Floods of December 1955-January 1956 in the Far Western States

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1650

This Water-Supply Paper was prepared as separate chapters A and B

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY

Thomas B. Nolan, Director CONTENTS

[Letters designate the separately published chapters] (A) Part 1. Description. (B) Part 2. Streamflow data.

Floods of December 1955-January 1956 in the Far Western States Part 1. Description

By WALTER HOFMANN and S. E. RANTZ

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1650-A

Prepared in cooperation with the States of California, Idaho, Nevada, Oregon, and Washington, and with other agencies

UNITED STATES GOVERNMENT PRINTING OFF.ICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. PREFACE This report on the floods of December 1955-January 1956 in the Far Western States was prepared by the U.S. Geological Survey, Water Resources Division. C. G. Paulsen, chief hydraulic engineer, suc ceeded by Luna B. Leopold, under the general direction of J. V. B. Wells, chief, Surface Water Branch. A preliminary report of peak discharges was released as Geological Survey Circular 380 in August 1956. Basic records of stage and discharge in the area, covered by Water- Supply Paper 1650-B, were collected by the U.S. Geological Survey as part of a continuous program in cooperation with the States of California, Idaho, Oregon, Nevada, and Washington; county and city agencies within these states; and agencies of the Federal Government. The records of stage and discharge were collected and computed under the direction of the following district engineers: California, R. C. Briggs, succeeded by R. S. Lord; Idaho, T. R. Newell; Oregon, K. N. Phillips; Nevada, M. T. Wilson; Washington, F. M. Veatch. The report was assembled and the text prepared under the general supervision of Tate Dalrymple, chief, Floods Section, Surface Water Branch. G. L. Bodhaine, Flood Specialist, contributed to the section on previous floods and coordinated the work of the Oregon, Idaho, and Washington district offices. The help of various district personnel in preparing the text is also acknowledged. in

CONTENTS

Page Abstract______A 1 Introduction.______2 Acknowledgments ______4 Precipitation______5 The Great Basin______5 Central-coastal California______^______7 San Joaquih Valley______-___ 8 Sacramento Valley______9 North-coastal California______10 West-central Idaho.___---_-_--______-______--___--_-__ 10 Willamette Valley. ______.___ 11 Coastal Oregon______12 Areas of minor flooding in Oregon, Washington, and Idaho.______13 General descriptions of floods.______13 The Great Basin______13 Walker River basin______-_-_-_- 15 Carson River basin______.______15 Truckee River basin______-___-___- 17 Black Rock Desert basin.______19 Humboldt River basin______-___- 19 Minor basins in California and Oregon.______-__--_-__- 20 Central-coastal California.______-______-__-_--_---___ 20 Salinas River basin and small adjacent basins.______-----_ 21 Pajaro River basin______22 San Lorenzo River basin______'__-__- 24 Small Santa Cruz County streams.______------_ 25 Small San Francisco peninsula streams.______-_----__-- 25 Santa Clara Valley.______-----_-_--- 26 Alameda Creek______- 27 Small basins east of San Francisco Bay______27 San Joaquin Valley.______------_ 28 Kern River basin__-______-____--_--___- 28 Tulare Lake basin______-__--_- 31 San Joaquin River basin______.______---_-_---- 33 Sacramento Valley.______38 Sacramento River basin above Feather River.______-_--- 38 Feather River basin______--_-----_---_ 41 Sacramento River basin below Feather River______-----_--_ 44 North-coastal California-.______-______-_-_----_----- 46 Napa River basin______-_---_---_--_-- 48 Sonoma and Petaluma Creeks____-______--_------48 Small basins in Marin County______-______------49 Russian River basin.______-_---_------50 Small coastal basins between Russian and Eel Rivers.______50 VI CONTENTS

General descriptions of floods Continued North-coastal California Continued Page Eel River basin.______A 52 Mad River basin______54 Redwood Creek basin.______54 Klamath River basin______54 Smith River basin.______55 West-central Idaho.______56 Boise River basin______59 Payette River basin______-______59 Weiser River basin______60 Little Salmon River basin______-______-______61 Snake River and tributaries below Weiser River______61 Willamette Valley.______62 Middle Fork Willamette River basin______63 Coast Fork Willamette River basin.______65 Eastside tributaries to main stem Willamette River from Eugene to mouth.______65 Westside tributaries of main stem Willamette River from Eugene to mouth______66 Main stem Willamette River from Eugene to mouth______66 Coastal Oregon______67 North-coastal streams______-_____-______-_-_____---_-____ 69 Umpqua River basin______71 Coos and Coquille River basins.______72 Rogue River basin______73 Areas of minor flooding in Oregon, Washington, and Idaho-______74 Flood damage______77 The Great Basin___.______-___-______--__ 77 Central-coastal California______-_____-_----_--._ 77 San Joaquin Valley.______79 Sacramento Valley______80 North-coastal California__-.______81 West-central Idaho._-______-______-___-_-_---_--_____ 82 Willamette Valley,______83 Coastal Oregon..______84 Areas of minor flooding in Oregon, Washington, and Idaho.______84 Flood-crest stages.______84 Storage regulation.______i______89 The Great Basin______.______89 Central-coastal California____-______-__-__---__------90 San Joaquin Valley.______91 Sacramento Valley______93 North-coastal California_-____-_-__-__-___----_-__---_------94 West-central Idaho.______94 Willamette Valley.______.______---_ 95 Coastal Oregon.______96 Records of previous floods and flood frequencies._____-____--__-__----- 97 The Great Basin____.______98 Central-coastal California___'_____-______-_---_--_---_- 98 San Joaquin Valley.______100 Sacramento Valley.______102 CONTENTS VII

Records of previous floods and flood frequencies Continued Page North-coastal California______-__-______-______-______A 105 West-central Idaho.______107 Willamette Valley..______.___.__ 109 Coastal Oregon______Ill Areas of minor flooding in Oregon, Washington, and Idaho..______114 Determination of flood discharge______-__-__--_____-______115 Summary of flood stages and discharges._-____--_-_____-__-_--____-__ 116 Station data______151 Index.______153

ILLUSTRATIONS

PLATE 1. Isohyetal map of total precipitation, Dec. 15-27, 1955-___ In pocket FIGUBE 1. Map showing aeas of severe flooding during December 1955- January 1956. ______A3 2. Map of The Great Basin region showing location of flood-data sites __-_-____-______-_____-_-___--___---- 14 3. Discharge hydrographs at selected gaging stations in the Great Basin region______-______--___--_---_--_ 16 4. Flood-damaged concrete bridge on Nevada State Highway 56 south of Gardnerville, Nevada.______17 5. Map of the Central Coastal California region showing location of flood-data sites_-_-____-_____-__--_------s 21 6. Discharge hydrographs at selected gaging stations in the Central Coastal California region______23 7. Map of the San Joaquin Valley region showing location of flood-data sites______29 8. Discharge hydrographs at selected gaging stations in the San Joaquin Valley region______30 9. Kaweah River flood at the Friant-Kern Canal crossing, California. ___-______-_-______-___----_------32 10. Map of the Sacramento Valley region showing location of flood-data sites______--_ 39 11. Discharge hydrographs at selected gaging stations in the Sacramento Valley region______-_-_____----- 40 12. Yuba City, California, under water as a result of Feather River levee failure._____--___-______-__-_------_ 42 13. Floodwaters of the Feather River at Nicolaus, California, on December 24______44 14. Map of the North Coastal California region showing location of flood-data sites..______-_-__----- 47 15. Discharge hydrographs at selected gaging stations in the North Coastal California region.______-----_ 51 16. Eel River flood damage near Fernbridge, California-..------53 17. Flooded conditions in the town of Klamath, California_-_-_- 55 18. Map of the West Central Idaho region showing location of flood-data sites.______57 VIII CONTENTS

Page FIGURE 19. Discharge hydographs at selected gaging stations in the West Central Idaho region______A 58 20. Map of the Willamette Valley region showing location of flood-data sites______-___-______-______62 21. Discharge hydrographs at selected gaging stations in the Willamette Valley region.______64 22. Map of the Coastal Oregon region showing location of flood- data sites-______68 23. Discharge hydrographs at selected gaging stations in the Coastal Oregon region.______70 24. Floodwaters over county road bridge across South Fork Ump- qua River, Oregon______72 25. Map of minor flooded areas in Oregon, Washington, and Idaho, showing location of flood-data sites ______75 26. Discharge hydrograph for Wind River near Carson, Wash___ 76 27. Flood-frequency curves for selected gaging stations in Central Coastal California and San Joaquin Valley, Calif------99 28. Flood-frequency curves for selected gaging stations in Sacra mento Valley, Calif, and North Coastal California. __--___ 104 29. Flood-frequency curves for selected gaging stations in Idaho, Oregon, and Washington.______108

TABLES

Page TABLE 1. Precipitation at selected stations during December 1955 and January 1956------_--- A 6 2. Flooded areas and flood damage in the Great Basin, Cali fornia, December 1955 and January 1956. ______78 3. Flood damage in central-coastal California, December 1955 and January 1956______79 4. Flooded areas and flood damage in San Joaquin Valley, California, December 1955 and January 1956______80 5. Flooded areas and flood damage in Sacramento Valley, Calif., December 1955 and January 1956.______81 6. Flood damage, in north-coastal California, December 1955 and January 1956______-_-_-___--___--___-_ 82 7. Flood damage, in Willamette Valley, Oregon, December 1955 and January 1956______83 8. Flood damage, in coastal Oregon, December 1955 and January 1956______-______---_---__------84 9. Flood-crest stages, December 1955-January 1956, San Joaquin Valley, Calif.______--_-___------_- 85 10. Flood-crest stages, December 1955-January 1956, Sacra mento Valley, Calif___-__-_--____-_------_------87 11. Eel River flood-crest stages, flood of Dec. 22, 1955, north- coastal California------89 12. Functioning of reservoirs in reduction of December 1955 flood discharge, San Joaquin Valley, Calif.______92 CONTENTS IX

Page TABLE 13. Functioning of reservoirs in reduction of December 1955 flood discharge, Sacramento Valley, Calif ______A 93 14. Reduction of December 1955 flood discharge by storage regulation, Willamette Valley, Oreg______96 15-34. Annual peak stages and discharges 15. Arroyo Seco near Soledad, Calif______100 16. Kern River near Kernville, Calif--__-__-______101 17. Kaweah River near Three Rivers, Calif______102 18. Merced River at Pohono Bridge near Yosemite, Calif. __ --_-_---_-__-_-_----__---_--_-___ 102 19. Feather River at Bidwell Bar, Calif. ______103 20. Middle Fork American River near Auburn, Calif __ 105 21. Eel River at Scotia, Calif-_--_------_---_--_ 106 22. Trinity River at Lewiston, Calif.______106 23. Klamath River near Klamath, Calif.______107 24. Boise River near Twin Springs, Idaho.______109 25. Little Weiser River near Indian Valley, Idaho.-__ 109 26. McKenzie River near Vida, Oreg__-_.______110 27. Willamette River at Albany, Oreg______110 28. Clackamas River near Cazadero, Oreg______111 29. South Fork Coquille River at Powers, Oreg-__ __ 112 30. Umpqua River near Elkton, Oreg______113 31. Rogue River at Raygold, near Central Point, Oreg_ 113 32. Asotin Creek near Asotin, Wash______114 33. John Day River at McDonald Ferry, Oreg. ______114 34. Wind River near Carson, Wash______115 35. Summary of flood stages and discharges__-_-__--__-_-- 118

FLOODS OF DECEMBER 1955-JANUARY 1956 IN THE FAR WESTERN STATES

PART 1. DESCRIPTION

By WALTEE HOFMANN and S. E. RANTZ

ABSTRACT The floods of December 1955-January 1956 in the Far Western States were in many respects the greatest in the area in the history of recorded streamflow. One outstanding feature of the floods was the unusually large area involved the western one-third of Nevada, the northern two-thirds of California, the western half of Oregon, one-third of western Idaho, and minor parts of Washington. Other outstanding features were the record-breaking peak discharges in much of the flooded area and the extensive flood damage. The loss of 72 lives was attrib utable to the flood and total damage amounted to about $190 million. The floods were caused by a series of storms from December 15 to January 27; three occurring between December 15 and 27 and three more from January 2 to 27. In all but a few areas the storm of December 21-24 was the most severe. The storms all reflected the effect of the combination of a moist, unstable airmass, strong west-southwest winds, and mountain ranges oriented nearly at right angles to the flow of air. The unusual feature of the storms was the persistence of the strong flow of moist air. The major storm of December 21-24 was accompanied by high temperature and high wind velocities. As a result, a considerable amount of the snow which had accumulated at higher altitudes was melted. This snowmelt, added to the heavy precipitation at lower altitudes, caused record-breaking runoff in the streams draining the Sierra Nevada, in Idaho, and in Washington. The coastal areas of northern California and southern Oregon had measurable rainfall on 39 of the 44-day period between December 15 and January 28. At several stations the recorded precipitation for the months of December and January exceeded 60 inches. Flood runoff in the streams not affected by regulation exceeded any previously recorded throughout much of the area. Some rivers that had particularly no table floods are: the Carson River, in the Great Basin, where the peak was nearly twice that of the record flood of 1950; the San Lorenzo River, in central-coastal California, which flooded the city of Santa Cruz; the Kaweah River, in the San Joaquin Valley, where the flood peak of December 23 was almost double the record peak of 1950, and which flooded the city of Visalia and the towns of Farm- ersville and Three Rivers; the Feather River, in the Sacramento Valley, where a levee failure flooded Yuba City and caused the loss of 38 lives; the Klamath River, in north-coastal California, where the peak discharge of 425,000 cfs at the gaging station near Klamath, Calif., was one and one-half times greater than the peak of record and was exceeded only by the legendary floods of 1861-62; the upper Boise River where the December 23 peak equaled the maximum during Al A2 FLOODS IN FAR WESTERN STATES

45 years of record; the Willamette River and many of its unregulated tributaries where the peak discharges were about equal to any previously recorded; and the Rogue River in coastal Oregon, where the peak flow of 414,000 cfs below the Illinois River near Agness was as high or higher than any flood in the last 65 years. This report presents a general description of the December 1955-January 1956 floods, details and estimates of the damage incurred, and a summary of peak stages and discharges and comparative data for previous floods at the 788 sites. Also included are a discussion of the storm precipitation during the 2-tnonth period, tables of flood-crest stages along the main stem and major tributary channels of the San Joaquin, Sacramento, and Eel Rivers in California, a dis cussion of flood regulation by storage reservoirs, and a summary of, and com parison with, previous floods. Flood-frequency tabulations and curves are presented for selected gaging stations. INTRODUCTION During the last 2 weeks in December 1955 and during January 1956 the Far Western States were subjected to the greatest floods in the history of recorded streamflow in the area. Intense flood-producing rains fell in about two-thirds of California, one-half of Oregon, one- third of Nevada and Idaho, and minor parts of Washington. The areas of severe flooding are outlined in figure 1. As a result of the flood, 72 lives were lost, and the direct property damage was about $190 million. In addition, there was an incalcu lable amount of indirect damage due to reduced crop production; losses in business volume, salaries and wages; traffic delays and re routing; reduced tourist trade; and losses in other intangible items affecting the general welfare. The largest concentration of damage was at Yuba City, Calif., where 38 persons were drowned and property damage exceeded $40 million. The principal storm period extended from December 15 to January 27, with intermittent intense storms throughout most of the area. The storm of December 21-24 was the most intense and caused the highest flood peaks. However, the streams were at or near flood stage during most of December and January. Additional storms occurred after January in some parts of the area, but the resulting floods were not as large as the ones in December and January. Because of the severity and the large area flooded all agencies in volved in the collection of hydrologic data increased their efforts toward the collection of data for this report. However, it was obvious that additional help would be needed. By the first week of January experienced technical help had been detailed to the flooded area from all parts of the United States to assist in the collection and preparation of these data. The coverage of the data in this report is much more extensive than it would have been without the all-out effort. Included in this report are: a discussion of the precipitation during the period; a description of the floods; information on flood damage; PART 1. DESCRIPTION A3

FIGURE 1. Map showing areas of severe flooding during December 1955-January 1956; the hydrologic regions used in this report; and the range in numbers of the flood-data sites in each region. a table summarizing flood stages and discharge; information on flood- crest stages; a discussion of the effect of storage regulation; and a summary of previous floods at selected sites. Station descriptions and A4 FLOODS IN FAR WESTERN STATES data on stages and discharges at stream-gaging stations and miscel laneous sites are given in Water-Supply Paper 1650-B. To facilitate presentation of the data, the area of severe flooding has been subdivided into eight subareas or hydrologic regions, as out lined by the heavy dashed line shown in figure 1. These regions are : The Great Basin, central-coastal California, San Joaquin Valley, Sacramento Valley, north-coastal California, west-central Idaho, Willamette Valley, and coastal Oregon. In addition, data are in cluded for minor areas under the heading "Areas of minor flooding in Oregon, Washington, and Idaho." The items included in this report are discussed individually for each of the hydrologic regions. This arrangement will enable the user interested in one region only to readily obtain the information on that region. The site numbers at which data on stages and discharge were collected in each region are shown in figure 1. The sites are numbered in downstream order and follow the sequence of parts used in the Geological Survey "Surface Water-Supply of the United States" published annually, starting with Part 10 and continuing through Part 14. Gaging stations, reservoir stations, and miscellaneous sites are included. The same identifica tion numbers are used throughout this report. The exact location of each site is shown in detail on the map included with the description of floods for each region. In the past there have been other notable floods covering parts of the area described in this report for which special reports have been prepared. The Geological Survey water-supply papers in which the information on earlier floods is published are: for western Nevada, Water-Supply Papers 843 and 1137-H; for central and northern California, Water-Supply Papers 843, 1137-E, 1137-F, 1260-D, and 1320-D; for Oregon, Water-Supply Paper 968-A, 1080, 1137-E, and 1320-D; for Idaho and Washington, Water-Supply Paper 1080. The historical data found in these earlier reports are not included in this report. A preliminary report entitled "Floods of December 1955-January 1956 in Far Western States" was published in 1956 as Geological Survey Circular 380. It consists primarily of a tabulation of peak discharges in the same area included in this report. ACKNOWLEDGMENTS Collection of field data necessary for the computation of peak dis charges by indirect methods was materially implemented by technical personnel of the Surface Water Branch detailed to the flood area. In addition, personnel for surveying parties were made available by the California Department of Water Resources, the Corps of Engineers, Department of the Army, and the U.S. Bureau of Reclamation. PART 1. DESCRIPTION A 5

Sources of the data are specifically acknowledged where they appear in the text. Although too numerous to mention individually, acknowledgment is made to the many individuals, corporations, and governmental agencies who furnished assistance and data for this report. PRECIPITATION The flood-producing rains of December 1955 and January 1956 in California, western Nevada, Oregon, and Idaho, and scattered basins in southern Washington were without precedent when considered in the light of total area affected and volume and duration of precipita tion. The principal storm period from December 15 to January 27 was ushered in by two minor storms in early December, which pro duced conditions favorable for subsequent high runoff. Between December 15 and 27 there were three distinct storm peri ods, and three more occurred from January 2 to 27. In all but a few areas the storm of December 21-24 was the most intense. The storms were associated with frontal passages and were generally centered over northern California. The storms reflected the combined effect of moist unstable airmasses, strong west-southwest winds, and coastal mountain ranges oriented nearly at right angles to the flow of air. The combination of these three factors is repeatedly found in Pacific Coast winter storms, but the persistence of the strong flow of moist air made the storms of December 1955-January 1956 unusual. In the 44-day period between December 15 and January 28, the coastal areas of northern California and southern Oregon had measurable rainfall on 39 days. At several stations the precipitation recorded for the months of December and January totaled more then 60 inches. The meteorology of the December storms has been described in detail in the Monthly Weather Review for December 1955, a U.S. Weather Bureau publication. The isohyetal map (pi. 1), furnished by the Weather Bureau and the Corps of Engineers, shows the generalized precipitation distribu tion for December 15-27 throughout the area of severe flooding. Table 1 lists storm totals at representative precipitation stations in the major hydrologic regions in this area. For the areas of minor flooding in Oregon, Washington, and Idaho, not shown on the isohyetal map, the tabulation has been expanded to include one precipitation station in each of the basins for which discharge figures are given in this report. The pages that follow present a brief discussion of precipitation in each hydrologic region. THE GREAT BASIN Two minor storms during the first 9 days of December brought greater than average precipitation to the region. The below-normal A6 FLOODS IN FAR WESTERN STATES

temperatures that prevailed during this period caused snow to fall at the higher altitudes. By December 15 ground-water and soil-moisture levels were moderately high; the snowline ranged from about 5,000 feet in altitude in the north to about 6,000 feet in the south, and about 45 inches of snow had accumulated at 9,000 feet altitude. The first major storm, December 15-20, brought about 2 to 3 inches of precipitation to the region, mainly as snow. There was no appreciable change in the altitude of the snowline, but snow depths at 9,000 feet increased to about 75 inches. The second major storm, and by far the more in tense, occurred during December 21-24. Heavy orographic rain, influenced by high wind velocities, was carried eastward into the Great Basin far beyond the

TABLE 1. Precipitation, in inches, at selected stations during December 1955 and January 1956

Storm precipitation Total monthly Anteced precipitation Precipitation station ent pre and subbasin cipitation Dec. 1-14 Dec. Dec. Dec. Jan. Jan. Jan. Decem Janu 15-20 21-24 25-27 2-8 13-16 25-27 ber ary

The Great Basin, Calif.: 2.07 4.01 10.36 1.50 1.21 1.68 2.17 18.17 6.15 Susanville (Honey Lake) - . ... _ 1.10 4.13 4.23 2.18 2.10 .58 1.57 12.39 4.98 Lake City (Surprise Valley) ... _ 2.43 2.19 4.94 .59 1.51 2.75 1.09 10.33 7.81 Central-Coastal California: San Luis Obispo Poly (Salinas River) - .-. _ ... __ .. 1.91 .55 5.39 2.71 .11 .08 5.74 10.88 6.51 Big Sur State Park (Sur River). 3.47 3.77 13.57 1.99 2.52 1.05 4.70 27.21 11.18 Boulder Creek Locatelli Ranch (San Lorenzo River) . __ ...... 8.45 7.11 19.66 3.34 3.77 5.01 3.24 39.28 17.39 San Joaquin Valley, Calif.: Giant Forest (Kaweah River)... ._ 6.21 .38 17.21 3.11 0 .77 9.61 28.31 11.97 Huntington Lake (Upper San 6.03 1.30 16.20 3.35 .28 1.57 4.68 28.05 10.01 Yosemite National Park (Merced River)...... 6.23 3.13 16.70 3.17 1.19 2.31 3.49 29.78 10.37 Tiger Creek powerhouse (Mokel- umne River)...... 6.23 4.72 14.31 2.68 3.54 4.27 3.74 29.13 15.37 Sacramento Valley, Calif.: Vollmers (upper Sacramento River)..-.- ---.-.-. _.. 3.88 11.20 8.06 3.62 8.49 5.60 2.14 26.79 21.86 Stonyford Ranger Station (Stony Creek)-. . .. 1.76 4.48 2.98 .99 1.35 1.72 1.80 10.72 6.70 Brush Creek Ranger Station (Feather River) ..--...... - 9.22 11.47 14.18 3.66 5.98 8.58 3.47 39.81 23.17 Blue Canyon (American River and Bear River)...... __ ___-._ 8.48 12.65 19.20 3.78 4.50 7.42 4.29 45.12 22.46 North Coastal California: Kentfleld (Corte Madera Creek).. 6.73 7.93 15.25 1.95 2.57 5.40 4.27 32.87 15.75 5.33 16.32 18.98 3.76 11.72 8.66 2.60 45.23 30.11 Upper Mattole (Mattole River)... 5.27 14.31 10.68 6.64 8.72 7.96 1.74 37.01 26.62 Gasquet Ranger Station (Smith River)...... 8.99 7.71 12.03 5.83 7.79 8.90 .53 34.64 28.96 West-Central Idaho: Anderson Dam (Boise River)... 2.31 1.35 3.14 T .91 1.94 .38 6.80 5.65 Deadwood Dam (Payette River) ._ 2.26 3.45 5.53 .54 .56 2.17 .76 11.82 4.89 Council (Weiser River) _ . _. . 2.53 2.37 2.04 .22 .20 2.21 .18 7.51 4.08 Willamette Valley, Oreg.: Cottage Grove Dam (Coast Fork). 5.93 4.28 4.39 3.66 4.14 2.69 .08 18.38 11.12 McKenzie Bridge (McKenzie River) .....- _. 9.74 2.51 7.02 1.77 3.38 5.04 .23 21.13 16.09 Willamina2S (Yamhill River).... 5.40 3.83 4.73 2.37 7.91 2.96 .78 16.46 15.81 Three Lynx (Clackamas River). __ 7.53 2.64 6.09 2.01 4.72 4.85 .50 18.32 16.29 Coastal Oregon: Tillamook 12E (Trask River).. ... 8.39 5.15 6.99 2.18 9.80 6.81 1.00 23.09 24.36 Alsea Fish Hatchery (Alsea River)....-. .... - 9.16 5.02 5.93 3.57 10.81 7.04 .73 23.68 25.96 Sitkum 28 W (Coquille River) .... 8.45 6.61 6.30 9.51 6.37 5.66 .75 30.92 21.24 Prospect 2SW (Rogue River).. . 4.91 2.43 6.27 .74 2.52 3.07 .34 14.45 10.30 PART 1. DESCRIPTION A7

TABLE 1. Precipitation, in inches, at selected stations during December 1955 and January 1956 Continued

Areas of minor flooding in Oregon, Washington, and Idaho: Spokane W. B. Airport, Wash. (Spokane Eiver). ______1.67 1.08 .77 .30 .87 .89 .32 3.82 2.87 Rimrock Tieton Dam, Wash. (Yakima River).... 3.55 1.06 2.58 .35 1.78 2.61 .35 7.54 7.75 Kahlotus 4SW, Wash. (Esquatzel Coulee)-----... . . 1.06 .24 .57 0 .45 1.17 .19 1.87 2.20 Anatone, Wash. (Asottn Creek) .93 .36 1.61 .31 .37 .92 .20 3.21 2.06 Clarkston Heights, Wash. (Dry Creek)-----..--. . .58 .30 .46 .17 .31 .86 .12 1.51 1.74 Moscow, Idaho (Palouse River) 1.84 .60 1.05 .05 .44 1.90 .27 3.59 3.51 Dayton 9SE, Wash. (Walla Walla River)_____...... 2.78 1.40 1.85 .34 1.04 2.35 .17 6.37 4.68 Meacham W. B. Airport, Oreg. (Umatilla River)...... ___.._. 2.94 .46 1.20 .16 .49 2.27 .16 4.89 5.59 Condon,Oreg. (John Day River).. 1.41 .47 1.24 T .10 1.59 .20 3.18 3.15 Friend iw, Oreg. (Deschutes River) ______-..___-___ . 1.66 1.15 1.77 .29 1.22 2.82 .38 4.87 6.36 Hood River Experiment Station, 4.10 .93 2.25 .45 2.33 3.38 .73 7.73 9.43 Goldendale, Wash. (Klickitat River)..-...... 2.29 .87 1.63 .17 1.21 1.68 .21 4.96 4.55 Wind River, Wash. (Wind River). 10.64 4.53 6.55 2.37 8.31 6.59 1.44 24.09 25.67 Headworks Portland Water, 7.31 4.25 2.60 2.36 6.12 4.14 .70 16.70 17.27 slopes of the western divide. During this period the freezing level rose to 10,000 feet at times, so that most of the precipitation was in the form of rain. Virtually all the precipitation fell in about 72 hours. Considerable snow was melted, the snowline retreated 500 to 1,000 feet in altitude, and snow depths decreased about 15 inches at all altitudes. On December 24 temperatures dropped rapidly, snow fell at altitudes as low as 4,000 feet, and snow depths were largely restored to those of December 20. Precipitation at the headwaters of the principal river basins during December 21-24 averaged from 10 to 13 inches. The storms of December 25-27, and January 2-8, 13-16, and 25-27 were not particularly noteworthy, but the ground was saturated from previous rains and rivers were still running high; these storms were of sufficient magnitude to maintain streams at near bankfull stage for most of January. Precipitation in January in general was about two times normal for the month, whereas precipitation in December was was about four times normal. CENTRAL-COASTAL CALIFORNIA Following normal precipitation in November over most of the re gion, two minor storms occurred December 1-9. Ground-water and soil-moisture levels, already high, were raised further by the storm of December 15-20. This was a major storm north of San Francisco 668521 O 62 2 A8 FLOODS IN FAR WESTERN STATES

Bay, but it was relatively light in the central coastal region. It did, however, set the stage for the deluge that followed. During December 21-24, intense precipitation fell throughout most of the region; only the extreme southern part received moderate amounts. All precipitation was in the form of rain, and the orographic influence of the Coast Range was accentuated by high wind velocities. The maximum amount for the area occurred in the San Lorenzo River basin. At Boulder Creek a 72-hour precipitation total of 19.53 inches was observed and maximum recorded 24-hour precipitation was 12.53 inches. Hourly precipitation in excess of 1 inch is uncommon in coastal California, but at Boulder Creek the highest hourly intensity recorded was 1.52 inches. The rains that followed in the storms of December 25-27, and Jan uary 2-8, 13-16, and 25-27 were much more moderate and, despite saturated conditions, caused only minor rises in the streams of the re gion, except in the upper Salinas River basin in the southern part of the region. Very little precipitation fell in the first two January storms, but the storm of January 25-27 was more intense than that of December 21-24. The southern part of the region also received moderate amounts of precipitation between December 30 and January 1. For the region as a whole, precipitation for December was about three to four times normal and that for January was generally about 50 percent greater than normal.

