No, they can't; a fact reinforced this week by Fish and Game's North Canterbury branch in contemplating a ban on winter sports fishing in parts of the Waimakariri " the South Island's busiest recreational river " as a "desperate measure" to save the fisheries from total collapse.
They blame Environment Canterbury for exacerbating the problems of over allocation and pollution by encouraging irrigation and intensified dairying.
Sounds familiar, doesn't it, when you consider the deterioration of the Tukituki in Hawke's Bay and the proposed Ruataniwha irrigation scheme.
The regulators, including central government, are quick to sidestep, saying the problems have developed over many years and will take as long to fix. True, but the worst of those "many years" have been under their watch; they need to admit they've failed in their duty to protect these precious resources, and up their game " or resign.
Greed and ignorance are equally to blame. Reacting to the Niwa report, Waikato River Authority co-chair Tukoroirangi Morgan expressed his surprise that areas in the upper catchment, thought to be pristine, were actually unhealthy.
Doubtless because farmers in the high rough country think they're far enough from easy view to get away with pollution and don't even consider cumulative downstream effects.
That attitude starts at the top: Supreme Court Chief Justice Sian Elias and husband Hugh Fletcher have got away with letting their cows wander unchecked in Lake Taylor at the foot of the Southern Alps, despite there being a DoC campground next door.
And idiots like the local Federated Farmers chair defend them by saying just because cows are in water doesn't mean they're defecating. Yeah, right.
Meanwhile Environment Minister Nick Smith claims it's "not practical" to restore rivers so they're safe enough to swim in, preferring to adopt a "wadeable" standard instead: allowing E.coli at twice the recommended standard for stock drinking water and four times that for safe swimming while using "keeping farming viable" as (contradictory) excuse.
What an insult to our "clean green" heritage and pride " to wash his hands in filthy water and give up without trying.
Is this really what we've come to? Accepting undrinkable unswimmable freshwater, even in our wildest places, for the sake of a tainted dollar?
To get your local waterhole back and keep your dog (and kids) safe from toxins, you've got til Tuesday to sign the online "Choose Clean Water" petition, or til April 22 to submit on the freshwater standards regime.
We don't want water "generally good by international standards" " we need it good by OUR standards.
That's the right of it.
Bruce Bisset is a freelance writer and poet.