REP00993

• Permit No: C1981012
• IBM Index Class Name: Report
• Doc Name: 3.2 GROUND WATER
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

flume. The hydrograph exhibits a dual peak with initial runoff from the lower drainage in
the first peak and a secondary peak as runoff travels from the upper reaches of the
drainage. Following a review of the data collected to date, ~~~ILR approval to
decommission the station was obtained in August and monitoring ceased on August 27,
1985.
Station ACF-1 is located in Apache Canyon approximately one-half mile from the
Purgatoire River. drainage area of the canyon is 7566 acres with cover comprised mostly
of woodland. Grazing and wildlife are the major land uses. D.4ining is also a land use with
two shafts and a power substation located in the canyon. The spring and seep survey
conducted in 1984 and 1985 (Appendix 4) monitored two seeps and one USGS spring, none
of which were major contributions to stream flow. The flume station was monitored
quaterly for water quality, however, no flow was encountered (Table 1-9 of Appendix 1).
Flaw was measured by the flume (Table 1-11 of Appendix l). Of the 239 days the station
was monitored, mean 24-hour discharge was 0.001 cfs or 0.72 ac-ft annually. The 1985
hydrograph for the station is presented in Figure 5 as 24-hour mean flow. Flow ranged
from 0.001 to 9.7 cfs (Table .1-11 of Appendix 1). Figure 7 presents the typical storm
water runoff hydrograph at the flume which exhibits a spike of flow for only those intense
showers producing significant runoff. This single spike of short duration may be a
function of land uses in the canyon. Since grazing is the major land use, vegetation in the
valley bottom is sparse which increases the runoff potential. Also, there are two on-
stream impoundments in the upper drainage which impound surface flow. The mine inflow
study conducted during 1985 (Appendix 3) identified the two shafts as contributing
approximately 10 gpm of inflow which may be coming from the alluvial system. All of
these factors contribute to the low runoff observed at the flume station. Following a
review of the data collected to date, DALR approval to decommission the station was
obtained in August and monitoring ceased on August 27, 1985.
3.2 Ground Water
Six wells in the Purgatoire River alluvium and one
Ciruela Canyons were monitored monthly during 1985.
Purgatoire alluvium responded directly to the level of water
canyons responded primarily to precipitation received in
contained in Tables 2-1 through 2-8 of Appendix 1.
-19-
well in each of Apache and
Generally, wells within the
in the river. \Vells in the two
the drainage. All data is