SAN JOAQUIN VALLEY The two minor storms during December 1-9 brought about 6 inches of rain to most of the Sierra Nevada. These storms raised ground water and soil moisture to moderately high levels in the mountain basins, melted back the abnormally low snowline, and compacted the snow at high altitudes. After a rainless period of 5 days the storm of December 15-20 occurred. This moderate storm was accompanied by low temperatures, and brought fairly heavy snowfall to the high altitudes and sufficient rain to low altitudes to maintain conditions favorable for subsequent high runoff. By December 20 about 50 inches of snow had accumulated in the Sierra Nevada above 8,000 feet. The advent of the storm of December 21-24 was marked by rising temperatures and high wind velocities. The freezing level reached altitudes above 10,000 feet at times, and most of the orographically influenced precipitation fell as rain. Virtually all the precipitation fell in 72 hours, and the total precipitation over the river basins of the western slope of the Sierra Nevada averaged more than 15 inches over the basins in northern two-thirds of the San Joaquin Valley and ranged from 5 inches to 15 inches over the basins in southern third of the PART 1. DESCRIPTION A9 valley. Giant Forest in the Kaweah River basin recorded a 24-hour precipitation of 11.04 inches. During December 21-24, the snowline retreated about 1,000 feet in altitude, and snow depths diminished uniformly by about 18 inches over a wide range of altitudes. It is believed that snowmelt added about 1 inch of water to the basin-mean rainfall. The deep snow at high altitudes had a general moderating effect on the flood runoff; and areas above 7,500 feet probably con tributed little to flood runoff. The ensuing storm of December 25-27 was moderate but maintained high stages in the streams. The storm of January 2-8 was insignificant in the San Joaquin Valley, and the storms of January 13-16 and 25-27 were also of minor importance, except in the southern part of the valley where the storm of January 25-27 was of sufficient magnitude to bring renewed flooding. Over the San Joaquin Valley as a whole December precipitation averaged four to five times normal, and January precipitation was about two times normal. SACRAMENTO VALLEY In the Sacramento Valley the antecedent storms of December 1-9 brought about 8 inches of rain to most of the Sierra Nevada and 2 to 3 inches to the northern Coast Range. As in the San Joaquin Valley, these storms raised ground water and soil moisture to mod erately high levels in the mountain basins, melted back the abnormally low snowline, and compacted the snow at high altitudes. The storm of December 15-20 was intense and was marked by low temperatures. This storm brought heavy snowfall to the high altitudes and suffi cient rain at low altitudes to cause minor flooding in the foothill streams. By December 20 about 50 inches of snow had accumulated in the Sierra Nevada at 7,500 feet. The major storm of December 21-24 was accompanied by high temperatures and high wind velocities. The freezing level at times rose to more than 10,000 feet and most of the precipitation fell as rain. All of this heavy orographic rain, which was influenced by high wind velocities, fell in about 72 hours. During this storm, the total basin-wide precipitation over the river basins of the Sierra Nevada ranged from about 8 inches in the north to about 16 inches in the south. For this same period the average basin-wide precipi tation over Coast Range basins ranged from about 4 inches in the north to about 9 inches in the south. Blue Canyon near the Ameri can River-Bear River divide had a maximum 24-hour precipitation of 9.31 inches and a maximum recorded hourly intensity of 0.95 inch. As in the San Joaquin Valley, the snowline retreated about 1,000 feet in altitude during December 21-24, and snow depths diminished uniformly by about 18 inches over a wide range of altitudes. It is A10 FLOODS IN FAR WESTERN STATES

believed that snowmelt added about 1 inch of water to the basin- mean rainfall. The deep snow at high altitudes had a general mod erating effect on the flood runoff from areas above 7,500 feet. The four ensuing storms of December 25-27, and January 2-8, 13-16, and 25-27 were all moderate, but the ground was saturated from previous rains and rivers were still running high; these storms main tained streams at near bankfull stage for most of January. Precipitation in January in general was about two times normal for the month, whereas precipitation in December ranged from 2% to 5 times normal. NORTH-COASTAL CALIFORNIA Following a November of normal precipitation over most of the region, two minor storms occurred during December 1-9 which raised ground water and soil moisture to high levels. The next storm, accompanied by high winds, occurred during December 15-20. This storm, which was intense throughout the region, centered over the Eel and Russian River basins and produced relatively minor flooding. This storm was closely followed by the more intense one of De cember 21-24. The freezing level was exceptionally high and vir tually all precipitation occurred as rain. The orographic influence of the Coast Range was accentuated by high wind velocities; practically all the rain fell in 72 hours, and widespread major flooding occurred throughout the region. Such widely separated precipita tion stations as Gasquet Ranger Station near the California-Oregon border and Kentfield in the San Francisco Bay area each received about 7.5 inches of precipitation in 24 hours. Cazadero in the Russian River basin reported 10.75 inches of precipitation in 24 hours. Even larger daily amounts were unofficially reported else where. The storm of December 25-27 was moderate in the north where it tended to sustain flows above critical stages, but it was of minor importance in the southern part of the region. This same precipi tation distribution was also found in the storm of January 2-8. The storm of January 13-16 was moderate throughout the region 'and maintained streamflow at high levels; that of January 25-27 was generally of minor importance except in the southern part where rainfall was moderately heavy. For the region as a whole, precipitation for the month of December was 2% to 3% times normal. Precipitation in January was generally about two times normal. WEST-CENTRAL IDAHO Minor storms and low temperatures during the first 12 days of the month brought snow to the high altitudes and sufficient rain at low PART 1. DESCRIPTION All altitudes to raise soil-moisture conditions to moderately high levels. The storm, which hit the Pacific Coast on December 15, arrived in west central Idaho on December 16. Again, the precipitation pattern was snow at high altitudes and rain at the lower levels. By December 20, precipitation had fallen in moderately heavy amounts and conditions were very favorable for subsequent high runoff. The major storm of December 21-24 was accompanied by high temperatures and high winds. On December 22 and 23, temperatures were as much as 20° to 25° above normal. During this abnormally warm period, rain was recorded up to unseasonally high levels, and snow was melted at intermediate altitudes by the rain and warm winds. At several stations the exceptionally heavy precipitation amounted to more than 2 inches in 24 hours and more than 4 inches in 48 hours, and was combined with runoff from melting snow to produce record discharges in some areas and serious flooding in nu merous localities. A general drop in temperature started the night of December 24, and precipitation from the storm of December 25-27 was light and principally in the form of snow. Of the three January storms, those of January 2-8 and 25-27 were moderate, but the storm of January 13-16 was fairly intense and raised the streams to high levels. Be cause temperatures were mild throughout most of January, much of the precipitation was in the form of rain and there was appreciable runoff from melting snow. Nevertheless, considerable snow fell at the higher altitudes and, caused a substantial increase in the snow pack. Precipitation for January did not greatly exceed normal, but December precipitation was about two times normal. WILLAMETTE VALLEY A series of minor storms during the first 12 days of December brought snow to the high altitudes and rain to the low altitudes in the Willamette Valley. In the Cascade Mountains precipitation ranged from 10 inches in the south to 6 inches in the north, and in the Coast Range about 5 inches of precipitation fell. Ground water and soil moisture were raised to levels favorable for subsequent high runoff. The storm of December 15-20 was accompanied by low temperatures and high winds. The moderately heavy precipitation fell mostly in the form of freezing rain or snow for the first 4 days, but rain pre dominated on December 19 and 20 as temperatures rose. The major storm of December 21-24 was accompanied by high temperatures and high winds. Temperatures were generally 10° or more above normal; an unseasonably high freezing level resulted and most of the precipitation fell as rain. The orographic effect of the Coast and Cascade Mountain ranges was accentuated by the high A12 FLOODS IN FAR WESTERN STATES

wind velocities. About 8 inches of precipitation fell on the west slopes of the Cascade Mountains and about 6 inches fell on the east slopes of the Coast Range. The runoff from melting snow at intermediate altitudes augmented the precipitation available for direct runoff. During December 21-24, several stations received more than 4 inches of rainfall in 24 hours. The storm of December 25-27, brought more intense rains to the east slopes of the Coast Range. Streams, already swollen from the previous storm, reached dangerous stages once more. The storms of January 2-8 and 13-16 also were effective in maintaining high stages throughout the region. The earlier January storm was more intense on the west side of the valley than it was over the Cascade Mountain drainage basins. Serious flooding was averted, however, by a drop in temperature after January 6. The storm of January 13-16 was more intense than that of January 2-8 over the Cascade Mountain drainage basins, and the resulting rapid runoff from rains and melting snow caused some renewed flooding. The storm of January 25-27 was very light and was almost entirely in the form of snow; its effect on runoff was not significant. Precipitation for the month of December was about 250 percent of normal; that for the month of January was about two times normal. COASTAL OREGON The minor storms of December 1-12 ushered in the flood-producing series of storms of December 15 to January 27, and raised ground water and soil moisture to high levels. Precipitation for the 12 days totaled about 9 inches at several stations, and only in the upper Rogue River and upper Umpqua River basins was precipitation relatively light. The next storm, accompanied by high winds and low temperature, occurred on December 15-20. About 6 inches of pre cipitation fell in the upper'Rogue River basin but precipitation was light over most of the remainder of the region. By December 20 streams were running high and saturated soil conditions prevailed. Closely following this storm was the more intense one of December 21-24. The freezing level was exceptionally high, and virtually all the precipitation occurred in the form of rain. All of this heavy orographic rain, which was influenced by high wind velocities, fell in about 72 hours. About 6 or 7 inches of precipitation was brought to most of the region; several stations recorded more than 4 inches in 24 hours. Widespread flooding resulted. The storm of December 25-27 was generally more moderate except in the southwestern part of the region where heavy rain fell. Gold Beach Ranger Station near the mouth of Rogue River received 12.64 inches of rain in 48 hours; 7.34 inches fell in 24 hours. In the upper PART 1. DESCRIPTION A13

Rogue River basin precipitation was fairly light. Several streams in the Umpqua basin reached their highest peak during this storm. The storms of January 2-8 and 13-16 were of high intensity throughout the region, except in the upper Rogue River basin, and major stream rises resulted. The storm of January 25-27 was very minor and had little effect on runoff. Precipitation for the month of December was about three times normal; that for the month of January was about two times normal. AREAS OF MINOR FLOODING IN OREGON, WASHINGTON, AND IDAHO During December and January in north-central Oregon, south- central Washington, and the tristate region of Oregon, Washington, and Idaho the storm pattern was very similar to that in the areas of more severe flooding. The rains of early and mid-December were climaxed by the more intense storm of December 21-24. Snow melted by the rains of December 21-24 and by Chinook winds aug mented the precipitation in some areas. At the weather station at Wind River, Washington, 8.2 inches of rain fell during December 20-22, and the depth of snow on the ground was reduced from 13 to 5 inches. At the weather station at Anatone, Wash., near the Asotin Creek drainage, 1.46 inches of rain fell during December 21-22, and the temperature was unseasonably warm. Minor storms in late December and during January caused fairly high runoff on December 27 and on January 4, 16, and 23. Chinook winds during the early part of January were a factor in the rapid melting of snow.

GENERAL DESCRIPTION OF FLOODS THE GREAT BASIN The area of the Great Basin region discussed in this report (fig. 2) includes only the western part of the Great Basin from the Walker Lake basin on the south to the Black Rock Desert basin on the north east, and to the small closed basins in northeastern California and south-central Oregon on the north. Figure 2 also shows the location of the sites at which stage and discharge data were collected for the flood period. The sites are numbered from 1 to 47, and correspond to the numbers used in the section of this report headed "Summary of flood stages and discharges," and to the numbers for station identification in Water Supply Paper 1650-B. In general, the flood of 1955 was similar to the 1950 flood, which until 1955 was the greatest in more than 50 years. One notable difference between the two floods wag that rainfall intensities and amounts were greater at lower altitudes in 1955, and unprecedented A14 FLOODS IN FAR WESTERN STATES

122° . 121° _ 120°______119° 118°

Crest stage or miscellaneous site Numbers conform to those in

FIGURE 2. Map of the Great Basin region showing location of flood-data sites flows from minor creeks and small drainages caused widespread damage in areas far removed from the larger streams. There was no loss of life attributable to the 1955-56 floods. Livestock losses were PART 1. DESCRIPTION A15

not excessive when compared to the magnitude of the floods and the . area affected. Discharge hydrographs at selected gaging stations in the Great Basin (fig. 3) show time distribution of the discharges from December 1 to January 31. The relative size of the several peaks at each station are represented graphically by the hydrographs. WALKER RIVER BASEST Floods in the Walker River basin were of lesser magnitude than other notable floods of record such as those of December 1937 and November 1950. The most intensive storm area was to the north and west of the Walker River drainage basin. Reports from a reconnaissance flight over the area showed that considerable snow remained at high altitudes in the Walker River basin on December 23, and evidence indicated that at least part of the precipitation during the most severe storm period fell as snow at the higher altitudes. There was relatively little damage to bridges and other structures along the Walker River and its major tributaries. Some agricultural areas bordering the Walker River were flooded, but damage was not wide spread or severe. The principal flood damage was in the smaller drainage areas in which roads and fields were flooded. Considerable protection was afforded the downstream areas in the Walker River basin by storage reservoirs located at the intermediate altitudes. Bridgeport Reservoir retained all of the flood waters from the East Walker River above Bridgeport, Calif. Topaz Reservoir, an off-channel storage site on the West Walker River, provided some relief when part of the flood waters were diverted to storage during the critical period. The discharge hydrograph for the gaging station on West Walker River below East Fork, near Coleville, Calif., is shown on figure 3. CARSON RIVER BASIN The Carson River drainage basin was completely blanketed by the intense storm. With virtually no upstream storage facilities, the area above Lahonton Reservoir was unprotected, and damage from the flood reached major proportions. Flood waters along Silver Creek and the upper reaches of the East Fork Carson River washed out large sections of California State Highways 4 and 89. Damage was so extensive that State Highway 4 was not opened to travel again until the summer of 1956. Floodwaters from the East and West Forks of the Carson River spread out in upper Carson Valley and damaged farm and pasturelands, fences, farm buildings and highways. Bridge approaches on Nevada State Highway 37 between Minden, Nev., and Woodfords, Calif., were washed out, and a large concrete bridge across the East Fork Carson River on Nevada State Highway 56 south of Gardnerville was completely destroyed (fig. 4). sa.iv.LS NHa.isaAi av^ MI SCOOTS 9XY PART 1. DESCRIPTION A17

FIGURE 4. Flood-damaged concrete bridge across the East Fork Carson River on Nevada State Highway 56, south of Oardnerville, Nev. Photograph by Nevada State Highway Department.

The broad overflow areas in lower Carson Valley reduced the flood peak, but even with this attenuation the peak discharge at the gaging station below Carson Valley was nearly double that of the 1950 flood. Cradlebaugh Bridge in lower Carson Valley was covered to a depth of about 4 feet but escaped major damage; all other bridges crossing the Carson River between Carson City and Weeks were destroyed. At Weeks Crossing the highway approaches to the bridge were washed out. Travel and communications in the entire area above Lahonton Reservoir were seriously disrupted, as every major road and highway was severed or inundated by the floodwaters. Lahonton Reservoir, which was at low level prior to the floods, was able to contain the floodflows, and thus provided adequate pro tection for the city of Fallen and the highly developed irrigated areas in that vicinity. Part of the stored water was released at a later date to prepare for heavy flows during the spring runoff. Discharge hydrographs for East Fork Carson River near Gardner- ville, Nev., and Carson River near Carson City, Nev., are included on figure 3. TRUCKEE RIVER BASIN The Truckee River basin and its urban communities attracted the most attention in western Nevada. The peak discharge of the Decem ber 1955 flood at Reno, Nev., slightly exceeded that of November A18 FLOODS IN FAR WESTERN STATES

1950; however, damage to establishments adjacent to the Truckee River was not as severe as that inflicted by the 1950 flood. Forewarned residents had limited opportunity to move perishable merchandise, and strategic use of sandbag barriers also helped to avert some losses. For instance, the Riverside and the Mapes Hotels on the banks of the Truckee River escaped practically unscathed behind sandbag dikes supplemented by pumping. Many other business establishments and homes adjacent to the river, however, were severely damaged by the floodwaters which spilled over into the streets for several blocks on each side of the river front. As in past floods the low bridges spanning the river in Reno were jammed with debris which reduced the effective carrying capacity of the river channel. Floodwaters from tributary streams draining the area surrounding the cities of Reno and Sparks inflicted severe damage on private and public property in areas far removed from the river front, as streams and ditches were swelled to overflowing from local rains. The Reno airport was flooded to a depth of about 4 feet by waters from surround ing drainages and from waters impounded in the broad Truckee Mead ows just downstream from Sparks. Peavine Creek in northwest Reno caused its usual destruction and there were many other places throughout the area where local flooding added to the disaster. Air, rail, and automotive travel in the area came to a halt. U.S. Highways 40, 50, and 395 were blocked by washouts and landslides; inundated subgrades in Truckee Meadows and landslides in the Sierra Nevada passes halted rail traffic; and Reno airport was out of operation for several days until the water had drained from the landing field. Probably the greatest single loss in the Reno-Sparks area was the destruction of the nearly completed Kietske Lane bridge across the Truckee River between Reno and Sparks. Workmen poured the bridge floor just prior to the flood to provide sufficient weight and stability for the structure to withstand the surging river. However, the structure collapsed and was almost a complete loss. Upstream from Reno the flood damage inflicted by the Truckee River was not as severe as that of the 1950 flood, but areas down stream from the city were damaged extensively as the flood was swelled by the inflow of small tributaries. The reefs at Vista, which form a natural barrier, limited the Truckee River flow and afforded some protection to downstream areas; but the retardation caused the inundation of the Truckee Meadows area east of Sparks. Boca Reservoir, at the mouth of the Little Truckee River, had a major role in reducing the flood peak; capacity of the reservoir was sufficient to retain the floodflows of the Little Truckee River for a relatively short but very critical period. During the 1950 flood, Boca Reservoir was full before the peak flow of the Little Truckee PART 1. DESCRIPTION A19

River occurred, and was therefore ineffective as a flood-control facility in reducing the peak discharge. Peak floodflows for the intermediate and lower reaches of the Truckee River during the two floods were about equal. If Boca Reservoir had not retained the peak flow of the Little Truckee River during the 1955 flood, the discharge through Reno and other reaches below the reservoir may have been about 8,000 or 9,000 second-feet (30 or 40 percent) higher than the 1955 peak, and much greater damage would have occurred. Also com parison of peak discharges between the Carson and Truckee Rivers for the two floods would be more consistent when adjusted for the discharge held in Boca Reservoir. The unadjusted hydrograph for the gaging station on Truckee River at Reno, Nev., is shown in figure 3. Two dams were breached by flood waters in the Truckee River basin. Hobart Dam on the headwaters of Franktown Creek failed on De cember 23, and the released water sped down the steep and narrow channel, tumbling large boulders and slabs of granite toward Washoe Lake. The swift, turbulent floodwaters eroded the granite-rock streambed nearly 20 feet in some places and severely damaged U.S. Highway 395 at the crossing between Reno and Carson City. Derby Dam, an earth-fill diversion structure on the Truckee River 25 miles downstream from Reno, was overtopped during the early morning hours of December 24, and a section of the dam was washed out. The break sent water and debris spilling over ranches on the flood plain below the dam and stopped traffic on U.S. Highway 40. The bridge at Wadsworth was endangered but was saved by hardworking highway crews. Livestock was moved to higher ground before the flood crest struck. BLACK ROCK DESERT BASIN Record-breaking flood peaks occurred on McDermitt Creek and the East Fork Quinn River in December and again in January; the maxi mum peaks occurred in January. Quinn .River near McDermitt, which includes the combined flow of McDermitt Creek and the East Fork Quinn River, did not reach flood stage due to short flood periods, overland flooding, and channel storage. Traffic between McDermitt and Cordero mine was discontinued for a short period in December and again in January when the floods washed out a section of road. Flood damage in this area was primarily limited to diversion structures and agricultural areas.

HUMBOLDT RIVER BASIN The intensity of the December storms was less in the Humboldt River basin than in the western part of Nevada. Martin Creek near Paradise Valley was the only stream that reached flood stage, and its peak discharge was far below the maximum of record. A20 FLOODS IN FAR WESTERN STATES

In January rain again fell on the area, already well saturated, and flood stage was reached in the Owyhee River basin and again on Martin Creek. Near flood stage was recorded on Susie, Pine, and Rock Creeks but major floods were averted when the rain ceased and cold air moved into the area. Damage in these areas was confined to diversion structures and agri cultural areas adjacent to the streams. MINOR BASINS IN CALIFORNIA AND OREGON Floods in the minor basins such as Honey, Eagle, Warner, Abert, and Silver Lakes, and others were of about the same magnitude as earlier notable floods such as the one in December 1937. In general, the streamflow records are too short for adequate comparison. How ever, at the gaging station on Deep Creek above Adel, Oreg., the December 1937 peak was only 10 percent higher than the 1955 peak, while at the station on Chewaucan River above Conn ditch, near Paisley, Oreg., the 1955 peak was about twice as large as the one in December 1937. Flood damage was relatively small in these basins and was confined to agricultural areas, roads, and highways. The peak discharge of the Susan River was reduced materially by upstream storage in McCoy Flat and Hog Flat Reservoirs. This storage limited the flood damage in the town of Susanville to minor amounts. CENTRAL-COASTAL CALIFORNIA The central-coastal California region consists of the Pacific slope drainage basins from the city of San Luis Obispo on the south to the San Francisco Bay tributaries on the north (fig. 5). Streamflow-data sites 48 to 102 are included in this region, and their locations are plotted on the map. The numbers correspond to those used in the sections of this report pertaining to records of stage and discharge. The floods of December 1955-January 1956 were the greatest of rec ord in 65 years in the northern half of central-coastal California. In the southern half of the' region these floods were of lesser rank, and diminished from north to south to such a degree that they were not particularly noteworthy in the extreme southern basins. The 2-month period was marked by a series of storms that occurred in close succes sion, but only the storm of December 21-24 caused serious flooding. The rainfall prior to December 21, however, saturated the watersheds and produced conditions conducive to flood runoff. Santa Cruz received the greatest damage in the San Lorenzo River basin. Other communities severely damaged were Ben Lomond and Soquel in the north Monterey Bay area and Palo Alto, Alviso, and Alvarado in the south San Francisco Bay area. Nine lives were lost as a result of the floods in central-coastal California, five of them in the city of Santa Cruz. PART 1. DESCRIPTION A21

121' 120 C 119 C

35 Crest stage or miscellaneous site umbers conform to those in table 35

FIGURE 5. Map of the central-coastal California region showing location of flood-data sites.

The pages that follow describe the floods in the various drainage basins of the region. A tabulation of flood damage is found in another section of this report.

