11125500 LAKE CACHUMA NEAR SANTA YNEZ, CA
LOCATION.-Lat 34°34'57", long 119°58'47", in Lomas de la Purification Grant, Santa Barbara County,
Hydrologic Unit 18060010, at Bradbury Dam on Santa Ynez River, on upstream face near left end of dam, and 6.1 mi
east of Santa Ynez.
DRAINAGE AREA.-417 mi2.
PERIOD OF RECORD.-November 1952 to current year. Prior to October 1985, only monthend elevations and contents and
total diversions published. November 1952 to October 1960, published as "Cachuma Reservoir near Santa Ynez."
CHEMICAL DATA: Water Year 1998.
GAGE.-Water-stage recorder. Datum of gage is sea level (U.S. Bureau of Reclamation benchmark). Prior to Oct. 1,
1965, nonrecording gage.
REMARKS.-Reservoir is formed by earthfill dam. Storage began November 1952. Dead storage below outlet gage to
river, elevation, 600 ft, 531 acre-ft, included in contents. Capacity below sill of inlet to Tecolote Tunnel,
elevation, 660 ft, 26,771 acre-ft; below spillway level, elevation, 720 ft, 113,716 acre-ft; and below top of
four radial gates, elevation, 750 ft, 190,409 acre-ft. Water is released from outlet to Santa Ynez River to
satisfy downstream water rights. Water diverted to Tecolote Tunnel for use by city of Santa Barbara, nearby
communities, Santa Ynez River Water Conservation District, and Cachuma Recreation Area. Records, including
extremes, represent total contents at 0800 hours. See schematic diagram of Santa Ynez River Basin.
COOPERATION.-Reservoir elevation, contents, and diversion figures provided by U.S. Bureau of Reclamation.
Contents not rounded to U.S. Geological Survey standards.
EXTREMES FOR PERIOD OF RECORD.-Maximum contents, 221,100 acre-ft, Feb. 24, 1969, elevation, 755.11 ft; minimum
since initial filling in April 1958, 27,681 acre-ft, Feb. 27, 1991, elevation, 661.06 ft.
EXTREMES (AT 0800) FOR CURRENT YEAR.-Maximum contents, 186,756 acre-ft, Apr. 27, elevation, 748.79 ft; minimum,
168,772 acre-ft, Sept. 30, elevation, 742.57 ft.
Capacity table (elevation, in feet, and contents, in acre-feet)
(Based on surveys by U.S. Bureau of Reclamation)
680 47,346 710 93,627 740 161,730
690 60,576 720 113,716 750 190,409
700 75,972 730 136,306 760 222,431
RESERVOIR STORAGE (ACRE-FEET), WATER YEAR OCTOBER 1998 TO SEPTEMBER 1999
DAILY OBSERVATION AT 0800 HOURS
DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
1 185381 181675 180212 179219 178752 180534 183773 186666 184099 181205 177364 172812
2 185231 181616 180329 179161 178781 180504 183833 186607 183980 181118 177220 172642
3 185112 181528 180329 179102 178810 180446 183862 186517 183892 181030 177104 172473
4 184962 181439 180387 179044 178810 180358 183833 186457 183773 180884 176989 172304
5 184843 181322 180358 178985 178839 180300 183803 186397 183685 180767 176845 172135
6 184753 181205 180358 178898 178839 180271 183862 186338 183626 180621 176700 171966
7 184603 181088 180387 178810 178927 180212 183951 186278 183567 180475 176556 171797
8 184454 181059 180387 178752 178956 180183 184039 186248 183478 180358 176412 171629
9 184305 180972 180358 178722 179102 180154 184128 186158 183389 180212 176268 171460
10 184128 180884 180358 178664 179716 180125 184187 186068 183301 180095 176152 171319
11 183951 180796 180300 178576 180095 180125 184305 185979 183183 179949 176037 171121
12 183833 180738 180300 178518 180241 180125 185231 185949 183094 179832 175893 170953
13 183714 180680 180241 178489 180387 180095 185530 185889 183005 179716 175748 170812
14 183655 180563 180154 178431 180475 180125 185859 185799 182917 179628 175604 170699
15 183537 180446 180095 178374 180534 180271 186098 185710 182857 179511 175433 170558
16 183389 180417 180066 178316 180592 180621 186308 185650 182680 179365 175320 170389
17 183301 180358 180037 178287 180621 180709 186487 185560 182562 179219 175177 170221
18 183153 180300 179949 178287 180680 180855 186547 185440 182473 179102 175063 170108
19 183035 180271 179891 178230 180709 180855 186637 185291 182385 178985 174892 169995
20 182916 180241 179803 178258 180738 181147 186726 185171 182325 178869 174750 169884
21 182798 180212 179745 178230 180738 181293 186696 185052 182207 178752 174579 169745
22 182650 180124 179716 178201 180738 181469 186666 184932 182119 178635 174408 169633
23 182532 180124 179657 178143 180709 181528 186666 184872 182060 178518 174237 169522
24 182444 180095 179599 178172 180680 181646 186726 184813 181941 178403 174094 169411
25 182325 180066 179540 178230 180680 181971 186726 184753 181823 178287 173923 169300
26 182237 180037 179511 178258 180650 182887 186726 184693 181675 178172 173724 169189
27 182178 179949 179482 178345 180621 183183 186756 184633 181587 178028 173609 169077
28 182060 180124 179424 178827 180563 183360 186696 184543 181469 177912 173438 168994
29 182000 180124 179394 178345 --- 183508 186696 184454 181381 177768 173267 168883
30 181882 180095 179336 178345 --- 183626 186666 184364 181293 177624 173096 168772
31 181764 --- 179248 178664 --- 183714 --- 184246 --- 177479 172954 ---
MAX 185381 181675 180387 179219 180738 183714 186756 186666 184099 181205 177364 172812
MIN 181764 179949 179248 178143 178752 180095 183773 184246 181293 177479 172954 168772
a 747.11 746.54 746.25 746.05 746.70 747.77 748.76 747.95 746.95 745.64 744.06 742.57
b -3736 -1669 -847 -584 +1899 +3151 +2952 -2420 -2953 -3814 -4525 -4182
c 2938 2281 1606 1865 1091 1329 1437 2429 2355 2871 3146 2889
CAL YR 1998 b +47413
WTR YR 1999 b -16728
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