Matt And Danny

Personally i would wait until we have a better forecast, i understand your idea witch could work but it's not worth the cost of materials for the concrete to fail in the lower temperatures and crack

Hi, would you know if this is a foul or storm manhole and is there a rodding eye near by? this sounds like a lateral manhole and will need access into it so we would not be able to cover up the corners for acces, if its not or is a storm manhole and there is a rodding eye in the drainage run we can put in a recess manhole and square everything back up

It shouldn't really be getting blocked, as most gullys are weight assisted and have the outlet at the top, as this would run into foul drainage any off the shelf drainage unblocker would help keep the run clear, or popping off the grid and getting the silt/detergent out regularly would help