SALINA8 RIVER BASIN AND SMAIX ADJACENT BASINS In the Sur River basin the heavy rains of December 22 and 23, totaled 11.38 inches at Big Sur State Park and caused the Sur River to slightly exceed bankfull stage from the State park to the mouth. This minor flooding caused no damage of consequence. In the Carmel River basin the storm of December 21-24 brought 7.25 inches of rain to San Clemente Dam; at least 4 inches fell in 24 A22 FLOODS IN FAR WESTERN STATES

hours. On December 23, Carmel River rose 2 to 4 feet above its banks in many places. Considerable flood-fighting activity by local volun teers, county forces, and troops from Fort Ord was required to prevent inundation of residential development just downstream from the Carmel, River bridge on State Highway 1, where the river nearly overtopped a levee. The total damage in the Carmel Valley amounted to $58,000, three-fourths of which was agricultural damage. In the Salinas River basin there was negligible flooding along the main stem, although flows exceeded their normal annual peak values. However, in the principal downstream tributary basins of the Naci- miento and San Antonio Rivers, and Arroyo Seco, peak discharges were the greatest ever recorded. Damage to facilities of Hunter-Liggett Military Reservation amounted to about $30,000, and road and bridge damage totaled about $100,000. The discharge hydrograph for the gaging station on Arroyo Seco near Soledad for December 1 to January 31 is shown in figure 6.

PAJARO RIVER BASIN In the Pajaro River basin, flooding was confined almost entirely to that part of the basin downstream from the San Benito River. Over this downstream area and over the lower reaches of the San Benito River, precipitation was very heavy. During the 72-hour storm of December 21-24, San Juan Bautista near the mouth of the San Benito River received 8.20 inches of rain, and Corralitos Enos Ranch in the Corralitos Creek basin received 10.25 inches of rain. Of the downstream Pajaro River tributaries, only Llagas Creek had low discharge; it was partly controlled by storage in the recently con structed Llagas Creek Reservoir. The other downstream tributaries and the Pajaro River main stem all experienced maximum peaks of record. Large-scale flooding occurred at the mouths of all tributary streams entering the Pajaro River upstream from the Chittenden gaging sta tion. The Pajaro River channel is sharply constricted a few miles downstream from the gaging station, but upstream from the gage the topography is flat and the channel capacity is limited to low dis charges. Consequently backwater from the Chittenden constriction cause flooding of more than 7,900 acres of agricultural land. Floodflow in Carnad'ero Creek, one of the tributaries upstream from Chittenden, caused considerable damage along its channel. Channel banks and adjacent land were scoured upstream from the town of Gilroy, and agricultural land downstream from Gilroy was inundated. Along Corralitos Creek, which enters the Pajaro River just upstream from the city of Watsonville, there was also considerable bank damage, but overflow was limited to 4 acres in the lower reaches of the stream.

A24 FLOODS IN FAR WESTERN STATES

On the main stem of the Pajaro River, the towns of Watsonville and Watsonville Junction are protected by levees. The inundation of these cities was prevented by the flood-fighting activities of about 400 volunteers, National Guard, Santa Cruz and Monterey County forces, and troops from Fort Ord. Five levee breaks on the tributary, Salsipuedes Creek, were contained as were the localized scoured and undercut sections of the main levee along the Pajaro River. The river crested at Watsonville about noon on December 24, just 10 inches from the top of the levees. However, localized flooding in 29 city blocks occurred as a result of the drainage canals back of the levees. There was considerable agricultural damage along the Pajaro River from its junction with the San Benito River to the levees upstream from Watsonville, but from Watsonville to the ocean the river was contained between the levees. There was no loss of life in the Pajaro River basin. As a precau tionary measure 1,058 persons were evacuated from their homes for 2 days 972 persons from Watsonville and 86 from Gilroy. The greatest losses were agricultural, but residential and highway and bridge damage was also appreciable. SAN LORENZO RIVER BASIN The most destructive flooding in central-coastal California occurred in the San Lorenzo River basin. During the storm of December 21-24, the precipitation station at Boulder Creek recorded a 72-hour rainfall of 19.53 inches; 12.53 inches fell in 24 hours. The resulting flood in the San Lorenzo River exceeded the previous maximum flood of 1940 by about 2.5 feet in the lower basin and approximately 3 to 3.5 feet in the upper basin. The discharge hydrograph for the gaging station on San Lorenzo River at Big Trees for December 1 to January 31 is shown in figure 6. The heavy rains and overflows from the headwaters to the mouth of the river scoured out large trees which floated downstream, became lodged at points of constriction in the channel and valley, impounded the flow, and caused extremely severe local flooding. The numerous log jams and other channel obstructions also diverted the high velocity flows and caused the streams to change from their normal alinement and undercut and scour out numerous bridges, road fills, small dams, and private developments. The river overflowed its banks in the lower part of the city of Santa Cruz at about 7:30 p.m. on December 22. By 9 p.m. floodwaters reached Front Street and by 11 p.m. had attained a depth of 2 feet in the vicinity of the intersection of River and Water Streets. By 3 a.m. on December 23, when the flood peaked, water reached a depth of 4 feet along Pacific Avenue and about 6.5 feet in the 100 block on Front Street. The duration of the flood in the business district was approximately 11.5 hours and was PART 1. DESCRIPTION A25 considerably longer in the low-lying areas. The total area flooded was 107 city blocks of business, warehouse, industrial, and residential property. Despite storm and flood warnings issued by local radio, a con siderable part of the population was unaware of the danger of the impending flood. In addition, people in the area subject to flooding were reluctant to believe the flood waters could reach such proportions. These and other factors contributed to the fact that seven persons in the San Lorenzo River basin lost their lives; five of the deaths occurred in Santa Cruz. It is estimated that 2,830 persons were displaced by floods; about 2,440 were in Santa Cruz.

SMALL, SANTA CRUZ COUNTY STREAMS Severe flooding occurred on Aptos, Soquel, and Scott Creeks as a result of the storm of December 21-24. On Aptos and Soquel Creeks, a principal contributing factor to the damage was log jams which blocked culverts and bridges. A log jam at the Soquel Creek bridge in the village of Soquel impounded the rapidly flowing stream which overtopped both banks. Eight city blocks, comprising the entire business district and the most thickly populated residential area, were inundated. This flood in the village of Soquel caused the dis placement of about 350 persons; about 30 of them were rescued from flooded homes. Farther downstream, in the village of Capitola, 35 persons evacuated their homes as a precautionary measure. The greatest damage on Scott Creek occurred near the mouth of Little Creek, a tributary. Flow in Little Creek was impounded behind landslides until about 4 a.m. on December 23 when the confined water broke through, carrying heavy timbers and boulders, and inundated the area near the mouth. Several homes and farm buildings were destroyed and one death resulted. Several rises occurred on the lower Scott River between December 22 and 25; the greatest rise overtopped the banks by 5 to 6 feet.

SMALL SAN FRANCISCO PENINSULA STREAMS Damage occurred in the small drainage basins of Pescadero, San Gregorio, Tunitas, Pilarcitos, Colma, San Bruno, and San Mateo Creeks. The first four of these streams flow into the Pacific Ocean; the last three streams flow into San Francisco Bay. On the four coastal streams, the December flood exceeded anything in the memory of local inhabitants. Unofficial reports for the storm of December 21-24 indicate that precipitation ranged from 5 to 11 inches in all four basins. Agricultural damage and damage to roads and bridges occurred in all of these basins, and, in addition, Pescadero Creek flooded 15 homes to a depth of about one-half foot in the town of Pescadero. A26 FLOODS IN FAR WESTERN STATES

The three San Francisco Bay streams, Colma, San Bruno, and San Mateo Creeks, all flow through thickly populated urban areas. Damage that resulted from the December flood affected, primarily, city streets and sewer systems. Kemoval of large quantities of silt was required. High tides in San Francisco Bay contributed to the flooding in the city of San Mateo by San Mateo Creek.

SANTA CLARA VALLEY

Santa Clara Valley streams are those entering San Francisco Bay south of and including San Francisquito and Coyote Creeks. Heavy rainfall over Santa Clara Valley during the storm of December 21-24 caused severe flooding on all streams except those controlled by large storage reservoirs. These storage reservoirs are primarily for water conservation, but they also have an important flood-control function. Unregulated streams reached peaks that are believed to be among the greatest in the past century. On many streams the plugging of cul verts and bridges by debris and by log jams caused greater inundation than would otherwise have occurred as was the case on San Francis quito Creek, which flows through the city of Palo Alto. Two log jams at bridges in Palo Alto caused the flooding of 1,170 acres of commercial and residential area; a maximum inundation of approxi mately 3.5 feet above floor levels occurred in the Green Park sub division. Additional flooding in the city resulted when Matadero Creek overflowed its banks. It is estimated that more than 1,000 persons were displaced in Palo Alto as a result of the flood. In the Stevens Creek basin the extremely heavy rains, rapid runoff, and the inadequate drainage system would undoubtedly have resulted in a much more severe flood had it not been for control by Stevens Creek Reservoir in the headwaters of the basin. Drainage was im paired, however, by the clogging of culverts, drains, and constricted openings with large accumulations of orchard cuttings, debris, and trash in the stream. In addition to inundation, erosion of streambanks and damage to roads and bridges was severe. The flow of the Guadalupe River main stem would undoubtedly have surpassed all previous flood and flood damage records had it not been for the controlling effect of conservation reservoirs in the head water streams. Nevertheless, damage on the main stem and the trib utaries was very heavy in this basin. Practically the entire town of Alviso was inundated to depths up to 5 feet. The urban areas of New Almaden, Los Gatos, Saratoga, Santa Clara, and Sunnyvale were all affected to varying degrees. Debris-choked channels sent water coursing over adjoining lands, eroding topsoil near the banks and depositing silt and debris elsewhere. Bank erosion and damage to roads and bridges was severe. PART 1. DESCRIPTION A27

The flow of the Coyote Creek main stem is almost completely con trolled by Coyote and Anderson Reservoirs, and damage along this stream was confined to the low pasturelands near the mouth, where considerable silt was deposited. Greater inundation of agricultural land by the tributaries accounted for most of the damage in the Coyote Creek basin. ALAMEDA CREEK The peak discharge on Alameda Creek, resulting from the storm of December 21-24, was the greatest of record in the basin. Consider ing that the discharge from an important tributary, Calaveras Creek, was completely controlled, it is believed that this flood was among the greatest since January 1862. Mount Hamilton received 10.97 in-ches of rain in 48 hours, 6.87 inches of which fell in 1 day. Factors contributing to the flooding were the reduced capacity of Alameda Creek and some of its tributaries due to large quantities of brush and growth in the creek beds and inadequate levees which were over topped in some places or which failed without having been overtopped in other places. It is estimated that more than 15,000 acres of agricultural land were inundated to an average depth of 2 feet. A residential development, Valle Serra, was flooded to an average depth of 3 feet, and water rose to an average depth of 1.5 feet in the town of Alvarado. Industrial damage was especially severe in the Niles area where $1 million damage occurred to a steel mill as a result of 4 feet of flooding. Highways, railroads, and public utilities were also heavily damaged.

SMALL BASINS EAST OF SAN FRANCISCO BAY The east San Francisco Bay streams affected most by the floods of December 21-24 were San Lorenzo Creek in Alameda County and Walnut, Rodeo, Wildcat, Alhambra, Pinole, and San Pablo Creeks in Contra Costa County. An average of about 6 inches of rain fell over these basins during the 72-hour storm. It is believed that the resulting flood peaks have been exceeded several times since January 1862, The principal damage in the San Lorenzo Creek basin occurred in a residential district of the city of Hay ward where 130 homes were flooded to depths up to 6 feet and averaging about 2.5 feet. Bank cutting by the streams endangered or destroyed several bridges and 70 homes. In the Walnut Creek basin, more than 1,000 homes and nearly 50 business establishments were damaged, either by inundation or as a result of bank cutting. Agricultural damage was estimated at $180,000. About 1,075 persons were evacuted as a precautionary measure. In the smaller basins of Rodeo, Wildcat, Alhambra, Pinole, and San Pablo Creeks, the impairment of roads and bridges consti- A28 FLOODS IN FAR WESTERN STATES

tuted most of the damage. Storage in San Pablo Reservoir prevented some damage along San Pablo Creek.

SAN JOAQUIN VALLEY The southern half of the Central Valley of California is termed "the San Joaquin Valley region" in this report. The major stream systems in the region are the Kern River, Tulare Lake, and San Joaquin River basins. Figure 7 is a map of the region showing the location of streamflow-data sites 103 to 236. The site numbers are the same as those used in the sections of this report presenting data on stages and discharge. The storms, which culminated in the prolonged and intense rains of December 21-23, caused record-breaking flood flows on nearly all streams in the San Joaquin Valley. Previous records broken by the December 1955 floods include those established by the notable floods of December 1937 and November-December 1950. The relative mag nitude of the various peak flows during December 1955 and January 1956 at selected sites in the region are illustrated by the discharge hydrographs in figure 8. As a result of the record flows, virtually-every major stream in the San Joaquin Valley overflowed its banks at some point, and many levees were broken. The most significant levee breaks were on the San Joaquin River downstream from the mouth of Stanislaus River and on islands in the Sacramento-San Joaquin delta. The total area flooded one or more times in the San Joaquin Valley was estimated by the Corps of Engineers at about 393,000 acres. Most of the inundated areas consisted of agricultural property although, parts of some cities, suburban areas, and urban communities were flooded and about 20,000 persons were forced to evacuate their homes. The largest concentration of damage was in the lower Kaweah River basin where about 126,000 acres of farmland and most of Visalia and Farm- ersville were flooded, causing losses of almost $12 million.

KERN RIVER BASEST On Kern River at the station near Kernville (upstream from the South Fork) the flood peak on December 23 barely exceeded the previous maximum established by the November 1950 floods. How ever, the peak inflow of 25,000 cfs to Isabella Reservoir, as determined by the Corps of Engineers, was much less than the November 1950 peak of 39,000 cfs below Isabella Dam, then under construction. On the South Fork, the flood peak at the Onyx station was less than the March 1938 maximum of record. The December flood flows were completely controlled by the storage of about 60,000 acre-feet of water in Isabella Reservoir, and PART 1. DESCRIPTION A29

120° 119" 118°

36° -

35°-

EXPLANATION

.66 Stream-gaging station 34° - 0 61 Crest stage or miscellaneous site

Numbers conform to those in table 35

FIGURE 7. Map of the San Joaquin Valley region showing location of flood-data sites. by nondamaging releases of not more than 600 cfs. Above the reservoir, roads along the river were damaged by erosion, the diver sion dam to Borel Canal was washed out, the intake works for Kern 08V PART 1. DESCRIPTION A31

River No. 3 powerplant were damaged, a fish hatchery was flooded and its stock of fish washed away, and a Foresl; Service camp and the Kernville picnic grounds were flooded.

TULARE LAKE BASIN The peak discharge at the Tule River station near Porterville (above the South Fork) was only slightly less than the previous maximum during the November 1950 flood. At the South Fork station near Success, the peak discharge from the storm of January 25-27 exceeded the peak of December but was less than half the record peak established by the flood of November 1950. About 38,000 acres of agricultural land between the foothills and Tulare Lake were flooded in December; the January flood inundated about 27,000 acres, including much of the same land. Permanent plantings were damaged, growing crops were destroyed, and alfalfa and cotton stored in fields were severely damaged. Homes, farm build ings, farm equipment, highways, and bridges were damaged. The depth of flooding was about 3 feet for periods of 2 to 15 days. Above the foothills damage occurred to roads and bridges, a small dam on the North Fork, a powerplant intake structure, canal headworks, and summers cottages. On the Kaweah River the flood of December 23 greatly exceeded the flood of November 1950 in both peak and volume, although in this respect the 1950 flood had been the largest since stream gaging was begun on that river in 1903. At the Three Rivers gaging station the flood volume of 186,600 acre-feet for December 1955 exceeded that for November 1950 by 106,800 acre-feet. About 126,000 acres of land were flooded by the Kaweah River during the December and January storms. Most of the flooded area was along the river and its principal tributaries: the St. Johns River, Mill, Cameron, Packwood, and Cross Creeks, and Elk Bayou. The city of Visalia and the towns of Farmersville and Three Rivers were flooded. Most of the irrigation diversion structures on the river were washed out. Large quantities of debris accumulated against bridges and canal crossings and caused severe damage to most of these structures. Streambank erosion was severe, and great quantities of sand were deposited on farmlands adjacent to the streams. Nearly all roads in the area were flooded and damaged. In January, much of the area damaged by the December flood was re-flooded. The McKay Point weirs, dividing the flow between the Kaweah and St. Johns rivers, were partly bypassed by severe bank erosion. A large part of the flow formed a new channel to the St. Johns River, but debris and sand later plugged this channel to direct the entire flow down the Kaweah channel. Water backed up against the A32 FLOODS IN FAR WESTERN STATES

FIGURE 9. Kaweah River flood at the Friant-Kern Canal crossing, California. The canal was breached by floodwaters in several places as shown in the upper part of the picture. Photograph by United Aerial Survey. Friant-Kern Canal and overtopped and washed out large sections (fig. 9). Residences in the southern part of the town of Woodlake were flooded and damaged. More than half of the city of Visalia was flooded in December, and nearly a fourth of the city was reflooded in January. Several thousand people were forced to evacuate their homes. Damage was heavy in the business section and in a newer residential section in the southwestern part of the city where water in homes was as deep as 30 inches for about 6 days. The area flooded PART 1. DESCRIPTION A33 in December by the St. Johns River, Cottonwood Creek and Cross Creek above Tulare Lake was about 38,000 acres, much of which was in pasture, alfalfa, and grain. Most of that area was flooded again in January. Upstream from Three Rivers gaging station, many roads, bridges, and canal headworks were washed out. Hydroelectric plants were submerged and their headworks damaged. Residences, summer homes, motels, recreational facilities, and commercial establishments in and near the town of Three Rivers were flooded and damaged, or destroyed. In the Tulare Lake area, floodwaters from the Tule and Kaweah Rivers began overflowing in the sump area of the lake on December 25 and by December 31 had covered all 12 sections of land. The levee system prevented further spreading of the floodwater. As reported by the Corps of Engineers, about 55,000 acre-feet of floodwater reached the lake area during the December and January floods. No inflow to the lake came from the Kings or Kern Rivers, which were completely controlled by Pine Flat and Isabella Reservoirs, respec tively. Principal flood damages were the loss of a crop of barley growing on the flooded land, the loss of irrigation equipment, and the erosion of levees and land. As on the Kaweah River, the December flood on the Kings River exceeded the records in both peak and volume, established by the November 1950 flood for a 55-year period of record. At the gaging station at Piedra, downstream from Pine Flat Dam, the December 1955 runoff, adjusted for storage in Pine Flat Reservoir, was 428,200 acre-feet; the November 1950 runoff was 224,800 acre-feet. Pine Flat Reservoir completely controlled the floodflows of the Kings River to nondamaging releases, and no flooding occurred below the reservoir. Above the reservoir, State and county roads and bridges, a service road, and a powerhouse were flooded. SAN JOAQUIN RIVER BASIN The December flood established a new record for peak discharge on the upper San Joaquin River. The peak discharge at the site of the destroyed gaging station below Kerckhoff powerhouse was 92,200 cfs. In comparison, the maximum discharge of record below Friant was 77,200 cfs during the flood of December 1937 (prior to the construction of the reservoir). On December 21 there was about 625,000 acre-feet of available storage in Friant Reservoir and the upstream power reservoirs. Inflows to the power reservoirs were controlled, and maximum releases from Friant Reservior were about 6,400 cfs. Above Mendota Dam only negligible areas were flooded. Between Mendota Dam and the mouth of the Merced River, about 2,300 acres of cropland were flooded. A34 FLOODS IN FAR WESTERN STATES

In the lower San Joaquin River, floodflows were high for a pro longed period but in general were substantially less than the flows in the 1950 flood. The peak flows from the major tributaries Merced, Tuolumne and Stanislaus Rivers did not coincide. At the Vernalis gage, downstream from the Stanislaus River, the peak discharge oc curred on December 25 and resulted largely from Stanislaus River flows. About 25,500 acres of valley-floor land were flooded between the mouth of the Merced River and Mossdale at the head of the San Joaquin River delta. The crops in the flooded area between the Stanislaus River and Mossdale included alfalfa, irrigated pasture and grain, and sizeable acreages of tomatoes, sugarbeets, and truck crops. It includes also a number of residences in and around Mossdale, resorts containing permanent homes and summer cottages, and commercial establishments. On westside tributaries downstream from the Merced River, a total of 10,700 acres was flooded by Los Banos, Orestimba and Marsh Creeks. Floodwaters ponded against the Delta-Mendota Canal, broke it in two places, washed out ballast and ties of the Southern Pacific Railroad, and inundated about 1,600 acres of farmland to an average depth of 2 feet. Los Banos Creek overflowed the mainline of the Southern Pacific Railroad, the Delta-Mendota Canal, and several roads, and flooded about 6,100 acres of farmland near the town of Los Banos and a residential section on the south side of the town. Marsh Creek flooded homes on the outskirts of Brentwood and Knightsen and about 2,000 acres of orchards. About 20,000 acres, most of which was irrigated and highly pro ductive farmland west of U.S. Highway 99, were flooded by the Fresno River and its tributary, Cottonwood Creek. Land remained flooded to depths of as much as 4 feet for 2 to 7 days. Three small areas in the city of Madera were flooded. On Chowchilla River at Buchanan damsite gaging station the peak discharge on December 23 exceeded the previous record discharge of November 18, 1950 by 7,500 cfs. The river and its tributaries, Ash and Berenda Sloughs, overflowed their banks and levees and flooded about 27,500 acres of cotton, alfalfa, orchards, grain and permanent pastureland south and southwest of the city of Chowchilla. Water from Ash and Berenda Sloughs flooded six residences and six business establishments east of U.S. Highway 99 and nine residences in the southwestern part of the city. In these sections the water was 1 to 3 feet deep for several days. Flows on all of the principal streams of the Merced County Stream Group were outstanding in both peak and volume. The drainage area of this group, including Bear, Black Rascal, Burns, Mariposa, PART 1. DESCRIPTION A35

Miles, Owens, and Deadman Creeks, lies between the drainage basins of the Merced River on the north and the Chowchilla River on the south. Flood-control reservoirs have been constructed on each of Burns, Bear, Owens, and Mariposa Creeks, with an aggregate capac ity of 33,300 acre-feet. The Corps of Engineers reported that the computed peak inflow to Burns, Bear, and Owens Reservoirs sub stantially exceeded the previous record flows in November 1950; all four reservoirs filled and spilled, and the total peak outflow exceeded the project-design outflow in each case. Overflows from the streams of this group flooded about 3,000 acres of pastureland and about 12,000 acres in orchards, alfalfa, cotton, grain, and other cultivated crops to a depth of about 18 inches for 5 to 8 days. A group of homes on the north side of the city of Merced was flooded, and on the west side of the city a low-rental area of about 40 dwellings suffered considerable damage. On the Merced River the flood peaks of December 23 exceeded the previous maxima established by the November 1950 flood at the Happy Isles and Pohono Bridge gaging stations in Yosemite Valley, at South Fork near El Portal, and at Bagby, upstream from Lake McClure. On December 21 Lake McClure was virtually empty; the entire flood was stored in the reservoir and releases were controlled so that the maximum discharge of the river at Exchequer, on Decem ber 27, was 10,400 cfs. Above Lake McClure, roads and telephone lines in the mountain reaches were washed out. Below the reservoir, the river overflowed its banks and flooded about 1,400 acres of crop and pastureland in the river bottom and about 2,500 acres in the lowlands between the Merced and San Joaquin Rivers. About 515,000 acre-feet of storage space was available in Lake Eleanor, and in Cherry Valley, Hetch Hetchy, and Don Pedro Reser voirs on December 21, and the discharge of the Tuolumne River below Don Pedro Reservoir was controlled to a peak of 41,700 cfs on Decem ber 24. However, the computed peak inflow to Don Pedro Reservoir of 100,000 cfs substantially exceeded the peak inflow during the 1950 flood. Downstream from the foothill line, floodwaters of the Tuolumne River inundated about 7,100 acres of agricultural land. Depth of flooding on most of this area was about 6 feet. Below the town of Waterford, orchard and croplands were flooded when many private levees were overtopped. A few residences were flooded near the city of Modesto. The sewage-sludge drying ponds of the city were partly flooded, and levees of several cells were badly eroded. The December floodftows of the Stanislaus River broke all previous records. The peak inflow to Melones Reservoir of about 100,000 cfs on December 23 exceeded the previous record peak inflow in Novem- A36 FLOODS IN FAR WESTERN STATES her 1950 by 10,000 cfs. About 90,000 acre-feet of storage was avail able on December 21, and the reservoir filled and spilled on December 23. The peak outflow on December 23 exceeded the peak outflow in 1950 by 13,300 cfs. Areas flooded by the Stanislaus River extended from the foothills near the community of Knights Ferry to the San Joaquin River a total of about 15,000 acres. Knights Ferry was flooded, and the Knights Ferry firehouse (built in 1852), which withstood the large floods of 1862, 1907 and 1950, was completely destroyed. Above Ripon, the overflow was confined to bottomlands along the river. Be low Ripon, intermingled waters of the Stanislaus and San Joaquin Rivers inundated large areas of orchards, vineyards, truck and spe cialty crops, alfalfa, and pasturelands. All of the small private lev ees along lower reaches of the river were overtopped and breached, and levees of the reclamation district failed in a number of places. Between the drainage basins of the Calaveras River on the north and the Stanislaus River on the south, December floodwaters of the Littlejohn Creek Group (Duck, Littlejohn, and Lone Tree Creeks) inundated about 1,800 acres of land, of which about 1,400 acres, largely in barley crops, were on the south branch of Littlejohn Creek and about 400 acres, including a number of residences and small business establishments, were on the north branch of the creek near U.S. Highway 99. At all gaging stations in the Calaveras River basin the December flood peaks equaled or substantially exceeded those of November 1950. The maximum outflow from Hogan Reservoir, near the foothill line, plus heavy local inflow below the dam, caused a peak of 14,200 cfs at the Jenny Lind station. This was far below the record of 50,000 cfs established by the flood of January 1911, before construction of Hogan Reservoir. Downstream from Bellota, where most of the flow is diverted by Mormon Slough and the Stockton diverting canal, floodwaters broke out of the old channel of the Calaveras River in several places to flood farmlands near Linden and a small area in the northern part of Stock- ton. Levees of Mormon Slough were broken; an area along the slough from Bellota to the diverting canal and along the north side of the diverting canal through Stockton, and a large area in the southern part of Stockton along the old Mormon Slough channel were flooded. The flooded area was about 6,900 acres, of which about 1,500 acres were in the city of Stockton. The flooded farmland was planted in orchards, permanent pasture, and alfalfa. Depths of flooding ranged from a few inches to 4 feet for 1 to 8 days. Four thousand persons were evacuated from their homes. Damage to residences and fur- PART 1. DESCRIPTION A37

nishings, stores, factories, and other commercial establishments was severe. On Bear Creek, the peak discharge at the station near Lockeford exceeded the peak of December 7, 1950, but was less than the record discharge of February 2, 1945. The creek overflowed its banks and flooded about 7,000 acres of farmlands between the foothills and a point northwest of Stockton. The floodwaters stood in depths of a few inches to 3 feet for a few days to 2 weeks. Several residences were flooded; a service station, a cafe, and a grocery store were dam aged; and 28 persons were evacuated from the area. Although new records of peak discharge were established at the stations on the Middle and South Forks of the Mokelumne River, the peaks on the main river at the stations near Mokelumne Hill, Lancha Plana, and near Clements were less than the previous maxima of the 1950 floods. Pardee Reservoir below the Mokelumne Hill gaging station was nearly full on December 21 and started spilling on December 22. Floodwaters of the Mokelumne River overtopped the levees and inundated about 19,000 acres of land on both sides of the river from nestr the town of Clements to the mouth. Merging floodwaters of the river and its valley-floor tributaries, Cosumnes River and Dry Creek, created a large lake near the town of Franklin. Water stood in the flooded areas for 1 to 7 days in depths of as much as 8 feet. Rural residences, farm equipment, irrigation systems, and pumps were flooded, and roads, bridges, levees, transmission lines, and large acreages of alfalfa, orchards, and vineyards were damaged. At the Gait station on Dry Creek the peak discharge on December 24 exceeded the previously recorded maximum of February 2, 1945. The creek overflowed its banks and flooded about 5,200 acres of bottomland, largely in permanent pasture, to depths of as much as 10 feet and for as long as 3 months. Flooding of the town of lone was prevented only by sandbagging of the levee. Some livestock was lost owing to standing water and water-carried disease. On the Cosumnes River the record peaks of November 1950 were greatly exceeded. The floodwaters caused about 30 breaks in river levees and inundated about 25,000 acres of land along the Cosumnes River and Deer Creek, from Michigan Bar to the mouth of the river. The flooded area consisted of cultivated land along the north bank of the river and grazingland along the south bank. Land near the river was eroded in places and covered with deposits of sand, silt and debris in other places. Hop fields were severely damaged; other damaged crops were alfalfa, irrigated pasture, and winter grains. Water stood on the flooded land for 1 day to nearly 3 weeks in depths of as much as 8 feet. A38 FLOODS IN FAR WESTERN STATES

SACRAMENTO VALLEY The Sacramento Valley region includes the northern half of the . Central Valley of California and the closed Goose Lake basin in Oregon (fig. 10). The Sacramento River drains almost the entire region. The locations of sites where stage and discharge data were collected (Nos. 237 to 369) are plotted on figure 10. The December storms resulted in record-breaking runoff throughout most of the Sacramento Valley. However, damage in the upper part of the region was relatively light, because the area is sparsely popu lated, and the streams did not overflow their banks to any great extent. In the lower part of the region the record flows were too large to be contained within the levee systems and many were overtopped or breached. The most catastrophic levee failures occurred on the west bank of the Feather River at Shanghai Bend downstream from Yuba City, and on the east bank downstream from Nicolaus. Thirty-eight persons in Yuba City and two persons in the Nicolaus area lost their lives. Damage was estimated to exceed $40 million in the Yuba City area alone. The total area flooded in the Sacramento Valley was estimated Jby the Corps of Engineers to be 382,000 acres. Much of this area was under water for many days and some of it for months. About 30,000 persons were forced to evacuate their homes during the holiday season. To illustrate the relative magnitude of the flood peaks during the 2 months, the discharge hydrographs for selected gaging stations in the Sacramento Valley are presented in figure 11.

