Catch basins are the structures of Pucca chamber and a stout cover. They are meant for the retention of suspended grit, sludge and other heavy debris and floating rubbish from rain water which otherwise might have entered and cause choking problems. The outlet pipe from the catch basin may be submerged in order to prevent the escape of odors from the sewer and provision that also cause retention of floating matter. Their use is not recommended since they are more of a nuisance and source of mosquito breeding apart from posing substantial maintenance problems.