392:. The heaviest rains fell in the San Gabriel Mountains, swelling the San Gabriel River; on the night of March 2–3, 1938 a flood of 150,000 cu ft/s (4,200 m/s) poured out of the mountains and into San Gabriel Reservoir. San Gabriel Dam was able to knock about 40,000 cu ft/s (1,100 m/s) off the peak of the flood. Further downstream, Morris Reservoir was able to absorb roughly 30,000 cu ft/s (850 m/s), reducing the flood to less than half of what it would have been if not for the dams.
338:
765:), where it percolates into the local groundwater basin. Dam operations are coordinated by the San Gabriel River Water Committee (Committee of Nine), established in 1889 to represent water-rights holders on the San Gabriel River and with rights to 97,700 acre-feet (120,500 dam) of river water; and the San Gabriel Valley Protective Association, which has rights to all water flows above 97,700 acre-feet as well as all storage space in San Gabriel, Cogswell and Morris Dams.
354:. To be named the San Gabriel Forks Dam, the project was canceled by the State Engineer after having convened an inquiry to investigate problems which were occurring at San Gabriel Dam site, including a landslide that destroyed a large portion of the construction site, in early November 1929. The inquiry panel concluded and issued a report to the State Engineer stating that the proposed dam "cannot be constructed without creating a menace to life and property."
769:
29:
1255:
813:
The dam supports two small hydroelectric plants producing a maximum of 4.95 MW and owned by the
Department of Public Works. Water from the reservoir can be bypassed through a tunnel called the Azusa Conduit to another power plant downstream of Morris Dam. The power plant is located on the south side
781:
has reduced the water volume. Interest in sediment removal began in the 1980s, after several major wildfires in the San
Gabriel Mountains and subsequent flooding caused millions of cubic yards of sediment to wash into the reservoir. The reservoir was dewatered in 2004 to allow for sediment removal,
776:
The large reservoir, known as San
Gabriel Reservoir No. 1, is nearly 3 miles (4.8 km) long when full. The 525-acre (212 ha) reservoir stores 44,183 acre⋅ft (54,499,000 m) of water when full, creating one of Southern California's largest instream reservoirs. This is 17% less than
785:
Disposal of the removed sediment has been a contentious issue. The 2005 sediment removal project stored about 6,100,000 cubic yards (4,700,000 m) of sediment in a nearby canyon, but this is now prohibited due to environmental and safety issues. Another option would have been to truck the
814:
of the San
Gabriel River directly below the mouth of San Gabriel Canyon. The original power plant was first built in 1898, by the San Gabriel Electric Company, and during its first few decades of operation powered electric railway lines in Los Angeles. At the time, this 2000
822:, before being incorporated into the Pasadena municipal electric system. The completion of San Gabriel Dam in 1939 ensured a steadier water supply for the power plant, and in the late 1940s a new 3000 KW facility was built to replace the old one.
357:
Subsequently, the design of the San
Gabriel River flood control project was changed from one large dam to two smaller dams: San Gabriel No. 1 (San Gabriel Dam), about 2 miles (3.2 km) below the original Forks site, and San Gabriel No. 2
345:
In the 1920s, the Los
Angeles County Flood Control District proposed to impound the San Gabriel River just below the confluence of the East and West forks with a 512-foot (156 m) high, 2,500-foot (760 m) long concrete
384:
The San
Gabriel No. 1 dam was to be made of rock-fill, which provides greater seismic stability. Construction of the 315-foot (96 m) high San Gabriel Dam at this site began in 1932 and was completed in 1939.
309:. Completed in 1939, the dam impounds the main stem of the San Gabriel River about 2.5 miles (4.0 km) downstream from the confluence of the river's East and West Forks, which drain a large portion of the
1507:
362:), on the West Fork about 15 miles (24 km) above the confluence. The cost of San Gabriel No. 1 was greatly understated, creating a scandal; in context with the
341:
Satellite view showing four major dams in the San
Gabriel River system. San Gabriel (above right) was built in conjunction with Cogswell (top left) in the 1930s.
