ARKANSAS RIVER BASIN

07133000 ARKANSAS RIVER AT LAMAR, CO

LOCATION.--Lat 38°06'21", long 102°37'05", in NE14SE14 sec.30, T.22 S., R.46 W., Prowers County, Hydrologic Unit 11020009, on left bank at left downstream end of downstream bridge on U.S. Highways 50 and 287, and 1.3 mi north of courthouse in Lamar.

DRAINAGE AREA.--19,780 mi2, of which 950 mi2 is probably noncontributing.

PERIOD OF RECORD.--May 1913 to September 1955, April 1959 to current year. Monthly discharge only for some periods, published in WSP 1311. Statistical summary computed for 1949 to current year, subsequent to completion of John Martin Reservoir. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=07133000

REVISED RECORDS.--WSP 1341: 1921(M), 1945-46(M), drainage area; WDR CO-86-1: 1985.

GAGE.--Water-stage recorder with satellite telemetry and crest stage gage. Datum of gage is 3,597.39 ft above NGVD of 1929. See WSP 1731 for history of changes prior to Apr. 4, 1959. Apr. 4, 1959 to Mar. 26, 1968, at site 525 ft upstream at datum 2.42 ft higher. Mar. 27, 1968 to Nov. 17, 1982, at site 375 ft downstream at datum 4.00 ft lower. March 18, 1987 to March 6, 2002, at site 75 ft upstream at same datum.

