UKC

In the British Isles, streams are generally considered a reasonably safe water source if there is nothing within sight that is obviously polluting the water upstream.

Thoughts?  

If I am above the intake and cannot see animals around, or other obvious contamination I go for it.

Less confident if the water has been dammed upstream though (more of an issue in Scotland than England/ Wales). 

I live in the Highlands and often refill my water bottle from burns when out hillwalking; never had any problems. I always try to go for fast running burns, either coming from a spring or just down a hillside with no infrastructure or popular walking routes above!

I do it less often when I'm in the Lake District, mainly because there's more farming and more people ...

(...hmmmm ... so basically I'll drink water where deer might have gone to the toilet, but not where people or herdwick sheep have ...)

I seem to recall that the advice was to walk a few metres up stream and if there was nothing obvious contanimating the flow it's likely to be OK. Can't remember the distance but 15 metres is ringing a bell. I did it for many years in North Wales, the Lakes and the Peak with no ill affects.

Personally I don't trust streams unless it's somewhere really remote and I'm quite a way up a hill (and certainly upstream of any agriculture or buildings). Just don't like the thought of there being a dead sheep somewhere upstream or a decaying human turd or rat pee or whatever. I always filter or pop a tablet in it before drinking if I collect any water anywhere I don't fully trust .

Then again I know people who are a lot more trusting of streams and they've never got dysentery or anything as far as I know, so maybe I'm over-cautious. I'm happy being cautious about drinking water though. 

Similarly to everyone else, I drink from streams in the hills but not really in lowland areas. I wouldn't take water from streams below houses and farm buildings or where there are grassy fields grazed intensely by sheep but even high up in the hills you have to accept there is a good chance at some point you will drink from a stream where a deer or sheep or wolf died further up the stream as they roam basically absolutely everywhere that isn't a vertical cliff face, even if you can't see any sign of them.

However, I've not only not ever been ill from drinking from a stream, I've also never spoken to or heard from anyone who has got ill that way so I'm pretty sure that if you use a little bit of common sense, the chances of ill effects are so remote that you can ignore them (like you ignore the chance of meteors or nuclear war).

I did of course mean contaminating, not contanimating, didn't spot the error until it was too late. I think the idea is that after [15 metres] or whatever the recommended distance is the rocks, the loose stones, the lichen and the moss act as a suffficient filter.  I did indeed once do that.  Checked upstream several metres, drank the water then walked a little further to find a dead sheep across the stream and fully immersed.  It was the stream on the bend just down the road from Fox House in the Peak. Needless to say I survived but I was worried for a few days

The last time I drank from a stream it was clear and fast flowing over rock on Scafell after heavy rain.  What could possibly go wrong ?

The rain was directly from the Chernobyl disaster and full of highly radioactive particles.  But nobody had been told yet.  So you never know.

But that affected ALL the water surely.  Is it more potent when it's directly from the stream? I suppose by the time it reaches the tap it's been diluted somewhat but does radioactivity work like that? I don't know.

Some elements have a shorter half life so they decay quite rapidly, there were differing rules across northern Europe on how long to wait before it was safe to eat grazing animals and or the need to cull. An apt topic just now. 

As I understand it, almost all of the radioactivity that reached Cumbria, fell in a single day. The rain in the streams on that day would have been almost 100% from that rain.  It was so severe that restrictions on movement of sheep in the area were imposed for the next 26 years.

So lots of climbers and walkers were probably adversley affected!  Explains a lot of the content on this forum

The main area I walk in is around Gairloch, Torridon and the Fisherfield and provided I am far enough away from any habitation/areas with farm animals I have no problem with drinking from streams and in 40+ years of doing so I have never had any problems.

Even though some of the hills in Torridon are popular I have no issue with drinking from high streams there but I don't think I would do the same on the Ben.

One suggestion(or word of advice) if you find a stream which looks a source of clean water on the hill and you drink from it, make sure you walk away from it and not  upstream.

If you go upstream find a dead sheep or deer in the water, you are likely to feel rough, even if there is nothing wrong with the water.

Dave

After my other half ended up on a rapid weight loss programme drinking water in Scotland during hot weather a few years back. He couldn't get above the sheep, they were on the summits! Probably he was unlucky but the result of his experience is that we both use a filter bottle (Lifestraw or Watertogo). 

I was thinking of taking some water on a couple of weeks ago at a point about 600m on my way up the Howgills. Thought I'd check upstream as far as the watershed and found a deliquescing puddle of wool, bone, & entrails that looked like something straight out of a Cronenberg film. Most off-putting.

It does seem to me the trouble of filtering on the go is trivial nowadays (I used to use a Sawyer mini; am now using a Katadyn which is as fast & easy as filling a bottle). Though I have to confess that I find the fell water in some areas so delicious, I'd hazard it even if I'd left the filter at home...

