COLORADO RIVER MAIN STEM

09019500 COLORADO RIVER NEAR GRANBY, CO

LOCATION.--Lat 40°07'15", long 105°54'00", in SW14NW14 sec.22, T.2 N., R.76 W., Grand County, Hydrologic Unit 14010001, on right bank 0.3 mi upstream from bridge on U.S. Highway 34, 1.3 mi upstream from Willow Creek, and 3.2 mi northeast of Granby.

DRAINAGE AREA.--323 mi2.

PERIOD OF RECORD.--October 1907 to September 1911 (published as Grand River near Granby), October 1933 to September 1953. May 1961 to current year (irrigation season only). Monthly discharge only for some periods, published in WSP 1313. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09019500

REVISED RECORDS.--WSP 2124: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Elevation of gage is 7,960 ft above NGVD of 1929, from topographic map. June 10, 1908 to Sept. 30, 1911, and May 12 to June 10, 1934, nonrecording gage, at site 300 ft upstream at different datums. June 11, 1934 to Sept. 30, 1953, water-stage recorder at present site and datum.

REMARKS.--Records good except for estimated daily discharges, which are poor. Flow regulated by Lake Granby (station 09018500) since Sept. 13, 1949. Several diversions for irrigation of hay meadows upstream from station. Transmountain diversions upstream from station by Eureka and Grand River ditches and Alva B. Adams tunnel (see elsewhere in this report). 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.

EXTREMES FOR PERIOD OF SEASONAL RECORD.--Maximum discharge, 2,520 ft3/s, June 22, 1996, 5.76 ft; minimum daily, 9.6 ft3/s, Sept. 21, 1981.

EXTREMES FOR PERIOD OF CONTINUOUS RECORD.--Maximum discharge observed, 4,100 ft3/s, June 20, 1909, gage height 5.5 ft site and datum then in use; minimum daily, 6.6 ft3/s, Jan. 29, 1950; minimum observed prior to starting construction of Shadow Mountain Lake, 20 ft3/s, Apr. 6, 1936 (discharge measurement).

EXTREMES FOR CURRENT YEAR (seasonal only).--Maximum discharge, 115 ft3/s, June 12, gage height, 1.37 ft; minimum daily, 16 ft3/s, Oct. 3, Nov. 3, 4.

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	18	18	---	---	---	---	---	e90	81	82	42	27
2	18	17	---	---	---	---	---	e90	81	78	38	23
3	16	16	---	---	---	---	---	e90	82	76	37	23
4	18	16	---	---	---	---	---	e90	79	78	39	23
5	23	17	---	---	---	---	---	e90	75	78	38	24
6	22	18	---	---	---	---	---	e89	82	79	39	25
7	24	18	---	---	---	---	---	e89	78	79	40	24
8	18	---	---	---	---	---	---	e89	78	77	39	24
9	18	---	---	---	---	---	---	e87	78	72	37	24
10	18	---	---	---	---	---	---	e86	78	76	35	23
11	18	---	---	---	---	---	---	e85	80	75	36	22
12	18	---	---	---	---	---	---	e85	93	72	36	22
13	18	---	---	---	---	---	---	e85	85	73	39	20
14	18	---	---	---	---	---	---	e82	81	74	43	22
15	18	---	---	---	---	---	---	e82	77	71	43	21
16	19	---	---	---	---	---	---	e82	84	73	43	22
17	19	---	---	---	---	---	---	e80	84	72	44	22
18	19	---	---	---	---	---	---	e80	81	72	42	22
19	19	---	---	---	---	---	---	e80	81	72	39	22
20	19	---	---	---	---	---	---	79	84	73	39	22
21	18	---	---	---	---	---	---	77	79	73	42	21
22	18	---	---	---	---	---	---	78	77	72	41	21
23	19	---	---	---	---	---	---	80	80	73	42	21
24	18	---	---	---	---	---	---	75	78	72	42	21
25	18	---	---	---	---	---	---	76	77	72	42	21
26	18	---	---	---	---	---	---	78	82	73	41	21
27	18	---	---	---	---	---	---	71	80	71	40	22
28	18	---	---	---	---	---	---	73	79	71	40	22
29	18	---	---	---	---	---	---	73	80	75	40	22
30	17	---	---	---	---	---	---	78	80	73	44	22
31	17	---	---	---	---	---	---	81	---	71	45	---
TOTAL	575	---	---	---	---	---	---	2,550	2,414	2,298	1,247	671
MEAN	18.5	---	---	---	---	---	---	82.3	80.5	74.1	40.2	22.4
MAX	24	---	---	---	---	---	---	90	93	82	45	27
MIN	16	---	---	---	---	---	---	71	75	71	35	20
AC-FT	1,140	---	---	---	---	---	---	5,060	4,790	4,560	2,470	1,330

e Estimated.