In your sobering article on April 22 about the water situation in Payson, the term "safe yield" was frequently used. That term is not in my dictionary or in the big one at the library.
A somewhat similar term, "carrying capacity," is in the dictionaries. In my older, 1975, dictionary, the definition of carrying capacity is "the population (as of deer) that an area will support without undergoing deterioration." In the 1993 edition, the 2nd definition is, "2 Ecol (Ecology) The maximum number of individuals or inhabitants that an environment can support without detrimental effects."
With "safe yield," the implication seems to be on the amount of the resource, in this case, water, that the environment can supply.
With carrying capacity, the definitions emphasize the population or the number of individuals using the resource. Payson is 1 percent from carrying capacity with water.
Safe yield is like a natural average of some resource in the environment. (Average and normal are not the same.)
Ecological principles dictate that all individuals over the carrying capacity will be eliminated, or must move. (Or live in the most horrible conditions as in poverty stricken countries.)
It isn't just the population that suffers. Note in the definitions of carrying capacity that the "area would undergo deterioration" or that the "environment would be detrimentally affected" (not direct quotes). This is the serious part of exceeding the carrying capacity. The environment is damaged which may take years to recover. With the recent drought, much of the local grazing range has been deteriorated with detrimental effects. Besides erosion, this allows the invasion of weeds as the native forage plants decrease.
The article in the paper also frequently used the term conservation, which I'm all for. And did you know what it is that we try to conserve? All or parts of the environment. Try living without it.
Max L. Partch, Payson