KANSAI PORACON provides nature- and environment-friendly products ofrainwater penetration, including penetration inlets, penetrationgutters, penetration manholes, and catchment gutters.

Concept

Water is essential for our livelihood. Water is continuously circulating by flowing in rivers and changing its form into clouds by evaporation. However, 97.4% of all the water on the earth is seawater, while freshwater constitutes only 2.6% of the total. More than 70% of this freshwater is composed of ice layers in the Antarctic continent and Greenland. The relatively unknown fact is that almost all the remaining freshwater is groundwater. (Lakes and ponds: 0.01% of the total; Rivers: 0.0001% of the total) Since Japan has rich water resources, this fact hardly catches our attention. However, the water available for us to use is only few amounts of the all water on the earth. Additionally, Japan depends heavily on groundwater for rich freshwater of good quality and our daily life water. During 100 years after 1900, the annual rainfall amount difference between the year with low rainfall and the year with high rainfall expanded. Expansion of this difference in rainfall amounts between the year with heavy rain and the year with drought decreases the amount of freshwater which is available to use. Returning rainwater under the soil controls urban surface runoffs, resulting in decreasing the peak flood rate. The rainwater stored underground penetrates belowgrand through penetration facilities, while flowing into groundwater layers. The rainwater flown into groundwater layers continues to flow under its own weight and pressure applied. Over time, such water then reappears on the earth's surface as natural spring water and by trees pumping groundwater. River waters are replaced in about 10 days. On the other hand, the average retaining period of groundwater is quite long, around 600 years. Therefore, once groundwater dries up, it is extremely difficult to recover the amount of groundwater lost. In addition, without groundwater, we cannot produce traditional Japanese foods, such as Sake and Tofu of good quality. Groundwater serves as an essential lifeline for Japan. For these reasons, we can see that groundwater is an extremely valuable natural resource. In the U.S., recently, there have been many cases where farmland becomes unavailable to use because of groundwater depletion. Japan appears to have rich water resources. However, sound water cycle systems in Japan are gradually being lost because of various factors including urbanization, wasting of water resources, and water pollution. In order to hand over our precious water resources to the next generations, we would like to propose the fostering of sound water cycle as an urgent issue on which we have to seriously work.