The problem with wizard cum is that it tends to concentrate the wizard's magic. So even a mediocre magician can have very potent cum.
The University's Reclaimed Water Project wasn't so much a serious attempt to conserve water, as it was to avoid the cost of new piping when the old clay line to the sewer failed. Since only sink and shower water fed that pipe it was filled with mostly grey water, not as nasty as water from the toilets which enjoyed an iron pipe to the sewer. Coincidentally, at the time the clay pipe collapsed, the garden well went dry, so it wasn't difficult to simply direct the broken grey water line into a barrel, and run a rubber hose from the bottom of the barrel out to the garden where it connected to the sprinkler system.
The potent magic laden cum flowed through this primitive plumbing system and out into the garden. Almost all of it ended up pouring on to...