ARKANSAS RIVER BASIN

07124410 PURGATOIRE RIVER BELOW TRINIDAD LAKE, CO

LOCATION.--Lat 37°08'38", long 104°32'50", in NE14SW14 sec.27, T.33 S., R.64 W., Las Animas County, Hydrologic Unit 11020010, on left bank of flip bucket outlet 500 ft downstream from base of Trinidad Dam, 0.8 mi upstream from Santa Fe Railroad bridge, and 3.0 mi southwest of courthouse in Trinidad.

DRAINAGE AREA.--672 mi2.

PERIOD OF RECORD.--December 1976 to current year. Suspended-sediment data available, March 1977 to September 1984. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=07124410

GAGE.--Water-stage recorder with satellite telemetry and concrete control. Datum of gage is 6,073.64 ft above NGVD of 1929 (levels by U.S. Army, Corps of Engineers). Supplementary water-stage recorder about 1,000 ft downstream at same datum, for use when flows exceed approximately 1,500 ft3/s.

REMARKS.--Records good except for those below 0.5 ft3/s, which are fair, and estimated daily discharges, which are poor. Natural flow of stream affected by storage reservoirs, diversions for irrigation and municipal use, ground-water withdrawals, and return flows from irrigated areas. Flow completely regulated by Trinidad Lake (station 07124400) immediately upstream since Aug. 19, 1977. 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	0.03	0.05	0.44	0.19	0.56	0.87	0.68	11	189	83	74	123
2	e0.01	0.03	0.44	0.18	0.51	0.87	0.61	e16	264	70	55	82
3	e0.01	0.03	11	0.18	0.51	0.87	0.51	e19	233	68	41	65
4	e0.01	0.03	6.0	0.18	0.51	0.80	0.51	e19	200	66	40	257
5	e0.01	0.03	0.58	0.18	0.51	0.77	0.51	e19	234	66	43	421
6	e0.01	1.5	0.52	0.18	0.51	0.71	0.51	e29	347	55	43	182
7	e0.01	2.1	0.44	0.18	0.51	0.58	0.51	56	348	41	45	51
8	e0.01	1.8	0.44	0.18	0.51	0.58	0.51	87	345	44	53	119
9	e0.01	1.5	0.44	0.18	0.51	0.58	0.51	97	343	54	56	124
10	0.00	1.2	0.44	5.0	0.51	0.58	0.51	94	340	58	55	121
11	0.00	0.44	0.44	7.5	0.51	0.58	0.51	92	232	65	55	182
12	0.00	0.03	0.51	7.2	0.51	0.58	0.51	92	113	68	55	247
13	0.00	0.03	0.51	7.2	0.51	0.55	0.51	122	109	67	62	232
14	0.00	0.03	0.51	4.9	0.52	8.5	0.51	137	109	60	65	170
15	0.00	0.03	0.51	0.58	0.51	13	5.5	143	109	55	61	126
16	0.00	0.02	0.51	0.58	0.51	13	8.0	178	109	55	58	97
17	0.02	0.01	0.51	0.58	0.51	6.3	8.0	205	109	55	59	96
18	0.02	9.7	0.51	0.58	9.3	0.58	8.0	208	173	53	49	109
19	0.02	9.2	0.51	0.58	18	0.55	3.1	213	205	52	44	112
20	0.02	8.0	0.51	0.58	20	0.51	0.61	215	217	52	44	106
21	0.02	8.0	0.45	0.58	17	0.51	0.68	198	188	59	46	96
22	0.02	6.6	0.44	0.58	15	0.51	0.66	191	141	63	47	106
23	0.02	0.04	0.44	0.58	8.1	0.51	0.61	154	111	86	47	81
24	0.45	0.04	0.44	0.58	4.5	0.51	0.52	118	81	125	47	67
25	17	0.04	0.38	0.58	4.5	0.74	0.51	150	57	69	53	74
26	25	0.36	0.33	0.58	2.4	0.87	0.53	177	50	36	63	96
27	25	0.50	0.32	0.58	1.1	0.77	0.53	183	60	35	81	105
28	12	0.44	0.27	0.58	1.1	0.77	0.55	130	76	47	79	65
29	1.0	0.44	0.19	0.58	---	0.70	0.47	119	116	69	61	46
30	0.11	0.44	0.21	0.58	---	0.68	8.2	150	117	100	124	50
31	0.08	---	0.22	0.58	---	0.68	---	163	---	111	184	---
TOTAL	80.89	52.66	29.46	43.29	109.73	58.61	53.88	3,785	5,325	1,987	1,889	3,808
MEAN	2.61	1.76	0.95	1.40	3.92	1.89	1.80	122	178	64.1	60.9	127
MAX	25	9.7	11	7.5	20	13	8.2	215	348	125	184	421
MIN	0.00	0.01	0.19	0.18	0.51	0.51	0.47	11	50	35	40	46
AC-FT	160	104	58	86	218	116	107	7,510	10,560	3,940	3,750	7,550
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1977 - 2003, BY WATER YEAR (WY)
MEAN	22.6	5.29	2.34	2.56	3.00	2.89	30.0	161	198	168	143	112
MAX	96.0	25.9	11.9	14.7	13.1	17.8	106	375	614	306	310	283
(WY)	(1984)	(1984)	(1979)	(1977)	(1977)	(1977)	(2000)	(1994)	(1983)	(1983)	(1999)	(1984)
MIN	0.35	0.015	0.001	0.012	0.046	0.007	0.073	25.5	33.8	17.0	8.81	5.15
(WY)	(1989)	(1982)	(1995)	(1985)	(2001)	(1982)	(1984)	(1980)	(2002)	(2002)	(2002)	(1987)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1977 - 2003
ANNUAL TOTAL	4,563.43	17,222.52
ANNUAL MEAN	12.5	47.2	73.1
HIGHEST ANNUAL MEAN			146 1983
LOWEST ANNUAL MEAN			12.6 2002
HIGHEST DAILY MEAN	130 Sep 20	421 Sep 5	917 Sep 11, 1981
LOWEST DAILY MEAN	0.00 Oct 10	0.00 Oct 10	a0.00 Aug 20, 1977
ANNUAL SEVEN-DAY MINIMUM	0.00 Oct 10	0.00 Oct 10	0.00 Nov 18, 1979
MAXIMUM PEAK FLOW		458 Sep 5	b963 Sep 10, 1981
MAXIMUM PEAK STAGE		7.01 Sep 5	7.89 Sep 10, 1981
ANNUAL RUNOFF (AC-FT)	9,050	34,160	52,960
10 PERCENT EXCEEDS	36	146	238
50 PERCENT EXCEEDS	3.1	5.0	8.8
90 PERCENT EXCEEDS	0.05	0.05	0.04

e Estimated. a No flow on many days during many years. b From rating curve extended above 919 ft3/s.