WSP04354

• File Number: 8102
• Description: Arkansas River Hydrology
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 1/1/1997
• Author: USGS
• Title: Description of the Program Changes 1989 97 and a User Manual for a Transit Loss Accounting Program Applied to Fountain Creek Between Colorado Springs and the Arkansas River Colorado
• Water Supply Pro - Doc Type: Report/Study

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stores the data, and transntits the stored data every
4 hours to a satellite. Additionally, each data-collec-
tion platform is programmed to transmit every
15 minutes when threshold gage-height limits are
exceeded during times of high flow. The data are
retransntitted from the satellite to satellite downlinks
and transferred to the streamflow data base contained
in the USGS computer system.
Discharge data are computed from the gage-
height data using a stage-discharge rating developed
from discharge measurements that are made at vari-
able gage heights. The sand, shale, and cobble chan-
nels at all of the gaging stations are extremely unstable
and require discharge measurements at weekly to
biweekly frequencies, depending on the extent of
hydraulic changes in the channel conditions. Because
of changes in the channel conditions, the stage-
discharge relations at the gaging stations may differ
from \he stage-discharge rating that was developed.
Therefore, to compute the current correct discharge,
corrections are made to the stage-discharge rating by
applying shifts to the transntitted gage-height data; the
shifts usually are distributed on the basis of time and
stage. The discbarges are calculated by the computer
as they are received from the satellite downlink and
stored in the data base. The discharge data are checked
for accuracy on a daily basis, including weekends;
during high flows and extreme low flows, the data may
be checked several times a day. Shift adjustments also
are made if the discharge at a gaging station does not
appear consistent with discharge at the adjacent
stations, after allowing for possible known inflows and
diversions between the stations.
The discharges that are computed at 15-minute
intervals and stored in the data base are retrieved auto-
matically on a nightly basis by additional computer
programs developed for that purpose. These programs
compute the daily mean discharge for each gaging
station for the appropriate 24-hour period (fig. 3) and
write the discharges to a data file accessible by the
agencies that use the accounting program. The daily
mean discharge data also are reviewed daily by USGS
personnel; any corrections in these data that are
needed as a result of changes in the applied shifts are
loaded into a second data file of revised discharges for
use as needed (see the ''Transit-Loss Accounting
Program Files" section, p. 27-30).
Operation of \hese gaging stations requires thor-
ough knowledge of the hydrology of Fountain Creek
and the ability to interpret the changing channel and

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control conditions at each station. The entire process
of providing the most accurate real-time discharge
data as possible for the accounting program requires
constant and intensive attention.

CHANGES TO THE TRANSIT-LOSS
ACCOUNTING PROGRAM
DURING 1991-92

In 1991, the CCS planned to modify the TRF
use and reuse program to enable ditch owners along
Fountain Creek to purchase and divert some of the
TRF's to supplement their NSF diversions. This diver-
sion (1) would benefit the ditch owners, especially
those having the more junior water rights, by
providing an additional source of irrigation water and
(2) would benefit the CCS by decreasing transit losses
because losses would not accrue downstream to the
mouth of Fountain Creek for the diverted TRF's.
Through an agreement with \he SEcWCD, the
diverted TRF's were considered to be return-flow
deliveries of FAF water, and the divened TRF's could
be exchanged by the CCS for equivalent quantities of
FAP water being stored in Pueblo Reservoir
(Thomas C. Simpson, SECWCD, oral commun.,
1997).
In addition, the CCS wanted to include TRF's in
the accounting program that resulted from water use
on the Fort Carson Military Reservation (south of the
CCS and west of Fountain Creek; not shown in figs. 1
and 2) and that entered Fountain Creek through Clover
Ditch (actually a drain) in the vicinity of station
07105800 (fig. 2). Finally, besides changing the
program to accommodate the proposed diversion of
TRF's for irrigation and the additional TRF source, the
physical structure of the program was changed to
make it more modular, and the program output also
was changed.
The changes to the program are described in the
next four sections of this report; \he modified
accounting program that resulted from these changes
was put in operation in April 1992. Although these
and subsequent changes made to the program were
considerable, the changes primarily affected \he input
and output handling of the various discharge quanti-
ties; the basic algorithms used to calculate transit
losses (Kuhn, 1988, p. 76-85) were not changed.

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14 Descriptions of the Program Changes (198~7) and a User Manuat for a Tran.lt.Loas Accounting Program
Apptled to fountain Creek Betwaen Colorado Sprtnga and the Arkanaa. Rtver, Cotorado