Recently, increasing the occurrence of extreme climate has brought the environmental protection by corporations to the attention of their stakeholders including stockholders, consumers and local residents. The main part of the countermeasures was carbon dioxide emissions reduction, this control have been regarded as objective for mitigating the negative effects on global environment. On the other hand, environmental practices aiming to the positive effects have attracted attention such as installation of rainwater storage tank. This installation have the effect of not only utilization of rainwater but also flood control. In this paper, the author looked into the information related to the installation over the environmental reports by a remarkable corporation. The result led to the fact that environmental practices with positive effects had been generally dismissed as far as this investigation.