SAN JUAN RIVER BASIN

09371000 MANCOS RIVER NEAR TOWAOC, CO

LOCATION.--Lat 37°01'39", long 108°44'27", Ute Indian Reservation, Montezuma County, Hydrologic Unit 14080107, on left bank 700 ft upstream from bridge on U.S. Highway 666, 2.0 mi north of Colorado-New Mexico State line, 6.0 mi upstream from Aztec Creek, and 12 mi south of Towaoc.

DRAINAGE AREA.--526 mi2.

PERIOD OF RECORD.--October 1920 to September 1943, February 1951 to current year. Monthly discharge only for some periods, published in WSP 1313. Sediment data available, April to December 1961. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09371000

REVISED RECORDS.--WSP 1733: 1924 (monthly figures only). WDR CO-83-3: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Datum of gage is 5,055.98 ft above NGVD of 1929. See WSP 1713 or 1733 for history of changes prior to Mar. 11, 1954.

REMARKS.--Records fair except those for Mar. 14-26, Apr. 12-14 and estimated daily discharges, which are poor. Diversions for irrigation of about 10,000 acres upstream from station. One diversion upstream from station for irrigation of about 100 acres downstream from station. Flow regulated by Jackson Gulch Reservoir, capacity, 10,000 acre-ft since March 1949. 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	0.00	0.87	0.00	0.00	e1.4	4.7	e6.3	5.7	1.9	0.00	0.00	23
2	2.4	1.3	0.00	0.00	e1.4	e4.3	7.2	3.5	3.5	0.00	0.00	14
3	5.5	0.92	0.04	0.00	e1.2	e3.9	e13	3.7	2.4	0.00	45	9.3
4	12	0.78	e0.14	0.00	0.76	e4.5	e15	2.9	2.0	0.00	9.4	5.2
5	2.1	0.50	0.11	0.00	0.28	e5.3	10	2.9	1.4	0.00	1.7	6.1
6	0.58	0.47	0.03	0.00	0.06	e5.4	8.5	4.0	0.44	0.00	0.29	3.2
7	0.15	0.18	0.00	0.00	0.01	e3.7	e7.7	3.5	0.15	0.00	0.00	2.8
8	0.02	0.13	0.00	0.09	e0.34	e3.4	e6.9	2.1	0.04	0.00	0.00	20
9	0.00	4.6	e0.09	e0.83	e0.37	e4.4	e5.8	0.91	0.00	0.00	0.00	649
10	0.00	12	e0.06	e1.0	0.19	e6.1	5.6	0.36	0.00	0.00	0.00	1,810
11	0.00	8.5	0.02	e0.94	e0.14	e11	5.7	0.19	0.00	0.00	0.00	83
12	0.00	3.6	0.00	e0.63	0.00	23	17	0.05	0.00	0.00	6.5	33
13	0.00	2.3	0.00	e0.63	1.3	40	44	0.02	0.00	0.00	2.1	19
14	0.00	1.8	0.00	e0.72	18	43	33	0.05	0.00	0.00	0.17	14
15	0.00	1.3	0.00	e0.82	14	32	40	0.00	0.00	0.00	48	10
16	0.00	1.00	0.00	e0.84	6.7	26	33	0.91	0.00	0.00	6.9	7.1
17	0.00	0.32	0.00	e0.64	4.7	34	19	5.8	0.00	0.00	16	5.4
18	0.00	0.23	0.22	e0.70	4.2	41	13	3.1	0.00	0.00	2.1	6.4
19	0.00	0.03	0.02	e0.70	3.9	27	15	4.5	0.00	0.00	1.2	9.4
