PLATTE RIVER BASIN

06730400 COAL CREEK NEAR LOUISVILLE, CO

LOCATION.--Lat 39°58'34", long 105°07'00", in NW14SE14 sec.9, T.1 S., R.69 W., Boulder County, Hydrologic Unit 10190005, on left bank on upstream side of County road 62 bridge, and 1.1 mi northeast of Louisville.

DRAINAGE AREA.--32.0 mi2 (revised).

PERIOD OF RECORD.--July 1997 to current year. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=06730400

GAGE.--Water-stage recorder with satellite telemetry. Elevation of gage is 5,280 ft above NGVD of 1929, from topographic map.

REMARKS.--Records fair except for estimated daily discharges, which are poor. Natural flow of stream affected by diversions for irrigation, and return flow from irrigated areas. 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	2.5	0.29	0.21	0.02	0.11	0.03	11	8.2	5.8	6.3	0.89	0.06
2	5.4	0.31	0.24	0.03	0.08	0.10	10	6.8	4.6	6.0	0.78	0.03
3	1.5	0.36	0.20	0.05	0.09	0.11	9.9	4.4	4.1	5.8	0.70	0.03
4	1.4	0.29	0.17	0.07	0.05	0.03	6.1	4.6	4.0	4.8	0.55	0.04
5	1.3	0.33	0.15	0.09	0.07	0.05	5.0	4.8	3.8	2.6	0.49	0.05
6	1.3	0.38	0.12	0.11	0.05	0.03	8.7	4.2	3.6	1.6	0.54	0.05
7	1.3	0.32	0.09	0.07	0.03	0.11	5.2	4.1	4.7	1.4	0.62	0.08
8	1.4	0.59	0.10	0.08	0.03	0.13	5.0	3.5	2.7	1.4	1.0	0.11
9	1.6	0.84	0.08	0.05	0.03	0.10	6.6	4.5	2.2	1.8	1.7	0.11
10	1.5	0.73	0.05	0.03	0.02	0.16	5.4	14	2.6	1.9	0.84	0.09
11	1.4	0.61	0.04	0.03	0.02	0.21	4.7	4.9	2.3	1.8	0.91	0.07
12	1.3	0.45	0.04	0.03	0.04	0.27	4.2	4.1	2.6	2.1	0.85	0.07
13	1.1	0.51	0.04	0.04	0.04	0.34	5.5	4.0	2.9	2.1	0.70	0.06
14	1.0	0.67	0.04	0.07	0.07	0.37	12	3.9	3.0	1.9	0.53	0.08
15	0.96	0.66	0.04	0.05	0.06	0.44	8.6	3.9	3.4	1.8	0.59	0.10
16	0.87	0.52	0.07	0.03	0.06	0.34	6.3	4.7	3.6	1.8	0.50	0.14
17	0.82	0.55	0.08	0.04	0.06	1.1	4.8	4.8	8.9	1.7	0.26	0.88
18	0.82	0.44	0.07	0.03	0.06	3.0	4.4	3.7	15	1.9	2.0	0.86
19	0.80	0.44	0.04	0.06	0.09	2.7	19	2.9	12	4.3	1.3	0.31
20	0.81	0.50	0.06	0.06	0.07	4.5	13	2.7	6.9	1.8	0.92	0.27
21	0.84	0.53	0.03	0.06	0.08	6.5	7.4	2.9	7.0	1.6	0.86	0.32
22	0.70	0.42	0.03	0.04	0.07	6.0	5.6	3.2	6.4	1.7	0.97	0.34
23	0.53	0.43	0.02	0.07	0.03	6.8	9.3	4.1	7.0	1.7	0.87	0.69
24	0.49	0.32	0.03	0.10	0.03	5.7	18	3.7	7.5	1.7	0.95	1.4
25	0.56	0.29	0.04	0.10	0.02	5.0	8.1	3.3	6.6	1.6	0.95	1.7
26	0.63	0.14	0.08	0.11	0.04	10	7.6	5.5	6.0	1.6	0.66	1.7
27	0.65	0.11	0.03	0.17	0.05	14	8.3	9.1	5.9	1.5	0.72	1.7
28	0.56	0.13	0.02	0.12	0.06	7.6	8.1	8.0	6.0	1.5	0.76	1.6
29	0.86	0.24	0.02	0.10	---	5.4	8.1	16	6.1	1.4	2.0	1.5
30	0.38	0.22	0.02	0.09	---	5.7	12	13	6.4	1.1	9.0	1.6
31	0.30	---	0.02	0.11	---	e10	---	9.0	---	1.3	0.19	---
TOTAL	35.58	12.62	2.27	2.11	1.51	96.82	247.9	176.5	163.6	71.5	34.60	16.04
MEAN	1.15	0.42	0.073	0.068	0.054	3.12	8.26	5.69	5.45	2.31	1.12	0.53
MAX	5.4	0.84	0.24	0.17	0.11	14	19	16	15	6.3	9.0	1.7
MIN	0.30	0.11	0.02	0.02	0.02	0.03	4.2	2.7	2.2	1.1	0.19	0.03
AC-FT	71	25	4.5	4.2	3.0	192	492	350	325	142	69	32
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2003, BY WATER YEAR (WY)
MEAN	2.58	2.17	1.86	1.51	1.43	2.83	12.3	13.1	7.02	2.76	4.14	2.10
MAX	3.85	3.42	3.23	2.45	2.44	6.17	36.1	34.9	13.2	4.25	14.5	3.10
(WY)	(1998)	(2000)	(2000)	(2000)	(2000)	(1998)	(1998)	(1999)	(1999)	(1999)	(1999)	(2000)
MIN	1.15	0.42	0.073	0.068	0.054	1.28	1.08	2.03	1.11	0.69	0.32	0.53
(WY)	(2003)	(2003)	(2003)	(2003)	(2003)	(2001)	(2002)	(2002)	(2002)	(2002)	(2002)	(2003)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1997 - 2003
ANNUAL TOTAL	378.55	861.05
ANNUAL MEAN	1.04	2.36	4.45
HIGHEST ANNUAL MEAN			8.48 1999
LOWEST ANNUAL MEAN			1.48 2002
HIGHEST DAILY MEAN	16 May 24	19 Apr 19	277 Apr 30, 1999
LOWEST DAILY MEAN	0.01 Jul 31	0.02 Dec 23	a0.01 Jul 31, 2002
ANNUAL SEVEN-DAY MINIMUM	0.01 Aug 7	0.02 Dec 27	0.01 Aug 7, 2002
MAXIMUM PEAK FLOW		123 Jun 18	b643 Apr 30, 1999
MAXIMUM PEAK STAGE		2.23 Jun 18	3.42 Apr 30, 1999
ANNUAL RUNOFF (AC-FT)	751	1,710	3,220
10 PERCENT EXCEEDS	1.7	6.8	9.0
50 PERCENT EXCEEDS	1.1	0.82	2.2
90 PERCENT EXCEEDS	0.07	0.04	0.51

e Estimated. a Also occurred Aug 1, 7, 10-13, 22-23, 2002. b From rating curve extended above 150 ft3/s.