Water Carriers

Water is a vital resource in the arid Desert of Desolation, only available at a handful of oases where deep aquifers rise near the surface, or else in painstakingly-dug wells. Stone is mortared to form each well's walls to protect it from the elements, and then it is carefully capped to ensure the dry air cannot evaporate too much precious water, sand cannot blow into it, and it is protected from being fouled by wild animals. Encampments cannot be built too close to the water source, for fear of fouling or damaging it.
Settlements and waystations exist at each of the reliable water sources, but the water must be carefully doled out, and transported from its source to where it is needed. This is where the water carriers come into play. Each approaches the water source - which is usually guarded both to protect it and to ensure none take more than their share - and fills their jars or water-skins. They then must make the arduous trip from the water source to the settlement or caravan, then divide out the water.
The degree of respect water carriers is afforded varies from place to place in the desert. They are both low-status labourers performing a routine back-breaking menial job, and individuals entrusted with the most precious resource in the desert. They are able to move almost anywhere, but are often ignored while doing so.
Water carriers must often labour in the hottest part of the day to get water to the community whilst those they serve take shelter from the blazing midday sun. In some places, where the leader of the local community charges a fee to access the water, the water carriers must pay the guards to access the water source, then recoup their costs in the money they charge the residents for performing the service.