Water Loss?

what is a acceptable amount of water loss--due to evaporation etc?
Trying to figure out if I have a leak....

Pond is in So Cal, where we get hot days over 98 and cold nights below
70, so the ponds goes through some big temp swings. ANyway

the pond has a 3 to 4ft waterfall into a 5 by 4 2ft deep pond that
drops into a 5 ft, few inch deep stream. the water then ends in the
final pond about 11ft by 8, witha depth from 2ft to a bog shelf around
9 inches deep! anyway windering how much water people loss and how
often they top off their pond? It seems I have to do it every other
day, as I lose about a inch or so in that time in the bottom pond only!