L = total P income, g m
= mean depth, m
(1976) and Vollenweider (1976) found that the
specific phosphorus sedimentation rate, a term that is very difficult to
determine empirically, can be estimated as
Equations 9 and 10 are thus rewritten as
It should be noted, as first pointed out by Uttormark and Hutchins
that phosphorus sedimentation is inversely related to flushing rate so that
the amount of incoming phosphorus that is deposited in the reservoir bottom
will decrease as the inflow is diluted with additional water.
The effect of
dilution is that a decrease in the concentration in the inflow may'reduce
in-lake concentration, but the decrease in sedimentation will increase lake
Uttormark and Hutchins (1978) derived an expression from Equation 11
which allows comparison of predicted in-lake phosphorus concentrations, fol-
lowing dilution, with that before the addition of dilution water.