SACRAMENTO RIVER BASIN ABOVE FEATHER RIVER The December floods established new records of peak discharge on the Sacramento River and its tributaries above Shasta Dam. The peak inflow to Shasta Lake of 195,000 cfs on December 22 exceeded by 9,000 cfs the record flow on February 28, 1940, at the Keswick station prior to regulation by the reservoir. The flood inflow was completely controlled by Shasta Lake. Below Shasta Dam, local inflow from numerous tributaries increased the controlled release to a maximum discharge of 115,000 cfs on January 15 at the Red Bluff gaging station. Flood peaks on tributaries of the Sacramento River between Shasta Dam and the mouth of the Feather River were large but exceeded previous maxima only on Paynes, Elder, and Thomes Creeks. Cotton- wood Creek and its tributaries flooded about 4,800 acres of farmlands, mostly planted in alfalfa and grain. Elder Creek overflowed its banks above the town of Gerber, broke the levees in several places below the town, and flooded about 1,100 acres of farmland. Thomes Creek overflowed its banks in some places broke through levees in other PART 1. DESCRIPTION A39 123' 122° 121' 120' EXPLANATION Stream-gaging station 0247 Crest stage or miscellaneous site Numbers conform to those in table 35

FIGURE 10. Map of the Sacramento Valley region showing location of flood-data sites. 66'8521 O 63 4 > ht ^

OFF PART 1. DESCRIPTION A41 places, and flooded about 1,700 acres of farmland. A nursery was severely damaged. On Pine, Rock, and Mud Creeks, levees were broken and about 3,100 acres farmland were flooded. About 60 pigs were drowned in one field. Big Chico Creek overflowed and inun dated about 800 acres of farmland. Grain crops, farm buildings, irri gation systems, and roads were damaged. In the city of Chico, Bidwell Park and residences were flooded and eight persons were evac uated from their homes for 1 to 2 days. Little Chico Creek flooded about 500 acres of farmland, and 10 persons were evacuated from the area. On Butte Creek the levees were broken and about 10,000 acres of farmland were flooded to an average depth of 3 feet for about 2 weeks. Barley and oat crops were severely damaged, and levees and irrigation facilities were washed out. Flooding in the town of Durham was prevented by sandbagging of the levees, but 20 persons were evac uated from their homes for a few days.

FEATHER RIVER BASIN In the Feather River basin the December flood peaks exceeded pre vious maxima of record at nearly all gaging stations on the North, Middle, and South Forks and the West Branch. At the main-stem station near Oroville a peak flow of 175,000 cfs on December 22 was followed by a peak of 203,000 cfs on December 23 which was less than the record established by the floods of March 1907. The December 23 flood peak was confined by levees along the river to the confluence with the Yuba River below Marysville; the peak reached that point at about 5:00 a.m. on December 24, about 4% hours after the west levee broke at Shanghai Bend 3 miles south of Yuba City, and 5% hours after the peak outflow from the Yuba River. The most extensive flooding occurred as a result of the levee break at Shanghai Bend and a break in the east levee about 1 mile south of the town of Nicolaus. The areas flooded by the Feather River totaled about 100,000 acres. About 165 residences and 12 stores were flooded in the town of Chester, on the North Fork above Lake Almanor, and roads, bridges, railroads, and power facilities were washed out at scattered points along the river upstream from Oroville. In the city of Oroville about 100 acres were flooded, including 36 homes and 15 commercial buildings. Below the city about 900 acres of agricultural land were flooded. Approximately 200 persons were evacuated from the flooded areas for 3 days. High water in the Feather River prevented free runoff of Honcut Creek waters, and about 7,000 acres of farmland were flooded. Nearly 100 persons were evacuated from the area for 4 days. A42 FLOODS IN FAR WESTERN STATES

Similarly, free runoff was prevented in the Jack Slough area north of Marysville, and about 6,800 acres of farmland were flooded east of Levee District 10. Eleven buildings were flooded and four were de molished. Twenty-eight persons were evacuated from the area. Although the levees of District 10 held and that area was not flooded, 650 persons were evacuated for 3 or 4 days. The failure of the west levee of the Feather River at Shanghai Bend occurred about 12:10 a.m. on December 24. Water from this break entered Yuba City and flooded about 95 percent of the city (fig. 12). The depth of flooding varied from a few inches on the north side

FIGURE 12. Yuba City, Calif., under water as a result of Feather River levee failure. The city of Marys ville is the "island" in the background surrounded by floodwaters of the Yuba and Feather Rivers. Photograph by Corps of Engineers. to more than 12 feet in the low areas on the south. Because flooding occurred so quickly and in the middle of the night, practically none of the contents of homes and business buildings could be saved. Thirty-eight persons were reported to have lost their lives in this area as a result of the flood, and about 12,000 persons were evacuated for periods ranging from a few days to several months. A total of 3,134 homes was flooded, of which 31 were demolished and 45 were swept away completely. The business district was flooded in depths of 2 to 3 feet for 1 to 2 days, and very little merchandise, materials, or equipment could be removed. The Yuba City Union High School and three grade schools were flooded in depths of a few inches to 6 PART 1. DESCRIPTION A43 feet over the floors. The 5th Street highway bridge and the Sacra mento Northern Railroad bridge over the Feather River connecting Yuba City and Marysville were washed out, and one of the two trunk telephone lines serving the two cities was severed. After the levee broke at Shanghai Bend, the entire agricultural area south of Yuba City was flooded rapidly, and floodwaters from the river continued to flow into the area for 2 weeks. By January 7 the levee break had been repaired sufficiently to shut off the flow; a second rise of the river in mid-January was barely prevented from overtopping the newly repaired levee by the heroic work of troops called out from Beale Air Force Base. The vast lake of floodwater became known locally as Tudor Lake, for the community of Tudor which it inundated. The Feather River levee was cut at the lower end of the lake to drain it. Drainage through the cut continued for more than a month; then the cut was closed and the remaining water was pumped out. About 57,000 acres were flooded in this area, in cluding about 8,800 acres of peach orchards, 3,900 acres of prune orchards, 2,000 acres of almond and 1,700 acres of walnut trees, 1,700 acres of alfalfa, 4,200 acres of grain crops, and 26,700 acres of rice land. In areas near the levee break, trees were toppled and washed out, and in other places 2 to 3 feet of sand and silt were deposited in orchards. The floodwaters had a maximum depth of about 19 feet; the maximum duration of flooding was about 65 days. All homes and buildings in the area, including five public schools were flooded. Where water was deep, prolonged wave action demolished many buildings. The loss of livestock included 2,975 head of cattle, 2,500 sheep, 247 hogs, and 125 horses. At Nicolaus part of the highway bridge across the Feather River was washed out, and the break in the east levee downstream from Nicolaus caused the flooding of about 24,600 acres of well-developed farmland (fig. 13). Two persons were reported to have lost their lives as a result of the flood in this area; approximately 98 farms and 12 nonfarm homes were flooded, and more than 400 persons were evacuated. The depth of floodwaters was 16 to 20 feet over most of the lower part of the area and 5 to 10 feet near Nicolaus. The levee was cut at the lower end to drain the floodwaters into the Sacra mento River. Inflow through the Nicolaus break continued for 34 days until the gap was closed, and outflow through the lower cut continued for another 2 weeks. Then the cut was closed, and the remaining water was pumped out. On the Yuba River, the peak discharge of 148,000 cfs on December 23 at Englebright Dam plus the nearly simultaneous peak of 11,300 cfs on Deer Creek near Smartville, amounted to 159,000 cfs. This figure represents the peak discharge at the former gaging-station site FLOODS IN FAR WESTERN STATES

FIGURE 13. Floodwaters of the Feather River at Nicolaus, Calif., on December 24. The break in the east levee is in the foreground. The Nicolaus gaging station is visible a short distance upstream from the break. at Smartville, and compares with the previous maximum of 120,000 cfs at that site during the flood of March 1928. A combined peak of 114,000 cfs for the Englebright Dam and Deer Creek stations occurred during the November 1950 flood. Upstream from Englebright Dam several areas on tributaries were flooded, and roads and power facilities were washed out. On the North Yuba River the flooding caused heavy damage in Downieville below the Downie River confluence. On the valley floor the peak discharge was confined by the levees along the river to the confluence with the Feather River at Marysville. However, in the area east of Marysville, about 4,400 acres of orchard and farmland between the project levees were flooded to a maximum depth of 8 feet for 3 to 4 days. Roads, railroads, communication facilities, other utilities, and trailer courts, a hog farm, and a sand and gravel pit were flooded. Losses included 1,095 head of livestock. On December 23 about 8.500 persons were evacuated from the city of Marysville, but through the heroic efforts of the townspeople and and troops from Beale Air Force Base, the levees held and the city was not flooded. SACRAMENTO RIVER BASIN BELOW FEATHER RIVER The peak discharge of Bear River near Wheatland gaging station on December 22 exceeded the record peak of January 21, 1943, but PART 1. DESCRIPTION A45

the main levees did not break. The Feather River backed up into and broke the levees of Dry Creek, Yankee Slough, and the Western Pacific interceptor canal, which are tributary to the river near its mouth. Breaks on the interceptor canal flooded farmland east of the Feather River levee; embankments of the Western Pacific and Sacramento Northern Railroads were broken, and bridges were damaged. About 12,500 acres of orchards and farmland were flooded by Bear River and Yankee Slough. The flood waters were 10 feet deep for as long as 60 days. Some homes and tourist cabins were flooded, and about 500 persons were evacuated from the area. About 1,100 head of livestock were lost. In the American River basin records of peak discharge were broken at virtually all gaging stations; most of the records had been established by the flood of November 1950. The computed peak inflow to Folsom Reservoir was 219,000 cfs on December 23, whereas, the peak discharge was 180,000 cfs at the downstream Fair Oaks station on November 21, 1950, prior to the construction of the reservoir. The operation of the reservoir controlled the outflow to a maximum dis charge of 71,500 cfs at Fair Oaks on December 24, and this bankfull flow was carried to the Sacramento River through Sacramento without out causing damage or overflow. Above Folsom Reservoir the town of Coloma and the State Historical Monument at the gold-discovery site were flooded. Residences, summer homes, commercial buildings, roads, bridges, diversion structures, flumes and canals were severely damaged, but no agricultural lands were flooded. At Sacramento weir on the Sacramento River, most of the inflowing American River floodwaters were discharged to Yolo bypass through 30 of the 48 gate openings, and the maximum discharge was 61,000 cfs on December 23. During the flood of November 1950 all gates were opened and passed a maximum discharge of 111,000 cfs. Flood peaks in the Cache Creek basin were large, but did not exceed previous record flows. Extensive flooding and damage oc curred on the tributaries to Clear Lake. The flooded areas included about 2,000 acres of orchards and farmland on Middle and Clover Creeks, 3,000 acres on Scott Creek, 2,600 acres on Adobe Creek, and 1,500 acres on Kelsey and Manning Creeks. Water from Clover Creek reached a depth of 4 feet in the town of Upper Lake and flooded 101 homes and 34 business establishments. Overflows from Adobe Creek flooded five homes in the town of Finley, and transmission lines, road surfacing, and a road bridge were damaged. Downstream from Clear Lake, Cache Creek flooded about 900 acres of farmland, washed away a bridge near the town of Guinda, and eroded streambanks and a bridge abutment near the town of Capay and the highway west of the town of Woodland. A46 FLOODS IN FAR WESTERN STATES

Although the floodflows of Putah Creek were regulated to some extent by the partly completed Monticello Dam, the peak discharge near Davis on December 24 exceeded the previous maximum discharge on December 7, 1952. The principal flood damages on Putah Creek were streambank erosion, and the flooding of about 400 acres of farm land; construction work on Monticello Dam was interrupted. Streams flowing into Cache Slough (which carries Yolo bypass waters to the lower Sacramento River) flooded about 10,400 acres of farmland and pastureland and caused damage to crops, fences, roads, bridges, and some levees, and the loss of 300 head of sheep and 1,200 chickens. Floodflows in Yolo bypass substantially exceeded the flows during November 1950. Downstream from the inflow through Sacramento weir, the peak discharge on December 23 was about 310,000 cfs. This flow was sufficient to cause failure of the levee system designed to afford partial protection to four tracts of highly productive farm land (Little Holland, Liberty, Prospect, and Egbert) within the flow- age easement area in the lower reaches of the bypass. About 12,800 acres were flooded on the four tracts. In the lower Sacramento-San Joaquin delta area the combination of floodflows in the delta channels and exceptionally high tides during the December flood period caused failure of levees and flooding of Quimby Island and Empire Tract, and other islands were flooded by over topping of levees and by seepage. About 25,000 acres of intensively cultivated farmlands were flooded. The maximum tide at Venice Island was 10.7 feet; the November-December 1950 maximum was 9.8 feet. NORTH-COASTAL CALIFORNIA The north-coastal region of California consists of those Pacific slope river basins extending from the Napa River basin on the south to the Klamath and Smith River basins on the north (fig. 14). The sites in this region at which data on stages and discharge were collected are numbered from 370 to 469, and their locations are plotted on figure 14. The floods of December 1955-January 1956 rank among the greatest in north coastal California since the great winter floods of 1861-62. During the 2-month period a series of storms occurred; the greatest, on December 21-24 caused extremely high peak rates of runoff. The rainfall prior to December 21 saturated the watersheds and produced conditions favorable for flood runoff. The storms subsequent to December 24 caused the reoccurrence of flooding in some areas, but because these later peaks occurred so soon after the major peak, there was little additional damage. Only in some small basins in southern PART 1. DESCRIPTION A47

124° 123° 122° 121' 120°

Crest stage or miscellaneous site

( Numbers conform to those in table 35

FIGURE 14. Map of the north-coastal California region showing location of flood-data sites. Marin County was there appreciable damage from a second flood, and this occurred during the storm of January 13-16. The most severely damaged communities were Cloverdale, Healds- burg, and Guerneville in the Russian River basin; Weott, Myers A48 FLOODS IN FAR WESTERN STATES

Flat, Pepperwood, and Shively in the Eel River basin; Orick in the Redwood Creek basin; and Klamath and Klamath Glen in the lower Klamath River basin. Sixteen lives were lost, ten of them in Humboldt County. The pages that follow briefly describe the floods in the various drainage basins of the region. A tabulation of flood damage is found in another section of this report.

NAPA RIVER BASIN Severe flooding occurred in the Napa River basin as a result of the storms of December 15-20 and 21-24. At Saint Helena, 5.76 inches of rain fell on December 19, and a total of 9.08 inches was recorded during the 72-hour storm on December 21-24. The tributary stream of Dry Creek reached its peak on December 19, but the main stem and Conn Creek peaked during the second storm. The flow of Conn Creek is regulated by Lake Hennessey, and it was not until 1 a.m. on December 22 that the water surface in this reservoir reached spillway level. Peak discharge over the spillway occurred at noon on Decem ber 23; this was about 30 hours after the flood crest on the Napa River reached the mouth of Conn Creek. The most extensive flooding in the basin occurred along the Napa River main stem between the cities of St. Helena and Napa. The 12,580 acres of flooded area was more than 1 mile wide in some places and the water was as much as 7 feet deep. Water remained on some areas for as long as 8 weeks. In the city of Napa a log jam at the Napa River bridge at Behrens Street caused flooding in 14 city blocks.' Riverbanks were eroded in many places and highway damage was appreciable. SONOMA AND PETALUMA CREEKS Both Sonoma and Petaluma Creeks reached their peaks during the storm of December 21-24, but only on Sonoma Creek was flooding serious. Near Glen Ellen a slide nearly closed the channel of Sonoma Creek. The flow in that restricted channel gained sufficient velocity to scour and undermine the left bank, causing serious erosion to a small agricultural area and damage to residences. Approximately 6,300 acres of agricultural land were flooded in the 5-mile reach of the creek upstream from its junction with East Branch. The flooding in the Petaluma Creek basin was relatively minor compared with previous floods. Light local flooding occurred in the city of Petaluma, and downstream from the city scattered flooding in the reclaimed marshland area caused damage to farm equipment and crops and deposited silt and light debris over planted fields. Total damage amounted to about $55,000, two-thirds of which was PART 1. DESCRIPTION A49 sustained by agricultural developments; almost all of the remaining damage was to roads and bridges.

SMALL BASINS IN MAKIN COUNTY The streams causing the principal damage in Marin County were Novato, Miller, Gallinas, San Rafael, Corte Madera, and Lagunitas Creeks. Rainfall was extremely heavy in Marin County during the storm of December 21-24. In 72 hours Kentfield received 15.23 inches of rain; 7.41 inches fell in 24 hours. In the Novato Creek basin 4,080 acres were inundated, almost all of which was agricultural land. Flooded runways at Hamilton Field caused the evacuation of airplanes to higher ground. Damage in Novato was light, but might have been much greater had it not been for the regulating effect of Novato Reservoir. Spill from the reser voir began at 10:15 p.m., December 22, more than 15 hours after peak flooding occurred in the town of Novato. On Miller Creek flooding was confined to 770 acres of agricultural land south of Hamilton Field. On Gallinas Creek, damage was primarily limited to the erosion of a concrete-lined drainage channel in Santa Margarita Valley. Repairs to this channel were estimated to cost $100,000. San Rafael Creek overflowed into the city of San Rafael and damaged large stocks of merchandise in stores and warehouses. Corte Madera Creek overflowed its banks in the towns of Fairfax, San Anselmo, Ross, and Kentfield. Overflow from local drains also flooded part of the town of Corte Madera. Roads and bridges suf fered much damage, as did homes and stores in the inundated urban areas. Some of these areas are subject to frequent flooding, and resi dents have learned by experience to take preventive measures when floods threaten. Before the flood crest, automobiles were moved to high ground, low-lying buildings were emptied of valuables, and furni ture and mercantile stock was removed from ground floors. As a result,-flood damage was minimized. On Lagunitas Creek 800 acres of agricultural land were flooded and levees were damaged, but the principal damage was to roads and bridges. In southern Marin County the moderately severe storm of January 13-16, which brought 5.40 inches of rain to Kentfield, caused local flooding and additional damage. The streams affected were: Stinson, Redwood, and Tennessee Valley Creeks which drain into the Pacific Ocean, and Coyote and San Rafael Creeks which drain into San Francisco Bay. These streams pass through low, flat, partly- reclaimed marshlands at their mouths and are subject to tidal influ ence in their lower reaches. The direct flood damage in January totaled $186,400. A50 FLOODS IN FAR WESTERN STATES

RUSSIAN RIVER BASIN As a result of the major storms of December 15-20 and December 21-24, the Russian River and its tributaries exceeded flood stage on two occasions. The flood peaks of December 21-23, however, were much larger than those of December 19-20 and rank with the greatest that have occurred since the flood of the winter of 1861-62. Such widely separated precipitation stations as Cazadero in the lower part of the basin and Ukiah 4 W in the upper part received 24-hour rainfall of 10.75 inches and 6.60 inches, respectively. Cazadero also reported a 72-hour total of 18.83 inches during the storm of December 21-24. The discharge hydrograph for the stream-gaging station on Russian River near Guerneville for December 1 to January 31 is shown in figure 15. When it became apparent that the several small towns and resort areas along the Russian River would be inundated, local Civil Defense authorities declared a state of emergency at midnight December 21, and an orderly evacuation of the areas most likely to be flooded was started. This evacuation and the removal of belongings probably saved many lives and hundreds of thousands of dollars. When the full impact of the flood washed out highways and bridges and disrupted communications, evacuation of persons was carried out by rescue teams from all branches of the armed services, the National Guard, and Coast Guard. Equipment such as helicopters, Army ducks, jeeps, swamp buggies, aintracks, rubber rafts, and private craft were used day and night to rescue 961 people from such temporary sanctuaries as house tops and islands. In the upper basin the principal damage was to agricultural lands. Riverbank erosion washed away many local bank-protection works and many acres of highly-developed cropland. Approximately 30,000 acres of agricultural land were inundated. Many residential and commercial areas were affected; homes, sawmills, wineries, and food-processing plants bore the brunt of the damage. The, lower basin, primarily a resort area with many summer homes, was also ravaged. A total of 1,000 dwellings and small business buildings throughout the entire basin was destroyed or damaged. Practically all major county roads were closed to traffic as a result of inundation from the floods or slides from the unprecedented rains. The North western Pacific Railroad, which parallels the flood plain from Healds- burg to Ukiah, was out of operation for 2 weeks owing to track washouts at several places.

SMALL COASTAL BASINS BETWEEN RUSSIAN AND EEL RIVERS Flooding occurred during each of the storms of December 15-20 and 21-24 in all of the small basins beween the Russian and Eel Rivers. TSY A52 FLOODS IN FAR WESTERN STATES

Stages were considerably higher, however, during the second storm, and they rank among the greatest since the floods of 1861-62. Such widely separated precipitation stations as Yorkville in the Navarro River basin and Upper Mattole in the Mattole River basin each received 5 inches of rain on December 21 and a total of about 10 inches for the storm of December 21-24. Because the entire area is very sparsely settled, practically all damage was confined to roads and bridges. Only in the Mattole River basin was there any appreciable loss of private property. Agricultural losses consisted mainly of silted pastures, loss of livestock and damaged fences. Lumber industry facilities were destroyed and stocks of logs and finished lumber were lost; indirect losses resulted from the inability to move out finished lumber over the severely damaged roads. One person was drowned in the Mattole River basin.

BEL RIVER BASIN Major flood peaks occurred during the storms of December 15-20 and 21-24, but the peak during the later storm was by far the greater. The stage of 61.9 feet on Eel River at Scotia on December 22 is known to be the greatest since 1910, and was probably of about the same magnitude as that reached by the winter floods of 1861-62. The discharge hydrograph for the Scotia gaging station for December 1 to January 31 is shown in figure 15. Extensive flooding in the basin normally occurs only in the three principal agricultural areas; Eel River delta, Round Valley, and Little Lake Valley. Because of the virtually unprecedented dis charges of the floods of December 1955, however, many small com munities along the river received damage for the first time. It is estimated that 43,000 acres of agricultural, urban, and industrial property were flooded. On December 18, the U.S. Weather Bureau begun issuing flood warnings, and advised the evacuation of farm animals from the Eel River delta area. Advisory warnings continued to be issued period ically during the flood period, and these warnings undoubtedly saved numerous lives and property worth hundreds of thousands of dollars. Nevertheless, the damage that resulted from the flood was catastro phic. Because commercial and residential development is concentrated along U.S. Highway 101, which parallels the South Fork Eel River and the Eel River main stem downstream from the junction with the South Fork, this part of the basin suffered the greatest damage. The communities of Stafford, Elinor, Pepperwood, Shively, South Fork, Weott, Myers Flat, Phillipsville, and Bull Creek were devastated. The high velocity flow carrying heavy debris either flattened buildings or swept them from their foundations. The chief industrial damage PART 1. DESCRIPTION A53

was to the lumber industry, as facilities were destroyed and large stocks of logs and finished lumber were swept away. Two lives were lost and 27 persons injured, but the toll of deaths and injuries would have been much higher had it not been for spectacular rescues by members of the Armed Forces, National Guard, Coast Guard, county employees, and volunteer workers.