20	0.00	0.07	0.00	0.44	4.7	22	7.9	1.7	0.00	0.00	0.59	10
21	0.00	e0.11	0.00	e0.95	e3.5	27	5.8	0.94	0.00	0.00	0.17	9.1
22	1.3	e0.16	0.00	e1.3	e3.4	28	3.6	0.67	0.00	0.00	3.6	7.8
23	0.54	e0.17	0.00	e1.6	e3.3	31	1.8	0.58	0.00	0.00	19	7.0
24	0.00	e0.19	0.00	e1.6	e3.4	32	1.2	0.68	0.00	0.00	61	5.2
25	0.42	e0.14	0.00	e1.5	e3.9	23	1.0	2.6	0.00	0.00	4.3	4.2
26	1.3	0.15	0.00	e1.5	5.0	17	0.89	1.8	0.00	0.00	13	3.1
27	15	0.06	0.00	1.6	6.2	e15	1.4	1.1	0.00	0.00	0.99	2.4
28	9.0	0.00	0.00	e1.4	6.4	e11	21	0.61	0.00	0.00	2.0	1.5
29	8.5	0.00	0.00	e1.4	---	e9.4	32	0.16	0.00	0.00	15	0.98
30	1.3	e0.13	0.00	e1.4	---	e3.7	27	0.02	0.00	0.00	43	0.50
31	0.49	---	0.00	e1.4	---	e3.7	---	0.17	---	0.00	38	---
TOTAL	60.60	42.01	0.73	24.63	98.75	545.5	409.29	55.22	11.83	0.00	340.01	2,781.68
MEAN	1.95	1.40	0.024	0.79	3.53	17.6	13.6	1.78	0.39	0.000	11.0	92.7
MAX	15	12	0.22	1.6	18	43	44	5.8	3.5	0.00	61	1,810
MIN	0.00	0.00	0.00	0.00	0.00	3.4	0.89	0.00	0.00	0.00	0.00	0.50
AC-FT	120	83	1.4	49	196	1,080	812	110	23	0.00	674	5,520
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1921 - 2003, BY WATER YEAR (WY)
MEAN	26.6	19.4	14.0	13.2	24.8	56.9	121	172	81.9	28.5	28.3	27.0
MAX	459	113	45.5	45.6	92.1	198	330	642	395	185	364	137
(WY)	(1942)	(1987)	(1942)	(1942)	(1993)	(1993)	(1980)	(1922)	(1957)	(1921)	(1921)	(1970)
MIN	0.11	1.00	0.024	0.31	3.53	5.26	0.15	0.000	0.000	0.000	0.000	0.000
(WY)	(1978)	(1935)	(2003)	(1960)	(2003)	(1977)	(1977)	(1959)	(1951)	(1939)	(1922)	(1922)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1921 - 2003
ANNUAL TOTAL	1,223.98	4,370.25
ANNUAL MEAN	3.35	12.0	50.4
HIGHEST ANNUAL MEAN			138 1973
LOWEST ANNUAL MEAN			4.28 1959
HIGHEST DAILY MEAN	60 Sep 11	1,810 Sep 10	3,050 Oct 14, 1941
LOWEST DAILY MEAN	0.00 May 2	0.00 Oct 1	a0.00 Jul 12, 1922
ANNUAL SEVEN-DAY MINIMUM	0.00 May 2	0.00 Oct 9	0.00 Jul 12, 1922
MAXIMUM PEAK FLOW		b3,530 Sep 10	c5,300 Oct 14, 1941
MAXIMUM PEAK STAGE		d9.09 Sep 10	f7.30 Oct 14, 1941
ANNUAL RUNOFF (AC-FT)	2,430	8,670	36,510
10 PERCENT EXCEEDS	10	17	138
50 PERCENT EXCEEDS	0.05	0.91	15
90 PERCENT EXCEEDS	0.00	0.00	0.04

e Estimated. a No flow at times in most years. b Based on slope-area measurement of peak flow. c Present site and datum, from rating curve extended above 200 ft3/s, on basis of slope-area measurement of peak flow. d From floodmarks. f Maximum gage height, 9.09 ft, Sept. 10, 2003.