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861:
974:
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851:
145:
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1208:
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1085:
Ecology of the San
Gabriel River Catchment: Anthropogenic Influences on Black Flies (Diptera: Simuliidae) and Other Benthic Macroinvertebrates
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377:
necessary for financing of the project was defeated by a narrow margin of 52 to 48 percent. As a result, the city turned to the federal
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794:. Currently, most of the sediment is sold for building material or ends up as landfill, but these options are highly limited.
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Flood control releases are coordinated in conjunction with the other mountain dams, Morris and
Cogswell; and with
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the original capacity of 53,344 acre⋅ft (65,799,000 m) when the dam was first built, because
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View of a nearly full reservoir in 2011 from the north, with the dam and spillway in the background
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but work was delayed after heavy rains during the winter of 2004–2005 refilled the reservoir.
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818:(KW) plant drew water directly from the San Gabriel River. In 1917, the plant was sold to
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during the dry season of April through October. Water from San Gabriel, Cogswell and
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975:"Morris Dam upgrades improve L.A. County's water preservation, management efforts"
1134:
882:"Impacts of the 1928 St. Francis Dam Failure on Geology, Engineering and America"
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observed that "it is not now necessary to gamble $ 26 million on a ". The
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1167:"San Gabriel River and Montebello Forebay Water Conservation System"
937:. Suburban Emergency Management Project. 2006-06-07. Archived from
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336:
1190:
959:
907:
Hazardous Metropolis: Flooding and Urban Ecology in Los Angeles
749:
Water stored behind San Gabriel Dam is an important source for
1024:"Alphabetical List of California Dams (over 40,000 acre feet)"
157:
321:
flows and hydroelectricity for the heavily populated
1462:
1429:
1351:
1262:
1225:
931:"Los Angeles Basin's 1938 Catastrophic Flood Event"
761:at San Gabriel Canyon (Azusa) and Peck Basin (near
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1508:Los Angeles County Department of Public Works dams
1030:. University of California Davis. Archived from
838:. The dam was also a location for the 1934 film
757:is released gradually through the dry months to
1173:. Los Angeles County Department of Public Works
1139:. University of California Press. p. 159.
887:. Missouri University of Science and Technology
1202:
1136:Managing Water: Avoiding Crisis in California
1000:Managing Water: Avoiding Crisis in California
862:List of the tallest dams in the United States
8:
830:The dam appears in the 2001 action/war film
390:Southern California was hit by record floods
388:In early 1938, before the dam was finished,
313:. It is located directly upstream from the
1209:
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1187:
400:
27:
18:
852:List of dams and reservoirs in California
146:Los Angeles County Flood Control District
33:The dam seen from Glendora Mountain Road
1078:
1076:
1062:. California State University Fullerton
993:
991:
880:Rogers, J. David (September 28, 2007).
872:
790:, but this has also been banned by the
1053:"Flood Control and Water Conservation"
805:Dams on the lower San Gabriel River.
217:44,183 acre⋅ft (54,499 dam)
16:Dam in Los Angeles County, California
7:
404:Climate data for Camino, California
1109:"Barnard Construction Company, Inc"
1028:Civil and Environmental Engineering
381:for money to complete the project.
1083:Solek, Christopher Walter (2008).
1002:. University of California Press.
909:. University of California Press.
317:. The dam provides flood control,
14:
1538:1939 establishments in California
1111:. barnard-inc.com. Archived from
227:205 sq mi (530 km)
1353:LA Department of Water and Power
1253:
1227:CA Department of Water Resources
1060:San Gabriel River Flood Control
1518:San Gabriel River (California)
1219:Los Angeles County, California
977:. sgvtribune.com. 24 July 2013
786:sediment to local beaches for
350:to capture floods and provide
1:
1420:Van Norman (aka San Fernando)
1264:LA Department of Public Works
792:California Coastal Commission
667:Average snowfall inches (cm)
964:Retrieved on August 7, 2013.
