U.S. Department of the Interior U.S. Geological Survey Utah Water Science Center

Upper Colorado River Streamflow and Reservoir Contents

Provisional Data for: OCT 2019 to FEB 2020

All data contained in this report is provisional and subject to revision.

Available online at usgs.gov/centers/ut-water PROVISIONAL DATA U.S. GEOLOGICAL SURVEY SUBJECT TO REVISION UTAH WATER SCIENCE CENTER STREAMFLOW AND RESERVOIR CONTENTS IN UPPER COLORADO RIVER BASIN DAYS IN contact 435-259-4430 or [email protected] MONTH October 2019 31 MONTHLY DISCHARGE (a) MAXIMUM DAILY MINIMUM DAILY POR(A) (A)MEAN PERCENT TOTAL TOTAL DATE RANGE 3 3 3 3 3 STREAM ft /s MEAN ft /s OF POR ft /s ACRE ft /s DATE ft /s DATE FOR POR FOR POR THIS MONTH MEAN DAYS FEET CALCULATION DOLORES RIVER NR CISCO, UTAH 225 137 61% 4,242 8,400 173 29-Oct 53 2-Oct Dec-1950 ADJUSTED (E) -14 -6% -429 -851 Sep-2019 COLORADO RIVER NR CISCO, UTAH 4,069 4,133 102% 128,335 254,104 5,009 30-Oct 3,677 1-Oct Oct-1913 ADJUSTED (B) 3,259 80% 101,035 200,404 Sep-2019 GREEN RIVER AT GREEN RIVER , UT 2,997 2,581 86% 80,164 158,725 2,857 3-Oct 2,369 22-Oct Oct-1894 ADJUSTED (C) 2,009 67% 62,276 123,525 Sep-2019 SAN JUAN RIVER NEAR BLUFF, UT 1,466 701 48% 21,781 43,126 904 15-Oct 567 5-Oct Oct-1914 ADJUSTED (D) 374 26% 11,609 23,026 Sep-2019

(A) POR; Period of record. (B) ADJUSTED FOR CHANGE IN STORAGE IN BLUE MESA RESERVOIR. STORAGE BEGAN OCT. 27, 1965 (C) ADJUSTED FOR CHANGE IN STORAGE IN FLAMING GORGE RESERVOIR & FONTENELLE RESERVOIR, STORAGE BEGAN NOV. 1, 1962 & OCT., 1964 RESPECTIVELY. (D) ADJUSTED FOR CHANGE IN STORAGE IN NAVAJO RESERVOIR (STORAGE BEGAN JUNE 27, 1962) AND SINCE AUGUST 1964, RELEASES TO NAVAJO INDIAN IRRIGATION PROJECT (NIIP). RELEASES TO NIIP BEGAN JANUARY 1976. (E) ADJUSTED FOR CHANGE IN STORAGE IN MCPHEE RESERVOIR. STORAGE BEGAN MAR 20, 1984

DRAINAGE USABLE END OF MO. CHANGE DURING RESERVOIR ABOVE DAM CAPACITY USABLE CONTENTS MONTH PREVIOUS (MI2) (AC-FT) (AC-FT) (AC-FT) MONTH MCPHEE RESERVOIR, MONTEZUMA COUNTY, CO 809 229,200 291,695 -9,251 300,946 BLUE MESA RESERVOIR NEAR SAPINERO, COLORADO 3,426 829,500 682,100 -53,700 735,800 FLAMING GORGE RESERVOIR AT FLAMING GORGE DAM, UT (b) 15,100 3,739,000 3,392,800 -17,200 3,410,000 FONTENELLE RESERVOIR AT FONTENELLE , WYOMING (b) 4,280 344,300 253,300 -18,000 271,300 NAVAJO RESERVOIR NEAR ARCHULETA, NEW MEXICO (b) 3,320 1,696,000 1,361,600 -26,500 1,388,100 NIIP 6,400 LAKE POWELL RESERVOIR AT GLEN CANYON DAM, ARIZONA (b) 107,700 25,002,000 13,033,600 -243,800 13,277,400

