Loop PNG was at this reservoir area recently for a tour of the facility; the city has three other reservoirs.
The multi-purpose reservoir covers a stadium area, called the Nissan Stadium. The stadium has a number of facilities built using the raised floor style so that even when there is an overflow and the stadium’s basement comes into use for excess water storage, the above facilities will not be flooded.
The basement of the stadium can store water for up to 10 metres.
Opposite the stadium and still within the reservoir area lies a tennis court that turns into a storage reservoir whenever it rains and the river overflows.
The city has integrated monitoring measures to notify residents in the event of heavy rain so they can easily move to higher grounds.
They do so using weather information, CCTV, cell phones, websites and the river information boards. The Tsurumi River reservoir centre’s Basin Training Center also carries out education disaster prevention awareness.
(The Nissan Stadium at Yokohama, Japan)