Water-Data Report CA-2005 11269500 LAKE MCCLURE AT EXCHEQUER, CA San Joaquin River Basin LOCATION.--Lat 37°35′02″, long 120°16′09″ referenced to North American Datum of 1927, in NW ¼ SE ¼ sec.13, T.4 S., R.15 E., Mariposa County, Hydrologic Unit 18040008, on left end of New Exchequer Dam on Merced River, 0.9 mi east of Exchequer, and 5.5 mi northeast of Merced Falls. DRAINAGE AREA.--1,037 mi². WATER-STAGE RECORDS PERIOD OF RECORD.--April 1926 to September 1930 (daily gage heights; also summary of yearly contents in WSP 881), October 1930 to current year. REVISED RECORDS.--WSP 881: 1926-32 (yearly summaries only). WSP 1345: 1951(M). WSP 1930: Drainage area. GAGE.--Water-stage recorder. Datum of gage is NGVD of 1929 (levels by Merced Irrigation District). Prior to Oct. 1, 1964, indicator in powerplant at same datum. Oct. 1, 1964, to July 31, 1966, nonrecording gage at center of upstream face of dam at same datum. REMARKS.--Reservoir is formed by a rockfill dam with a reinforced concrete face completed in March 1967. Dam is downstream from and connected to the original concrete arch and gravity-type dam which was completed in April 1926. Usable capacity, 1,024,000 acre-ft, between elevations 440.0 ft, invert entrance to outlet tunnel, and 867.0 ft, top of spillway gates. Dead storage, 300 acre-ft. Water is released through Exchequer Powerplant (station 11269700) down the Merced River to a diversion dam for Merced Irrigation District's main canal. Records, including extremes, represent total contents at 2400 hours. COOPERATION.--Records, including diversion through Exchequer Powerplant, were provided by Pacific Gas and Electric Co., under general supervision of the U.S. Geological Survey, in connection with Federal Energy Regulatory Commission project no. 2179. EXTREMES FOR PERIOD OF RECORD.--Maximum contents, 1,026,000 acre-ft, July 14, 15, 1969, elevation, 867.2 ft; practically no storage at times in 1926, 1930-31, 1964-65 when reservoir was drained for inspection or construction. Minimum since construction of New Exchequer Dam in 1966 and since lake first filled, 66,100 acre-ft, Feb. 28, 1991, elevation, 588.4 ft. EXTREMES FOR CURRENT YEAR.--Maximum contents, 1,000,000 acre-ft, July 2-10, elevation, 863.76 ft, July 6, 7; minimum, 256,000 acre-ft, Oct. 18, 19, elevation, 697.19 ft, Oct. 19. Capacity table (elevation, in feet, and contents, in acre-feet) (Based on table provided by Merced Irrigation District, dated June 1966) Elevation Contents Elevation Contents Elevation Contents 590 67,900 660 173,500 780 534,500 600 79,900 680 215,200 820 729,600 610 92,800 700 263,000 840 845,800 620 106,700 720 317,800 860 975,700 640 137,800 750 415,900 870 1,046,000 U.S. Department of the Interior U.S. Geological Survey Water-Data Report CA-2005 11269500 LAKE MCCLURE AT EXCHEQUER, CA—Continued RESERVOIR STORAGE, ACRE FEET WATER YEAR OCTOBER 2004 TO SEPTEMBER 2005 DAILY OBSERVATION AT 2400 HOURS Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep 1 278,000 262,000 268,000 298,000 477,000 569,000 679,000 641,000 886,000 998,000 944,000 822,000 2 277,000 263,000 268,000 301,000 479,000 572,000 676,000 642,000 893,000 1,000,000 940,000 818,000 3 275,000 264,000 268,000 306,000 481,000 575,000 672,000 644,000 900,000 1,000,000 936,000 815,000 4 274,000 265,000 268,000 309,000 483,000 578,000 669,000 647,000 907,000 1,000,000 932,000 812,000 5 272,000 265,000 268,000 312,000 484,000 580,000 666,000 651,000 913,000 1,000,000 