2.0

Table Of Contents
Chapter 2 Working with Ponds
142
Storage Indication Method Dialog Box - Display Fields
The following are display fields in the Storage Indication Method dialog box:
n
Time: Duration of time for the hydrograph in increments.
NOTE
The Time column has the only values that you can edit; the rest of the
columns have values that cannot be edited.
n
Inflow: Amount of flow coming into the structure.
n
I1+I2/2: Average of two flow rates (I1 and I2) calculated at different times.
For example, to calculate the I1+I2/2 value for T2 (the second time
increment), you convert the Inflow value of T1 and T2 to volume amounts,
then divide the total by 2. If the Inflow is in cfs units (cubic feet per second),
and the Time increment is one-tenth of a second, then you multiply the
Inflow value by 360 to obtain the volume of flow.
n
H1: Calculated headwater for the structure at the beginning of the time
period.
n
S-(0/2)T: Calculated storage volume for the structure at the beginning of the
time period. (S=storage volume at time 1, T=routing time period, and
O=outflow rate.)
n
S+(0/2)T: Calculated storage volume for the structure at the end of the
time period. (S=storage volume at time 1, T=routing time period, and
O=outflow rate.)
n
H: Calculated headwater for the structure at the end of the time period.
n
Outflow: Calculated flow out of the structure.
Specifying Curves to Use in Calculations
Use the Input Curves option to specify the following files for use in the storage
indication method calculations:
n
Post-development hydrograph file (.hdc)
n
Stage-storage curve file (.ssc)
n
Stage-discharge curve file (.sdc) or a rating curve (.rtc)
In addition, you can optionally use a pre-development .hdc file for viewing the
plot of the multiple hydrographs. All but the pre-developed hydrograph file are
required.