Water shortages creep up quietly on communities for many years; droughts generally accentuate them. Often the occurrence of a water shortage has been delayed by normal or above-normal rainfall even though the causes have been growing in strength, ever ready to assert themselves at the first opportunity. The chief reasons for most water shortages can be attributed to greater than anticipated population increases, decreases in well capacity, sediment accumulations in reservoirs, and increased water requirements, both domestic and industrial.