GREEN RIVER BASIN

09237500 YAMPA RIVER BELOW STAGECOACH RESERVOIR, CO

LOCATION (REVISED).--Lat 40°17'07", long 106°49'51", in SW14SE14 sec.29, T.4 N., R.84 W., Routt County, Hydrologic Unit 14050001, on left bank, 50 ft downstream from Stagecoach Reservoir, 1.1 mi upstream from Morrison Creek, and 6.5 mi east of Oak Creek.

DRAINAGE AREA.--228 mi2.

PERIOD OF RECORD.--September 1939 to September 1944, monthly discharge only for some periods, published in WSP 1313; October 1956 to September 1972; October 1984 to current year. Prior to October 1990, published as Yampa River near Oak Creek. Statistical summary computed for 1989 to current year. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09237500

REVISED RECORDS.--WDR CO-00-2: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Elevation of gage is 7,050 ft above NGVD of 1929, from topographic map. Sept. 1939 to Nov. 15, 1939, nonrecording gage, Nov. 16, 1939 to Sept. 1944 and Oct. 1956 to Sept. 1972, water-stage recorder at site 0.2 mi upstream, at different datum. Oct. 1984 to July 15, 2003, water-stage recorder at site 0.3 mi downstream, at different datum.

REMARKS.--Records fair except for estimated daily discharges, whcih are poor. Flow regulated since Dec. 20, 1988, by Stagecoach Reservoir (capacity 33,275 acre-ft), 50 ft upstream. Diversions for irrigation of about 12,000 acres upstream from station. Natural flow of stream affected by 2 diversions for irrigationto Egeria Creek into Colorado River basin and by storage in Stillwater, Yampa and YamColo Reservoirs (total capacity 15,820 acre-ft). Several measurements of specific conductance and water temperature were obtained and are published in the "Supplemental Water-Quality For Gaging Stations" section of this report.

Discharge, cubic feet per second 

WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003

DAILY MEAN VALUES

DAY	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP
1	e31	e56	37	31	33	32	41	78	123	88	64	59
2	e32	87	35	34	28	29	40	93	164	90	64	61
3	e31	76	30	28	28	34	42	98	164	97	64	58
4	e30	61	30	28	31	29	42	97	146	89	64	59
5	e30	46	30	28	28	29	43	79	129	79	62	49
6	e30	49	29	28	26	28	42	89	116	80	63	44
7	e30	48	31	28	21	29	41	90	115	79	63	43
8	e30	55	30	28	28	29	41	90	111	76	64	43
9	e30	75	30	28	28	29	41	90	109	71	61	43
10	e30	50	30	28	28	29	41	87	107	66	60	42
11	e30	49	30	28	28	29	40	87	110	66	64	41
12	e29	49	30	28	28	29	41	89	113	62	64	41
13	e29	48	29	29	28	29	40	89	112	62	64	40
14	e29	46	28	28	28	29	39	89	110	65	64	39
15	e29	40	28	28	28	30	39	89	107	e65	63	39
16	e29	39	28	28	28	29	39	89	102	63	60	38
17	e29	39	28	28	28	30	39	87	98	63	60	38
18	e29	38	28	28	28	30	39	87	96	63	59	38
19	e29	36	28	28	29	31	38	89	95	60	63	38
20	e29	35	27	28	29	35	37	89	95	60	63	36
21	e29	33	27	28	29	38	38	89	95	63	47	44
22	e29	35	27	28	29	39	38	90	94	63	51	62
23	e29	34	27	28	29	39	38	90	97	57	40	55
24	e29	34	27	28	29	40	37	90	98	56	49	37
25	e29	33	27	28	29	40	41	91	93	62	50	37
26	e29	34	27	28	29	41	38	91	86	59	50	57
27	e29	34	27	28	29	41	38	91	91	60	50	75
28	e29	32	27	28	29	41	44	91	86	62	54	74
29	e29	30	27	28	---	39	50	92	86	62	58	71
30	e29	34	27	28	---	38	55	96	90	62	58	73
31	e30	---	27	28	---	43	---	103	---	63	58	---
TOTAL	915	1,355	893	878	793	1,037	1,222	2,789	3,238	2,113	1,818	1,474
MEAN	29.5	45.2	28.8	28.3	28.3	33.5	40.7	90.0	108	68.2	58.6	49.1
MAX	32	87	37	34	33	43	55	103	164	97	64	75
MIN	29	30	27	28	21	28	37	78	86	56	40	36
AC-FT	1,810	2,690	1,770	1,740	1,570	2,060	2,420	5,530	6,420	4,190	3,610	2,920
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY)
MEAN	62.0	60.2	57.5	59.9	59.6	60.5	69.6	107	111	87.5	79.9	71.1
MAX	110	94.7	93.3	89.8	84.8	90.3	166	303	377	172	156	135
(WY)	(1998)	(1996)	(1996)	(1998)	(1997)	(2000)	(1996)	(1996)	(1997)	(1995)	(1997)	(1997)
MIN	25.8	37.3	27.0	28.3	28.3	18.0	32.3	12.4	12.8	22.3	34.4	31.8
(WY)	(1991)	(1991)	(2001)	(2003)	(2003)	(1989)	(1989)	(1989)	(1989)	(1989)	(1989)	(1990)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1989 - 2003
ANNUAL TOTAL	14,035	18,525
ANNUAL MEAN	38.5	50.8	a73.9
HIGHEST ANNUAL MEAN			134 1997
LOWEST ANNUAL MEAN			32.1 1989
HIGHEST DAILY MEAN	87 Nov 2	164 Jun 2	b611 Jun 9, 1997
LOWEST DAILY MEAN	13 May 18	21 Feb 7	c9.4 Jun 1, 1989
ANNUAL SEVEN-DAY MINIMUM	16 Jun 1	27 Feb 5	10 May 29, 1989
MAXIMUM PEAK FLOW		176 Jun 2	d641 Jun 11, 1997
MAXIMUM PEAK STAGE		f2.70 Jun 2	g3.82 Jun 11, 1997
ANNUAL RUNOFF (AC-FT)	27,840	36,740	53,570
10 PERCENT EXCEEDS	54	91	114
50 PERCENT EXCEEDS	42	39	64
90 PERCENT EXCEEDS	19	28	34

e Estimated. a Average discharge for 25 years (water years 1940-44, 1957-72, 1985-88), 89.4 ft3/s; 64,770 acre-ft/yr, prior to completion of Stagecoach Reservoir. b Maximum daily discharge for period of record, 1,020 ft3/s, Apr 16, 1962. c Minimum daily discharge for period of record, 8.9 ft3/s, May 22, 1963. d Maximum discharge and stage for period of record, 1,400 ft3/s, Apr 16, 1962, gage height, 7.56 ft, from rating curve extended above 570 ft3/s, site and datum then in use. f Maximum gage height, 3.64 ft, Oct 31, backwater from beaver dam. g Maximum gage height, 8.08 ft, Mar 8, 1987, backwater from ice.