I am a very thirsty person and never go anywhere without a drink (usually my Nalgene bottle of water). Therefore access to water when outdoors is always something I plan carefully.
There seems to be a lot of difference in opinions and behaviours up here in Scotland regarding drinking water when out in the countryside. My first taste of “wild” water was from Glenrosa Water in Glen Rosa on Arran; Chris and I camped in the glen for two days, it was very hot and we couldn’t take enough water to last the whole trip. I was quite nervous as prior to that I had only ever drank clearly marked drinking/ tap water.
It turned out to be delicious and did me no harm whatsoever. Indeed, drinking stream water in remote locations seems to be common up here, and indeed essential on multi-day trips. Yet, I remain wary: in summer I carry a 2 litre platypus on single day walks and only drink stream water when absolutely necessary. In contrast, Chris never carries more than a litre of water and tops up on many of our days out.
I’ve discussed this with others and come across very differing opinions. The general rules seem to be that if you are well-away from people, high up and the water is clear and fast-flowing, it is fine to drink, and this rule has been effective so far for us.
However, this time last year, we were planning for our TGO Challenge and I was very preoccupied by our water supply. I trawled the internet and the advice I found was very confusing! I found people who stated that when walking in Scotland they carried nothing but a mug as water is plentiful and clean, and others who always avoided drinking water straight from the source and preferred using tablets or a variety of filters.
I looked up the price, weight and ease of use of many suggested options and came up with a plan that worked extremely well for us. We had planned a fairly low-level route from the west coast of Scotland to the east, which meant that we might not have access to clear little mountain streams for much of the time. I also read and heard a few stories of people who had become ill from drinking stream water, so I didn’t fancy relying on it for two weeks.
On the other hand, we are in Scotland and water generally isn’t in short-supply, so we opted for a small (500ml) and inexpensive filter water-bottle each (Water-to-Go ~£13), to use when on the move, and which we kept topped up whenever we came across a suitable water source. We both also carried a 1l water bottle that we filled up and added a water purification tablet to, before stopping to camp each night. We used this for cooking and drinking in the evening and next morning. If water sources looked scarce, it also allowed us to carry more than our 500ml during the day. We used the more expensive purification tablets (Life Systems Chlorine dioxide tablets ~£10.50) that supposedly remove the taste, which they seemed to do; the only problem was that in cold Scottish spring water, they took many hours (and lots and lots of shaking) to dissolve. We would also recommend keeping them in their little box, not your first aid kit as we did, because the foil got damaged and many of them got ruined when they became exposed.
Spring 2017 was very dry in Scotland and we actually found that many small streams were sluggish and the water was discoloured or contained algae. Although lochs and lochans were still plentiful, it is not recommended to drink unpurified standing water either, so we were very pleased with our strategy: it wasn’t particularly expensive, we didn’t have to carry any extra filter equipment, spend time filtering water in advance, or carry large quantities of water.