RIO GRANDE BASIN

08246500 CONEJOS RIVER NEAR MOGOTE, CO

LOCATION.--Lat 37°03'14", long 106°11'13", in SE14SE14 sec.34, T.33 N., R.7 E., Conejos County, Hydrologic Unit 13010005, on left bank 75 ft downstream from bridge on State Highway 174, 0.4 mi downstream from Fox Creek, 5.3 mi west of Mogote, and 10 mi west of Antonito.

DRAINAGE AREA.--282 mi2.

PERIOD OF RECORD.--April 1903 to October 1905, October 1911 to current year. Monthly discharge only for some periods, published in WSP 1312. Records for March 1900 at site 5.5 mi upstream and May 1905 to September 1911 (some missing periods most years) at site 3.2 mi upstream not equivalent to present site due to inflow. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=08246500

REVISED RECORDS.--WSP 898: 1911(M). WSP 1312: 1903-5 (monthly discharge and runoff).

GAGE.--Water-stage recorder with satellite telemetry. Datum of gage is 8,269.39 ft (revised) above NGVD of 1929, Colorado State Highway datum.
Apr. 17, 1903 to Oct. 31, 1905, nonrecording gage 400 ft downstream at different datum. Oct. 5, 1911 to early 1915, nonrecording gage, and from early 1915 to Oct. 1, 1988, water-stage recorder at site 100 ft upstream at datum 2.15 ft higher (revised).

REMARKS.--Records good except for estimated daily discharges, which are poor. Natural flow of stream affected by diversions for irrigation and return flows from irrigated areas. Some regulation by Platoro Reservoir (station 08244500) about 59 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.--Maximum stage 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	50	38	e29	e29	e33	e29	91	308	1,250	237	145	88
2	59	40	e27	e30	e31	e28	104	299	1,310	230	138	71
3	67	38	e28	e32	e30	e29	90	305	1,160	224	134	69
4	72	38	e27	e33	e29	e34	80	301	1,120	230	108	95
5	74	35	e23	e34	e28	e33	76	273	1,090	210	106	114
6	70	32	e23	e34	e25	e32	72	244	898	206	108	158
7	61	35	e22	e33	e24	e38	63	224	677	201	99	151
8	53	37	e23	e32	e25	e40	52	199	643	189	112	138
9	52	46	e23	e34	e26	e43	62	191	658	184	115	142
10	51	48	e23	e33	e26	e43	76	198	685	174	116	828
11	51	41	e23	e32	e28	53	95	185	663	157	102	704
12	48	36	e23	e32	e32	59	113	206	609	171	108	663
13	44	37	e23	e32	e36	73	120	275	537	169	101	488
14	43	42	e24	e34	e39	87	153	353	465	136	101	362
15	43	42	e24	e33	e40	84	184	477	396	132	92	323
16	42	30	e24	e32	e37	78	173	469	393	164	84	294
17	41	36	e25	e33	e39	63	184	604	453	151	72	220
18	37	36	e24	e32	e41	56	174	752	447	143	58	161
19	36	36	e24	e33	e36	51	151	890	440	129	48	199
20	35	40	e23	e34	e34	46	116	847	469	109	44	202
21	35	42	e24	e35	e34	51	116	862	407	98	44	143
22	34	42	e24	e34	e32	45	140	1,020	364	88	46	110
23	37	41	e26	e34	e31	54	154	1,230	293	108	59	96
24	41	39	e25	e35	e33	61	149	1,340	252	140	70	104
25	44	40	e25	e34	e33	68	161	1,280	278	128	71	97
26	49	33	e25	e31	e31	68	183	1,090	284	108	67	85
27	44	28	e27	e33	e30	75	225	1,210	246	105	63	76
28	45	e30	e28	e33	e30	66	297	1,340	221	150	70	72
29	45	e32	e29	e31	---	58	370	1,500	232	193	105	86
30	39	e30	e30	e32	---	64	352	1,380	236	222	96	93
31	39	---	e30	e33	---	77	---	1,360	---	205	108	---
TOTAL	1,481	1,120	778	1,016	893	1,686	4,376	21,212	17,176	5,091	2,790	6,432
MEAN	47.8	37.3	25.1	32.8	31.9	54.4	146	684	573	164	90.0	214
MAX	74	48	30	35	41	87	370	1,500	1,310	237	145	828
MIN	34	28	22	29	24	28	52	185	221	88	44	69
AC-FT	2,940	2,220	1,540	2,020	1,770	3,340	8,680	42,070	34,070	10,100	5,530	12,760
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1903 - 2003, BY WATER YEAR (WY)
MEAN	116	93.3	51.1	47.5	51.3	79.4	312	1,086	1,265	469	205	131
MAX	515	467	116	116	159	153	800	2,053	3,163	1,502	626	484
(WY)	(1905)	(1966)	(1987)	(1986)	(1983)	(1989)	(1936)	(1937)	(1920)	(1957)	(1952)	(1927)
MIN	34.7	29.9	25.1	22.7	30.0	41.0	138	282	118	37.1	17.1	26.8
(WY)	(1957)	(1931)	(2003)	(1918)	(1904)	(1904)	(1970)	(2002)	(1934)	(2002)	(2002)	(1956)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1903 - 2003
ANNUAL TOTAL	27,891	64,051
ANNUAL MEAN	76.4	175	324
HIGHEST ANNUAL MEAN			592 1920
LOWEST ANNUAL MEAN			80.6 2002
HIGHEST DAILY MEAN	409 May 16	1,500 May 29	4,490 Jun 5, 1905
LOWEST DAILY MEAN	10 Aug 19	e22 Dec 7	a10 Jul 18, 1904
ANNUAL SEVEN-DAY MINIMUM	12 Aug 14	e23 Dec 5	12 Aug 14, 2002
MAXIMUM PEAK FLOW		1,640 May 29	b9,000 Oct 5, 1911
MAXIMUM PEAK STAGE		4.80 May 29	c8.50 Oct 5, 1911
ANNUAL RUNOFF (AC-FT)	55,320	127,000	234,700
10 PERCENT EXCEEDS	220	458	1,010
50 PERCENT EXCEEDS	38	68	95
90 PERCENT EXCEEDS	23	29	41

e Estimated. a Also occurred Aug 19, 2002. b Present site and datum, from rating curve extended above 3,100 ft3/s. c From floodmarks.