If you can't say anything nice, then don't say anything at all. That's what my mama used to tell me.
Warning! What follows is probably unnecessarily revolting. Perhaps you should skip this post.
The following was written by Friedrich Engels (yes, THAT Friedrich Engels) whose mother, apparently, didn't tell him the same thing.
"The south bank of the Irk is here very steep and between fifteen and thirty feet high. On this declivitous hillside there are planted three rows of houses, of which the lowest rise directly out of the river, while the front walls of the highest stand on the crest of the hill in Long Millgate. Among them are mills on the river, in short, the method of construction is as crowded and disorderly here as in the lower part of Long Millgate. Right and left a multitude of covered passages lead from the main street into numerous courts, and he who turns in thither gets into a filth and disgusting grime, the equal of which is not to be found - especially in the courts which lead down to the Irk, and which contain unqualifiedly the most horrible dwellings which I have yet beheld. In one of these courts there stands directly at the entrance, at the end of the covered passage, a privy without a door, so dirty that the inhabitants can pass into and out of the court only by passing through foul pools of stagnant urine and excrement. This is the first court on the Irk above Ducie Bridge - in case any one should care to look into it. Below it on the river there are several tanneries which fill the whole neighbourhood with the stench of animal putrefaction. Below Ducie Bridge the only entrance to most of the houses is by means of narrow, dirty stairs and over heaps of refuse and filth. The first court below Ducie Bridge, known as Allen's Court, was in such a state at the time of the cholera that the sanitary police ordered it evacuated, swept and disinfected with chloride of lime. Dr. Kay gives a terrible description of the state of this court at that time. Since then, it seems to have been partially torn away and rebuilt; at least looking down from Ducie Bridge, the passer-by sees several ruined walls and heaps of debris with some newer houses. The view from this bridge, mercifully concealed from mortals of small stature by a parapet as high as a man, is characteristic for the whole district. At the bottom flows, or rather stagnates, the Irk, a narrow, coal-black, foul-smelling stream, full of debris and refuse, which it deposits on the shallower right bank."
Here's a much more recent photo of the Irk, at its confluence with the Irwell. Doesn't look so bad.
Incidentally, regarding the top picture, I've learned that where there's a weir there's a way. No, no. Where there's a weir there's an electrical generating power plant. I don't see one here, unless that's it on the hill on the left poking out of the bushes. Perhaps the weir is only to regulate the flow. Never mind.
Anyway, just one further irking note from our friends over at Wikipedia, who never lie, say that on August 15, 1953, the front coach of a Manchester to Bury electric train fell from the viaduct over the River Irk after colliding with a local steam train. 10 people were killed (jeez but I hope not drowned!) and 58 injured.
Incidentally, did you know that New York's Hudson River was at one time so polluted that people could walk across it? If they could make it before their shoes were eaten off their feet. Or that Lake Erie used to catch on fire from time to time due to fuel pollution? The former is a lie, the latter is the truth. Lest you think Mancunian filth is superior to American corporate disregard for the environment.
In related news, I was watching an odd TV program not too many months ago in which the world's worst jobs were shown. For example, we were taken along (so to speak) with a sewer diver in Mexico City. His job was to don a wet suit and air tank and dive down through the gelatinous water, through the floating "debris" affectionately known by your local water treatment personnel as "solid waste" and find the major plug that was backing up the whole system. Fouling it up, as it were. Yeah, that would be on my list of world's worst jobs, too.
I'm not sure why this came to mind. There is no comparison to Manchester's pristine Irk and the Mexico City thing.