1987 年 29 巻 1 号 p. 1-8
Now the conservation project of groundwater resources is very important one.
How to conserve and maintain the groundwater resources is attained its o b ject by several ways.
The way to let permeate rain water into the aquifer shallow-seated through by a big diameter well is the most general and reliable one. However, it is easy to be bring out a fatal trouble in clogging of void spaces underground, when instilation of rain water would be continued for a long time. The leading cause is invasion of air or gas and all kinds of dust or colloidal materials.
So we had developed special filtration system which is able to prevent such obstructions. We have newly developed filtration system by our patent to let flow out through the filtration bed from the lower horizon to the upper horizon.
Invasion of air or gas into underground could be almost p e rfectly prevent by a trifline contrivance.
The River Shinkashi near Tokyo Metropolitan Districts have a troublesome hydrological weak point on its drainage capacities.
Town Hole System is a series of advantage o us permeating facilities to instil and enclose superabundant rain water into the sandgravel formation underground. Town Hole System consists of newly developed receiving pit in Kangaroo-type, permeating well including the above-mentioned system inside and so on.
We believe that Town Hole System could be use f u l of preventing inundation in the Shinkashi River Basin which is to be had by heavy rain following by Typhoon and at the same time to cultivate directly groundwater resources in Kanto Basin.