PLATTE RIVER BASIN

06758500 SOUTH PLATTE RIVER NEAR WELDONA, CO

LOCATION.--Lat 40°19'19", long 103°55'17", in SW14SW14 sec.7, T.4 N., R.58 W., Morgan County, Hydrologic Unit 10190003, on left bank 500 ft downstream from bridge on State Highway 144, 2.8 mi southeast of Weldona, and 4.2 mi upstream from Bijou Creek.

DRAINAGE AREA.--13,190 mi2 (revised).

WATER-DISCHARGE RECORDS

PERIOD OF RECORD.--October 1952 to current year. Statistical summary computed for 1976 to current year, subsequent to completion of Chatfield Dam. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=06758500

REVISED RECORDS.--WSP 1710: Drainage area.

GAGE.--Water-stage recorder with satellite telemetry. Datum of gage is 4,307.80 ft above NGVD of 1929. Prior to May 2, 1991, gage located 100 ft upstream, at same datum.

REMARKS.--Records fair except for estimated daily discharges, which are poor. Natural flow of stream affected by transmountain and transbasin diversions, storage reservoirs, power developments, ground-water withdrawals, and diversions for irrigation, and return flow from irrigated areas.

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

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	163	614	133	152	214	226	523	404	1,220	183	189	1,110
2	198	321	123	148	216	220	530	537	2,060	235	176	1,440
3	208	194	114	146	216	217	526	509	2,220	320	142	446
4	202	124	108	142	216	223	506	373	1,810	281	176	464
5	314	131	99	147	219	217	494	247	1,460	265	233	417
6	337	210	99	146	216	220	443	188	1,480	220	244	383
7	282	138	96	146	214	218	364	154	1,230	163	220	408
8	248	106	89	147	229	217	299	177	930	145	273	408
9	232	105	84	147	244	217	217	220	1,060	190	262	420
10	238	93	81	144	216	216	218	301	785	191	252	457
11	256	91	78	152	211	218	227	880	590	162	282	439
12	254	114	72	146	213	228	227	1,880	676	148	297	409
13	240	113	68	142	226	237	222	1,270	846	170	297	366
14	242	101	68	143	227	e258	219	998	881	221	292	319
15	249	96	68	142	223	253	202	960	818	243	274	333
16	269	90	68	143	222	249	166	944	789	221	258	338
17	284	90	68	146	218	244	212	924	802	215	252	331
18	296	90	68	146	216	200	324	1,020	930	206	244	318
19	318	115	67	147	216	191	391	868	1,000	205	253	322
20	330	148	73	145	215	345	367	861	1,010	198	287	291
21	345	142	68	140	213	401	427	924	1,030	244	292	278
22	374	136	67	175	214	314	420	829	807	233	291	271
23	383	131	66	239	216	464	302	564	676	265	211	255
24	408	133	75	213	207	753	502	479	690	301	170	224
25	419	138	76	205	254	852	1,080	392	766	297	154	210
26	430	142	123	205	280	733	1,230	361	768	285	158	194
27	476	141	188	209	296	524	745	380	648	270	154	172
28	467	142	149	213	241	500	414	366	369	244	161	158
29	520	143	80	213	---	504	357	388	168	213	165	153
30	556	141	57	214	---	483	348	638	194	255	175	156
31	573	---	138	213	---	444	---	912	---	193	258	---
TOTAL	10,111	4,473	2,811	5,156	6,308	10,586	12,502	19,948	28,713	6,982	7,092	11,490
MEAN	326	149	90.7	166	225	341	417	643	957	225	229	383
MAX	573	614	188	239	296	852	1,230	1,880	2,220	320	297	1,440
MIN	163	90	57	140	207	191	166	154	168	145	142	153
AC-FT	20,060	8,870	5,580	10,230	12,510	21,000	24,800	39,570	56,950	13,850	14,070	22,790
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1976 - 2003, BY WATER YEAR (WY)
MEAN	541	499	575	711	662	521	753	1,726	2,288	744	620	651
MAX	3,119	2,298	1,266	1,443	1,562	1,494	3,226	10,130	12,310	5,121	2,208	2,118
(WY)	(1985)	(1985)	(1986)	(1984)	(1984)	(1983)	(1983)	(1980)	(1983)	(1995)	(1984)	(1984)
MIN	134	100	90.7	166	225	132	119	183	101	173	77.5	107
(WY)	(1977)	(1977)	(2003)	(2003)	(2003)	(1978)	(1982)	(1981)	(1977)	(2002)	(2002)	(2002)

SUMMARY STATISTICS	FOR 2002 CALENDAR YEAR	FOR 2003 WATER YEAR	WATER YEARS 1976 - 2003
ANNUAL TOTAL	73,959	126,172
ANNUAL MEAN	203	346	a857
HIGHEST ANNUAL MEAN			2,995 1983
LOWEST ANNUAL MEAN			229 2002
HIGHEST DAILY MEAN	1,040 May 26	2,220 Jun 3	e,b16,300 Jun 11, 1995
LOWEST DAILY MEAN	28 Apr 14	57 Dec 30	c28 Apr 7, 1999
ANNUAL SEVEN-DAY MINIMUM	48 Apr 11	68 Dec 13	30 Apr 3, 1999
MAXIMUM PEAK FLOW		2,330 Jun 3	d18,400 May 3, 1999
MAXIMUM PEAK STAGE		4.75 Jun 3	10.42 May 3, 1999
ANNUAL RUNOFF (AC-FT)	146,700	250,300	620,800
10 PERCENT EXCEEDS	446	794	1,500
50 PERCENT EXCEEDS	153	232	456
90 PERCENT EXCEEDS	70	115	150

e Estimated. a Average discharge for 22 years (water years 1953-74), 572 ft3/s; 414,400 acre-ft/yr, prior to completion of Chatfield Dam. b Maximum daily discharge for period of record, 20,800 ft3/s, May 9, 1973. c Also occurred Apr 14, 2002. d Maximum discharge and stage for period of record, 26,800 ft3/s, May 8, 1973, gage height, 11.68 ft, from rating curve extended above 16,000 ft3/s.