857:List of lakes in California
523:Mean daily minimum °F (°C)
453:Mean daily maximum °F (°C)
379:Public Works Administration
121:; 85 years ago
103:; 92 years ago
1554:
1431:US Army Corps of Engineers
820:Southern California Edison
736:
403:
293:is a rock-fill dam on the
188:1,520 ft (460 m)
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1171:Water Resources District
1528:Angeles National Forest
998:Green, Dorothy (2007).
834:and is set in southern
307:Angeles National Forest
264:Installed capacity
235:525 acres (212 ha)
180:315 ft (96 m)
98:Construction began
1533:Dams completed in 1939
773:
342:
277:Annual generation
134:Construction cost
82:34.20556°N 117.85917°W
1523:San Gabriel Mountains
771:
340:
311:San Gabriel Mountains
209:San Gabriel Reservoir
158:Type of dam
905:Orsi, Jared (2004).
751:groundwater recharge
319:groundwater recharge
255:Commission date
87:34.20556; -117.85917
960:"Noaa weather data"
329:metropolitan area.
327:Greater Los Angeles
223:Catchment area
214:Total capacity
78: /
1470:Brown Mountain Dam
1240:Elderberry Forebay
1133:Green, D. (2007).
832:Behind Enemy Lines
774:
352:water conservation
343:
323:San Gabriel Valley
299:Los Angeles County
193:Spillway type
51:Los Angeles County
1495:
1494:
1380:(unsafe: emptied)
1374:(unsafe: emptied)
1094:978-1-10909-746-7
1009:978-0-52094-122-9
759:spreading grounds
741:
740:
295:San Gabriel River
288:
287:
232:Surface area
171:San Gabriel River
152:Dam and spillways
137:$ 17 million
116:Opening date
1545:
1513:Rock-filled dams
1454:Whittier Narrows
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745:Water management
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364:Great Depression
196:Ungated overflow
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291:San Gabriel Dam
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1361:Baldwin Hills
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1146:9780520941229
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1115:on 2014-01-01
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1101:
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1073:
1061:
1054:
1048:
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1034:on 2012-02-05
1033:
1029:
1025:
1019:
1016:
1011:
1005:
1001:
994:
992:
988:
976:
970:
967:
962:. Noaa. 2013.
961:
955:
952:
941:on 2009-05-09
940:
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918:
916:0-52093-008-8
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789:
788:replenishment
783:
780:
779:sedimentation
770:
766:
764:
760:
756:
752:
744:
737:Source: Noaa
735:
729:
724:
719:
714:
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669:
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629:
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595:precipitation
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257:
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249:City of Azusa
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240:Power Station
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52:
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42:United States
41:
37:
30:
25:
20:
