The invention relates to the technical field of measurement, in particular to a 
water depth detection device for municipal 
engineering. The 
water depth detection device for municipal 
engineering comprises an opening mounting box and a detection 
assembly, the detection 
assembly is erected on the opening mounting box, and the 
water depth of a 
constructed wetland for municipal gardens is measured through the detection 
assembly. According to the water depth detection device for municipal 
engineering provided by the invention, a winding piece and an adjusting piece in the detection assembly can ensure the smoothness of a measuring thread 
rope during take-up and pay-off, so that the problem that the measuring thread 
rope wound on the winding roller is excessively wound locally and excessively wound locally is solved; when a reciprocating screw rotates to carry out pay-off and take-up, a through cavity in a limiting clamping plate can remove sundries attached to the measuring thread 
rope, the cleanliness of the measuring thread rope is improved, a water inlet assembly additionally arranged in a 
plumb bob tank can enable water to be injected to improve the weight of the 
plumb bob tank only when the water depth is detected, and therefore the 
plumb bob tank cannot be too heavy and is easy to lift when measuring is not carried out.