Hi Kozmo,
Regarding your point about peeing into the river,
"...whereas if some corporate company did that we would have their head on a stake, then we bitch about the lakes downstreeam being too green and going eutrophic and dioxins in the fish and oh the HORROR."
here are a couple of points to consider:
First, there's probably been a study done to evaluate the impacts of some average number of boating parties discharging some average quantity of pee and gray water into the river, and its likely been determined that the impact would be minimal under average flow conditions, etc. etc. The whole reason we pee into Western desert rivers is because the land ecosystem is more easily harmed than the river is. In other areas that are more humid, where rain washes the soils more frequently, (like Idaho) boaters pee on land.
Secondly, if a big corporation or municipal wastewater treatment facility discharged to the river, which they do on a regular basis and in full compliance with the laws of the land, they'd probably be putting hundreds of thousands of gallons of pee and lots of other nasty stuff into the river daily. This is typically done under a discharge permit, which would have all kinds of allowable quantities of all kinds of chemicals and bacteria, human waste, oil and grease, etc. that can be legally dumped into the waters we'd like to boat.
Smell the South Platte River at Confluence when the river's low for a good whiff of what I'm talking about here. If you take a look downstream of Denver you'll see the eutrophic conditions (during low flows) that result from most of the river's flow consisting of sewage treatment plant effluent (and who knows what else it picks up through Commerce City and the rest of Urban Denver). During periods of non-peak runoff, many Western rivers that flow through urban areas are referred to as "effluent dominated streams." You can see this during low flow periods in the daily peaks and valleys on the hydrographs, which in turn can be traced back to that peak flow hitting the sewage treatment plant from an entire city's morning flush and shower.
So its not really fair to compare peeing into 3000 cfs on the Colorado or even 600 cfs on the Ark with the kind of discharge that comes from corporate or municipal wastewater plants.
And if I were a little crawdaddy or brown trout or damselfly nymph trying to live in that habitat, I'd probably be saying "oh the HORROR" too.
-Andy