COLORADO RIVER MAIN STEM

THREE LAKES WATER-QUALITY STUDY

In November of 2000, a water-quality data-collection program was initiated in the Upper Colorado River basin including Grand Lake, Shadow Mountain Lake, Lake Granby, and the tributary streams to these lakes that make up a large portion of the Colorado/Big Thompson Water Diversion project. This is a cooperative effort between the USGS and Northern Colorado Water Conservancy District, Colorado River Water Conservation District, Grand County, and the Colorado Department of Public Health and Environment, and may help to determine the trophic status of these upper basin lakes.

09011000 COLORADO RIVER NEAR GRAND LAKE, CO

WATER-QUALITY RECORDS

LOCATION.--Lat 40°13'08", long 105°51'25", in NE14SW14 sec.13, T.3 N., R.76 W., 200 ft downstream from bridge on U.S. Highway 34, 400 ft upstream from high-water line of Shadow Mountain Reservoir at elevation 8,376 ft above NGVD of 1929, and 3 mi southwest of town of Grand Lake.

DRAINAGE AREA.--102 mi2.

PERIOD OF RECORD.--November 2000 to current year. For a complete listing of historical data available for this site, see http://waterdata.usgs.gov/co/nwis/inventory/?site_no=09011000

WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003

Date	Time	Instan- taneous dis- charge, cfs (00061)	Dis- solved oxygen, mg/L (00300)	Specif. conduc- tance, wat unf uS/cm 25 degC (00095)	Temper- ature, water, deg C (00010)	Hard- ness, water, unfltrd mg/L as CaCO3 (00900)	Calcium water, fltrd, mg/L (00915)	Magnes- ium, water, fltrd, mg/L (00925)	Potas- sium, water, fltrd, mg/L (00935)	Sodium adsorp- tion ratio (00931)	Sodium, water, fltrd, mg/L (00930)	Alka- linity, wat flt fxd end lab, mg/L as CaCO3 (29801)	Chlor- ide, water, fltrd, mg/L (00940)
OCT
22...	1045	3.6	10.7	91	2.0	38	10.9	2.52	1.32	0.2	2.72	--	0.73
NOV
22...	1205	60	10.9	92	0.8	36	10.2	2.45	1.23	0.2	2.71	36	0.32
MAR
03...	0915	12	12.0	96	0.1	40	11.4	2.70	1.56	0.2	2.97	40	0.35
MAY
01...	1345	99	9.6	74	5.5	29	8.25	2.09	1.45	0.2	2.33	23	0.60
12...	1400	70	8.5	72	9.5	29	8.26	2.01	1.51	0.2	2.44	25	0.72
21...	0935	313	10.0	52	3.7	21	6.00	1.50	0.96	0.2	1.80	17	0.41
JUN
02...	1300	1,160	9.9	39	7.9	15	4.17	1.06	0.867	0.1	1.20	11	0.25
18...	0945	556	11.1	43	6.3	18	5.13	1.24	0.654	0.1	1.10	13	0.22
JUL
08...	0945	155	8.9	42	9.6	24	6.91	1.54	0.675	0.1	1.25	18	0.22
AUG
14...	1300	49	7.6	78	17.0	41	12.9	2.17	1.26	0.2	2.24	29	0.32
SEP
16...	1100	37	9.5	82	7.9		--	--	2.68		--	30	0.24

WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003

Date	Silica, water, fltrd, mg/L (00955)	Sulfate water, fltrd, mg/L (00945)	Residue water, fltrd, sum of consti- tuents mg/L (70301)	Residue water, fltrd, tons/ acre-ft (70303)	Residue water, fltrd, tons/d (70302)	Ammonia + org-N, water, unfltrd mg/L as N (00625)	Ammonia water, fltrd, mg/L as N (00608)	Nitrite + nitrate water fltrd, mg/L as N (00631)	Ortho- phos- phate, water, fltrd, mg/L as P (00671)	Phos- phorus, water, unfltrd mg/L (00665)	Organic carbon, water, fltrd, mg/L (00681)
OCT
22...	--	8.34	--	--	--	--	--	0.005	0.002	--	--
NOV
22...	12.5	7.64	58	0.08	9.44	--	--	--	--	--	1.2
MAR
03...	14.9	6.75	65	0.09	2.13	0.25	0.013	0.084	E.003	E.006	1.1
MAY
01...	11.0	8.12	49	0.07	13.1	0.48	<0.015	0.317	<0.007	0.015	6.6
12...	9.88	7.81	48	0.07	9.12	0.42	<0.015	0.046	<0.007	0.027	6.9
21...	8.47	5.35	35	0.05	29.4	0.35	<0.015	0.067	<0.007	0.038	7.0
JUN
02...	6.35	4.44	25	0.03	78.7	0.40	<0.015	0.062	<0.007	0.068	6.3
18...	5.98	4.94	28	0.04	41.6	0.19	<0.015	0.077	<0.007	0.031	4.4
JUL
08...	5.38	7.30	34	0.05	14.4	0.23	<0.015	0.064	<0.007	0.011	2.1
AUG
14...	8.26	6.60	51	0.07	6.82	0.11	<0.015	<0.022	<0.007	0.009	1.7
SEP
16...	5.55	7.62				E.08	<0.015	<0.022	<0.007	0.006	1.6
< -- Actual value is known to be less than the value shown. E -- Estimated laboratory analysis value.