So with 7.8 million gallons in the reservoir , and a very healthy piss being around half a Liter, that works out to a urine concentration in the reservoir of about 0.00000169%. And I assume that they actually TREAT the water before using it. Yup makes PERFECT sense, TO A FREAKING MORON, to dump the reservoir.
And of course to add to the irony, Portland has a low-flush toilet ordinance on the books.