5th International Conference on Rain Water Cistern Systems
"Rainwater Catchment for Future Generations"
Keelung, Taiwan, R.O.C. - August 1991

Section 3: Catchment and Storage System Designs

Page 134

Investigation Into Feasibility Of Usage For Domestic Use Of Collected Rain Water From Open Areas In Urban Regions In Japan

Tadafusa Uchida
Shimizu Corporation, Japan

Abstract

The purpose of this study is to examine the feasibility of collecting rain water for reuse not only from roofs, but also open areas, such as park and public lands. I examined the recovery rate and quality of collected rain water through the use of permeable test pieces representing several types of ground compositions.

The results are as follows:

1. The recovery rate of collected rain water ranges from 40-70% of the total rainfall during the course of one year and these values depend upon the compositions of the test pieces. 
2. The quality of collected rain water from non-fertilized test pieces satisfies the Japanese flush water requirements for toilets, and it can be used for a wide variety of purposes, including sprinkler systems. 
3. The collected rain water from fertilized test pieces contains a high concentration of organic and inorganic substances during the first stages., so its reuse must be restricted to plant cultivation.

However, during the last stages, its quality is almost equal to that of non-fertilized test pieces, so it could be used for a wide variety of purposes.

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