Outside a Honda Motor Co. factory on Bangkok's outskirts, Thai soldiers guide gravel bags lowered from a crane into a canal as guards stationed on the plant's plastic-lined walls monitor rising floodwaters.

"This is our final stand," Pongdej Sriwachirapradit, general manager of Thai Honda Manufacturing Co., told reporters Thursday. "The government needs to show it can protect this last major industrial estate. Foreign investors, especially the Japanese, are watching closely."

Japan's third-biggest automaker has already seen Thailand's worst floods in 50 years inundate its auto factory in Ayutthaya Province. Company officials, determined not to let its motorcycle plant in Bangkok's Lat Krabang Industrial Estate suffer the same fate, used personal ties to secure 200 soldiers to build a levy around the facility, Pongdej said.