TOTALS 31,620,800 18,723,400 -359,200 19,082,600 (a) Preliminary Data (b) Approximate PROVISIONAL DATA U.S. GEOLOGICAL SURVEY SUBJECT TO REVISION UTAH WATER SCIENCE CENTER STREAMFLOW AND RESERVOIR CONTENTS IN UPPER COLORADO RIVER BASIN DAYS IN contact 435-259-4430 or [email protected] MONTH November 2019 30 MONTHLY DISCHARGE (a) MAXIMUM DAILY MINIMUM DAILY POR(A) (A)MEAN PERCENT TOTAL TOTAL DATE RANGE 3 3 3 3 3 STREAM ft /s MEAN ft /s OF POR ft /s ACRE ft /s DATE ft /s DATE FOR POR FOR POR THIS MONTH MEAN DAYS FEET CALCULATION DOLORES RIVER NR CISCO, UTAH 191 152 80% 4,568 9,045 188 22-Nov 134 15-Nov Dec-1950 ADJUSTED (E) 101 53% 3,032 6,014 Sep-2019 COLORADO RIVER NR CISCO, UTAH 3,786 4,325 114% 129,977 257,354 5,209 3-Nov 3,605 29-Nov Oct-1913 ADJUSTED (B) 3,653 96% 109,581 217,354 Sep-2019 GREEN RIVER AT GREEN RIVER , UT 2,860 2,658 93% 79,889 158,181 3,048 30-Nov 2,322 5-Nov Oct-1894 ADJUSTED (C) 2,297 80% 68,909 136,681 Sep-2019 SAN JUAN RIVER NEAR BLUFF, UT 1,162 698 60% 20,965 41,511 986 23-Nov 515 19-Nov Oct-1914 ADJUSTED (D) 474 41% 14,223 28,211 Sep-2019

(A) POR; Period of record. (B) ADJUSTED FOR CHANGE IN STORAGE IN BLUE MESA RESERVOIR. STORAGE BEGAN OCT. 27, 1965 (C) ADJUSTED FOR CHANGE IN STORAGE IN FLAMING GORGE RESERVOIR & FONTENELLE RESERVOIR, STORAGE BEGAN NOV. 1, 1962 & OCT., 1964 RESPECTIVELY. (D) ADJUSTED FOR CHANGE IN STORAGE IN NAVAJO RESERVOIR (STORAGE BEGAN JUNE 27, 1962) AND SINCE AUGUST 1964, RELEASES TO NAVAJO INDIAN IRRIGATION PROJECT (NIIP). RELEASES TO NIIP BEGAN JANUARY 1976. (E) ADJUSTED FOR CHANGE IN STORAGE IN MCPHEE RESERVOIR. STORAGE BEGAN MAR 20, 1984

DRAINAGE USABLE END OF MO. CHANGE DURING RESERVOIR ABOVE DAM CAPACITY USABLE CONTENTS MONTH PREVIOUS (MI2) (AC-FT) (AC-FT) (AC-FT) MONTH MCPHEE RESERVOIR, MONTEZUMA COUNTY, CO 809 229,200 288,664 -3,031 291,695 BLUE MESA RESERVOIR NEAR SAPINERO, COLORADO 3,426 829,500 642,100 -40,000 682,100 FLAMING GORGE RESERVOIR AT FLAMING GORGE DAM, UT (b) 15,100 3,739,000 3,388,100 -4,700 3,392,800 FONTENELLE RESERVOIR AT FONTENELLE , WYOMING (b) 4,280 344,300 236,500 -16,800 253,300 NAVAJO RESERVOIR NEAR ARCHULETA, NEW MEXICO (b) 3,320 1,696,000 1,348,300 -13,300 1,361,600 NIIP 0 LAKE POWELL RESERVOIR AT GLEN CANYON DAM, ARIZONA (b) 107,700 25,002,000 12,854,500 -179,100 13,033,600