FIGURE 16. Eel River flood damage near Fernbridge, Calif. Undercutting is on downstream side of Fernbridge-Ferndale highway. Flood-damaged homes are in middleground. Photograph by Proctor's, Eureka, Calif.

Agricultural damage in the delta area was tremendous. Despite the efficacy of flood warnings, entire herds of valuable dairy stock, developed over many years of breeding, were lost. Numerous farm homes, out-buildings, and machinery were destroyed or damaged. The damage to highways and bridges throughout the basin isolated many communities for as long as several weeks (fig. 16). Slides, washouts, and trestle losses shut down the Northwestern Pacific Railroad for about 7 weeks. Communication lines and equipment were washed away or destroyed by slides throughout a large part of the basin. Long-distance trunk lines were inoperative for 1 to 2 weeks, except for intermittent operation for emergency calls. Subsequent to the main rise of the river, lesser rises caused reflood- ing in the lower Eel River basin. Additional damage was light, except for bank erosion. - A54 FLOODS IN FAR WESTERN STATES

MAD RIVER BASIN The flood in the Mad River basin on December 22 was the greatest of record, but other floods of this magnitude probably have occurred since the great flood of the winter of 1861-62. At the station at Kneeland 7 SSE, a 24-hour precipitation of 5.46 inches was recorded on December 21. The flood inundated 6,300 acres, of which 4,500 were agricultural and industrial land between the town of Blue Lake and the Pacific Ocean. U.S. Highway 101 was inundated and the north approach to the bridge over the Mad River was washed out. Damage to agricultural lands from erosion, scour, silt, and debris deposits was severe and loss of dairy cattle was high. Considerable damage was suffered by sawmills and wood-products mills. Sweesey. Dam, which diverts domestic water supply for the city of Eureka, suffered minor damage. The peak stage of the Mad River reached the levee crest near the towns of Blue Lake and Korbel, but the river was contained there.

REDWOOD CREEK BASIN Virtually all the damage from the flood of December 21-22 in the Redwood Creek basin occurred in the town of Orick and its environs. The maximum stage and discharge of the stream at Orick were iden tical to those of the flood of January 1953, and several other floods of this magnitude have probably occurred since the great floods of the winter of 1861-62. The creek rose rapidly at Orick until water covered most of the area to a depth of about 4 feet; nearly every home and business establishment in the town was flooded. Residents were evacuated to higher ground and there was no loss of life. About 910 acres of agricultural land were inundated, and damage to roads and bridges was appreciable. During late December and January, further rises of Redwood Creek caused inundation of some areas, but the addi tional damage was light.

KLAMATH RIVER BASIN The heavy December rains throughout the Klamath River basin culminated in a peak discharge of 425,000 cfs on December 22 at the gaging station near Klamath (fig. 15). This peak is the maximum of record, but it probably was equaled in the flood of February 1890 and exceeded in the floods of the winter of 1861-62. Major damage occurred in the lower reaches of the basin where six persons lost their lives as a direct result of the floods. The greatest damage was in and near the town of Klamath and in Hoopa Valley. The town of Klamath and the community of Klamath Glen, about 3 miles upstream, were almost completely destroyed (fig. 17). Much PART 1. DESCRIPTION A55

FIGURE 17. Flooding in the town of Klamath, Calif., on the right bank of the Klamath River. Photograph by Proctor's, Eureka, Calif. of the economy of the area is based on the production of lumber and lumber products, and several mills in the vicinity were severely damaged or demolished. Loss of stocks of finished lumber and logs was very high. In the delta area of the Klamath River about 700 acres of agricultural land were inundated. In Hoopa Valley on the Trinity River, several lumber mills were damaged but the principal losses involved very extensive damage to roads and bridges. Because the Klamath River basin in California is very sparsely settled, there was only scattered damage to residential and commercial properties elsewhere in the basin. In the Scott River valley, however, approximately 6,300 acres of agricultural land were inundated. Throughout the entire basin and particularly in its interior, roads and communications were destroyed by the rains and high water. Slides and bridge and road washouts completely isolated large areas for weeks; during this time radio was the only means of communication. In the upper Klamath River basin in Oregon, damage was negligible and was confined mainly to local flooding in the upper Sprague River drainage basin. SMITH RIVER BASIN The flood of December 22 in the Smith River basin was the maxi mum recorded since 1931, when the mainstem of the river was first gaged. Daring the storm of December 21-24, Gasquet Ranger Station received 12.03 inches of rain, two-thirds of which fell in 24 668521 O 63 5 A56 FLOODS IN FAR WESTERN STATES hours. As the Smith River rose, flood warnings for the delta area were issued by the Weather Bureau. These warnings were particu larly effective in keeping cattle loss to a minimum. It is estimated that 7,600 acres of pasture and agricultural land in the delta area were inundated to an average depth of about 3 feet. Floodwaters from the Smith River flowed into Lake Earl Slough and raised the elevation of Lake Earl so that 3,200 acres of land bordering the lake were flooded. Agricultural damage consisted primarily of the scouring of pastureland and the deposition on the land of silt, gravel, and debris from timber operations. Damage to roads and bridges was severe as a result of the rain and high water, which caused slides and washouts. The principal industrial damage was the inundation of lumber mills and the attendant loss of finished lumber and logs.

WEST-CENTRAL IDAHO A winter flood in central or southern Idaho is an extraordinary occurrence. In the lower valleys, early spring thaws commonly cause localized freshets on the smaller tributary streams. In the higher country most of the flood potential is due to heavy snow accumula tions, and rivers usually remain low from November to March. Winter floods are more common in the Coeur d'Alene River drainage basin where an exceptionally high flood occurred in December 1933 as a result of warm rains on accumulated snow. A similar condition caused the December 1955 flood in west-central Idaho. Warm rains on snow generated record streamflows within a period of 48 to 72 hours. The Idaho flood was a product of a storm that caused simul taneous floods in northern California and southwestern Oregon. The broad path of the parent storm was marked by a number of spot reactions as it approached Idaho, namely, Satus Creek in the Yakima area, John Day River on the lower Snake River, and Asotin Creek and Palouse River in southeastern Washington and Idaho. In Idaho the flood was centered in the Weiser and Payette River basins which are flanked by the Little Salmon River on the north and the Boise River on the south (fig. 18). The locations of the sites, 481-566, at which streamflow data were collected, are shown on the map. Hydro- graphs illustrating the relative pattern and magnitude of discharge during December 1955 and January 1956 at selected gaging stations are shown in figure 19. The storm extended from December 18 to 23, and at some points it was reported that the rain was nearly continuous. The Weather Bureau reported that eight of its stations within the primary flood area recorded more than 6 inches of precipitation during the week. This precipitation fell as snow at the highest altitudes; part of the precipitation, which fell as rain at medium altitudes was absorbed by PART 1. DESCRIPTION A57 118° 117° 116° 115° 114°

EXPLANATION .564 \ Stream-gaging station 566 Crest stage or miscellaneous site

Numbers conform to those in table 35

FIGURE 18. Map of the west-central Idaho region showing location of flood-data sites. the snow cover and did not contribute to the December flood. An ex ample of the heavy precipitation at high altitudes is the measured amount of 8.11 inches of water which entered the snowpack at Dead- wood Dam (alt, 5,300 ft) during December 19-23. 8SY PART 1. DESCRIPTION A59

BOISE RIVER BASIN The drainage area above the city of Boise is 2,760 square miles. On December 23, while a major flood discharge was being recorded upstream, the flow at Boise was only 32 cfs. The combined capacities of Anderson Kanch, Arrowrock, and Lucky Peak Keservoirs served to regulate the river completely. On the day of greatest discharge these reservoirs cut off a daily mean flow of about 22,000 cfs. The maxi mum rates of inflow to Arrowrock, Lucky Peak, and Anderson Ranch Reservoirs were 16,700, 5,800, and 4,600 cfs, respectively. The South Fork Boise River, on which Anderson Ranch Reservoir is located, did not react to the storm as strongly as the remainder of the basin, and the total basin runoff was thereby less than that which might have been experienced had the storm pattern or other factors been slightly different. It is noteworthy that Moore Creek peaked in step with the river (fig. 19), as this tributary normally peaks in advance of the river during the annual spring freshet. The gaging station on Boise River near Twin Springs records the unregulated flow of the main stem above Arrowrock Reservoir from a drainage area of 830 square miles. At this station the river rose rapidly with but one break from 1,200 cfs to the peak flow of 10,300 cfs; this peak equals the maximum peak previously recorded in 45 years of record. The peak flow of the flood of 1943 was 8,920 cfs, and peak flows exceeding 9,000 cfs were recorded in 1917, 1921, 1928, 1952, and 1953. Small tributaries in the upper basin, such as Dixie, Smith, Slide Gulch, Sheep, Logging, Cottonwood, and Thorn Creeks and many others eroded their channels to an unusual degree and probably were higher than they had been for many years. Flood damage in the Boise River basin amounted to about $250,000 and was confined chiefly to roads and highways.

PAYETTE RIVER BASIN The drainage area above Black Canyon Dam near Emmett is 2,680 square miles; this area is slightly less than that of Boise River at Boise. The maximum discharge of the Payette River near Emmett for the the previous 30 years was 22,800 cfs on May 1, 1938. On December 22, 1955, the peak discharge was 22,700 cfs. This is especially signifi cant when it is considered that on the day of greatest discharge the upstream reservoirs intercepted a daily mean flow of about 9,000 cfs. The major regulation was effected at Cascade Reservoir on the North Fork. This reservoir had not been constructed when the previous maximum was recorded, and at that time regulation by the smaller reservoirs was less than 2,000 cfs. These factors indicate that a much A60 FLOODS IN FAR WESTERN STATES

higher flood generation occurred in December 1955 than had been previously recorded for the river basin as a whole. The unregulated condition for a section of the basin can be simulated by setting apart the inflow between the Garden Valley and the Banks gaging stations. The drainage area of this section of the South Fork includes that of the Middle Fork and a few smaller tributaries and comprises an area of 421 square miles. The differential flow on December 22, 1955, exceeded any other corresponding differential of record by almost 20 percent. Also, inflow from Shafer, Harris, and Squaw Creeks between the town of Horseshoe Bend and Black Canyon Dam was exceptionally high. Flood damage was about $225,000, most of which was to farmland, livestock, and structures. Some sections of roads and highways were washed out, but damage of this type was a relatively small part of the total. The Payette basin, like the Boise, was not contributing at the maximum rate. High altitude drainage areas above McCall, Low- man, and Deadwood Dam, comprising 700 to 800 square miles, were largely frozen in. WEISER RIVER BASIN The Weiser River was in flood throughout its length. Rain and warm temperatures greatly reduced the snow cover, particularly on the lower slopes bordering the valley. Following the flood period some snow remained on the valley floor and, as in the Boise and Payette River basins, the snowpack at higher altitudes remained relatively undisturbed. The discharges on some of the tributary streams were very high although they may have been less than the previous niaximums of record. The upper reaches of the Little Weiser River and the West Fork Weiser River did not contribute significant amounts of runoff. Also, Mann Creek flows were well within previous extremes. However, the upper Weiser River flood, even as far upstream as Tamarack, is believed by old residents to have been the greatest in more than 40 years. The most critical flood conditions occurred in the vicinity of Cambridge and Midvale where considerable damage to farmland, livestock, and structures was inflicted. The gaging station 2% miles upstream from Cambridge and the adjacent road bridge were destroyed prior to the peak of the flood; which was 10,100 cfs on December 22. The previous maximum in 16 years of record at this station was 6,670 cfs in 1940. The drainage area of the Weiser River above Crane Creek is 1,160 square miles and that of Weiser River near Weiser (below Crane Creek) is 1,460 square miles. Lost Valley and Crane Creek Reservoirs were impounding in December, and the latter probably reduced the peak PART 1. DESCRIPTION A61 in the lower Weiser River noticeably. A peak discharge of 19,900 cfs occurred at the station below Crane Creek early on December 23, when lower Crane Creek (under regulation) was discharging only about 100 cfs. The indicated peak for the river above Crane Creek was therefore 19,800 cfs; which is substantially higher than the maximum from 1920 to 1952. At the city of Weiser and in the lower Weiser River Valley, flood conditions depend on the magnitude of coincident discharges in the Weiser and Snake Rivers. At the time of the Weiser River peak the Snake River at Weiser was discharging about 45,000 cfs, which is unusually high for December. Flow in the Weiser River had dropped to about 12,000 cfs by the time the Snake River reached its peak. Impounded storage on the Boise River and the upper Snake River effectively reduced the Snake River peak. Despite the mitigating influence of storage, considerable flooding of low-lying farmland near Weiser occurred, and there was some disruption of traffic and damage to highways. LITTLE SALMON RIVER BASIN The upper end of the Little Salmon River basin is characterized by a fan-shaped pattern of small tributaries entering the New Meadows Valley. After leaving the broad, relatively flat, mountain valley the main stream drops sharply for several miles as it flows through a constricted canyon and thence through a narrow valley to its con fluence with the Salmon River at Riggins. The meandering upper valley stream was heavily iced at the beginning of the flood period. Breakup of the ice and accompanying jams undoubtedly contributed to damaging effects of the flood downstream. Most of the damage was done in and just downstream from the canyon section where parts of U.S. Highway 95, the only through north-south route in Idaho, were completely destroyed. Although the peak discharge of 8,500 cfs on December 22 was lower than the 1948 flood peak, the damage in the canyon section was much greater than during the 1948 flood. The greater damage was probably due to the ice jams and the high flows from side streams which overflowed and loosened road fills adjacent to the main stream.

SNAKE RIVER AND TRIBUTARIES BELOW WEISER RIVER Discharges on the Snake River from Weiser to Lewiston were high for a winter period, yet were generally within the capacity of the channel and serious flooding did not occur. The peak flow at the gaging station at Oxbow was 52,100 cfs on December 24 whereas the maximum peak during 32 years of record was 89,700 cfs on April 28, 1952. Tributary runoff below the Weiser River was variable.. The Burnt and Powder Rivers, although adjacent to the flood area, were A62 FLOODS IN FAR WESTERN STATES

not especially high, but Wild Horse and Indian Creeks on the Idaho side of Pine Creek in Oregon in the vicinity of Oxbow were in flood; Brownlee Creek just south of Wild Horse Creek did not react significantly. WILLAMETTE VALLEY The floods of December 1955-January 1956 were outstanding in the Willamette River basin (fig. 20). Streamflow-data sites 588 to 683 are in this region and their location is plotted on the map. Al though the peak discharges were unusually high, only a few were the

124' 123 122 C

o stage or miscellaneous site Numbers conform to those in table 35 10 20 30 40 50 MILES

FIGURE 20. Map of the Willamette Valley region showing location of flood-data sites. PART 1. DESCRIPTION A63 maximum for the period of record for gaging stations in operation 20 or more years. During October and November about 8 inches of precipitation had fallen in each month over the entire area so that by December the soil was well primed, streamflow had increased, and conditions were favorable for runoff of flood proportions. Heavy precipitation con tinued 88 a series of storms moved over the area in rapid succession from December 18 through January 22. In the upper Willamette Valley, precipitation averaged nearly 20 inches in December and 10 to 15 inches in January. Average precipitation for the lower valley was about 12 and 13 to 15 inches for the same periods. The storm of December 18-21 produced the highest peaks during the 2-month period almost everywhere in the basin. Rainfall generally ranged from 3 to more than 7 inches during December 20-21. Precipitation occurred on about 75 percent of the days in both months; the resulting floods were outstanding, and exceeded the floods of 1943 and 1945 in volume and extent of flooding. Five flood-control reservoirs were effective in minimizing damage on some of the tributaries and on the main stem. However, it was reported that velocities in the lower reaches of unregulated tributaries were greatly increased due to increased gradients resulting from lower main-stem discharge. Damage in the basin amounted to $8.7 million of which $5.4 million was to agricultural properties. The Corps of Engineers has estimated that operation of flood-control reservoirs averted another $13.6 million in damage. Two lives were lost in this region as a direct result of the flood. Tabulation of flood damages is found in given "Flood damage" section of this report. The time distribution and relative magnitude of peak discharges at selected gaging stations during the months of December and January are illustrated by the hydrographs in figure 21.

MIDDLE FORK WILLAMETTE RIVER BASIN At West Fir, 5.07 inches of precipitation occurred during December 20-21, and at Oakridge a total of 3.91 inches was recorded for virtually the same period. The floods resulting from this inundated 300 acres and caused damages amounting to $152,000. One fatality occurred in the area when a motorist and his car fell into Salmon Creek, just above Oak- ridge, where a bridge was washed out. The Willamette Highway was blocked by a 150-foot washout above Oakridge. Willamette City just downstream from Oakridge was under 3 feet of water and 200 persons were evacuated from their homes. Lookout Point Reservoir, the largest of the five flood-control reservoirs in the Willamette River basin, effectively controlled the

PART 1. DESCRIPTION A65 flow of the lower Middle Fork Willamette River. Peak outflow from the reservoir was only about 20 percent of peak inflow and was delayed until about 6 days after the natural peak. .

COAST FORK WILLAMETTE RIVER BASIN This stream joins the Middle Fork Willamette River near Eugene to form the Willamette River main stem. During December 20-21, 3.72 inches of rain fell at London and 3.26 inches fell at Dorena Dam. Runoff in excess of 90 cfs per square mile occurred on unregulated streams. Damage amounted to $180,000; 530 acres were inundated, and about 200 persons were forced to evacuate their homes. Ambulances were used to evacuate elderly patients from "Twilight Acres Rest Home" to a nearby church. Six of seven Southern Pacific locomotives, pulling 78 freight cars over the divide near Cottage Grove, were derailed at a washout. Two small storage reservoirs in this area were operated on a special schedule because of the magnitude of the flows. Although not 100 percent effective in controlling the flow, these reservoirs appreciably reduced the floodflows in the lower Coast Fork Willamette River. The peak outflow was delayed about 8 days at Cottage Grove Dam and then was only about 40 percent of the peak inflow. Peak release at Dorena Reservoir on the Row River was also cut to about 40 per cent of peak inflow but was delayed only about 12 hours after the peak inflow.

EASTSIDE TRIBUTARIES TO MAIN STEM WILLAMETTE RIVER PROM EUGENE TO MOUTH The important eastside tributaries, the McKenzie, Calapooya, Santiam, Pudding, Molalla, and Clackamas Rivers rise in the Cascade Mountains. During December 20-21, 5.94 inches of rain fell at McKenzie Bridge in the McKenzie River basin, 5.51 inches at Holley in the Calapooya River basin, 7.32 inches at Detroit in the Santiam River basin, 2.34 inches at Aurora in the Pudding River basin, 2.64 inches at Molalla in the Molalla River basin, and 5.35 inches at Three Lynx in the Clackamas River basin. In the Pudding River basin, floodflows were not particularly high, but in some basins the flow was the maximum of record or close to the maximum at a few gaging stations with periods of record ranging from 10 to more than 20 years. Maximum for at least the past 20 or 25 years occurred on the Mohawk River, a trib utary of the McKenzie River, and on Calapooya River at Albany. At some points, the flow of the Clackamas River was the maximum or near the maximum the past 56 years. Many acres of farmland were inundated by these record-breaking floods. A66 FLOODS IN FAR WESTERN STATES

On the North Santiam River, Detroit Eeservoir effectively con trolled floodflows; peak outflow was only 40 percent of peak inflow and occurred about 19 days afterward. There was no recorded dam age in the North Santiam River basin. In the remainder of the Santiam River basin, 4,730 acres were inundated and damage amount ed to $324,000. A railroad-track washout along the South Santiam River resulted in minor injuries to three trainmen. A six-car Spokane, Portland and Seattle freight train hit the washout (30 ft long and 12 ft deep) at a speed of 5 miles per hour. The locomotive nosed over into the mud but the cars were not derailed. In the Molalla River basin a logging truck evacuated 12 families from their homes in Sandy Dell. In Clackamas County, 212 persons were evacuated from their homes and in Marion County, 11 persons were evacuated. Duration of overbank flow was about 3 to 4 days on the major unregulated streams. Revetment and bank protection works, although not fully effective, prevented damages of many thousands of dollars.

WESTSIDE TRIBUTARIES OF MAIN STEM WILLAMETTE RIVER FROM EUGENE TO MOUTH The important westside tributaries, the Long Tom, Marys, Lucki- mute, Yamhill, and Tualatin rivers originate in the Coast Range. The severest flooding occurred in the Tualatin, Yamhill, and upper Long Tom River basins. Precipitation throughout this area ranged from about 5% inches to almost 10 inches during December 18-21. At Falls City in the Luckiamute River basin, a catch of 4.55 inches was recorded for the 24-hour period ending 7 a.m. December 22, while at Haskins Creek Dam in the Yamhill River basin, 4.08 inches fell in the 24-hour period ending 4 p.m. December 21. In the Long Tom River basin, almost 14,000 acres were inundated and damages totaled $520,000. In Ben ton, Polk and Washington Counties 15, 35, and 300 persons, respectively, were evacuated from their homes. State Highway 210 was closed because of flooding at Tualatin River bridge near Scholls and 12 families were evacuated from this area. Several families were evacuated when the town of Tualatin near the mouth of the Tualatin River was inundated. Des pite faulty gate operation for about half an hour Fern Ridge Reservoir on the Long Tom River appreciably controlled the flow downstream. Peak outflow occurred about 4% days after, peak inflow and was only about 40 percent of peak inflow.

MAIN STEM WTLLiAMETTE RIVER FROM EUGENE TO MOUTH Precipitation and antecedent conditions were the same for the main stem as for the eastside and westside tributaries. Although the flood- PART 1. DESCRIPTION A67 control reservoirs greatly reduced the flood in the main stem, there was still considerable overflow and damage. There was no overbank flow between Eugene and Springfield; damage in that area amounted to only about $29,000. Other areas were affected as shown below: Acreage flooded Damage Harrisburg area______16, 000 $451, 000 Albany to Corvallis_-__-_____-_-_-_-_--______28,000 669,000 Salem area______33, 000 1, 552, 000 Oregon City to Portland______._-___----__-____ 4,800 551,000 Two homes were almost completely destroyed. Train service be tween Portland and San Francisco was interrupted for 2 days. Revetments and channel improvements prevented many thousands of dollars of damage, but the five flood-control reservoirs were by far the most effective control factors. These reservoirs reduced main- stem stages by several feet. For a more detailed account of the effect of these reservoirs see the section on "Storage regulation" in this report. Because of the effect of the reservoirs on the Middle and Coast Forks of the Willamette River, peak flow at Springfield did not occur until December 26, but peaks at Albany, Salem, and Wilsonville corre sponded to the tributary peaks of December 21 and 22 and occurred on December 23 and 24. COASTAL OREGON The floods of December 1955-January 1956 produced outstanding peak flows in the Coastal Oregon region; many of which were maxi mum for periods of record of 30 to 50 years; some were exceeded only by the historical peaks of 1861 and 1890. The region (fig. 22) consists of the Pacific Slope basins in Oregon from Youngs River on the north to the Oregon-California border on the south. The floods were par ticularly noteworthy in the south coastal area. Locations of streamflow-data sites 684 to 788 in the Coastal Oregon region are shown on figure 22. In the north-coastal area, precipitation during October, November, December, and January averaged about 12, 15, 18 and 18 inches respectively. During the same months in the south coastal area precipitation averaged about 8, 10, 25, and 20 inches. For the 4- month period the entire area received more than 60 inches of pre cipitation, but during the 2 months of serious flooding the southern basins received about 45 inches and the northern basins received about 36 inches. Greatest intensities occurred in the southern part where Gold Beach Ranger Station recorded 7.34 inches for the 24-hour period ending at 4 p.m. December 26. A68 FLOODS IN FAR WESTERN STATES

124° 123° 122° 121' 120°

EXPLANATION ,684 Stream-gaging station

Crest stage or miscellaneous site Numbers conform to those in table 35

FIGUBE 22. Map of the coastal Oregon region showing location of flood-data sites. In Coastal Oregon, as in the Willamette Valley, snow that had fallen earlier contributed appreciably to flood volume but had only a minor effect on flood peaks. PART 1. DESCRIPTION A69

The extent and volume of the floods were outstanding, rivaling the historic peaks of 1861 and 1890. Maximum peaks during periods of record were almost equaled on North Umpqua River at Winchester and South Umpqua River near Brockway, the principal tributaries above Umpqua River at Elkton. The peak at Elkton, however, was the maximum for the period of record and equaled the historic peak 1861, the greatest previously known. The reason for this apparent inconsistency is probably that runoff was high for the entire basin and very high flow occurred on the intervening tributaries below Win chester and Brockway. Thirteen persons lost their lives as a direct result of the floods in coastal Oregon; most of the fatalities occurred in the Umpqua and Coquille River basins. Property damage amounted to more than $9 million. A tabulation of flood damages is found in another section of this report. The time distribution and relative magnitudes of peak discharges at selected gaging stations in the coastal Oregon region are shown by the discharge hydrographs in figure 23.

NORTH-COASTAL, STREAMS The major streams in North Coastal Oregon are the Nehalem, Wilson, Trask, Nestucca, Siletz, Alsea, and Siuslaw Rivers. Because these streams rise in the Coast Range and flow directly to the sea, they are relatively short and steep. During December 18-27, precipitation totaling 10.67 inches fell at Seaside, 11.60 inches at Tillamook, 9.11 inches at Newport, and 13.57 inches at Alsea Fish Hatchery. The greatest 24-hour pre cipitation was 4.40 inches at Tillamook and 4.25 inches at Alsea Fish Hatchery on December 21. The flooding in the north coastal area was not as severe as in the south but even so, the maximum discharges for 16-year periods of record occurred on Alsea River near Tidewater and on Nehalem River near Foss; on Trask River near Tillamook the peak discharge was the maximum for a 25-year period of record. In general, the floods were below the peaks of 1921 and 1933 and the historic peak of 1890. One man was drowned in the Nehalem River when his boat appar ently capsized. Highways through Clatskanie and from Newport to Corvallis were closed by slides. From Newport to Depoe Bay, fallen powerlines made driving hazardous. In Tillamook County the high winds of December 21-22 blew the roofs from three school- houses. Damage in the area was more than $400,000, over 50 per cent of which was agricultural damage. In the Siuslaw River basin, damage was chiefly to industry and amounted to $120,000; the

PART 1. DESCRIPTION ATI lumbering industry lost many logs stored in booming areas and recovered others only at large cost. Because these streams are relatively short and steep and flood runoff was flashy, floodflows lasted for less than 2 days. There are no flood-control reservoirs in this area and natural flow occurred. Levees on the Nehalem, Nestucca, and Siuslaw Rivers were over topped, and tide gates failed at several locations. On streams entering Tillamook Bay (Kilchis, Trask, Tillamook, Wilson, and Miami Creeks) levees were not overtopped, but some flooding occurred when water flanked these levees upstream.

