RIO GRANDE BASIN

08245000 CONEJOS RIVER BELOW PLATORO RESERVOIR, CO

LOCATION.--Lat 37°21'18", long 106°32'37", Conejos County, Hydrologic Unit 13010005, Rio Grande National Forest, on left bank 1,100 ft downstream from valvehouse for Platoro Reservoir and 0.7 mi northwest of Platoro.

DRAINAGE AREA.--40 mi2, approximately.

PERIOD OF RECORD.--May 1952 to current year. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=08245000

GAGE.--Water-stage recorder with satellite telemetry, and concrete control. Datum of gage is 9,866.60 ft above NGVD of 1929, (levels by U.S. Bureau of Reclamation).

REMARKS.--Records good except for estimated daily discharges, which are fair. Flow completely regulated by Platoro Reservoir (station 08244500) 0.2 mi upstream since Nov. 7, 1951.

COOPERATION.--Records collected and computed by Colorado Division of Water Resources and reviewed by Geological Survey.

EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of Oct. 5, 1911, is the greatest since at least 1854, from information obtained from local residents in 1959.

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	17	e7.2	e7.2	e7.2	e6.8	e6.4	31	95	593	138	59	23
2	17	e7.2	e7.2	e7.2	e6.7	e6.3	31	92	501	138	63	17
3	26	e7.2	e7.2	e7.2	e6.7	e6.3	27	99	426	150	53	26
4	31	e7.2	e7.2	e7.2	e6.7	e6.3	26	98	475	141	55	42
5	31	e7.2	e7.2	e7.1	e6.7	e6.3	25	87	449	131	64	44
6	20	e7.2	e7.2	e7.1	e6.7	e6.3	17	64	295	130	54	42
7	15	e7.2	e7.2	e7.1	e6.7	e6.3	13	42	241	127	52	42
8	15	e7.2	e7.2	e7.1	e6.7	e6.3	13	42	251	124	56	42
9	17	e7.2	e7.2	e7.1	e6.6	e6.2	15	50	277	122	56	36
10	19	e7.2	e7.2	e7.1	e6.6	e6.2	24	39	291	108	53	120
11	15	e7.2	e7.2	e7.1	e6.6	e6.2	25	33	291	112	55	336
12	13	e7.2	e7.2	e7.0	e6.6	e6.2	29	45	264	121	55	323
13	13	e7.2	e7.2	e7.0	e6.6	e6.2	37	85	221	98	62	201
14	13	e7.2	e7.2	e7.0	e6.6	e6.2	40	132	164	87	62	164
15	13	e7.2	e7.2	e7.0	e6.6	e6.2	55	149	144	110	48	164
16	8.6	e7.2	e7.2	e7.0	e6.5	e6.1	67	187	200	113	38	112
17	6.0	e7.2	e7.2	e7.0	e6.5	e6.1	63	208	249	104	21	52
18	6.1	e7.2	e7.2	e7.0	e6.5	e6.1	46	311	208	93	14	78
19	7.0	e7.2	e7.2	e6.9	e6.5	e6.1	25	330	179	61	14	106
20	7.4	e7.2	e7.2	e6.9	e6.5	e6.1	18	281	186	38	14	67
21	7.4	e7.2	e7.2	e6.9	e6.5	e6.1	26	314	191	38	14	29
22	7.7	e7.2	e7.2	e6.9	e6.5	e6.1	37	385	132	58	15	22
23	8.4	e7.2	e7.2	e6.9	e6.4	e6.0	49	500	83	87	19	36
24	e16	e7.2	e7.2	e6.9	e6.4	e6.0	44	548	111	91	21	35
25	e11	e7.2	e7.2	e6.9	e6.4	e6.0	28	482	151	72	21	25
26	e5.4	e7.2	e7.2	e6.8	e6.4	e14	27	433	136	53	19	18
27	e5.4	e7.2	e7.2	e6.8	e6.4	25	61	426	97	48	17	18
28	e5.4	e7.2	e7.2	e6.8	e6.4	24	123	506	111	53	15	37
29	e5.4	e7.2	e7.2	e6.8	---	23	135	582	129	83	23	47
30	e6.4	e7.2	e7.2	e6.8	---	23	110	526	136	119	29	39
31	e7.2	---	e7.2	e6.8	---	24	---	509	---	78	28	---
TOTAL	395.8	216.0	223.2	216.6	183.8	287.6	1,267	7,680	7,182	3,026	1,169	2,343
MEAN	12.8	7.20	7.20	6.99	6.56	9.28	42.2	248	239	97.6	37.7	78.1
MAX	31	7.2	7.2	7.2	6.8	25	135	582	593	150	64	336
MIN	5.4	7.2	7.2	6.8	6.4	6.0	13	33	83	38	14	17
AC-FT	785	428	443	430	365	570	2,510	15,230	14,250	6,000	2,320	4,650
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1952 - 2003, BY WATER YEAR (WY)
MEAN	40.5	58.4	10.6	10.9	11.6	10.3	52.5	238	329	211	89.7	46.7
MAX	158	406	50.0	50.0	102	27.5	252	492	609	610	429	164
(WY)	(1958)	(1966)	(1986)	(1986)	(1983)	(1986)	(1995)	(1974)	(1982)	(1952)	(1952)	(1982)
MIN	1.92	2.00	2.00	3.20	3.00	3.00	3.00	16.9	87.0	18.6	3.90	3.34
(WY)	(1957)	(1957)	(1957)	(1991)	(1957)	(1957)	(1957)	(1958)	(1977)	(2002)	(2002)	(1956)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1952 - 2003
ANNUAL TOTAL	11,821.00	24,190.0
ANNUAL MEAN	32.4	66.3	91.6
HIGHEST ANNUAL MEAN			137 1986
LOWEST ANNUAL MEAN			34.8 2002
HIGHEST DAILY MEAN	231 May 19	593 Jun 1	1,150 Oct 28, 1957
LOWEST DAILY MEAN	0.60 Aug 17	5.4 Oct 26	a0.00 Oct 16, 1955
ANNUAL SEVEN-DAY MINIMUM	0.97 Aug 16	6.1 Oct 26	0.16 Oct 15, 1955
MAXIMUM PEAK FLOW		626 Jun 1	1,160 Nov 1, 1957
MAXIMUM PEAK STAGE		3.11 Jun 1	b4.02 Nov 1, 1957
ANNUAL RUNOFF (AC-FT)	23,450	47,980	66,350
10 PERCENT EXCEEDS	125	186	301
50 PERCENT EXCEEDS	7.6	17	17
90 PERCENT EXCEEDS	4.0	6.4	6.2

e Estimated. a Also occurred Oct 17-20, 1955. b Maximum gage height, 4.29 ft, Jun 15, 1958.