Make sure that the covers to inspection chambers are not broken as this can encourage rats, as well as allowing debris, such as stones and earth, to get into the pipe and block it.
Gwnewch yn siŵr nad yw gorchuddion siambrau archwilio wedi torri gan y gall hyn ddenu llygod mawr, a pheidiwch ychwaith â gadael i ddeunyddiau fel cerrig a phridd fynd i mewn i'r bibell a'i blocio.