UMPQUA RIVER BASIN From December 18 to 27, precipitation generally averaged between 10 and 15 inches over the entire basin; a maximum 24-hour precipi tation of 5.75 inches was recorded for December 25 at Reston in the South Umpqua River basin. At the headwaters of the North Umpqua River, much of the precipitation infiltrated the porous soils and ran off later. As a result peak runoff was less than in the South Umpqua River or in the lower North Umpqua River basin. The floods in December 1955 were double crested in the Umpqua River basin. On the main stream and larger tributaries the peaks that occurred late on December 21 or early December 22 were the maximums for the flood period and were the result of the heavy rains on December 18-22. On the smaller tributary streams, particularly near Roseburg, the peaks that occurred early on December 26 were the maximums for the flood period and were the result of rains of shorter duration but higher intensity on December 25-26. According to a report by the Oregon State Civil Defense Agency, five lives were lost in the basin as a direct result of the floods. At Toketee Falls, in the headwaters of the North Umpqua River, about 200 families and 150 construction workers were isolated for several days. A small diversion dam on Fish Creek was washed out, and 3 feet of mud was deposited in the control station of the main power house. The town of Myrtle Creek was without light and power, and communication lines were down. The town of Riddle was evacuated and later was completely surrounded by water. Pacific Highway between Dillard and Myrtle Creek was blocked by water, and the Drain to Reedsport highway was closed by slides. There was also considerable damage to the county road system (fig. 24). More than 300 families were evacuated from danger points in the basin. Damages were estimated at $2,143,000; the major types were agricultural (32 percent), residential (26 percent), and industrial (21 percent).

668521 O 63 6 A72 FLOODS IN FAR WESTERN STATES

FIGURE 24. Floodwaters over county road bridge across South Fork Umpqua River at Kice Creek, 2 miles upstream from Dillard, Oreg., at 11 a.m., December 22,1955. Photograph by Dick Oilman, Koseburg, Oreg. In general, streams were above bankfull stages for 1 to 2 days at the time of the December 21-22 peak and for less than 1 day at the time of the December 26 peak. There are no significant storage or flood-control reservoirs in the basin. All levees were overtopped except those protecting the towns of Reedsport and Gardiner, which proved adequate and prevented extensive damage. COOS AND COQUELLE RIVER BASINS The Coos and Coquille Rivers rise in the Coast Range, and are the principal streams in Coos County and the only large streams between the Umpqua and Rogue Rivers. Precipitation during December 18-27 was 16.47 inches at North Bend in the Coos River basin and about 20 inches for Powers and Sitkum in the Coquille River basin. Maximum peaks of record did not occur except at gaging stations with short periods of record. However, peaks approached previous maximums at stations with 20 to 40 years of record. Although there is no gaging station on the main Coquille River, the lower Coquille River may have had the greatest discharge known. However, the tide is a major factor in the lower Coquille and all that is certain is that the stage was higher than ever before observed. One person was drowned in the Coos River as a direct result of the PART 1. DESCRIPTION A73 flood. Damage to the Coast Highway in the Coos Bay area amounted to about $100,000, and most of the main roads were closed for about a week. The community of Arago on the coast was completely isolated by floodwaters. In the Coquille River basin, the town of Coquille was isolated with out light, power, and communications for several days; the town of Myrtle Point was also isolated without electric power and drinking water. U.S. Highway 101 near Coquille was under 3 feet of water, and the road from Coquille to Bandon remained closed for about 8 days. Railroad service from Coquille to Coos Bay was interrupted for 2 weeks. About 350 persons in Coos County were evacuated. Coastguardmen from Newport brought in boats to help Coquille Valley farmers move their belongings to higher ground. There were six fatalities in the Coquille River basin as a direct result of the floods. A slide at Remote, Oreg., killed five members and injured three children of one family. The huge slide, about 300 feet wide and 14 feet thick, moved their home about 400 feet and demolished it. High winds collapsed a barn near Coquille and killed 132 dairy cattle. Total damage in Coquille River basin was $2,597,000, of which 40 percent was agricultural, 36 percent industrial, and 14 percent was damage to railroads and utilities. Most of the damage was in the lowlands below Myrtle Point, where more than 20,000 acres of farm land was inundated. In the lower Coquille River, stages were above flood level for 4 to 5 days. The lowlands were inundated for several weeks, a common occurrence in this area whenever there is appreciable overbank flow. There are no storage reservoirs in these basins, and the only flood- control structures are levees in the Fat Elk and Beaver Hill drainage districts in the Coquille River basin and on the lower reaches of the Coos River. The levees on the Coos River were adequate but those in the Coquille River basin were not designed to protect against major floods and were overtopped early in the flood period. ROGUE RIVER BASIN December precipitation was generally less than in other coastal basins and was confined more to the December 18-22 storm; the great est intensities occurred on December 21. The resulting flood peaks occurred late on December 21 or early on December 22. One notable exception to this precipitation pattern was Gold Beach Ranger Sta tion at the mouth of the Rogue River where the total rainfall for December 18-27 was 21.91 inches, of which 12.64 inches fell on December 25-26. The maximum 24-hour rainfall in Oregon for the entire flood period, 7.34 inches, occurred at this station on December 26. For the rest of the basin, 2 to 9 inches of precipitation fell during December 18-22; the lesser amounts fell in the southeastern A74 FLOODS IN FAB WESTERN STATES part of the basin and the larger amounts in the northeastern and southwestern parts. Except for the southeastern part of the basin the peaks of December 21-22 were the maximum for periods of record on most tributaries and at main-stem stations. Some of these stations have records of 17 to 50 years. The highest peak rates of discharge were in the Illinois Valley; on Rogue River below Illinois River near Agness a tremendous discharge of 414,000 cfs occurred from 4,890 square miles. This flood in the Rogue River basin was as high or higher than any flood in the last 65 years including those of 1927, 1945, and 1953, and was exceeded only by the historic floods of 1861 and 1890. No fatalities occurred as a result of the flood. Damage in the basin amounted to $4,049,000; agricultural damage was 34 percent of the total, residential damage 27 percent, and commercial damage about 17 percent. About 14,500 acres of farmland were flooded. Three railroad bridges were washed out, and the powerhouses at two hydroelectric plants were flooded. The Applegate River washed out 200 feet of the Redwood Highway bridge. Parts of U.S. Highway 99 were under 4 feet of water and in the Grants Pass area damage to two large telephone cables put about 1,000 telephones out of service. About 400 persons were evacuated from then* homes. The heaviest precipitation was concentrated during December 18-22, and the flood peaks were flashy. Duration of floodflow was only IK to 2 days on the main stem and less than 1 day on most of the tributaries. There are no flood-control reservoirs in the basin. Flood-control works are limited to low levees and revetments, most of which were destroyed or seriously damaged. In some locations revet ments aided greatly in preventing serious damage. AREAS OF MINOR FLOODING IN OREGON, WASHINGTON AND IDAHO The floods of December 1955-January 1956 were not serious in the areas of minor flooding. In some cases the peaks ranked second high during the period of record, but in all locations where the record is long or historic data are available, these peaks ranked much below those of the greatest floods. However,, the peaks were extremely unusual in that they occurred during the winter in an area where they generally result from spring snowmelt. The area of minor flooding (fig. 25) includes parts of eastern Oregon, eastern Washington and northern Idaho. The location of the 32 sites (470-480 and 567-587) for which data on stage and discharge are included in this report are shown on the map. The discharge hydrograph for the gaging station on the Wind River near Carson for the 2-month period is presented in figure 26. Damage was negligible in the areas of minor flooding. 115° 123° 122

EXPLANATION .560 Stream-gaging station 557 45 Crest stage or miscellaneous site

Numbers conform to those in table 35

FIGURE 25. Map of areas of minor flooding in Oregon, Washington, and Idaho, showing location of flood-data sites. OX DISCHARGE, IN THOUSANDS OF CUBIC FEET PER SECOND

oo __ o PART 1. DESCRIPTION A77

FLOOD DAMAGE Loss of 72 lives was attributed to the floods of December 1955- January 1956 in the Far Western States. Total damage amounted to about $190 million. Virtually all the damage occurred as a result of the major floods of December, although there was a reoccurrence of flooding in some areas in January. Because the January peaks occurred so soon after the major peak, the additional damage was slight. Immediately after the December floods, surveys of flood damage were begun by the Corps of Engineers, U.S. Forest Service, National Park Service, and Soil Conservation Service, the American Red Cross, various State and county agencies, and other organizations. The Corps of Engineers assembled all available damage reports made by other agencies as well as reports of interviews with many property owners, local organizations, public utilities, and private firms. Flood damage is summarized for each of the principal hydrologic regions.

THE GREAT BASIN Flood damage in the Great Basin amounted to about $4 million; this figure closely approximates the loss sustained in the major floods of November-December 1950. Most severely affected was the city of Reno, Nev., where damage amounted to about $885,000. There were no deaths in the Great Basin attributable to the flood. Table 2 summarizes flood damages by river reaches under five categories of damage. The data in table 2 cover only the flood damage in the three major stream systems of the region the Walker, Carson, and Truckee Rivers. No estimate is included for the minor damage which occurred in other parts of the region.

CENTRAL-COASTAL CALIFORNIA Nine lives were lost in central-coastal California as a result of the floods of December 1955-January 1956, and flood damage totaled more than $27 million. Five lives were lost in the city of Santa Cruz, and damage amounted to $7,629,600 as follows: Flood damage in city of Direct damage Santa Cruz Residential-_-_-_____-_-______._..__...._...____..___ $786, 500 Nonresidential-______5, 442, 400 Roads and streets-_-----.______.______70, 000 Emergency aid______-______199, 800 Indirect damage______1, 130, 900

TotaL--.___-______-. 7, 629, 600 A78 FLOODS IN FAR WESTERN STATES

TABLE 2. Flooded areas and Hood damage in the Great Basin, California, December 1955 and January 1956 [Compiled by Corps of Engineers, Sacramento District]

Flood damage in dollars Flooded Stream and reach area (acres) Agricul Resi Com Industry Public tural dential mercial and facilities Total utilities

Walker River: East Walker River above 9,000 9,000 East Walker River below 1,600 43, 000 43,000 Walker River Reservoir- West Walker River above 7,000 7.000 West Walker River below Pickle Meadows damsite. 4, 500 121, 000 124, 000 245, 000 3,300 67, 000 5,000 104, 000 176, 000 TotaL...... 9,400 231, 000 0 0 5,000 244,000 480,000 Carson River: East Fork above Wata- sheamu damsite.__. ... 245, 000 245, 000 East Fork below Wata- 3,700 237, 000 237, 000 West Fork to Centerville.. 2,000 62,000 20,000 82,000 East and West Forks, Cen- terville to Carson gage__.- 17, 800 147, 000 8,000 308, 000 463,000 Main Carson River, Car son gage to Lahontan-... 11, 500 225, 000 234, 000 459,000 Main Carson River, below 0 Total...... 35, 000 671, 000 0 0 8,000 807, 000 1,486,000 Truckee River: 10,000 10,000 Prosser Creek to Reno___-- 100 75, 000 210, 000 48,000 333, 000 200 55,000 430, 000 61, 000 526, 000 1,072,000 Reno to Vista. . . _ . 6,400 203, 666 42,000 23, 000 268, 000 1,300 68, 000 23,000 91, 000 Derby Dam to Pyramid 1,900 150, 000 102, 000 252, 000 Total- 9,900 496, 000 55,000 430, 000 313, 000 732, 000 2, 026, 000 54,300 1, 398, 000 55, 000 430, 000 326, 000 1, 783, 000 3, 992, 000

1. Agricultural: Damage to crops, farm improvements, and stored supplies; loss of livestock and poultry; and erosion of land and deposition of sand, silt, and debris. 2. Residential: Damage mostly to foundations, floors, furnishings, and yards. 3. Commercial: Damage principally to stores and inventories; to hotels and motels, and to other buildings. 4. Industrial and utilities: Damage largely to power, telephone and gas facilities; railroad facilities; manu facturing plants; and sand and gravel plants. 5. Public facilities: Damage to roads and bridges, levee systems, irrigation diversions and canals, municipal facilities and public schools; all of this property is owned or administered by public agencies or nonprofit political and semipolitical organizations. Also included in this category are expenditures by Federal, State, and local agencies for flood fighting, cost of repairs to flood-control works, cost of caring for evacuated people, losses to the traveling public resulting from damaged highways, and cost of making the flood surveys by the Corps of Engineers.

Table 3 summarizes flood damages in central-coastal California by basins under seven categories of damage. The figures shown in the indirect damage classification are conservative inasmuch as no attempt was made to estimate such intangibles as damage resulting from traf fic delays and re-routing, loss of wages from lack of lumber for con struction, and loss of tourist trade during 1956 as the result of adverse flood-damage publicity. PART 1. DESCRIPTION A79

TABLE 3. Flood damage in central-coastal California, December 1955 and January 1956 [Compiled by Corps of Engineers, San Francisco District]

Direct flood damage in dollars Indirect Total Stream basin flood flood Agri Resi Non- High Rail Emer damage damage cultural dential resi ways roads gency dential aid

Salinas River and small adjacent 49, 600 9,500 33, 900 97, 000 1,500 3,300 194, 800 1, 279, 000 251, 000 50, 500 270, 200 647, 700 763, 100 3, 261, 500 San Lorenzo River.... 159, 800 1, 229, 400 5, 612, 200 273, 800 7,000 232, 400 1,186,300 8, 700, 900 Small Santa Cruz County streams 2 ._ 142, 500 127, 700 394, 400 180, 300 2,100 153, 200 80, 300 1, 080, 500 Small San Francisco Peninsula streams 3 245, 800 40,300 5,800 148, 000 158,900 9,200 608, 000 Santa Clara Valley 1, 392, 700 2,015,900 725, 900 555, 100 15, 500 323,900 356, 600 5,385,600 986, 900 428, 400 1, 804, 300 180, 000 84, 000 641,000 4, 124, 600 Small streams east of San Francisco 347, 300 2, 279, 500 537,300 853, 300 10, 000 4, 027, 400 Total...... 4, 603, 600 6,381,700 9, 164, 300 2, 557, 700 108, 600 1,517,600 3, 049, 800 27,383,300

1 Includes coastal streams to the south, such as Sur and Carmel Rivers. 2 Includes Aptos Soquel, and Scott Creeks. 3 Includes Pescadero, San Gregorio, Tunitas, Pilarcitos, Colma, San Bruno, and San Mateo Creeks. 4 Includes all streams entering San Francisco Bay, south of San Francisquito Creek in the west and south of Coyote Creek. In the east (San Francisquito and Coyote Creeks are included). 5 Includes San Lorenzo, Walnut, Rodeo, Wildcat, Alhambra, Pinole, and San Pablo Creeks.

SAN JOAQUIN VALLEY The widespread flooding in the San Joaquin Valley that resulted from the storms of December 1955-January 1956 caused two deaths and damage totaling $29,580,000. This figure, which exceeds by 38 percent that of $21,591,000 for the severe floods of November-Decem ber 1950, does not include damage to U.S. Forest Service facilities. The flood damage sustained by these facilities in the San Joaquin and Sacramento Valleys was estimated at $1,730,000. Damage in excess of $2 million occurred along each of the following streams: Kaweah River, San Joaquin River main stem, and Calaveras River. The largest concentration of damage was in the Kaweah River basin downstream from the Terminus dam site, where the inun dation of about 125,000 acres of agricultural land and most of Visalia and Farmersville caused losses totaling $11,845,000. Table 4 sum marizes flood damages in the San Joaquin Valley (excluding those sustained by Forest Service facilities) by basins under five categories of damage. An explanation of the items included in each of the five classifications is found in table 2. A80 FLOODS IN FAR WESTERN STATES

TABLE 4. Flooded areas and flood damage in San Joaquiri Valley, Calif., December 1955 and January 1956 [Compiled by Corps of Engineers, Sacramento District]

Flood damage in thousands of dollars Flooded Stream basin area (acres) Agricul Residen Commer Industry Public Total tural tial cial and facilities utilities

Kern River and Tulare Lake basins: 0 62 74 136 11,000 228 44 5 12 26 315 38,000 1,252 116 0 145 412 1,925 126, 200 3.798 3,605 1,727 822 3,407 13, 359 0 14 241 255 Fresno County Stream 500 8 0 4 0 34 46 7,600 573 0 0 0 0 573 San Joaquin River basin: 3 Upper San Joaquin River 4. 2,300 149 0 0 285 55 489 20,100 253 4 0 2 72 331 Chowchilla River _____ 27, 500 257 13 32 9 259 570 Merced County Stream 15,300 233 74 17 24 174 522 3,900 20 0 0 24 542 586 7,100 340 10 0 0 289 639 15, 100 876 54 31 84 893 1,938 10, 700 171 65 4 4 203 447 Lower San Joaquin River r. 25, 500 1,364 53 26 32 379 1,854 8,400 168 0 0 0 0 168 Littlejohn Creek______1,800 22 0 0 4 4 30 6,900 161 1,269 311 97 514 2,352 7,000 199 7 2 0 31 239 27,600 879 1 1 139 329 1,349 5,200 51 0 0 0 47 98 24,900 1,090 0 0 41 228 1,359 Total...... 392, 600 12, 092 5,315 2,160 1,800 8,213 29,580

1 Includes White River, Peso, Cottonwood, and Sand Creeks. 2 Includes Big Dry, Redbank, and Faneher Creeks. 3 Includes Upper Delta. 4 Above Merced River. s Includes, Bear, Mariposa, and Deadman Creeks and their tributaries. 6 Includes Los Banos, Orestimba, and Marsh Creeks. 7 Below Merced River. SACRAMENTO VALLEY Flood damage was widespread throughout the Sacramento Valley and forty persons were reported to have lost their lives as a direct result of the flood; about 30,000 persons were forced to evacuate their homes during the Christmas holiday season. Flood damage in excess of $2 million occurred along each of the following streams: Feather River, Yuba River, and Sacramento River main stem. The largest concentration of damage was in the Yuba City area: damages were estimated at $41,215,000; more than 3,100 homes were flooded; and 38 persons were drowned. Damage in the entire Sacramento Valley was estimated at $66,010,000; this figure does not include damage to Forest Service facilities. The total flood damage sustained by these facilities in the San Joaquin and Sacramento Valleys was estimated at $1,730,000. The magnitude of the disaster wrought by this flood in the Sacramento Valley is strikingly demonstrated by the fact that damage was 6% times greater than the $9,934,000 loss sustained in the notable floods of November-December 1950. PART 1. DESCRIPTION A81

Table 5 summarizes flood damages in the Sacramento Valley (excluding those sustained by U.S. Forest Service facilities) by basins under five categories of damage. An explanation of the items in cluded in each of the five classifications is given in table 2.

TABLE 5. Flooded areas and flood damage in Sacramento Valley,1 Calif., December 1955 and January 1956 [Compiled by Corps of Engineers, Sacramento District]

Flood damage in t lousands of dollars Flooded Stream basin area (acres) Agricul Residen Commer Industry Public Total tural tial cial and facilities utilities

Sacramento River (main stem) and bypasses. 133,000 1,004 128 25 146 1,842 3,145 40,000 35 0 0 0 106 141 Sacramento Valley Creek 2.-._. 31,500 655 19 3 28 535 1.240 100.200 20,946 10.929 2,974 3,850 12, 846 51, 545 4.400 386 50 103 392 2,189 3,120 12,500 1.126 19 33 335 464 1,977 100 0 106 2 413 287 808 Cache Creek...... 11, 600 127 134 69 5 185 520 Putah Creek ______. 400 10 0 0 0 129 139 Tributaries to Cache Slough... 10,400 67 0 0 0 31 98 Lower Sacramento-San Joaquin Delta 3-.---.--. .--- .-- . 1,878 0 0 0 1,399 3,277 Total...... 382, 000 26. 234 11, 385 3,209 5.169 20,013 66, 010 1 Includes Lower Sacramento-San Joaquin Delta. 2 Includes Cow, Cottonwood, Battle, Paynes, Antelope, Mill, Elder, Thomes, Deer, Pine, Rock, Mud, Big Chico, Little Chico, Stony,"Butte, Dry (Placer County), and Elder (Sacramento County) Creeks. 3 Flooding of Little Holland, Prospect, Liberty, Egbert, Empire, Quimby, and other delta islands and tracts.

NORTH-COASTAL CALIFORNIA Sixteen lives were lost in north-coastal California as a result of the floods of December 1955-January 1956, and flood damage totaled more than $43 million. The Eel Kiver basin was hardest hit; flood damage amounted to $22,216,500, about half the total for the entire coastal region. Several communities in the basin, such as Weott, Myers Flat, Pepperwood, Shively, and Bull Creek, were almost completely destroyed. Table 6 summarizes flood damage by basins under seven categories of damage. The figures shown in the indirect-damage classification are conservative as no attempt was made to estimate such intangibles as damage resulting from traffic delays and re-routing, loss of wages from lack of lumber for construction, and loss of tourist trade during 1956 as the result of adverse flood-damage publicity. Only for areas adjacent to U.S. Highway 101, which parallels or traverses most of the flooded area in the region, has an estimate of these intangible losses been made. The conservative estimate of $350,000 was not included in the summary of table 6'because of uncertainty in dividing this loss among the numerous basins involved. A82 FLOODS IN FAR WESTERN STATES

TABLE 6. Flood damage in north-coastal California, December 1955 and January 1956 [Compiled by Corps of Engineers, San Francisco district]

Direct flood damage in dollars Indirect Total Stream Basin flood flood Agri Resi Non- High Rail Emer damage damage cultural dential resi ways roads gency dential aid

172,300 48, 500 121,800 136, 800 62, 600 542, 000 Sonoma and Peta- luma Creeks. _____ 361, 400 40,300 35, 800 26, 000 40, 000 10, 000 34, 700 548, 200 Small Marin County 281,300 191, 400 229, 600 267, 600 14, 200 117, 100 1, 101, 200 830, 400 864, 300 1,411,500 767, 700 55, 000 427, 600 660, 700 5, 017, 200 Streams between Russian and Eel 57, 400 3,700 104, 400 848, 500 50, 000 28, 200 1, 092, 200 Eel River...... 3, 575, 900 2, 729, 300 5, 836, 100 4, 192, 700 2, 050, 000 2, 131, 100 1,701,400 22,216,500 311,800 3,600 355, 900 354, 300 221,300 76, 200 1, 323, 100 44, 900 64,900 159, 500 130, 100 28, 900 168, 800 597, 100 467, 800 689, 200 3, 030, 200 4, 803, 900 1, 471, 100 10, 462, 200 49, 100 7,700 70, 000 336, 000 5,700 468, 500 Total.___ ...... 6, 152, 300 4, 642, 900 11,354,800 11,863,600 2, 145, 000 2, 883, 100 4, 326, 500 43, 368, 200

1 Includes December damage for Norato, Miller, Oallinas, San Rafael, Corte Madera, and Lagunitas Creeks; January damage for Stinson, Redwood, Tennessee Valley, San Rafael, and Coyote Creeks. 2 Mattole River basin was the only basin in which appreciable damage, other than highway damage, occurred. WEST-CENTRAL IDAHO Damage was comparatively light in west-central Idaho, and there was no loss of life attributable to the floods. The total damage amounted to about $1.5 million, almost half of this loss occurred in the Little Salmon River basin. A detailed breakdown of flood losses by various categories of damage is not available, but from information furnished by the Corps of Engineers, U.S. Forest Service, and the State of Idaho Department of Highways, the following tabulation has been made. Boise River basin Flood damage Highways----_-_---___-_-______-_--_-______-___.. $220, 000 Other______30,000 TotaL ______250,000 Payette River basin Highways--______50, 000 Other.______175,000 Total--______-_____-_-_--__--______-______-_--_- 225, 000 Weiser River basin Highways.-______85, 000 Other-_-_--______^______200, 000 TotaL______285, 000 Little Salmon River basin Highways---.______572, 000 Other-._----_--_-______-_-____-___-__-______-_-_-_---_ 113,000 Total- 685, 000 Grand total..______1, 445, 000 PART 1. DESCRIPTION A83

WILLAMETTE VALLEY Flood damage in the Willamette Valley was widespread and amount ed to about $8.7 million. Two lives were lost as a direct result of the flood. Losses undoubtedly would have been much higher had it not been for the flood-control reservoirs and protective bank works. The Eugene-Springfield area on the Willamette River main stem, Cottage Grove on the Coast Fork, and agricultural lands along the Middle Fork Willamette and North Santiam Rivers were protected from significant inundation by reservoirs, and in all other areas below reservoirs greater damages were prevented. Reduction of stages on the main stem was especially effective in reducing residential, industrial, and commercial property damage since such properties are generally at altitudes affected only by high floods. Of the total damage, 62 percent was agricultural; 17 percent was to flood control and navigation facilities; 14 percent was residential, commercial, and industrial; and 7 percent was damage to railroads, utilities, highways, schools, and other property. Table 7 summarizes flood damage by main-stem river reaches or tributary basins under five categories. The data were originally compiled by the Corps of Engineers, Portland District, under 14 categories but they have been combined to conform to the classifi cations described in table 2. Damage to navigation facilities, which was not a factor in the Great Basin discussion, is included under the public-facilities category. TABLE 7. Flood damage in Willamette Valley, Oregon, December 1955 and January 1956 [Compiled by Corps of Engineers, Portland District]

Flood damage in dollars Stream basin Agricul Res Com Industrial Public tural idential mercial and facilities Total Utilities

24, 210 27, 310 25,240 75,200 151, 960 30,000 78, 500 108, 500 306, 850 8,850 11, 660 31, 250 244, 800 603,410 Willamette River mainstem, Albany 806, 320 660 11, 020 19,630 311,910 1, 149, 540 Long Tom River and Amazon Creek. 174. 140 70,000 25,000 15, 000 236, 290 520 430 Marys River and West Muddy Creek. 49, 470 49, 470 49, 050 500 49, 550 144, 420 3,600 59, 950 23,600 231, 570 Willamette River mainstem below 1, 083, 000 23,220 20, 230 491, 400 484, 430 2, 102, 280 313, 400 4,500 7,500 2,000 164, 000 491, 400 254, 350 69,700 324, 050 159, 530 1,600 29, 480 190, 610 13, 250 29,440 4,220 26,920 10, 130 83,960 326, 160 19, 330 2,710 100, 600 107, 690 556, 490 66. 080 2,900 500 42. 470 111,950 517, 910 900 2,300 521, 110 1, 094, 250 93, 780 13,900 18, 810 62, 330 1, 283, 070 3,060 140 28, 150 31.350 5,100 50,200 22,380 9,840 19, 650 107, 170 5, 396, 340 330, 830 146, 830 802, 740 1,991,130 8, 667, 870 A84 FLOODS IN FAR WESTERN STATES

COASTAL OREGON As a result of the widespread floods in coastal Oregon, three lives were lost and damage totaled $9.3 million. About 43 percent of this damage occurred in the Rogue River basin; 28 percent occurred in the Coquille River basin; 23 percent occurred in the Umpqua River basin; and the remaining 6 percent was divided among five other coastal basins. Table 8 summarizes flood damages by basins under five cate gories. The data were originally compiled under 15 categories by the Corps of Engineers, Portland District, but have been combined to conform to the classifications described in table 2. The total damage of $540, 200 shown for "Other coastal streams" (table 8) was distrib uted among five basins as follows : Basin Damage Nehalem River______$25, 710 Tillamook Bay streams______110, 210 Nestucca River______67, 900 Siuslaw River______209, 160 Coos River______127, 220

Total-.______540,200

TABLE 8. Flood damage in Coastal Oregon, December 1955 and January 1956 [Compiled by Corps of Engineers, Portland District]

Flood damage in dollars Stream basin Agricul Res Com Industrial Public tural idential mercial and facilities Total Utilities

Umpqua River. ______673, 740 553, 870 108, 910 623, 140 183,480 2, 143, 140 CC AQft 9,600 1, 287, 710 248, 600 2, 596, 830 1, 366, 910 1, 097, 510 692, 880 387,860 503, 370 4, 048, 530 269, 540 24, 610 13,400 195, 670 36,980 540,200 Total...... 3, 304, 420 1, 732, 680 824, 790 2, 494. 380 972, 430 9, 328, 700

1 Includes Tillamook Bay streams, Nehalem, Nestucca, Siuslaw, and Coos Rivers.

AREAS OF MINOR FLOODING IN OREGON, WASHINGTON, AND IDAHO Damage in these areas as a result of the floods of December 1955- January 1956 was slight, and was not tabulated.

