SAN JUAN RIVER BASIN

09355000 SPRING CREEK AT LA BOCA, CO

LOCATION.--Lat 37°00'40", long 107°35'47", in SE14SW14 sec.15, T.32 N., R.7 W., La Plata County, Hydrologic Unit 14080101, on right bank in an excavated channel, 0.2 mi upstream from mouth, and 0.2 mi east of La Boca.

DRAINAGE AREA.--58.2 mi2.

PERIOD OF RECORD.--October 1950 to current year. Monthly discharge only for some periods, published in WSP 1733. Water-quality data available, May 1974, January 1988 to September 1991. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09355000.

REVISED RECORDS.-- WDR CO-00-02: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Elevation of gage is 6,160 ft above NGVD of 1929, from topographic map.

REMARKS.--Records fair except for estimated daily discharges, which are poor. Part of flow is return waste from irrigation. Nearly all irrigation in this basin is water diverted from Los Pinos River which causes a considerable change in the annual pattern and natural flow. 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	1.3	1.0	1.5	e0.48	0.34	7.2	0.90	0.17	30	40	43	46
2	1.8	0.92	e1.6	e0.49	0.13	5.6	0.90	3.4	31	42	50	63
3	2.0	0.85	1.7	e0.74	e0.28	5.2	0.97	9.4	29	41	71	69
4	1.6	1.2	1.5	e0.85	e0.51	5.2	0.90	1.7	29	38	56	48
5	1.4	1.2	1.2	e0.85	e0.58	5.9	0.96	1.4	28	42	49	45
6	1.3	0.82	e1.4	e0.79	e0.74	5.7	0.91	4.4	30	42	47	45
7	1.2	0.83	e1.6	e0.63	e1.3	5.7	0.82	7.3	37	41	48	48
8	1.1	1.2	e1.9	e0.46	e1.8	6.2	0.68	7.1	37	40	48	45
9	1.2	12	e2.4	e0.38	e2.3	8.1	0.67	9.2	34	39	51	276
10	e1.1	11	e2.9	e0.38	e3.0	12	0.67	9.4	36	35	46	281
11	e1.0	3.4	e3.0	e0.38	e3.4	22	0.66	8.2	39	41	41	9.1
12	e0.84	2.0	e3.3	e0.38	e3.9	40	0.64	9.3	41	42	40	0.99
13	0.96	1.4	e3.6	e0.35	6.0	34	0.60	8.9	45	43	40	0.33
14	0.89	1.2	e2.7	e0.37	7.7	20	0.45	7.7	43	44	46	0.12
15	0.92	1.1	e2.4	e0.42	7.7	13	0.53	11	41	44	49	0.08
16	0.82	e1.3	e2.0	e0.46	4.8	12	0.60	13	40	43	63	0.05
17	10	e1.4	e1.7	e0.53	3.8	48	0.48	13	41	43	61	0.04
18	6.1	e1.4	e1.5	e0.53	3.8	26	0.40	16	46	43	70	0.02
19	11	e1.3	e1.2	e0.51	3.7	14	0.44	19	49	41	59	0.02
20	17	e1.2	e1.1	e0.46	e2.9	7.1	0.39	19	54	42	52	0.01
21	4.9	e1.2	e0.86	e0.46	e2.7	6.2	0.41	19	43	45	49	0.05
22	1.5	e1.2	e0.86	e0.42	e2.8	7.8	0.39	18	41	48	54	0.02
23	e1.0	e1.2	e0.79	e0.38	e2.8	4.9	0.59	19	39	47	55	0.01
24	1.1	e1.3	e0.67	e0.38	e2.7	4.8	0.51	19	37	50	63	0.01
25	0.55	1.2	e0.67	e0.35	4.0	3.9	0.36	19	37	50	59	0.01
26	1.0	e1.2	e0.67	e0.27	6.5	3.1	0.32	26	40	64	60	0.05
27	3.8	e1.3	e0.67	e0.24	7.4	2.5	0.32	23	41	62	57	0.29
28	1.1	e1.3	e0.67	e0.24	15	1.8	0.27	23	40	95	63	0.78
29	0.77	e1.4	e0.61	0.41	---	1.5	0.23	20	39	46	70	1.4
30	1.1	e1.4	e0.58	0.12	---	e1.3	0.17	27	40	47	61	2.1
31	1.1	---	e0.48	0.39	---	1.1	---	28	---	43	68	---
TOTAL	81.45	59.42	47.73	14.10	102.58	341.8	17.14	419.57	1,157	1,423	1,689	981.48
MEAN	2.63	1.98	1.54	0.45	3.66	11.0	0.57	13.5	38.6	45.9	54.5	32.7
MAX	17	12	3.6	0.85	15	48	0.97	28	54	95	71	281
MIN	0.55	0.82	0.48	0.12	0.13	1.1	0.17	0.17	28	35	40	0.01
AC-FT	162	118	95	28	203	678	34	832	2,290	2,820	3,350	1,950
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1951 - 2003, BY WATER YEAR (WY)
MEAN	34.1	10.4	5.38	4.73	9.78	17.9	12.8	38.1	56.9	65.9	65.1	56.9
MAX	87.9	29.6	20.4	19.3	54.8	89.7	41.1	64.5	79.3	111	132	92.0
(WY)	(1973)	(1956)	(1985)	(1980)	(1980)	(1979)	(1979)	(1992)	(1986)	(1996)	(1996)	(1983)
MIN	2.63	1.98	1.54	0.45	2.06	2.36	0.57	13.5	24.4	1.07	0.45	0.93
(WY)	(2003)	(2003)	(2003)	(2003)	(2000)	(1999)	(2003)	(2003)	(1977)	(2002)	(2002)	(2002)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1951 - 2003
ANNUAL TOTAL	2,589.82	6,334.27
ANNUAL MEAN	7.10	17.4	31.9
HIGHEST ANNUAL MEAN			47.7 1987
LOWEST ANNUAL MEAN			9.78 2002
HIGHEST DAILY MEAN	64 Jun 11	281 Sep 10	918 Mar 6, 1995
LOWEST DAILY MEAN	0.00 Aug 1	0.01 Sep 20	0.00 Aug 1, 2002
ANNUAL SEVEN-DAY MINIMUM	0.03 Aug 12	0.02 Sep 19	0.02 Sep 19, 2003
MAXIMUM PEAK FLOW		742 Sep 10	a1,980 Sep 6, 1970
MAXIMUM PEAK STAGE		5.50 Sep 10	b4.62 Sep 6, 1970
ANNUAL RUNOFF (AC-FT)	5,140	12,560	23,090
10 PERCENT EXCEEDS	27	48	71
50 PERCENT EXCEEDS	1.7	3.0	21
90 PERCENT EXCEEDS	0.37	0.38	3.0

e Estimated. a From rating curve extended above 160 ft3/s, on the basis of field estimate of peak flow. b Maximum gage height, 5.98 ft, Mar 9, 1960, backwater from ice.