Finding and assessing water sources

Rain and meltwater soak into the ground or run off on the surface, always downhill. Where two slopes meet, a gully forms; many gullies make a stream, many streams a river. On a map you recognise valleys by contour lines that point uphill like a „V“ or „U“. Blue lines, spring symbols and lakes are the most direct clues.

Springs form where groundwater comes to the surface – often at the foot of slopes or at rock steps. In the terrain, water points give themselves away through strikingly green, dense vegetation, damp ground, swarms of midges, well-worn animal trails converging downhill, and birds flying in one direction in the morning and evening.

These are clues, not guarantees. A green patch may just be damp ground with no water you can collect, and animal trails sometimes lead to feeding places. The more clues agree, the more likely you are to find water. Saving energy means: map and overview first, then walk with a purpose.

Not every water point is equally good. As a rule of thumb, use this order: first precipitation collected from clean surfaces, then springs right at their outlet, then flowing water, and standing water last. The shorter the distance the water has travelled and the less contact it has had with animals, people and dirt, the better the starting point.

Avoid water with an oily film, an unusual smell, foam, unusual colouring or dead animals nearby. Mats of algae and slimy, strongly green or blue-green water are not a good starting point either. If you have the choice, a somewhat longer walk to a better source is often the wiser decision.

The key point: even the best natural source is still „raw water“. The ranking only helps you start with as little contamination as possible – it does not replace treatment.

The most common hazard in water is pathogens from human and animal faeces: bacteria, viruses and single-celled parasites. They are invisible and occur even in remote mountain regions, because wild animals carry them too. Treatment helps against them, for example boiling or suitable chemical disinfection.

Less common but harder to deal with are chemicals. They can get into water downstream of industry, mining, landfills, intensive agriculture and roads, and also with flood water that has swamped cellars, tanks and workshops. Boiling, filtering and disinfecting do not reliably remove such substances. If you suspect them, the only good solution is another source.

Whether water is really safe to drink cannot be determined without a laboratory – not with your eyes, nose or taste. That is why the question „What lies upstream?“ matters so much: settlements, grazing livestock, campsites, fields, roads. Collect above such places wherever possible.

Water points are often accident spots too. Steep, slippery banks, undercut edges, smooth stones and ice easily lead to falls. After heavy rain, streams in gorges can swell dangerously within a short time. Do not step onto ice whose load-bearing capacity you are not sure of, and do not wade through fast-flowing water just to fill a bottle.

Flood water is doubly dangerous: the current is stronger than it looks, and the water is often contaminated with sewage, fuel and chemicals. It is unsuitable as a drinking-water source.

If possible, fetch water in daylight and not alone, or tell someone where you are going. A small cup or a container on a cord helps you collect from the bank without taking risks.

Collect at the clearest spot, ideally without stirring up mud from the bottom, for example in calm but flowing water just below the surface. If the water is cloudy, let it settle or pour it through a clean cloth before disinfecting it.

Keep raw water and treated water strictly separate. The easiest way is two clearly different containers: a „dirty“ one for collecting and a „clean“ one for the finished water. A drop of raw water on a bottle thread is enough to contaminate clean water again.

Water from plants, dew or condensation usually yields only small amounts and does not replace a real source. Identifying plants for water is deliberately not covered in this atlas. In towns, when the water supply is disrupted: follow the authorities' instructions, for example boil-water advisories.