Efforts to regenerate a healthy water environment!

In order to promote the installation of "rainwater penetration masu", we have been examining penetration effects experiments.

As shown in Table 1, the amount of rainwater infiltration masu was 8.3 to 14.4 liters per minute.
For example, 10% of heavy rain (rains that bounces off the road) is 10%.
It seems to have a good effect.

As for the effect of rainwater infiltration masu, it was confirmed that the amount of rainwater soaking into the ground increased, reducing the amount of rainwater flowing into the river during heavy rain, and it was confirmed that the effect of preventing flooding. In addition, it is useful for regenerating the water cycle, such as increasing groundwater and increasing the amount of spring water and river water.

The penetration range of the rainwater infiltration masu was 30 cm from the outside of crushed stone of rainwater infiltration masu.
Regarding concerns about moisture to the building where you asked in the questionnaire, the rise in soil moisture within the range of 30 cm from the outside of crushed stone infiltration is only about 4%, and it is thought that there is almost no effect on the building So don't worry

Water was poured into the rainwater infiltration masu, and the amount of water supplied until the water level became constant. Table 1 shows the amount of water permeation at each experimental site if the amount of water supply is assumed to be "infiltration amount".

An experiment was conducted to reproduce the rainfall and examined the impact on the building.
In this experiment, we assumed 20 mm/day and 10 mm/hour, which accounts for more than 90% of the annual rainfall, and confirmed the following:

• The rise in soil moisture within 30 cm from the outside of crushed stone in rainwater infiltration masu was only about 4%, and it recovered to its initial state within 30 minutes after the experiment was completed.
• Soil water on the ground (about 5 cm) is 60% of the general saturation.

The experiment in the preceding paragraph requires equipment, equipment, and time, but if you try using the following experiment method, you can see the rough penetration effect.

You can see how the water pumped into the bucket flows into the rainwater infiltration basin. However, if the rain continues, the penetration capacity will decrease, so the ability of simple experiments will not continue.

1. Prepare a bucket and draw water.
   
2. Water is poured into rainwater into the masu.
   
3. At first, most of the water permeates.
   
4. As time passes, water begins to accumulate at the bottom of the masu.
   

Major Revisions

• In order to make it easier to install on limited residential premises, small (lightweight) rainwater infiltration facilities have been added to the standard.
• As for the separation of buildings, etc., we decided to secure a separation of about 30 cm in principle.
• Basically, the installation criteria have been clarified, such as using the “Infiltration Facility Installation Judgment Map”.

Small rainwater infiltration masu installation status

Thank you for your cooperation in promoting the installation of rainwater infiltration masu. We will continue to strive to install rainwater infiltration masu in the future, so we ask for your continued understanding and cooperation.