TOTALS 31,620,800 18,469,500 -253,900 18,723,400 (a) Preliminary Data (b) Approximate PROVISIONAL DATA U.S. GEOLOGICAL SURVEY SUBJECT TO REVISION UTAH WATER SCIENCE CENTER STREAMFLOW AND RESERVOIR CONTENTS IN UPPER COLORADO RIVER BASIN DAYS IN contact 435-259-4430 or [email protected] MONTH December 2019 31 MONTHLY DISCHARGE (a) MAXIMUM DAILY MINIMUM DAILY POR(A) (A)MEAN PERCENT TOTAL TOTAL DATE RANGE 3 3 3 3 3 STREAM ft /s MEAN ft /s OF POR ft /s ACRE ft /s DATE ft /s DATE FOR POR FOR POR THIS MONTH MEAN DAYS FEET CALCULATION DOLORES RIVER NR CISCO, UTAH 170 146 86% 4,085 8,088 208 26-Dec 87 22-Dec Dec-1950 ADJUSTED (E) 134 79% 4,153 8,237 Sep-2019 COLORADO RIVER NR CISCO, UTAH 3,272 3,875 118% 116,442 230,556 4,252 15-Dec 3,498 4-Dec Oct-1913 ADJUSTED (B) 2,862 87% 88,710 175,956 Sep-2019 GREEN RIVER AT GREEN RIVER , UT 2,363 3,331 141% 103,433 204,798 3,684 29-Dec 2,930 1-Dec Oct-1894 ADJUSTED (C) 1,867 79% 57,876 114,798 Sep-2019 SAN JUAN RIVER NEAR BLUFF, UT 1,038 929 90% 28,852 57,126 1,046 10-Dec 788 20-Dec Oct-1914 ADJUSTED (D) 562 54% 17,407 34,526 Sep-2019

(A) POR; Period of record. (B) ADJUSTED FOR CHANGE IN STORAGE IN BLUE MESA RESERVOIR. STORAGE BEGAN OCT. 27, 1965 (C) ADJUSTED FOR CHANGE IN STORAGE IN FLAMING GORGE RESERVOIR & FONTENELLE RESERVOIR, STORAGE BEGAN NOV. 1, 1962 & OCT., 1964 RESPECTIVELY. (D) ADJUSTED FOR CHANGE IN STORAGE IN NAVAJO RESERVOIR (STORAGE BEGAN JUNE 27, 1962) AND SINCE AUGUST 1964, RELEASES TO NAVAJO INDIAN IRRIGATION PROJECT (NIIP). RELEASES TO NIIP BEGAN JANUARY 1976. (E) ADJUSTED FOR CHANGE IN STORAGE IN MCPHEE RESERVOIR. STORAGE BEGAN MAR 20, 1984

DRAINAGE USABLE END OF MO. CHANGE DURING RESERVOIR ABOVE DAM CAPACITY USABLE CONTENTS MONTH PREVIOUS (MI2) (AC-FT) (AC-FT) (AC-FT) MONTH MCPHEE RESERVOIR, MONTEZUMA COUNTY, CO 809 229,200 288,813 149 288,664 BLUE MESA RESERVOIR NEAR SAPINERO, COLORADO 3,426 829,500 587,500 -54,600 642,100 FLAMING GORGE RESERVOIR AT FLAMING GORGE DAM, UT (b) 15,100 3,739,000 3,327,100 -61,000 3,388,100 FONTENELLE RESERVOIR AT FONTENELLE , WYOMING (b) 4,280 344,300 207,500 -29,000 236,500 NAVAJO RESERVOIR NEAR ARCHULETA, NEW MEXICO (b) 3,320 1,696,000 1,325,700 -22,600 1,348,300 NIIP 0 LAKE POWELL RESERVOIR AT GLEN CANYON DAM, ARIZONA (b) 107,700 25,002,000 12,603,900 -250,600 12,854,500

