GUNNISON RIVER BASIN

09132500 NORTH FORK GUNNISON RIVER NEAR SOMERSET, CO

LOCATION.--Lat 38°55'33", long 107°26'01", in SE14SW14 sec.10, T.13 S., R.90 W., Gunnison County, Hydrologic Unit 14020004, on left bank 2.3 mi east of Somerset and 4.8 mi upstream from Hubbard Creek.

DRAINAGE AREA.--526 mi2.

PERIOD OF RECORD.--October 1933 to current year. Monthly discharge only for some periods, published in WSP 1313. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09132500

REVISED RECORDS.--WSP 2124: Drainage area. WDR CO-77-2: 1976.

GAGE.--Water-stage recorder with satellite telemetry and crest-stage gage. Elevation of gage is 6,280 ft above NGVD of 1929, from topographic map. Prior to Oct. 1, 1982, at various sites 0.8 mi downstream, at different datums. See WDR CO-81-2, for history of changes.

REMARKS.--Records fair except for estimated daily discharges, which are poor. Natural flow of stream affected by small diversions for irrigation in nearby drainage areas, irrigation of about 3,000 acres upstream from station, storage in Overland Reservoir (capacity, 6,280 acre-ft), and storage in Paonia Reservoir (capacity, 18,300 acre-ft), since February 1962. 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	96	60	e72	e45	e41	e41	150	818	2,690	426	228	207
2	91	64	e71	e40	e43	e39	190	773	2,470	405	228	162
3	99	56	e63	e45	e43	e38	201	782	2,070	381	229	60
4	95	54	e52	e46	e38	e46	189	814	1,830	356	220	59
5	91	54	e64	e44	e41	e43	173	711	1,620	e327	217	59
6	88	46	e53	e40	e40	e47	162	632	1,380	e311	215	72
7	85	50	e48	e43	e34	e47	150	614	1,200	e289	211	94
8	86	58	e42	e42	e35	e51	141	589	1,110	e267	211	100
9	84	85	e37	e42	e40	67	153	570	1,110	e258	207	112
10	81	76	e26	e46	e42	77	206	563	1,110	257	212	269
11	75	66	e32	e46	e40	90	290	548	1,150	266	217	209
12	71	52	e46	e45	e43	119	339	650	1,110	248	214	166
13	69	e59	e51	e40	e50	140	410	e845	1,040	237	228	185
14	66	61	e49	e45	e54	155	595	e1,100	958	242	220	166
15	62	57	e45	e44	e56	158	534	e1,480	963	243	206	144
16	59	50	e49	e37	e51	169	490	e1,760	958	257	216	130
17	56	e53	e51	e43	e47	163	499	e2,180	862	280	215	119
18	55	71	e50	e39	e44	150	484	e2,550	833	287	203	110
19	53	61	e39	e45	e42	140	429	e3,150	797	278	205	104
20	53	e73	e38	e46	e38	132	430	e2,930	764	264	211	96
21	51	e76	e46	e46	e44	136	485	e2,930	698	255	222	90
22	49	e75	e41	e46	e45	138	610	e2,810	676	252	230	85
23	59	e73	e35	e43	e44	154	679	e2,760	639	251	241	82
24	62	e68	e39	e43	e39	177	578	e2,970	590	253	225	78
25	59	e63	e42	e45	e44	165	585	e2,900	518	237	219	75
26	57	e56	e38	e43	e45	161	731	2,630	496	247	218	72
27	61	e44	e38	e42	e44	160	860	2,640	485	256	215	70
28	58	e38	e38	e42	e46	139	947	3,210	478	247	213	69
29	60	e57	e43	e40	---	126	997	3,070	468	246	214	67
30	56	e65	e43	e37	---	123	893	3,060	447	223	219	65
31	60	---	e39	e42	---	123	---	2,640	---	224	214	---
TOTAL	2,147	1,821	1,420	1,332	1,213	3,514	13,580	55,679	31,520	8,570	6,743	3,376
MEAN	69.3	60.7	45.8	43.0	43.3	113	453	1,796	1,051	276	218	113
MAX	99	85	72	46	56	177	997	3,210	2,690	426	241	269
MIN	49	38	26	37	34	38	141	548	447	223	203	59
AC-FT	4,260	3,610	2,820	2,640	2,410	6,970	26,940	110,400	62,520	17,000	13,370	6,700
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1934 - 2003, BY WATER YEAR (WY)
MEAN	119	92.9	75.7	64.5	69.8	153	716	1,905	1,451	446	199	151
MAX	466	318	271	166	180	721	1,736	3,993	4,095	1,834	438	319
(WY)	(1987)	(1987)	(1966)	(1966)	(1986)	(1986)	(1986)	(1984)	(1957)	(1995)	(1957)	(1986)
MIN	47.9	35.2	33.1	29.6	30.4	40.2	166	314	179	64.6	48.1	47.6
(WY)	(1957)	(1990)	(1978)	(1990)	(1978)	(1964)	(1977)	(1977)	(1934)	(1934)	(1977)	(1934)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1934 - 2003
ANNUAL TOTAL	59,054	130,915
ANNUAL MEAN	162	359	455
HIGHEST ANNUAL MEAN			829 1984
LOWEST ANNUAL MEAN			114 1977
HIGHEST DAILY MEAN	654 May 31	3,210 May 28	7,080 May 24, 1984
LOWEST DAILY MEAN	e26 Dec 10	e26 Dec 10	17 Nov 10, 1950
ANNUAL SEVEN-DAY MINIMUM	35 Sep 1	39 Feb 4	25 Feb 17, 1978
MAXIMUM PEAK FLOW		a3,710 May 28	9,220 May 24, 1984
MAXIMUM PEAK STAGE		a5.15 May 28	b8.20 May 24, 1984
ANNUAL RUNOFF (AC-FT)	117,100	259,700	329,500
10 PERCENT EXCEEDS	439	915	1,480
50 PERCENT EXCEEDS	64	119	135
90 PERCENT EXCEEDS	41	42	52

e Estimated. a Maximum recorded, may have been higher during estimated period, May 13-25. b From outside high-water mark.