Taiwan is often visited by spells of drought and flood, problems which are not in the least helped by global climate change and the greenhouse effect and which adversely affect industrial development in the island. They threaten danger to life and limb and damage to property, and in general impair the quality of life. The related important issues are how to efficiently drain floodwater emanating from rainstorms, reduce land subsidence and increment the reserves of usable water. This research aims to provide a solution by using contradiction matrix (CM) to design a new device to cope with draining such floodwaters, reduce land subsidence, and increment water resources. The method uses CM to identify two inventive principles (IPs): IP22 (harm to benefit) and IP2 (taking out). Moreover, transferring floodwater during a typhoon to water reserves of use against drought is based on a time separated principle. Based on the above principles, the design of the device is innovative. It comprises sets of vertical parallel pipes lowermost and a fence uppermost, separated by a net. It solves the above-mentioned problems and helps achieve the research aim. The device has obtained a Taiwanese patent, and it was awarded the Bronze Medal in the Taipei International Invention Show & Technomart invention contest in September, 2008.Keywords: contradiction matrix, draining floodwater, increasing water resources, innovative device design, reduce land subsidence.