TOTALS 31,620,800 18,051,700 -417,800 18,469,500 (a) Preliminary Data (b) Approximate PROVISIONAL DATA U.S. GEOLOGICAL SURVEY SUBJECT TO REVISION UTAH WATER SCIENCE CENTER STREAMFLOW AND RESERVOIR CONTENTS IN UPPER COLORADO RIVER BASIN DAYS IN contact 435-259-4430 or [email protected] MONTH January 2020 31 MONTHLY DISCHARGE (a) MAXIMUM DAILY MINIMUM DAILY POR(A) (A)MEAN PERCENT TOTAL TOTAL DATE RANGE 3 3 3 3 3 STREAM ft /s MEAN ft /s OF POR ft /s ACRE ft /s DATE ft /s DATE FOR POR FOR POR THIS MONTH MEAN DAYS FEET CALCULATION DOLORES RIVER NR CISCO, UTAH 163 189 116% 5,868 11,618 269 17-Jan 89 1-Jan Dec-1950 ADJUSTED (E) 4,877 2990% 151,183 299,872 Sep-2019 COLORADO RIVER NR CISCO, UTAH 3,074 3,419 111% 106,172 210,220 3,994 1-Jan 3,140 31-Jan Oct-1913 ADJUSTED (B) 2,874 94% 89,095 176,720 Sep-2019 GREEN RIVER AT GREEN RIVER , UT 2,336 3,036 130% 94,280 186,675 1,703 3-Jan 3,672 27-Jan Oct-1894 ADJUSTED (C) 1,663 71% 51,563 102,275 Sep-2019 SAN JUAN RIVER NEAR BLUFF, UT 1,059 803 76% 24,936 49,372 968 28-Jan 696 9-Jan Oct-1914 ADJUSTED (D) 512 48% 15,867 31,472 Sep-2019

(A) POR; Period of record. (B) ADJUSTED FOR CHANGE IN STORAGE IN BLUE MESA RESERVOIR. STORAGE BEGAN OCT. 27, 1965 (C) ADJUSTED FOR CHANGE IN STORAGE IN FLAMING GORGE RESERVOIR & FONTENELLE RESERVOIR, STORAGE BEGAN NOV. 1, 1962 & OCT., 1964 RESPECTIVELY. (D) ADJUSTED FOR CHANGE IN STORAGE IN NAVAJO RESERVOIR (STORAGE BEGAN JUNE 27, 1962) AND SINCE AUGUST 1964, RELEASES TO NAVAJO INDIAN IRRIGATION PROJECT (NIIP). RELEASES TO NIIP BEGAN JANUARY 1976. (E) ADJUSTED FOR CHANGE IN STORAGE IN MCPHEE RESERVOIR. STORAGE BEGAN MAR 20, 1984

DRAINAGE USABLE END OF MO. CHANGE DURING RESERVOIR ABOVE DAM CAPACITY USABLE CONTENTS MONTH PREVIOUS (MI2) (AC-FT) (AC-FT) (AC-FT) MONTH MCPHEE RESERVOIR, MONTEZUMA COUNTY, CO 809 229,200 288,254 288,254 BLUE MESA RESERVOIR NEAR SAPINERO, COLORADO 3,426 829,500 554,000 -33,500 587,500 FLAMING GORGE RESERVOIR AT FLAMING GORGE DAM, UT (b) 15,100 3,739,000 3,273,600 -53,500 3,327,100 FONTENELLE RESERVOIR AT FONTENELLE , WYOMING (b) 4,280 344,300 176,600 -30,900 207,500 NAVAJO RESERVOIR NEAR ARCHULETA, NEW MEXICO (b) 3,320 1,696,000 1,307,800 -17,900 1,325,700 NIIP 0 LAKE POWELL RESERVOIR AT GLEN CANYON DAM, ARIZONA (b) 107,700 25,002,000 12,280,700 -323,200 12,603,900

