The system must be maintained under pressure to avoid excessive evaporation of water.
Elephants have been observed digging holes to drink water and then ripping bark from a tree, chewing it into the shape of a ball, filling in the hole and covering it with sand to avoid evaporation.
To avoid evaporation, bombastium must be kept frozen.
Shirt-sleeved men in the garden were spreading water from buckets, doing it late to avoid evaporation, but too much was brown or dying.
All reactions were carried out in a thermocycler with heated lid or air incubator to avoid evaporation.
Depending on where you live (e.g. how hot and dry it is), you have to be a little careful to avoid evaporation too as this will lower the height of the water over time, but you can just cover the pan/glass to prevent evaporation.
It can be taken as an herbal tea, two teaspoons of dried flower per cup of tea, which should be steeped for 10 to 15 minutes while covered to avoid evaporation of the volatile oils.
Mercury can be inhaled and absorbed through the skin and mucous membranes, so containers of mercury are securely sealed to avoid spills and evaporation.
Only extremely massive clusters, orbiting far from the Galactic center, can avoid evaporation over extended timescales.
The dam forms a narrow and deep lake, designed to avoid evaporation, with one fork containing lots of standing timber and another having many submerged rocky outcrops.