928,000 810,000 6 271,000 266,000 268,000 313,000 486,000 582,000 663,000 654,000 918,000 1,000,000 924,000 807,000 7 269,000 266,000 268,000 317,000 488,000 585,000 661,000 655,000 921,000 1,000,000 919,000 804,000 8 268,000 267,000 270,000 341,000 490,000 587,000 659,000 656,000 925,000 1,000,000 915,000 800,000 9 266,000 267,000 270,000 366,000 490,000 590,000 657,000 663,000 927,000 1,000,000 911,000 795,000 10 263,000 267,000 271,000 393,000 492,000 593,000 654,000 667,000 929,000 999,000 907,000 792,000 11 263,000 267,000 271,000 411,000 493,000 596,000 652,000 669,000 932,000 998,000 902,000 789,000 12 261,000 268,000 271,000 420,000 495,000 599,000 651,000 670,000 936,000 997,000 899,000 785,000 13 260,000 268,000 272,000 425,000 495,000 603,000 650,000 673,000 941,000 997,000 895,000 782,000 14 259,000 268,000 272,000 429,000 496,000 608,000 648,000 679,000 950,000 996,000 890,000 778,000 15 258,000 269,000 272,000 432,000 499,000 611,000 647,000 687,000 958,000 994,000 886,000 775,000 16 257,000 269,000 273,000 434,000 506,000 614,000 646,000 705,000 965,000 993,000 882,000 772,000 17 257,000 270,000 273,000 437,000 512,000 616,000 646,000 722,000 969,000 991,000 878,000 769,000 18 256,000 270,000 273,000 438,000 518,000 618,000 646,000 732,000 972,000 989,000 874,000 765,000 19 256,000 271,000 273,000 440,000 523,000 621,000 646,000 742,000 973,000 987,000 870,000 762,000 20 258,000 270,000 273,000 442,000 531,000 624,000 645,000 753,000 974,000 984,000 866,000 759,000 21 258,000 270,000 273,000 444,000 538,000 633,000 644,000 766,000 976,000 981,000 862,000 756,000 22 258,000 268,000 273,000 446,000 543,000 648,000 643,000 780,000 979,000 979,000 858,000 753,000 23 258,000 268,000 273,000 447,000 548,000 676,000 641,000 793,000 982,000 977,000 853,000 750,000 24 258,000 268,000 274,000 449,000 552,000 688,000 640,000 806,000 985,000 974,000 849,000 747,000 25 258,000 268,000 274,000 451,000 555,000 694,000 639,000 819,000 988,000 970,000 844,000 744,000 26 259,000 268,000 274,000 455,000 558,000 694,000 639,000 832,000 990,000 967,000 840,000 741,000 27 261,000 268,000 274,000 459,000 560,000 690,000 639,000 846,000 992,000 963,000 837,000 739,000 28 261,000 268,000 274,000 464,000 565,000 689,000 640,000 859,000 993,000 960,000 834,000 735,000 29 262,000 268,000 275,000 469,000 --- 687,000 641,000 868,000 995,000 956,000 831,000 733,000 30 262,000 268,000 279,000 472,000 --- 685,000 640,000 873,000 996,000 952,000 828,000 731,000 31 262,000 --- 292,000 475,000 --- 683,000 --- 878,000 --- 948,000 825,000 --- Max 278,000 271,000 292,000 475,000 565,000 694,000 679,000 878,000 996,000 1,000,000 944,000 822,000 Min 256,000 262,000 268,000 298,000 477,000 569,000 639,000 641,000 886,000 948,000 825,000 731,000 Elevation, in feet, at end of month 699.49 702.01 711.06 765.57 786.93 811.18 802.82 845.24 862.95 855.91 836.57 820.20 Change in contents, in acre-feet -17,600 +6,000 +24,000 +183,000 +90,000 +118,000 -43,000 +238,000 +118,000 -48,000 -123,000 -94,000 Diversion, in acre-feet, through Exchequer Powerplant 36,610 9,110 15,430 11,340 13,040 54,650 181,800 182,000 162,900 159,200 142,900 100,700 Calendar Year 2004 Water Year 2005 Change in contents, in acre-feet -95,000 +451,400 — 2 — Water-Data Report CA-2005 11269500 LAKE MCCLURE AT EXCHEQUER, CA—Continued 1,000,000 900,000 800,000 700,000 600,000 500,000 400,000 RESERVOIR CONTENTS, IN ACRE-FEET 300,000 200,000 O N D J F M A M J J A S 2004 2005 — 3 — .