TOTALS 31,620,800 17,592,700 -459,000 18,051,700 (a) Preliminary Data (b) Approximate PROVISIONAL DATA U.S. GEOLOGICAL SURVEY SUBJECT TO REVISION UTAH WATER SCIENCE CENTER STREAMFLOW AND RESERVOIR CONTENTS IN UPPER COLORADO RIVER BASIN DAYS IN contact 435-259-4430 or [email protected] MONTH February 2020 leap year 29 MONTHLY DISCHARGE (a) MAXIMUM DAILY MINIMUM DAILY POR(A) (A)MEAN PERCENT TOTAL TOTAL DATE RANGE 3 3 3 3 3 STREAM ft /s MEAN ft /s OF POR ft /s ACRE ft /s DATE ft /s DATE FOR POR FOR POR THIS MONTH MEAN DAYS FEET CALCULATION DOLORES RIVER NR CISCO, UTAH 206 165 80% 4,787 9,478 200 11-Feb 132 7-Feb Dec-1950 ADJUSTED (E) 137 67% 3,972 7,878 Sep-2019 COLORADO RIVER NR CISCO, UTAH 3,218 2,944 91% 85,512 169,313 3,206 11-Feb 2,593 6-Feb Oct-1913 ADJUSTED (B) 2,648 82% 76,790 152,313 Sep-2019 GREEN RIVER AT GREEN RIVER , UT 2,824 3,531 125% 102,579 203,107 4,027 25-Feb 3,012 8-Feb Oct-1894 ADJUSTED (C) 2,182 77% 63,276 125,507 Sep-2019 SAN JUAN RIVER NEAR BLUFF, UT 1,337 713 53% 20,716 41,018 849 11-Feb 608 29-Feb Oct-1914 ADJUSTED (D) 532 40% 15,436 30,618 Sep-2019

(A) POR; Period of record. (B) ADJUSTED FOR CHANGE IN STORAGE IN BLUE MESA RESERVOIR. STORAGE BEGAN OCT. 27, 1965 (C) ADJUSTED FOR CHANGE IN STORAGE IN FLAMING GORGE RESERVOIR & FONTENELLE RESERVOIR, STORAGE BEGAN NOV. 1, 1962 & OCT., 1964 RESPECTIVELY. (D) ADJUSTED FOR CHANGE IN STORAGE IN NAVAJO RESERVOIR (STORAGE BEGAN JUNE 27, 1962) AND SINCE AUGUST 1964, RELEASES TO NAVAJO INDIAN IRRIGATION PROJECT (NIIP). RELEASES TO NIIP BEGAN JANUARY 1976. (E) ADJUSTED FOR CHANGE IN STORAGE IN MCPHEE RESERVOIR. STORAGE BEGAN MAR 20, 1984

DRAINAGE USABLE END OF MO. CHANGE DURING RESERVOIR ABOVE DAM CAPACITY USABLE CONTENTS MONTH PREVIOUS (MI2) (AC-FT) (AC-FT) (AC-FT) MONTH MCPHEE RESERVOIR, MONTEZUMA COUNTY, CO 809 229,200 286,654 -1,600 288,254 BLUE MESA RESERVOIR NEAR SAPINERO, COLORADO 3,426 829,500 537,000 -17,000 554,000 FLAMING GORGE RESERVOIR AT FLAMING GORGE DAM, UT (b) 15,100 3,739,000 3,225,300 -48,300 3,273,600 FONTENELLE RESERVOIR AT FONTENELLE , WYOMING (b) 4,280 344,300 147,300 -29,300 176,600 NAVAJO RESERVOIR NEAR ARCHULETA, NEW MEXICO (b) 3,320 1,696,000 1,294,800 -13,000 1,307,800 NIIP 2,600 LAKE POWELL RESERVOIR AT GLEN CANYON DAM, ARIZONA (b) 107,700 25,002,000 12,011,500 -269,200 12,280,700