FLOOD-CREST STAGES Flood-crest stages are given for the San Joaquin River and 4 of its major tributaries (table 9), the Sacramento River and 2 tributaries (table 10), and the Eel River and 3 tributaries (table 11). Readings were made by the agency operating the gage, as indicated in the tables. PART 1. DESCRIPTION A85 TABLE 9. Flood-crest stages, December 1955 and January 1956, San Joaquin Valley, Calif.

Miles Altitude Stream and location above Day and hour (feet) mouth

San Joaquin River: 1955 268. 1 Dec. 26, 5 p.m____-_ 302.7 Friant Dam, left bank.1 Whitehouse, 13 miles down 219.8 Dec. 28, 3-9 a.m.-__ 178.8 stream from Gravelly Ford Canal, right bank.2 1956 206.2 154. 1 from Mendota Dam, left bank.3 186.0 129.8 from Temple Slough, left bank.3 1955 Fremont Ford Bridge, 5.7 miles 129.5 Dec. 29, l-8p.m.___ 69.9 upstream from Merced River.1 Newman, at Hills Ferry Road 123.7 Dec. 29, 5 and 10 65. 1 bridge, 300 ft downstream from p.m. Merced River.1 m e Dec. 30, 6 a.m _ _ _ 57.8 downstream from Merced River.4 96.0 Dec. 30, 10p.m _____ 42.0 Slough channel of San Joaquin River at Westley-Modesto highway bridge, 5 miles up stream from Tuolumne River.4 81.8 Dec. 26, 1 a.m___.__ 35.6 upstream from Stanislaus River.4 76.7 32.3 bridge, 3.0 miles downstream from Stanislaus River.1 Mossdale, just downstream from 58.9 Dec. 29, 10:30 a.m __ 20.6 U.S. Highway 50 bridge, right bank.4 4. 5 Dec. 26, 8 a.m_.____ 6.2 works, left bank.4 Merced River: 62.2 Dec. 27, 6 a.m______411 from Lake McClure.1 42. 1 Dec. 24, 4 p.m. ___ 190.5 highway bridge.4 97 fi Dec. 27, 8 a.m__-.__ 119.6 highway bridge, left bank.4 4.6 Dec. 28, 4 a.m______74.2 Tuolumne River: c7 fi Dec. 24, 11 a.m... _ 364 downstream from Don Pedro dam.1 50. 5 Dec. 24, 11 a.m____. 184. 1 Roberts Ferry Bridge, 7.5 miles 39.9 Dec. 24, 2:30p.m.___ 125.2 east of Waterford.4 Q1 7 Dec. 24, 6 p.m______91.9 16.0 66.4 U.S. Highway 99 bridge, left bank.1 3.4 Dec. 25, 9 a.m____ _ 46.3 bridge.4 See footnotes at end of table. A86 FLOODS IN FAR WESTERN STATES TABLE 9. Flood-crest stages, December 1955 and January 1956, San Joaquin Valley, Calif. Continued

Miles Altitude Stream and location above Day and hour (feet) mouth

Stanislaus River: 65.3 Dec. 23, (?)_..__-__. 529 mile downstream from Melones Dam.1 1956 Orange Blossom Bridge, 5.7 miles 44.7 Jan. 16, 9 a.m ___ __ 142.7 upstream from Oakdale.4 Riverbank, at Burneyville 32.0 Dec. 23, 11:30 p.m.. 103.2 Bridge.4 15.9 Dec. 24, 9 a.m...... 63.2 downstream from railroad bridge, left bank.1 Mokelumne River: 72.0 Dec. 23, 10 p.m. ___ 178. 1 stream from Pardee Dam, left bank.1 59.0 Dec. 24, 3 a.m___ _. 91.0 lone highway bridge, left bank.1 Woodbridge, 0.4 mile down 38.8 Dec. 24, 2 p.m....___ 43.9 stream from Woodbridge Irrig. Dist. diversion dam, left bank.1 Georgiana Slough, right bank, 3.4 Dec. 26, l:30p.m___ 10.3 300 ft upstream from Moke lumne River.4

i U.S. Oeol. Survey. * San Joaquin Canal Co. s U.S. Bur. Beclamation. 4 California Dept. Water Resources. Tables 9 and 10 present the maximum stages recorded during the entire December 1955-January 1956 flood period and are generally those of the December 22-26 floods. However, because the January floods in the upper Sacramento Valley in some instances exceeded those of December, and because storage and bypass regulation and intervening tributaries were controlling factors on both the Sacra mento River between Shasta Dam and the American River, and the San Joaquin River between Friant Dam and the Stanislaus River, the tabulation of crest stages does not represent the con tinuous downstream travel of a single flood crest. The stage records of tables 9 and 10 are of particular value in presenting a limiting factor with respect to the location of future flood-control along these rivers. Where it is obvious that the down stream travel of a single flood is represented in the tables (Tuolumne, Mokelume, and Feather Rivers), information in regard to velocity of transmission of flood crests, valley or channel storage, and other aspects of river behavior may be determined. PART 1. DESCRIPTION A87

TABLE 10. Flood-crest stages, December 1955 and January 1956, Sacramento Valley, Calif.

Miles Altitude Stream and location above Day and hour (feet) mouth

Sacramento River: 1955 Keswick, 0.6 mile downstream 309.5 Dec. 28, 8:30 a.m ____ 506.7 from Keswick Dam, right bank.1 1956 Redding, 0.5 mile downstream 299.7 Jan. 3, 11:30 a.m____ 451. 1 from Anderson-Cottonwood Irrig. Dist. diversion dam, left bank.2 1955 Balls Ferry, left bank 2 ______283.5 Dec. 22, 2 a.m______369.7 1956 Red Bluff, 5 miles upstream, 257.6 Jan. 15, 6:30 p.m _ _ 275.5 left bank.1 Red Bluff, U.S. Highway 99E 252.4 Jan. 15, 6 p.m______260.6 bridge.3 1955 225.5 Dec. 22, 7 p.m-_____ 184.3 208.5 Dec. 23, 6 a.m____._ 143.3 Bridge, left bank.2 1956 189.8 Jan. 16, 4 a.m __ __ 115.6 174.8 Jan. 16, 1 p.m _____ 91.6 left bank.1 162.9 80.2 bank.2 148.4 Jan. 17, 2 a.m __ __ 63.8 highway bridge, right bank.1 138.8 Jan. 17, 9 a.m __ ___ 58.2 Railway bridge.2 123. 2 Jan. 17, 8 p.m___ __ 47.9 bank.2 4 1955 122. 8 Dec. 24, 12 m _ .___ 48. 2 Company pumping plant, left bank.2 m a Dec. 24, 10 p.m__ _ 47.6 stream from Reel. Dist. 108 irrigation pumping plant, right bank.1 93.0 Dec. 23, 4 p.m______38.2 from Southern Pacific Railroad bridge, left bank.1 87.0 Dec. 23, 3 p.m______36.7 right bank.124 Fremont Weir, downstream end, 82.0 Dec. 23, 2:15 p.m_._ 35.6 right bank.2 78.6 Dec. 23, 3 p.m ___ _ 36.7 Feather River, left bank.1 1956 Sacramento Weir, 100 ft. down 63.2 Jan. 17, 1:30 a.m.___ 28.9 stream, right bank.2 4 1955 Sacramento, I Street bridge, left 59.4 Dec. 23, 4:30 p.m _ 28.8 bank.123 See footnotes at end of table. 66S521 O 63 7 A88 FLOODS IN FAR WESTERN STATES TABLE 10. Flood-crest stages, December 1955 and January 1956, Sacramento Valley, Calif. Continued

Miles Altitude Stream and location above Day and hour (feet) mouth

1955 Freeport, 2.6 miles upstream, 48.6 Dec. 23, 9:30p.m_._ 23.9 right bank.1 Clarksburg, dock of American 42.2 Dec. 23, 5:30p.m ___ 21.0 Crystal Sugar Company, right bank.1 2 36.7 Dec. 23, 5p.m.__ _ 17.5 stream, left bank.12 26. 5 Dec. 24, 10 a.m.____ 13. 0 from Georgiana Slough, left bank.2 17.4 Dec. 24, 1 p.m_ ___ 8.4 Rio Vista, 1 mile downstream, 11.7 Dec. 26, 12:15 p.m__ 7.2 right bank.4 Collinsville, right bank 2 _ ___ . 2 Dec. 26, 12:30p.m._ 6. 2 Feather River: Oroville, 75 ft. upstream from 71.0 Dec. 23, 12:30 p.m_. 258.6 U.S. Highway 40A bridge, left bank.1 4Q 7 Dec. 23, 7 p.m_._ __ 99. 2 way bridge, left bank.2 Yuba City, Sacramento Northern 28.0 Dec. 24, 12:20 a.m.. 79.4 Railway bridge, right bank.2 23. 0 Dec. 23, 12 p.m____. 73.8 Yuba City, right bank.2 Nicolaus, 0.5 mile downstream 9.2 Dec. 23, 12:20 p.m.. 48.6 from highway bridge, left bank.1 American River: 19.2 85. 1 old highway bridge, right bank.1 6.5 Dec. 26, 12 p.m_.___ 35.9 left bank.1 3.7 Dec. 24, 12 m._.__._ 32. 5 bridge.12 .2 Dec. 23, 5p.m______29. 6 bridge.2

1 U.S. Geol. Survey. 2 California Dept. Water Resources, s U.S. Weather Bur. 4 Corps of Engineers. 5 U.S. Bur. Reclamation. Table 11 differs from the preceding two tables in that it gives the maximum stages of only the flood of December 22, 1955. Many of the data were obtained by leveling to high-water marks left by the flood rather than from gage readings and as a result, time of occurrence could not be established. However, the records of peak stage should be of value for future developments along the Eel River. Some of the data presented in table 11 were furnished by the Corps of Engineers and the remainder by the Geological Survey. PART 1. DESCRIPTION A89

TABLE 11. Eel River flood-crest stages, flood of Dec. 22, 1953, north-coastal California

Miles Altitude Miles Altitude Stream and location above (feet) Stream and location above (feet) mouth mouth

Eel River Cmainstem) : South Fork Eel River: 163.5 71 1,400 163 1,760 T jftjrofpf*- 56 728.8 1 AQQ 3 52 664.8 Piercv 44 515. 0 152 40 443.6 116 1,000 34 380.5 Moutli of Middle Fork Eel 30 324.7 114 27 303.6 112 21 290 69 340 18.5 240.1 Mouth of South Fork Eel One mile downstream from River...... ______.. 165 f, 13.5 220.8 35 137.1 7.5 197.0 Shively...... 33 133 3 2.5 171.6 Elinor...... 30 128.6 Mouth (mile 41 on Eel Stafford-...... 118.6 .0 165.6 22.5 98.0 Mouth of Van Duzen River 14.7 58.0 Former gage at Bridgeville_ 20 622.0 32.0 16 420 7.0 14.0 6.5 131.3 Eel River School on Canni 2.8 80.2 bal Road...... 0.5 11.6 .3 58.0 Middle Fork Eel River: Mouth (mile 14.7 on Eel Mouth of Black Butte River 30.4 .0 58.0 Mouth of Williams Creek.. 27.9 1, 396. 4 Mouth (mile 114 on Eel 0.0 910

STORAGE REGULATION THE GREAT BASIN Reservoir storage in the major stream basins draining the eastern slope of the Sierra Nevada was effective in reducing the magnitude of the flood runoff in some parts of the Great Basin region. In the Walker River basin, Bridgeport Reservoir retained all of the flood waters from the East Walker River above Bridgeport, Calif. Topaz Reservoir, an off-channel storage site on the West Walker River, also provided some relief when part of the floodwaters was diverted to storage during the critical period. Between December 20 and 31, about 27,000 acre-feet of floodwater was stored in these two reservoirs; this storage significantly reduced the flood peak down stream. There is relatively little storage on the upper Carson River, and its regulatory effect on flood peaks was slight. However, Lahontan Reservoir on the lower Carson River, which was at a low level prior to the floods, was able to contain the floodflows and thus provided adequate flood protection for the city of Fallon and the rich farmland in that vicinity. The flood runoff from the Truckee River drainage area above the outlet of Lake Tahoe was all stored, as there was no outflow from the lake from December 21 to January 31. During this period, the lake rose 2.25 feet, and its contents increased 270,000 acre-feet. The A90 FLOODS IN FAR WESTERN STATES

storage capacity of Lake Tahoe is large compared to the yield of the contributing area. Thus, during all major floods for the period of record, outflow from Lake Tahoe has been insignificant compared with peak discharge downstream. Boca Reservoir near the mouth of the Little Truckee River played a major role in reducing the flood peak downstream. Although the available storage at the time of the peak inflow on December 23 was only between 10,000 and 15,000 acre-feet, this was sufficient to reduce somewhat, and detain, the peak outflow so that it did not coincide with the peak flow of the Truckee River. The retention of the Little Truckee River peak discharge in Boca Reservoir undoubtedly reduced the peak flow of the Truckee River through Reno and in reaches below the reservoir, perhaps as much as 8,000 or 9,000 cfs. Pyramid Lake at the lower end of the Truckee River rose 0.8 foot between October 20, 1955 and January 10, 1956, and 0.5 foot between January 10 and February 24.

CENTRAL-COASTAL CALIFORNIA

Reservoir storage appreciably affected flood runoff and reduced the magnitude of peak flow in the Santa Clara Valley in December 1955, but it was of lesser benefit in the other basins of central-coastal Cali fornia. In the Salinas River basin the only surface storage facility is the Salinas conservation reservoir in the upper part of the basin. Because this reservoir controls only 111 of the 4,231 square miles upstream from Salinas River gage near Spreckels, its effect on down stream peaks was slight. Of prime importance in reducing floodflow in the lower basin of the Salinas River is the natural storage afforded by the river channel and the pervious alluvium in which the wide streambed lies. As a result of natural storage, the peak discharge of Salinas River near Bradley was 25,000 cfs, although two upstream tributaries, the Nacimiento and San Antonio rivers, had peak dis charges of 58,600 and 14,500 cfs, respectively. At Salinas River near Spreckels gaging station downstream from Bradley, the peak dis charge was 23,600 cfs, despite the fact that a single intervening tributary, Arroyo Seco, had a peak discharge of 27,700 cfs. In the Pajaro River basin there are two conservation reservoirs; one on Uvas Creek and the other on Pacheco Creek. These reservoirs effectively reduced downstream peaks, but a more important factor was the combination of streambed percolation and channel storage upstream from the Chittenden gaging station on Pajaro River. The topography of the area is such that water was virtually pooled over 7,900 acres at the mouths of tributary streams upstream from the naturally constricted channel at Chittenden Pass. PART 1. DESCRIPTION A91

In the Santa Clara Valley there are eight principal conservation reservoirs ranging in capacity from 2,000 to 75,000 acre-feet. These reservoirs, especially the larger reservoirs that exercised complete control of Coyote Creek upstream from Madrone and Los Gatos Creek (a tributary of Guadalupe Creek upstream from the city of Los Gatos), were very effective in reducing peak discharge. The effect of this storage in reducing potential flood damage in north western Santa Clara County becomes evident when it is realized that the only divide between Coyote Creek and the Guadalupe River along the almost parallel courses through the city of San Jose to San Fran cisco Bay is formed by the leveelike banks of silt that have been deposited by the streams at high stages. In the Alameda Creek basin, downstream floodflows were reduced appreciably by a combination of the complete control of Calaveras Creek by Calaveras Reservoir, the natural storage provided by the stream channels, and stream-bed percolation. The peak rate of inflow into Calaveras Reservoir is not accurately known because reservoir stages were read only once daily, but these readings do in dicate a maximum 24-hour inflow rate of about 7,000 cfs. More striking in the matter of peak-flow reduction is the fact that two main-stem tributaries, Arroyo Valle and Arroyo de la Laguna, had peak discharges of 18,200 and 24,800 cfs. repsectively, whereas the peak discharge downstream on the main stem near Niles was only 29,000 cfs. On some of the small streams in the San Francisco Bay area, such as San Leandro and San Pablo Creeks, the entire runoff from the drainage areas above the reservoirs was stored. SAN JOAQUIN VALLEY Reservoir storage substantially reduced the magnitude of peak floodflow on many streams in the San Joaquin Valley area. All of the major reservoirs are on the east side of the valley on streams draining the Sierra Nevada. The most notable regulations were those by Isabella Reservoir on the Kern River, Pine Flat Reservoir on the Kings River, and Millerton Lake on the San Joaquin River. Each reservoir completely controlled the December floodflows to nondamaging releases. The increase in storage during the flood-runoff period, the estimates of peak inflow and outflow, and the resulting reduction in the peak discharge for these and the other major reser voirs in the San Joaquin Valley are given in table 12. The estimated reduction in peak discharge at the gaging stations downstream from these reservoirs was essentially the same as that shown in the last column of table 12, and varied only because of intervening tributary inflow. A92 FLOODS IN FAR WESTERN STATES

Additional regulation is afforded by the large storage capacity in the many miles of channels and sloughs, the bypass channels, and the many square miles of lowland subject to flooding.

TABLE 12. Functioning of reservoirs in reduction of December 1955 Hood discharge^ San Joaquin Valley, Calif. [Compiled by Corps of Engineers]

Available Reduc space at Space Peak Peak tion in Reservoir Stream basin beginning used inflow outflow peak of flood (acre-feet) (cfs) (cfs) discharge (acre-feet) (cfs)

64,000 25,000 575 24,400 Pine Flat...... 890,000 367,000 112,000 240 111,800 . .do...... 21,000 160 -.-do...... 332,000 282,000 96,000 6,000 90,000 16,900 15,000 5,800 9,200 3,840 2,800 600 2,200 7,700 8,940 11,000 4,450 6,550 8,470 8,600 2,600 6,000 257,000 256,000 102.000 10,700 91, 300 20,000 24,000 ..do...... 268.000 3 40, 700 20,000 3 9,000 11,000 .... .do...... 740 .....do...... 214.000 100,000 42.200 57,800 90,000 93,000 102, 000 62,800 39,200 52,000 31,700 20,000 1,900 18,100 76,000 53,600 31,000 11,100 19,900 .....do...... 103,500 59,300 Pardee ...... do...... 13,500 23,000 . 26,000 24,800 1,200

1 Southern California Edison Co. reservoirs: Florence, Huntington, and Shaver lakes. 2 Merced County Stream Group; Corps of Engineers. 3 Interim operation with uncontrolled outlets.

In the lower San Joaquin River, the peak discharge at the Vernalis gaging station did not exceed 50,900 cfs on December 25 because of (1) the regulation afforded by the reservoirs on the major tributaries, the Merced, Tuolumne and Stanislaus Rivers, (2) the channel storage on these tributaries below the reservoirs and on the main stem, and (3) the absence of coincidence in the peak flows from the tributaries. The peak flow of 11,200 cfs from the Merced River at Stevinson occurred on December 28. On the Tuolumne River, the maximum controlled release from Don Pedro Reservoir was 41,700 cfs on December 24. Channel storage was effective in reducing this peak to 37,600 cfs at the gaging station on the Tuolumne River at Modesto on December 25. On the Stanislaus River, Melones Reservoir filled and spilled on December 23, and the peak discharge of 62,800 cfs at the Melones station on that date was only slightly reduced to 62,500 cfs at the Ripon gaging station on December 24. Regulation by the tributary reservoirs and channel storage was such that during the November 18-23, 1950 flood the discharge at the Vernalis station did not exceed 33,000 cfs. However, during the second flood period of December 3-10, 1950 the tributary reservoirs were nearly full or spilling and maximum releases to maintain flood control PART 1. DESCRIPTION A93 capacity were coincidental. The result was the record peak discharge at the Vernalis gage of 79,000 cfs.

SACRAMENTO VALLEY Although there are fewer major storage reservoirs in the Sacra mento Valley than in the San Joaquin Valley, reservoir storage reduced the peak flow on a number of the larger streams. In the Sacramento Valley area, the outstanding regulations of the December floodflows were those of Shasta Lake on the Sacramento River and Folsom Reservoir on the American River. At each of these reser voirs a recordbreaking peak inflow was reduced to outflow of nondamaging proportions. Table 13 gives the reduction in the peak discharge due to storage in 12 reservoirs in the Sacramento Valley. Some of these reservoirs are on smaller headwater tributaries to the main stream, and as a result the full storage space available at the beginning of the flood period could not be utilized. The reduction in peak discharge at the gaging station on the Sacramento River at Keswick due to storage in Shasta Lake was estimated as 144,000 cfs, and that at the Fair Oaks gaging station on the American River below Folsom Reservoir was estimated as 154,000 cfs. These de creases in peak flows prevented much flood damage downstream. Channel storage is another moderating factor, particularly in the valley reaches of the Sacramento River and its tributaries. The miles of channels and sloughs, the extensive bypass system of the Sacra mento River Flood Control Project, and the many square miles of lowlands afford a large storage capacity which aids in the reduction of peak flow on the lower Sacramento River.

TABLE 13. Functioning of reservoirs in reduction of December 1955 Hood discharge, Sacramento Valley, Calif. [Compiled by Corps of Engineers]

Available Reduc space at Space Peak Peak tion in Reservoir Stream basin beginning used inflow outflow peak of flood (acre-feet) (cfs) (cfs) discharge (acre-feet) (cfs)

193, 000 46,800 146, 200 East Park...... 47, 000 37,000 6,700 0 6,700 Stony Gorge __ ...... do...... 44, 700 34, 300 14,000 9,600 4,400 21, 800 .-..do...... 390, 000 71,300 Butt Valley,...... do . OQ nnr\ 18,000 Bucks Creek...... do...... 28,500 61,000 South Yuba System '. --..do .. - ---.. 66.400 .do...... 15, 700 31,500 159, 000 153, 000 6,000 Folsom._ ____ ...... 790, 000 670, 000 210, 000 70,000 149, 000 221,000 158,000 30,000 3,100 26, 900

1 Pacific Gas and Electric Co. reservoirs. A94 FLOODS IN FAR WESTERN STATES

NORTH-COASTAL CALIFORNIA The few storage reservoirs in the basins of north-coastal California were effective in moderating flood damage during December 1955. The flow of Conn Creek, a tributary of the Napa River, is regulated by Lake Hennessey. The peak discharge of 3,600 cfs spilled over Conn Dam 30 hours after the flood crest on the Napa River reached the mouth of Conn Creek. On Novato Creek spill started over Novato Dam more than 15 hours after peak flooding occurred downstream in Novato. The one storage reservoir in the Eel River basin, Lake Pillsbury, receives the runoff from 288 square miles of headwater drainage. Lake Pillsbury filled before peak inflow occurred, so the peak outflow of 40,000 cfs was essentially natural flow. Runoff in the upper Klamath River basin is effectively controlled by Upper Klamath Lake. Further modification of peak-discharge rates results from the perviousness of the soil and mantle rock in the headwater regions, and from the natural storage provided by extensive marsh areas upstream from Upper Klamath Lake. In the flood of December 1955, the streams tributary to Upper Klamath Lake had only moderately high peak rates of runoff, and therefore no great reduction in outflow was made. On the Shasta River in the Klamath River basin, Lake Dwinnell stored the entire flood runoff from 139 square miles. The peak rate of inflow was about 4,300 cfs. WEST-CENTRAL IDAHO Reservoir storage played an important part in reducing the magni tude of flood peaks in the Boise, Payette, and Weiser River basins and on the main stem of the Snake River below the mouth of the Boise River. The three major reservoirs above Boise, namely, Arrowrock, Anderson Ranch, and Lucky Peak Reservoirs gave an outstanding example of flood control. Arrowrock Reservoir was built primarily for irrigation storage, Anderson Ranch Reservoir provides power, and Lucky Peak Reservoir has part of its capacity committed to flood control. Under the operating agreement, the three reservoirs are coordinated under runoff-forecasting procedures to effect flood control; during the December 1955 flood the reservoirs completely cut off the flow. The highest flood on the Boise River during 44 years of record occurred in 1943, when the peak discharge at Boise was 21,000 cfs. On the day of the peak flood runoff in December 1955, a daily mean flow of about 22,000 cfs went into storage. Computation of the actual reduction in peak flow at Boise has not been made, but it is evident that a damaging flood on the lower Boise River was averted. Major regulation in the Payette River basin was effected by Cascade Reservoir on the North Fork. The December 1955 peak discharge PART 1. DESCRIPTION A95 on Payette River near Emmett was approximately equal to the max imum peak of record. A significant effect of storage becomes evident when it is considered that a daily mean flow of about 9,000 cfs went into reservoir storage on the day of peak runoff in December 1955 compared with a peak of less than 2,000 cfs during the flood of 1938. Water was not released from Crane Creek Reservoir until about 14 hours after the crest on the Weiser River had passed the gaging station below the mouth of Crane Creek. The peak discharges of four tribu taries of the reservoir totaled 5,800 cfs and probably occurred at about noon on December 22. If unrestricted by the reservoir, this flow would have contributed to the Weiser River when its flow was about 19,300 cfs. If allowances are made for differences in timing of the tributary peaks and flattening of the crest as the flow proceeded down Crane Creek, it appears that the Weiser River peak discharge down stream from Crane Creek would have been about 24,000 cfs. The peak discharge on Snake River at Weiser was 52,500 cfs at 1 a.m. on December 24. Only the storage effects discussed above for the Boise and Payette Rivers materially affected the peak flow at Weiser. It appears that if this storage had not existed the peak discharge at Weiser would have been at least 20,000 cfs higher. It is pertinent to note that as a result of reservoir storage the discharge of Snake River at Milner did not exceed about 1,100 cfs during and prior to the flood peak on the lower river. Little Wood River Reservoir reduced what could have been a much more serious flood on the Little Wood River. Ice jams play an important part in the damaging effects of winter floods on this stream; hence the reduction of flow during the December 1955 flood is particularly significant. The peak discharge at the gaging station above the reservoir was 3,110 cfs on December 22, which exceeds by 760 cfs the previous maximum for 21 years of record. The reservoir was discharging only about 50 cfs at the time of the peak, thus reducing the peak discharge by more than 3,000 cfs.

