35 Ill. Adm. Code 302.658
Stream Flow for Application of Human Nonthreshold Criterion
Section 302
Section 302.658Â Stream Flow
for Application of Human Nonthreshold Criterion
The HNC applies at all times
except during periods when flows are less than the harmonic mean flow (Qhm), as
determined by:
Qhm = N /
SUM(1/Qi)
Where:
Qhm
=
harmonic mean flow,
N
=
number of daily values for streamflows,
and
Qi
=
daily streamflow value on day
i.