TOTALS 31,620,800 17,215,900 -376,800 17,592,700 (a) Preliminary Data (b) Approximate Dolores River near Cisco, Utah Monthly Mean Discharge (cubic feet per second) 3,000

2,500

2,000

1,500

DISCHARGE (cubic feet per second) 1,000

500

189 137 152 146 165 0 0 0 0 0 0 0 0 OCT-2019 NOV-2019 DEC-2019 JAN-2020 FEB-2020 MAR-2020 APR-2020 MAY-2020 JUN-2020 JUL-2020 AUG-2020 SEP-2020

Dolores River nr Cisco, UT WY 2020 Monthly Mean Dolores River nr Cisco, UT Monthly Mean for Dec-1950 to Sep-2019 Colorado River near Cisco, Utah Monthly Mean Discharge (cubic feet per second) 25,000

20,000

15,000

10,000 DISCHARGE (cubic feet per second)

5,000 4,325 4,133 3,875 3,419 2,944

0 0 0 0 0 0 0 0 OCT-2019 NOV-2019 DEC-2019 JAN-2020 FEB-2020 MAR-2020 APR-2020 MAY-2020 JUN-2020 JUL-2020 AUG-2020 SEP-2020

Colorado River nr Cisco, UT WY 2020 Monthly Mean Colorado River nr Cisco, UT Monthly Mean for Oct-1913 to Sep-2019 Green River at Green River, Utah Monthly Mean Discharge (cubic feet per second) 20,000

18,000

16,000

14,000

12,000

10,000

8,000 DISCHARGE (cubic feet per second) 6,000

4,000 3,331 3,531 3,036 2,581 2,658 2,000

0 0 0 0 0 0 0 0 OCT-2019 NOV-2019 DEC-2019 JAN-2020 FEB-2020 MAR-2020 APR-2020 MAY-2020 JUN-2020 JUL-2020 AUG-2020 SEP-2020

Green River at Green River, UT WY 2020 Monthly Mean Green River at Green River, UT Monthly Mean for Oct-1894 to Sep-2019 San Juan River near Bluff, Utah Monthly Mean Discharge (cubic feet per second) 6,000

5,000

4,000

3,000

DISCHARGE (cubic feet per second) 2,000

1,000 929 803 701 698 713

0 0 0 0 0 0 0 0 OCT-2019 NOV-2019 DEC-2019 JAN-2020 FEB-2020 MAR-2020 APR-2020 MAY-2020 JUN-2020 JUL-2020 AUG-2020 SEP-2020

San Juan River nr Bluff, UT WY 2020 Monthly Mean San Juan River nr Bluff, UT Monthly Mean for Oct-1914 to Sep-2019 Sum of Major Inflows to Lake Powell Monthly Mean Discharge (cubic feet per second) 50,000

45,000

40,000

35,000

30,000

25,000

20,000 DISCHARGE (cubic feet per second) 15,000

10,000 8,280 7,552 7,833 7,447 7,352 5,000

0 0 0 0 0 0 0 0 OCT-2019 NOV-2019 DEC-2019 JAN-2020 FEB-2020 MAR-2020 APR-2020 MAY-2020 JUN-2020 JUL-2020 AUG-2020 SEP-2020

Sum of Major Inflow to Lake Powell WY 2020 Monthly Mean Sum of Major Inflow to Lake Powell Monthly Mean for Period of Record Annual Total Discharge 14,000

12,000

10,000

8,000 FEET PER YEAR PER FEET -

6,000 THOUSAND ACRE

4,000

2,000

0 Dolores River near Cisco, UT Colorado River nr Cisco, UT Green River at Green River, UT San Juan River nr Bluff, UT Sum of Major Inflows to Lake Powell

Annual Total WY 2020 Total Discharge (kac-feet) Period of Record Mean Annual Total Discharge (kac-ft)