Exceptions to this pattern are rivers controlled by upstream dams--which might have daily flow fluctuations but which, in the course of the year, generally have less variation, less pronounced high and low water periods.
(Exceptions to this pattern; might have; daily flow fluctuations) (Exceptions to this pattern; generally have; less variation, less pronounced high and low water periods)
Exceptions to this pattern Exceptions to this pattern
might have generally have
daily flow fluctuations
less variation, less pronounced high and low water periods