REP45988

• Permit No: C1981041
• IBM Index Class Name: Report
• Doc Name: 1994 Annual Hydrology Report & Mine Inflows Study
• Annual Report Year: 1994
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

. 1994 Annual Hydrologic Report
Page 2
Creek and the addition of other minor drainages between the
monitoring site and the mine site. Data Pages SQ-# include
information supplied by USGS on this site. The total flow at this
site for the Year was 2,071,000 acre-feet which amounts to 74% of
the 1934-1994 average flow. The estimated TDS load for the year
was 1.314 million tons. This estimate is made using the sum of the
monthly average conductivity times monthly flow times a calculated
conductivity - tons/a.f. ratio. A conductivity - tons/a.f. ratio
of 0.007771 was calculated from information on data page SQ-7. The
low flow for the year was recorded as 1430 CFS on February 1, 1994.
As can be seen on data page SQ-9, conductivity was not recorded
this day but a reading of 1090 was made on January 31, 1994. The
closest pH reading to this date was 8.5 on January 20, 1994.
Comparing the calculated TDS load in the River and the potential
maximum discharge of TDS in March 1994, near the low flow, the
maximum increase in the River's TDS as a result of mine discharge
would have been 0.21%.
A mistake was made in preparation of flow information for
Cottonwood and Rapid Creeks for the 1993 AHR. The digitized
• conversion gave readings in million gallons per day rather than the
CFS that we normally report. The error was not noted until this
Year's F-charts were digitized. This submission includes
replacement data pages SG-15 & 16, SH-15 & 16, SI-15 & 16 and SK-1
& 2. This Year's mean daily flow values for the Cottonwood and
Rapid Creek flumes are included on data pages SG-17, SH-17, SI-17
and SK-3 and presented graphically on data pages SG-18, SH-18, SI-
18 and SK-4. As usual, the flow in these Creeks is largely
controlled by the City of Palisade, depending upon their need for
domestic water. Also, irrigation water is diverted from the creeks
by private water right holders at various locations. Table 594-1
was prepared to show the average monthly flows during the primary
irrigation season when low flow in the creeks is critical. The
0.000's shown on data page SH-17 for SWGS 02 indicate times when
the flow was below the recording level of the recorder.
There was no discharge from our CDPS discharge points 005 thru 014
during the year. These discharge points cover sediment pond
outfalls. A new discharge point 015 as permitted this Year to
allow pumping water from the south end of the Roadside South Portal
out the 2 West portals. Piping to this point has not been
installed yet and as a result there was no discharge from this
point during the Year.
Discharge point 001 is used as an overflow to a mine water system
• for the preparation plant. The source of the water is primarily
location 3 (see the Mine Water section of this report) in the
Roadside South but can include flow from location 5. Flow from this
site is not directly related to inflows and is discussed in more