1476:Las Virgenes
1415:Stone Canyon
1338:Sierra Madre
1321:
1312:Puddingstone
1287:Devil's Gate
1175:. Retrieved
1170:
1161:
1150:. Retrieved
1135:
1128:
1117:. Retrieved
1113:the original
1103:
1084:
1064:. Retrieved
1059:
1047:
1036:. Retrieved
1032:the original
1027:
1018:
999:
979:. Retrieved
969:
954:
943:. Retrieved
939:the original
935:Publications
934:
925:
906:
900:
889:. Retrieved
875:
829:
812:
796:
784:
775:
748:
597:inches (mm)
387:
383:
375:bond measure
369:
368:Los Angeles
360:Cogswell Dam
356:
344:
290:
289:
1481:Little Rock
1409:St. Francis
1404:Silver Lake
1394:Los Angeles
1327:Santa Anita
1322:San Gabriel
1277:Big Tujunga
809:Power plant
755:Morris Dams
245:Operator(s)
85: /
73:117°51′33″W
61:Coordinates
1502:Categories
1399:Mulholland
1378:Dry Canyon
1372:Chatsworth
1292:Eaton Wash
1272:Big Dalton
1177:2010-08-10
1152:2014-10-14
1119:2014-10-14
1066:2011-11-01
1038:2010-08-10
981:2014-10-14
945:2010-08-10
891:2014-04-09
868:References
315:Morris Dam
303:California
281:4,464,000
70:34°12′20″N
55:California
1488:(disused)
1472:(disused)
1449:Sepulveda
1334:(disused)
1317:San Dimas
662:(709.16)
201:Reservoir
162:Rock-fill
1444:Santa Fe
1422:(failed)
1411:(failed)
1389:Fairmont
1363:(failed)
1297:Live Oak
1282:Cogswell
1217:Dams in
846:See also
840:Spitfire
816:kilowatt
799:Santa Fe
593:Average
348:arch dam
167:Impounds
142:Owner(s)
47:Location
1367:Bouquet
1307:Pacoima
1245:Pyramid
1235:Castaic
763:Arcadia
732:(0.51)
672:(0.51)
632:(0.76)
588:(10.7)
573:(12.6)
568:(15.7)
563:(17.2)
558:(16.4)
553:(13.2)
548:(10.7)
518:(24.0)
513:(17.7)
508:(21.3)
503:(26.1)
498:(30.9)
493:(32.4)
488:(31.7)
483:(27.5)
478:(23.8)
473:(21.7)
468:(19.4)
463:(18.0)
458:(17.9)
396:Climate
333:History
325:in the
206:Creates
124: (
106: (
39:Country
1486:Rindge
1439:Hansen
1384:Encino
1332:Sawpit
1302:Morris
1143:
1091:
1006:
913:
836:Bosnia
826:Trivia
727:(0.0)
722:(0.0)
717:(0.0)
712:(0.0)
707:(0.0)
702:(0.0)
697:(0.0)
692:(0.0)
687:(0.0)
682:(0.0)
677:(0.0)
657:(104)
637:(5.8)
627:(3.6)
612:(114)
607:(148)
602:(166)
583:(6.0)
578:(8.7)
543:(8.6)
538:(7.2)
533:(6.3)
528:(6.3)
409:Month
366:, the
185:Length
177:Height
1463:Other
1056:(PDF)
885:(PDF)
660:27.96
652:(64)
647:(25)
642:(11)
622:(19)
617:(48)
448:Year
370:Times
1141:ISBN
1089:ISBN
1004:ISBN
911:ISBN
801:and
655:4.11
650:2.52
645:1.00
640:0.45
635:0.23
630:0.03
625:0.14
620:0.74
615:1.89
610:4.49
605:5.81
600:6.55
586:51.3
581:42.8
576:47.6
571:54.6
566:60.3
561:63.0
556:61.5
551:55.8
546:51.3
541:47.4
536:45.0
531:43.4
526:43.3
516:75.3
511:63.9
506:70.4
501:78.9
496:87.6
491:90.3
486:89.0
481:81.5
476:74.8
471:71.0
466:67.0
461:64.4
456:64.3
445:Dec
442:Nov
439:Oct
436:Sep
433:Aug
430:Jul
427:Jun
424:May
421:Apr
418:Mar
415:Feb
412:Jan
258:1940
126:1939
119:1939
108:1932
101:1932
730:0.2
725:0.0
720:0.0
715:0.0
710:0.0
705:0.0
700:0.0
695:0.0
690:0.0
685:0.0
680:0.0
675:0.0
670:0.2
297:in
283:KWh
1504::
1169:.
1087:.
1075:^
1058:.
1026:.
990:^
933:.
842:.
301:,
270:MW
268:3
53:,
1210:e
1203:t
1196:v
1180:.
1155:.
1122:.
1097:.
1069:.
1041:.
1012:.
984:.
948:.
919:.
894:.
358:(
128:)
110:)
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