The utility model discloses an urban flood
ponding predicting and warning device which comprises a protective
grating and a top supporting structure, the protective
grating comprises an outer frame and a trash holding
grating, and warning reflective strips are arranged on the surface of the trash holding grating; the jacking and supporting structure comprises a mounting
pipe, a water conveying screw, an
impeller, a hydraulic
pipe, a jacking and supporting hydraulic rod and the like. When the
water level of the
drainage ditch rises to a specified threshold value,
water flow impacts an
impeller to drive a water conveying screw rod to rotate, so that the
water flow enters a water fetching hole path, then a jacking hydraulic rod in a hydraulic
pipe is pushed to rise to jack up a trash holding grating, a warning reflective strip is more striking, pedestrians and vehicles are reminded to pay attention to the water accumulation danger, meanwhile, the trash holding grating is lifted to enlarge a water flowing opening, and the water flowing opening is closed. The device does not depend on external
electric power, is driven by
water flow, avoids
device failure caused by the
electric power problem during flood disasters, improves reliability and stability, reduces the
workload and cost of manual overhaul and maintenance, and is high in practicability.