ISFAPPC01131

• Case Number: 00CW0133
• Stream Name: East Fork Parachute Creek
• Watershed: Parachute Creek
• Water Division: 5
• Water District: 39
• County: Garfield
• Instream Flow App - Doc Type: Supplemental Data

measured discharge at the time of the survey (Q), the accuracy range of predicted 110ws based on
Manning's Equation (240% and 40% of Q). the summer !low recommendation based upon
meeting 3 of 3 hydraulic criteria and the winter flow recommendation based upon 2 of 3
hydraulic criteria.

Table I' Data

Part" Date Q 250%."0% Summer (3/3) "'inter (2/3)
BL:VI 7/8/98 4.32 10,8 - 1.7 5.0 1.ill

RL.l,.l : Bureau (I(Land \l:1nagl."mem (I ) Prrol~r...J 110'" our<Illc (I(rh... a...C>lr.lc~' r.lngl'of ~1anmng', Equallon
? '" CnlmJ nn,'r lTll'rln R~CROSS SUging labk

Biolo2:ic Flow Recommendations
The BLM recommended a 5.0. 2.3 and 1.3 cfs summer now and a 0.8 cfs wimer llow based on
their July 8th. 1998, data collection effort and their water availability analysis. C\VCB staff has
reviewed the data collected by the BU\1. The summer now recommendation. which lneets 3 of 3
criteria and is within the accuracy range of (he R2CROSS model. is 5.0 cfs. The winter flow
recommendation. \\'hich meets 2 of 3 criteria but falls outside of the accuracy of (he R2Cross
model. is 1.2 cfs. CWCB staff believe!'> recommendations that fall outside of the accuracy of the
model. below 40% of the measured discharge. may underestimate the required wimer llow. To
determine the winter now recommendation, staff looked at valid wimer llow recommendations
for the stream segment located above First Anvil Creek (2.1 c('i). After consulting with the
Colorado Division of Wildlife. staff believes 2.1 C(.. will be sufficiem to protect the natural
environment to a reasonable degree.

Hydrologic Data

After receiving the cooperating agencies' biologic recommendation. the C\VCB staff conducted
an evaluation of the stream hydrology to determine if water was physicalJy U\'ailable for an
instream llow appropriation. The hydrograph was derived from data collected by the USGS
stream gage for East Fork Parachute Creek near Anvil Points (lD #(9092960). which has a
drainage area of 14,5 square miles (see Gage Summary in Appendix C). The period of record for
this gage is 1976 to 1983. the period of record used by staff in their analysis was 1976.1983, or
seven years of record. The estimated drainage area of Easl Fork Parachute Creek upstream and
including First Anvil Creek is approximately 14.7 square miles. The drainage area upstream of
Bull Gulch is 19.4 square miles. Tables 2 and 3 below display the estimated now of East Fork
Parachute Creek at Ihe conlluence with and First Anvil Creek and Bull Gulch. in terms of a
percentage of exceedence. The orange shading highlights how otten the summer flow has been
available and the blue shading highlights ho\'.... often the wimer llow recommendations have been
available.

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d '90 '00 ,"00 95.00 "" '" "" '''' "0 091
'" 010 '''' 590 3950 '" 260 '50 '00 09' 097 0"
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Tab~ 2 East Forti ParaCllv1e C'ee~ downslream ol FIrst AnVll Cref'!<