Early snowman?

No, just another use for the ubiquitous dumpy bags.  Adding to the insulation of the undrained part of the tap tower by cutting a hole in the bottom of a bag and putting it over the tower then filling with mushroom compost that is ultimately destined for the vegetable garden (once the poisonous aminopyralids have decomposed).  An inverted bag over the top should reduce the amount of rain running into the compost.  20-25 cm of mushroom compost must approximate to a similar amount of earth and there is quite a lot of insulation inside the tower cladding anyway.

Suggestion for a design or environment class:  Non-returnable builders' dumpy bags must be being released into the wild at the rate of some 150,000 or more a week in the UK alone (10 bags a day fo 3,000 builders' merchants across the UK - 7.5m a year).  Never mind supermarket plastic bags and coffee cups - who can design a simple conversion to these bags to give them a new use?