GUNNISON RIVER BASIN

09147500 UNCOMPAHGRE RIVER AT COLONA, CO

LOCATION.--Lat. 38°19'53", long 107°46'44", in NW14NW14 sec.17, T.47 N., R.8 W., Ouray County, Hydrologic Unit 14020006, on right bank 75 ft downstream from county highway crossing, 0.2 mi north of Colona, and 1.0 mi upstream from Beaton Creek.

DRAINAGE AREA.--448 mi2.

PERIOD OF RECORD.--April 1903 to November 1905, April to June 1906 (gage heights and discharge measurements only), October 1912 to current year. Monthly discharge only for some periods, published in WSP 1313. Published as "near Colona" 1904-06, 1922-34. Statistical summary computed for 1986 to current year. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09147500

REVISED RECORDS.--WSP 1313: 1904. WDR CO-88-2: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Datum of gage is 6,318.80 ft above NGVD of 1929. See WSP 1713 or 1733 for history of changes prior to Sept. 30, 1949.

REMARKS.--Records good except for estimated daily discharges, which are fair. Flow regulated by Ridgway Reservoir, 7.7 mi upstream, since 1986, total capacity 84,590 acre-ft. Diversions upstream from station for irrigation of about 2,600 acres downstream from station. Several measurements of specific conductance and water temperature were obtained and are published in the "Supplemental Water-Quality Data 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	132	41	41	33	31	30	69	121	1,440	258	220	146
2	140	40	38	39	32	31	76	e115	1,390	262	231	156
3	155	36	39	36	32	30	66	e125	1,270	271	268	193
4	156	37	36	31	31	31	58	e110	1,170	270	250	176
5	169	35	37	30	31	31	49	e100	1,130	273	241	150
6	156	34	34	30	34	30	47	e90	1,030	271	236	183
7	152	35	34	32	37	31	46	72	989	263	234	185
8	127	38	32	33	34	33	40	84	968	258	241	169
9	109	49	32	33	33	36	51	90	840	261	232	208
10	123	46	32	32	36	39	73	102	562	292	230	253
11	124	45	32	31	33	43	84	100	485	312	231	121
12	121	40	32	30	32	45	92	101	458	311	230	112
13	118	40	34	31	33	53	99	116	432	312	229	134
14	114	40	32	32	37	62	122	123	418	302	239	116
15	108	40	34	32	32	49	120	130	434	297	234	109
16	105	36	33	33	31	51	92	138	435	296	237	109
17	102	40	34	32	31	47	102	237	391	284	238	105
18	100	41	33	34	32	47	88	252	357	290	228	97
19	98	39	32	35	31	44	72	220	365	290	212	95
20	96	39	34	34	30	41	65	239	380	286	204	89
21	71	42	34	33	31	44	67	229	368	286	198	84
22	37	44	33	31	30	42	70	322	365	294	199	84
23	41	45	36	30	29	58	68	440	355	289	196	78
24	43	41	32	30	29	70	51	477	312	290	193	94
25	45	41	34	30	30	61	74	496	274	292	191	142
26	44	39	37	30	30	61	144	506	239	292	190	170
27	46	34	39	30	30	52	180	562	235	291	194	182
28	46	35	37	30	30	48	190	797	227	291	168	180
29	45	37	33	30	---	42	167	1,390	221	261	138	178
30	42	37	34	30	---	41	132	1,540	241	267	143	179
31	42	---	35	30	---	56	---	1,450	---	229	150	---
TOTAL	3,007	1,186	1,069	987	892	1,379	2,654	10,874	17,781	8,741	6,625	4,277
MEAN	97.0	39.5	34.5	31.8	31.9	44.5	88.5	351	593	282	214	143
MAX	169	49	41	39	37	70	190	1,540	1,440	312	268	253
MIN	37	34	32	30	29	30	40	72	221	229	138	78
AC-FT	5,960	2,350	2,120	1,960	1,770	2,740	5,260	21,570	35,270	17,340	13,140	8,480
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 2003, BY WATER YEAR (WY)
MEAN	148	103	84.7	74.6	75.5	108	281	501	608	421	285	191
MAX	353	214	132	105	121	213	683	926	1,066	1,226	598	495
(WY)	(1998)	(1999)	(1993)	(1986)	(1997)	(1997)	(1997)	(1987)	(1995)	(1995)	(1999)	(1999)
MIN	51.6	39.5	34.5	31.8	31.9	44.5	62.6	160	184	141	114	52.3
(WY)	(1990)	(2003)	(2003)	(2003)	(2003)	(2003)	(1990)	(1988)	(2002)	(2002)	(2002)	(1989)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1986 - 2003
ANNUAL TOTAL	37,641	59,472
ANNUAL MEAN	103	163	a241
HIGHEST ANNUAL MEAN			396 1997
LOWEST ANNUAL MEAN			116 2002
HIGHEST DAILY MEAN	288 May 21	1,540 May 30	1,900 Jul 11, 1995
LOWEST DAILY MEAN	32 Dec 8	29 Feb 23	b25 Apr 28, 1990
ANNUAL SEVEN-DAY MINIMUM	32 Dec 8	30 Feb 22	29 Sep 24, 1989
MAXIMUM PEAK FLOW		1,740 May 30	c2,230 Jul 12, 1995
MAXIMUM PEAK STAGE		4.23 May 30	4.76 Jul 12, 1995
ANNUAL RUNOFF (AC-FT)	74,660	118,000	174,500
10 PERCENT EXCEEDS	187	311	568
50 PERCENT EXCEEDS	95	84	125
90 PERCENT EXCEEDS	37	31	56

e Estimated. a Average discharge for 76 years (water years 1904-1905, 1913-1986), 271 ft3/s, 196,300 acre-ft/yr, prior to completion of Ridgway Reservoir. b Minimum daily discharge for period of record, 12 ft3/s, Sep 19, 1956, and May 7, 1967. c Maximum discharge for period of record, 4,080 ft3/s, June 13-14, 1921, gage height unknown.