One exception that nobody else has mentioned is where there's been mining upstream. In Nidderdale I was suspicious of very orange lichen near one stream and later discovered it was downstream from an old lead mine. I don't know how hazardous drinking the occasional 500ml of unfiltered lead-polluted water would be but I'd rather avoid it.

Arriving at the Lairig Ghru yesterday, having descended Braeriach's Sron na Lairig with my tongue glued to the roof of my mouth, (a wee hydration/weight saving miss calculation)  I can honestly say the cool, crystal clear, life enhancing water I drank from the Allt Druidh was the best bevvy that has ever crossed ma lips. 

Depends how thirsty I am, really. If I think the danger of dehydration is greater than the risk of getting ill, then I'd drink it even if unfiltered (which I have done in the UK and abroad). When I did the GR20 I think I only drank unfiltered stream water the whole week. I did lose half a stone but I think that was all the sweating. But now I have a mini filter anyway... in the past I might have carried iodine drops but obviously they taste awful.

I wonder what you would catch off a decaying sheep carcass - there's difficult versions of ecoli, potentially, in the poo but are decay bacteria tricky?

In April 1986 I was backpacking and camping on a multi day trip through the hills of Wales, and was blissfully unaware of the events taking place from 26th April onwards in the USSR (Ukraine), so I was drinking from and using water from mountain streams for cooking and washing, it was only when I emerged from the trip that I learnt of the Chernobyl disaster with dire warnings being issued on the News about about high levels of nuclear contamination to the UK, and in particular the Welsh hills where the advice was not to drink from streams and there was initially concern about meat and milk from cattle and sheep drinking contaminated water getting into the food chain. 

I must say that I was a bit concerned at the time, but felt no ill effects and so far as I am aware I was not affected. I was diagnosed with Prostate cancer in 2012 resulting in surgery, and have sometimes wondered if this event eventually increased my chances of contracting the disease? But having said that tens of thousands of men get Prostate cancer every year, and how many of them were drinking contaminated water in 1986?!

You have now! Shat and puked my way up Observatory Ridge on the Ben - had to pendulum into the snows of Zero at one point to 'use the facilities' after drinking from a stream that was less clean than it looked.

Wolf ?? - Where in Britain do you go walking ?

A few years ago both myself and my partner caught Giardia from drinking water in Scotland - most likely the lower reaches of the River Lael (Beinn Dearg). The subsequent 6 weeks of recurrent stomach cramps and disgusting sulfurous burps isn't something I want to repeat.

Before I caught it, I wasn't aware that Giardia was a thing in the UK. I still routinely drink straight from fast flowing streams high up in Scotland but I avoid drinking from waters lower down. I also now won't drink water from anywhere close to intesive farming - I'd count the whole of the Lake District in that bracket, for example.

It's not my expertise but you made me wonder & go looking; seems that e.coli along with cryptosporidium, leptospira, campylobacter would be hazards as the entrails are decaying but the bacteria aren't, & some thrive in water. I guess a decaying corpse is actually a bit of a bacterial bun-fight.

innes commented earlier about getting giardia, & I suppose there are other parasites that can survive outside a carcass too.

East Proctor

Sheep do fall down cliffs though.

A long time ago I had a drink from the burn in the Clachaig Gully. The pool above the next pitch had a very decayed sheep in it. I was very sick that night.

I still drink from burns in the hills though.

I think I would avoid drinking from any burn on a popular winter climbing hill - who doesn't take a dump before putting on their harness?

Oh, ok, then I guess I'm just lucky when it comes to drinking from the right streams!

A colleague caught it from drinking water collected from a roof of a building in Sark about 20 years ago (no mains water there). The strong suspicion is that it came from seagulls who habitually perched on the ridge and crapped all over the roof.

It was seriously hot on the plateau on Saturday! - I think I drank from just about every water source available on the way round and had never tasted a better beverage!

Is there not a point here that often people associate sickness symptoms with drinking water from certain sources but cause and effect are not often established (lots of anecdotes about it but only a few with a true diagnosis where the source is likely to have been the water)? 
 

that said I do carry a sawyer squeeze even higher up in Scotland - it does give some peace of mind and feeling at lower risk of digging a long line of holes on a walk out is reassuring for me.

I drank from a stream high up on a Lakeland Fell 2 years ago. It was coming out of both ends that same night, and the world spun in 15 directions. ha ha!

I think this might be good advice actually.  When I caught Giardia it was on a winter climbing trip - late season (April) so the snow pack was probably melting out.  That and the fact there’s development upstream of where I was dossing...  However, it wasn’t a summertime low flow scenario.

I was doing my ML(Summer) assessmemnt at PYB when that happened.  Drank plenty of water on the hill - it was only when I got home/or back at PYB I heard - and realised the implications.

(So far - so good).

it might explain the visitor's behaviour.  A Bazooka would have been justified in this case

https://www.bbc.co.uk/news/uk-england-cumbria-62595386