REMARKS.--Records fair except for estimated daily discharges, which are poor. Natural flow of stream affected by storage reservoirs, power developments, transbasin and transmountain diversions, diversions for irrigation and municipal use, ground-water withdrawals, return flows from irrigated areas, and flows from sewage-treatment plants. Flow regulated by John Martin Reservoir (station 07130000) 21 mi upstream since Oct. 1948. 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	4.2	5.6	3.6	3.7	3.8	5.5	4.0	79	21	33	28	17
2	3.9	6.0	3.4	3.6	3.9	5.3	4.2	83	19	61	29	14
3	3.6	6.5	3.2	3.6	4.3	5.3	4.1	54	28	18	34	12
4	3.4	7.1	3.2	3.5	3.9	5.4	4.0	43	77	30	33	12
5	3.3	6.9	3.7	3.5	4.0	5.5	3.9	41	49	14	33	11
6	3.3	5.5	3.7	3.4	3.9	5.2	4.0	14	32	14	32	10
7	3.5	5.3	3.7	3.4	e3.9	8.6	4.0	9.6	82	12	40	13
8	4.4	5.0	3.6	3.5	e3.8	11	3.9	8.0	44	13	46	14
9	4.1	4.9	3.3	3.5	4.1	8.6	3.9	6.3	25	25	35	14
10	3.8	4.7	3.0	3.5	4.1	6.2	4.0	6.0	19	37	23	17
11	3.8	4.7	3.4	3.4	3.8	4.2	4.0	5.5	10	39	19	21
12	3.8	4.6	3.1	3.4	4.1	3.8	4.1	5.2	9.6	51	20	38
13	3.6	4.6	3.2	3.4	4.2	3.8	4.3	4.9	9.1	38	49	32
14	4.0	4.5	3.5	3.4	4.2	4.1	13	4.9	9.1	32	66	22
15	4.3	4.4	3.1	3.5	4.7	4.3	33	6.6	7.4	33	47	18
16	4.3	4.2	3.3	3.5	4.9	4.4	64	12	9.0	31	28	15
17	4.5	4.2	3.4	3.5	4.8	4.4	82	18	93	26	17	10
18	4.5	4.2	3.1	3.6	5.0	4.5	54	52	149	26	13	10
19	4.6	4.1	3.1	3.6	4.9	5.0	94	39	171	23	15	10
20	4.6	4.0	3.1	3.7	5.0	4.4	102	31	120	19	13	14
21	4.6	3.7	3.2	3.9	5.1	4.3	99	33	40	22	11	11
22	4.8	3.3	3.1	3.7	4.7	4.2	86	34	89	29	11	8.6
23	4.8	3.3	2.9	3.5	5.0	4.2	90	33	21	31	9.6	16
24	4.5	3.3	3.5	3.9	e4.8	4.3	89	18	16	29	7.8	38
25	4.6	3.3	e3.4	3.9	e5.0	4.2	93	6.1	16	27	9.2	45
26	5.0	3.3	e3.5	3.8	5.9	4.2	92	5.4	49	26	7.9	47
27	6.3	3.2	e3.4	3.8	5.9	4.4	93	5.0	21	27	7.1	52
28	5.2	3.1	3.9	4.3	5.4	4.1	87	5.2	12	30	6.5	55
29	5.8	3.1	3.7	3.9	---	4.0	79	8.8	19	28	8.9	57
30	5.6	3.4	3.7	3.9	---	4.0	77	6.7	11	30	33	55
31	5.5	---	3.7	3.8	---	4.0	---	6.0	---	28	28	---
TOTAL	136.2	134.0	104.7	112.6	127.1	155.4	1,379.4	684.2	1,277.2	882	760.0	708.6
MEAN	4.39	4.47	3.38	3.63	4.54	5.01	46.0	22.1	42.6	28.5	24.5	23.6
MAX	6.3	7.1	3.9	4.3	5.9	11	102	83	171	61	66	57
MIN	3.3	3.1	2.9	3.4	3.8	3.8	3.9	4.9	7.4	12	6.5	8.6
AC-FT	270	266	208	223	252	308	2,740	1,360	2,530	1,750	1,510	1,410
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1949 - 2003, BY WATER YEAR (WY)
MEAN	37.8	21.3	29.5	39.7	40.8	41.1	161	198	280	309	217	89.3
MAX	233	117	350	796	507	516	1,089	2,143	2,087	2,457	1,547	689
(WY)	(1949)	(1998)	(1998)	(1998)	(1966)	(1998)	(1987)	(1987)	(1987)	(1995)	(1965)	(1965)
MIN	0.84	1.81	0.56	0.47	0.72	1.11	5.90	6.41	3.80	10.2	10.9	1.37
(WY)	(1978)	(1978)	(1978)	(1978)	(1965)	(1965)	(1995)	(1963)	(1954)	(1964)	(1974)	(1974)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1949 - 2003
ANNUAL TOTAL	15,406.7	6,461.4
ANNUAL MEAN	42.2	17.7	a122
HIGHEST ANNUAL MEAN			537 1987
LOWEST ANNUAL MEAN			17.7 2003
HIGHEST DAILY MEAN	599 Aug 29	171 Jun 19	b25,000 Jun 18, 1965
LOWEST DAILY MEAN	2.9 Dec 23	2.9 Dec 23	c0.00 Dec 5, 1953
ANNUAL SEVEN-DAY MINIMUM	3.1 Dec 17	3.1 Dec 17	0.21 Jan 10, 1965
MAXIMUM PEAK FLOW		215 Jun 19	d73,800 Jun 18, 1965
MAXIMUM PEAK STAGE		5.80 Jun 19	f16.48 Jun 18, 1965
ANNUAL RUNOFF (AC-FT)	30,560	12,820	88,310
10 PERCENT EXCEEDS	76	48	410
50 PERCENT EXCEEDS	7.9	5.4	23
90 PERCENT EXCEEDS	3.6	3.4	4.2

e Estimated. a Average discharge for 30 years (water years 1914-43), 298 ft3/s, 215,900 acre-ft/yr, prior to and during construction of John Martin Dam. b Maximum daily discharge for period of record, 87,300 ft3/s, Jun 5, 1921. c Also minimum daily discharge for period of record; also occurred at times in 1913-15. d From current-meter and timed-drift measurement of peak flow, maximum discharge and gage height for period of record, 130,000 ft3/s, (determined by Colorado State Engineer) Jun 5, 1921, from rating curve extended above 10,000 ft3/s, gage height, 14.55 ft, site and datum then in use. f From floodmarks, site and datum then in use.