WILLAMETTE VALLEY Reservoir storage and flow regulation significantly reduced the flood peaks of the Willamette River and some of its larger tributaries. The five major flood-control reservoirs in the Willamette Valley are: Lookout Point Reservoir on the Middle Fork Willamette River, where about 228,000 acre-feet of runoff was stored during December 20-24; Cottage Grove Reservoir on the Coast Fork Willamette River, where 25,000 acre-feet of runoff was stored December 19-23; Dorena Reservoir on the Row River, where 60,000 acre-feet of runoff was stored December 19-23; Fern Ridge Reservoir on the Long Tom River, where 110,000 acre-feet of runoff was stored December 19-26; A96 FLOODS IN FAR WESTERN STATES and Detroit Reservoir on the North Santiam River where 160,000 acre-feet of runoff was stored December 19-24. The reduction of peak discharges from this storage regulation is shown in table ] 4 for the gaging stations below the reservoirs and on the main stem of the Willamette River. The peak outflow from the reservoirs generally occurred several days after the peak inflow. Channel storage was also effective in reducing the peak discharge, particularly in the lower reaches of the Willamette River. For instance, the peak flow of 240,000 cfs at Salem on December 23 was reduced to 235,000 cfs at Wilsonville on December 24, primarily as a result of channel storage, despite inflow from 1,120 square miles of intervening drainage area.

TABLE 14. Reduction of December 1955 flood discharge by storage regulation, Willamette Valley, Oreg.

Estimated Observed Reduction in peak unregulated regulated Gaging station peak dis peak dis charge1 charge Stage Discharge (cfs) (cfs) (feet) (cfs)

Middle Fork Willamette River near Dexter (below Lookout Point Res- 76, 000 16, 900 59, 000 Coast Fork Willamette River below 8, 000 3, 220 4, 780 Row River near Cottage Grove (be- 23, 200 9, 060 14, 100 Willamette River at Eugene _ _ _ 124, 000 1 40, 500 »9. 1 1 83, 500 190, 000 114, 000 3. 2 76, 000 Long Tom River below Fern Ridge 24, 000 10, 400 13, 600 Willamette River at Albany 231, 000 155, 000 4. 4 76, 000 North Santiam River at Niagara 37, 200 15, 100 22, 100 Willamette River at Salem 304, 000 240, 000 4. 0 64, 000 Willamette River at Oregon City _ 332, 000 1 279, 000 i 1.7 1 53, 000

1 Furnished by the Corps of Engineers.

COASTAL OREGON Surface storage regulation had little effect on flood peaks in coastal Oregon as there are no reservoirs or ponds of appreciable size in the area. However, water going into ground storage may have sub stantially reduced the flood peaks in the North Umpqua and Rogue River basins. In the upper part of these basins in the vicinity of Crater Lake the soil is derived from very porous volcanic mantle rock that absorbs an immense quantity of rain and snow water and PART 1. DESCRIPTION A97 releases it gradually as ground-water outflow during the ensuing weeks and months. This ground-water movement has considerable effect in maintaining relatively high flows during the low-water season and undoubtedly reduces floodflows significantly.

RECORDS OF PREVIOUS FLOODS AND FLOOD FREQUENCIES

Notable floods on major streams in western Nevada are discussed in Water-Supply Papers 843 and 1137-H, and descriptions of historic floods in California are found in Water-Supply Papers 843, 1137-E, 1137-F, 1260-D, and 1320-D. Similar information for Oregon is found in Water-Supply Papers 968-A, 1080, 1137-E, and 1320-D, and past floods in Idaho and Washington are discussed in Water- Supply Paper 1080. The historical data found in those reports are not repeated on the pages that follow, but the comparative rank of the various floods is discussed. No flood-frequency tabulations or graphs have been prepared for the Great Basin because no gaging stations on major streams in the flood area there have as much as 20 years of continuous record of natural momentary annual peak discharge. To illustrate the recurrence interval of floods at selected gaging stations in various regions in California, tabulations have been made of annual flood peaks and flood-frequency curves (figs. 27-28) have been prepared from them for nine gaging stations which have been in continuous operation since October 1916 and which are unaffected by regulation or diversion. A common base period of 40 years (October 1916 to September 1956) has been arbitrarily selected as the shortest period practicable to give results that may represent the probability of flood occurrences of various magnitudes. Frequency data based on shorter periods will likely be biased because of the unusal flood activity of the last 6 years, when 3 major floods occurred in many regions. Even 40 years is a small sample in time, and the flood- frequency curves shown may not be truly indicative of the flood potentials of the streams. Quantitative data on major floods that occurred prior to October 1916 have been incorporated in the graphs. The annual-flood series are arrays of the maximum gage height and discharge for each water year of record. In order to fit a time scale or recurrence interval (T) to a list of annual-flood peaks plotting positions must be selected: T=(n+l)/m, where T is in years, n is the number of years of record being considered and TO is the order number of the flood; the highest flood of record is order number 1. Graphs (figs. 27, 28) were drawn on the basis of A98 FLOODS IN FAR WESTERN STATES such data; the abscissa represents the recurrence interval, in years, and the ordinate represents the discharge. Flood-frequency curves for 11 selected gaging stations in Idaho, Oregon, and Washington (fig. 29) were drawn from composite-area data rather than from station data and are considered to be the better indication of frequency. THE GREAT BASIN The most severe floods known in the Great Basin occurred during December 1861-January 1862, December 1867, March 1907, March 1928, December 1937, November-December 1950, and December 1955. Quantitative data on the two earlier floods are lacking, but they apparently rank as the greatest floods that ever occurred in the region. On Carson River at Empire, the peak stage in January 1862 is reported to have been 2 feet higher than that reached in December 1867, whereas the peak of 1867 is said to have been the higher one on the Walker and Truckee Rivers. Of the five major floods since 1900, the flood of December 1955 ranks as the greatest, closely followed by the floods of November- December 1950. The flood of December 1955 appreciably exceeded that of 1950 on the Carson River, and slightly exceeded the 1950 flood on the Truckee River, but it was slightly lower than the 1950 flood on the West Walker River. The flood of December 1937 ranks below the flood of November- December 1950. The floods of 1907 and 1928 were severe only in the Truckee River basin. The 1907 flood was greater than that of 1928, and in the Truckee River basin it was probably somewhat higher than the 1937 flood. CENTRAL-COASTAL CALIFORNIA There is little information concerning the floods in California during 1798-99, 1819, 1849-50, and 1852-53. The great flood of January 1862, the earliest for which quantitative data exist, was probably the greatest that ever occurred in central-coastal California. On Salinas River near Spreckels the peak stage in 1862 was 6 feet higher than any attained since, and on Pajaro River at Watsonville, it was considerably higher than any peak since that time. It is difficult to rank the other floods that occurred in the region, particularly those that occurred prior to the establishment of gaging stations. Much of the region lies in the southern fringe of the belt of heavy precipitation that accompanies most general storms along the California coast. Consequently, there is considerable variability among basins in the amount of precipitation received during storms. It is very likely that over much of the region the general floods of January 1890 and December 1955 were of almost equal magnitude, PART 1. DESCRIPTION A99

30 I I I I I I I I 1 I I I I

Arroyo Seco near Soledad 10

1956

10 Kern River near Kernville

9 0

80 1956> Kaweah River near Three Rivers

ul 40 CD CC <

I 5 20

30 Merced River at Pohono Bridge near Yosemite 1956 20

1.5 2 2.33 3 5 10 20 50 100 RECURRENCE INTERVAL, IN YEARS

FIGURE 27. Flood-frequency curves for selected gaging stations in Central-Coastal California and San Joaquin Valley, Calif. A100 FLOODS IN FAR WESTERN STATES ranking second only to the flood of 1862. Other major floods resulted from the general storms of March 1907, December 1937-February 1938, February 1940, and January 1952. Annual flood peaks (table 15) at the gaging station on Arroyo Seco near Soledad in the 40 years from October 1916 to September 1956 were used to compute a flood-frequency curve (fig. 27). The greatest peak discharge listed, that for December 1955, has a computed recur rence interval of 41 years. It is likely that this flood was second in magnitude to that of 1862 on this basis the 1955 flood would have a computed recurrence interval of 48 years. It makes little practical difference which recurrence interval is used, and because of the uncer tainty of the rank of the 1955 flood in the long-term series, the figure of 41 years is used.

TABLE 15. Annual peak stages and discharges, Arroyo Seco near Soledad, Calif.

Gage Discharge Gage Discharge Water vear Date height (cfs) Water year Date height (cfs) (feet) (feet)

1906.. ------930 1907. .- .--- Mar. 23, 1907 10, 700 1932. - -- Dec. 27,1931 13.70 11,100 1908 9 0 7.31 2,340 1909 7,400 1 Q°.4 7,110 1P10 3,710 12.12 8,340 1911 Mar. 6,1911 20.0 17,300 Feb. 13,1936 13.70 11, 100 1912 7.6 1 350 1 QQ7 12, 200 1913 8.4 i oflfi Feb. 11,1938 16.5 16, 000 1939 IVTar G 1 Q^Q 1,380 1915 7,200 15.0 13,600 1916 Jan. 17,1916 Apr. 4, 1941 13.00 10,600 1917. 16.5 16,000 1 Q49 11.10 14,100 1918. Mar. 12, 1918 Jan. 21,1943 11.55 16,100 1919 - Feb. 10,1919 10.0 5 of)0 Mar. 4, 1944 9.20 7,100 1920 9 0 4 550 1 cue 12.55 21,100 1921 12.0 o enn 1946 Dec 91 1946 10.47 11, 600 1922 15.8 1947 7.55 3,480 1923 6.75 2,040 1943 A r»r Q 1 Q4ft 1924 6.7 1 900 1949 7.60 3,460 1925. ------Nov. 9, 1924 5.9 9.63 8,460 Feb. 23,1925 5.9 1,300 1951.. Nov. 19, 1950 12.46 20, 600 1926 Jan. 14,1952 11.32 15, 000 1927 16.5 16,000 1 Q53 Dee. 7, 1953 9.80 9.050 1928 7.33 3,120 1929 9 e 1955 6.50 2,080 1930 - 9 AO 14.30 27, 700

SAN JOAQUIN VALLEY Major floods occurred in the San Joaquin Valley in January 1862 and in December 1867. It is believed that the flood of January 1862 has not been exceeded since on the lower San Joaquin River and its tributaries from the Merced River and downstream. The flood of 1867, however, was the greatest to occur in the Kern River and Tulare Lake basins and on the San Joaquin River and its tributaries upstream from the Merced River. The flood of December 1955 was generally the second greatest flood throughout the region with the probable exception of the Kaweah River basin, where the 1955 flood was probably of about the same magnitude as the flood of 1867. The PART 1. DESCRIPTION A101 flood of November-December 1950 ranks third throughout the region, except on the upper San Joaquin River where it was exceeded by the flood of December 1937. Other major floods resulted from the general storms of January 1890, March 1907, January 1911, January 1914, February 1937, March 1943, and February 1945. Noteworthy, too, were the snowmelt floods of 1938 and 1952. Annual flood peaks (tables 16-18) at the gaging stations on Kern River near Kernville, Kaweah River near Three Rivers, and Merced River at Pohono Bridge near Yosemite in the 40 years from October 1916 to September 1956 were used to compute flood-frequency curves (fig. 27). The greatest peak discharge listed for Kaweah River, that for December 1955, was probably approximately equal to that of December 1867, and therefore the 1955 peak has a computed recur rence interval of 90 years. The second highest flood listed for Ka weah River, that of November 1950, is the third largest peak since 1867 and has a computed recurrence interval of 30 years. Similar reasoning has been used to draw the graph for Kern River, where the flood peaks of December 1955 and November 1950 are known to be the second and third largest respectively, since 1867. Little is known concerning early floods in the upper Merced River, and consequently, the greatest flood, that of December 1955, has been given a recurrence interval of 41 years. This flood was probably exceeded in 1867, but any adjustment to the graph for the 1867 flood would have a negli gible effect on the position of the curve.

TABLE 16. Annual peak stages and discharges, Kern River near Kernville, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1912...... June 4, 1912 3,330 1934 Apr. 20,1934 7.20 1,080 1913...... May 24, 25, 1,920 1935 June 8, 1935 9.68 2,920 1913. 1936. May 19,1936 9.27 2,980 1914...... June 4, 1914 4.6 1937 Feb. 6,1937 12.46 8,600 1915...... June 9, 1915 4.94 1938 Mar. 2,1938 11.68 7,000 1916 .. Jan. 17, 1916 8.8 11, 500 1939 May 14,1939 7.60 1,440 1917-.---..... June 17,1917 4.7 3,800 1940. May 25,1940 9.62 3,480 1918 May 5,1918 2.79 1941 . June 14,1941 11.14 5,510 1919 May 29, 1919 5.1 4,290 1942 - June 6, 1942 9.57 3,400 1920 May 21,1920 4.49 3,560 1943 Jan. 22,1943 12.57 8,310 1921 June 8, 1921 3.98 i 3, 000 8.54 2,310 1922 . 9 00 3 Q9O 1Q4.5 5,700 1923 May 17,1923 8.78 2,440 1924 May 11,1924 6.50 780 1947 . Nov. 23, 1946 9.08 2,770 1925...... June 13,1925 8.10 1,920 1948 May 17,1948 7 98 1,660 1926 May 20, 1926 8.17 1949 -- May 28, 1949 7.93 1,420 1927 -.... Nov. 26, 1926 10.35 4,420 June 1, 1950 8.78 2,420 1928 May 30, 1928 17.50 2 27, 000 1929 May 25, 1929 7.37 1,240 May 30, 1952 10.87 6,140 1930 - June 13,1930 8.01 1,730 Apr. 27,1953 9.03 3,120 1931 . May 7, 1931 6.16 610 1954 - May 21,1954 8.60 2,600 1932 June 22,1932 9.38 8.60 2,500 1933. . June 15,1933 17.55 3 27, 200

1 After March 1921, peak discharge data do not include flow in Kern River No. 3 Canal. 2 Probably third largest flood since 1867 (89 years'*. 3 Probably second largest flood since 1867 (89 years). A102 FLOODS IN FAR WESTERN STATES

TABLE 17. Annual peak stages and discharges, Kaweah River near Three Rivers, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1914 jo n jo OHO 1936 Feb. 13,1936 7.86 S nfln 1915 June 1, 1915 8.6 3,600 1937. _ ------Feb. 6. 1937 12.65 18. 900 1916 Jan. 17,1916 14, 700 1938 16.0 33, 300 1917. Feb. 21,1917 10.0 6,270 1939 1 9Q i Qf%n 1918 Mar. 19, 1918 7.1 1,570 1940 Feb. 26,1940 9.56 8,510 1919 8 1 o jwn 1941 Apr 4 1941 8.73 6,820 1920 Apr. 16,1920 9.8 5,850 1942 May 21, 1942 7.20 4,170 1921 3,180 1943 12.55 17, 000 1922 May 31, 1922 8.85 3,690 1944- _ - _ -- Mar. 4, 1944 6.25 3,100 1923 ------Apr. 6, 1923 6,060 194S ... Feb. 2, 1945 12.00 15,200 1924 6.90 1,200 1946 6.65 3,480 1925 - May 27, 1925 8.0 1947 Nov. 23, 1946 1926.,...... 8.0 1948 Apr. 10,1948 8.90 7,130 1927.. .-.. Feb. 18,1927 11.8 10, 100 May 26, 1949 5.83 2,500 1928 Mar. 27, 1928 8.80 3,140 1950 Feb. 6, 1950 6.93 3.860 1929 June 16,1929 9 45 3,780 17.8 i 52, 000 1930 Feb. 22,1930 8.80 3,060 1952 Jan. 25,1952 10.23 8,470 1931 May 6, 1931 7.43 1,570 1953 Apr. 27,1953 9.77 7,660 1932 Dec. 28,1931 11.84 8,900 1954 -- .... Jan. 24,1954 8.15 4,080 1933 June 14, 1933 9.07 3,620 Feb. 17,1955 9.28 6,480 1934.. Dec. 13,1933 8.10 2,230 1956 Dec. 23,1955 22.24 2 80, 700 1935 ------Apr. 8, 1935 11.76 8,900

1 Probably third largest flood since 1867 (89 years). 2 Probably same magnitude as floorfof January 1867. TABLE 18. Annual peak stages and discharges, Merced River at Pohono Bridge near Yosemite, Calif.

Gage, Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1917 June 10,1917 8.75 5,880 1937 May 15,1937 10.25 6,010 1918 ------June 12,1918 7.05 4,000 1938 Dec. 11,1937 19.1 22, 000 1919 6,150 1939 Apr. 22,1939 5.95 2,200 1920 May 20, 1920 8.80 1940 May 13,1940 8.45 4,750 1921 June 11,1921 8.40 4,610 1941 May 24,1941 9.55 6,410 1922 6,370 May 25, 1942 9.21 5,860 1923 May 16, 1923 8.30 4,500 1943 Apr. 28,1943 9.53 6,370 1924 C QC 2,120 1944 May 9,1944 7.36 3,470 1925... .. May 6,1925 8.30 1945 May 5, 1945 9.18 5,810 1926 ------May 5, 1926 7.77 3,950 1946 May 7, 1946 8.15 4,680 1927 May 17,1927 9.48 5,700 1947 May 3,1947 7.52 3,930 1928 4,680 1948 May 27, 1948 8.50 5,100 1929 9 25 1949 May 14, 1949 7.96 4,450 1930 .. May 28, 1930 7.23 1950 - May 28,1950 7.99 4,490 1931 May 7, 1931 6.10 1,840 1951 Nov. 19,1950 19.98 23, 000 1932 9 19 4,780 1952 - May 28, 1952 9.63 6,790 1933-.--.--... May 31, 1933 8.60 4,230 1953 .- Apr. 27,1953 7.11 3,480 1934 June 14,1934 5.43 1,470 1954 . - May 20, 1954 7.57 3,990 1935 9 44 May 22,1955 7.46 3,870 1936 .---... May 5,1936 8.84 4,450 1956 Dec. 23,1955 21.62 23,600

SACRAMENTO VALLEY Prior to 1900, major floods occurred in the Sacramento Valley in December 1852, January 1862, December 1867, and February 1881. On the lower Sacramento River tributaries including the Feather River, the flood of 1862 ranks as the greatest known. On the Sacra mento River and tributaries upstream from the Feather River, the flood of February 1881 generally exceeded all others known. After 1900 numerous major floods occurred in March 1907, January- February 1909, February 1915, March 1928, December 1937, Feb- PART 1. DESCRIPTION A103 ruary 1940, February 1942, November-December 1950, and December 1955. It is somewhat difficult to generalize in ranking these floods because no one flood was the most outstanding throughout the region. On the Sacramento River and many tributaries upstream from the Feather Eiver, the flood of December 1955 was the greatest of record, but on others it was exceeded by either the flood of December 1937 or that of February 1940. In the Feather Eiver basin, the flood of March 1907 was the greatest flood since 1900 on some tributaries, but on others, notably the Yuba Eiver, the flood of December 1955 was the greatest. On the lower Sacramento Eiver tributaries, the flood of December 1955 was generally the greatest since 1900; other high- ranking floods were those of March 1907, March 1928, and November 1950. Annual flood peaks (tables 19, 20) on Feather Eiver at Bidwell Bar and Middle Fork American Eiver near Auburn in the 40 years from October 1916 to September 1956 were used to compute flood-frequency curves (fig. 28). Historical data has not been incorporated in the flood-frequency plot because of the uncertainty involved in assigning rank to the floods prior to October 1916. TABLE 19. Annual peak stages and discharges, Feather River at Bidwell Bar, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1912.. ______Mar. 6,1912 3,920 1935-- ______Apr. 8, 1935 14.20 25, 500 1913.. ______May 9, 1913 6,820 1936 ______Feb. 21,1936 16.2 38,200 1914.. ______Dec. 31,1913 18.0 47, 100 1937 ______Apr. 15,1937 9.45 7,920 1915 ______May 11, 1915 15.5 31, 300 1938____. ______Dec. 11,1937 24.0 93, 000 1916 ______Mar. 20, 1916 12.7 16, 400 1939... ______Mar. 27, 1939 6.97 3,230 1917. ______Feb. 25,1917 14.0 23, 100 1940 ______Feb. 27,1940 20.15 60,200 1918._-___.____ Mar. 26, 1918 10.72 11, 400 1941. ______Feb. 10,1941 15.6 30,300 1919 ______Feb. 10,1919 12.00 14, 600 1942 ______Feb. 6, 1942 16.45 35, 100 1920 __._ . Apr. 15,1920 Q . 9,760 1943 ______Jan. 21,1943 18.70 54, 300 1921 ______Nov. 19, 1920 11.09 12, 200 1944. ______Mar. 4,1944 9.98 8,460 1922 ___ . _ May 20, 1922 n o Feb. 2, 1945 15.25 28,600 1923-______Apr. 6, 1923 9.6 8,880 1946 ____ _ Dec. 29,1945 13.96 22,000 1924 Feb. 8, 1924 10.04 9,760 1947 . . Feb. 12,1947 13.00 17,800 1925 _____ . Feb. 6, 1925 1Q4S Apr. 17,1948 12.70 16,600 1926 ______Apr. 7, 1926 12.3 15, 300 1949 ______Apr. 23,1949 8.68 6,140 1927... __. Feb. 21,1927 17.0 iQKft Feb. 6, 1950 13.02 17, 900 1928 ______Mar. 26, 1928 99 S 90,000 Nov. 21, 1950 18.25 50,200 1929 ______Feb. 4, 1929 7.4 4,720 1952 ______Feb. 2, 1952 13.75 21,000 1930 ______Dec. 13,1929 14.2 1953 ______Jan. 9, 1953 17.00 40,000 1931 Mar. 18, 1931 7.90 5,570 1954 ______Mar. 9,1954 14.16 22,900 1932.. ._____.__ Mar. 19, 1932 10.10 9 QRO May 9,1955 8.51 5,870 1933... ______May 30,1933 7.56 5,050 1956 ______Dec. 23,1955 25.2 104, 000 1934..... _._ _ 10.55 11, 100 A104 FLOODS IN FAR WESTERN STATES

120 I I I l^ I I M I 1 I I I Feather'River at Bidwell Bar

1956 80 Middle.Fork American River I near Auburn Q I 40

600 1956

Eel River at Scotia

O 400

O 200

a 0

I 1956 400 Klamath River near Klamath

200

1.5 2 2.33 3 5 10 20 50 100 RECURRENCE INTERVAL, IN YEARS FIGURE 28. Flood-frequency curves for selected gaging stations in Sacramento Valley, Calif., and in north-coastal California. PART 1. DESCRIPTION A105

TABLE 20. Annual peak stages and discharges, Middle Fork American River near Auburn, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1912 May 30,1912 5,350 1935. Apr. 8, 1935 19.5 25,000 1913 Apr. 26,1913 6,460 1936. Feb. 22,1936 19.4" 24,700 1914- .. Jan. 1, 1914 18.0 26, 400 1937 - Feb. 14,1937 13.5 10,600 1915 16.0 99 fiftfi 1QOQ Dec. 11,1937 27.3 47, 900 1916 Mar. 20, 1916 13.7 17, 100 1939 Apr. 4, 8, 1939 9.05 3,830 1917 . Feb. 25,1917 13.0 1940 Mar. 30, 1940 23.2 35,600 1918 Apr. 10,1918 8.0 6, 100 1941 Dec. 27,1940 16.9 18, 400 1919 . Feb. 11,1919 17.5 25, 000 1942 -. .... Jan. 27,1942 21.6 32, 300 1920 Apr. 16,1920 10.5 Q ftfifi 1943 Jan. 21,1943 28.0 58, 000 1921 .. ... Jan. 18,1921 11.5 1944 May 8, 1944 11.1 6,440 1922 May 20,1922 12.7 11, 400 1945 Feb. 2, 1945 23.9 40,400 1923 Dec. 13,1922 17.7 91 1fifi 1946 16.18 16,300 1924. .. Feb. 8, 1924 5,100 1947 Feb. 12,1947 14.15 11,600 1925 Feb. 6, 1925 25.0 36, 300 1948 Apr. 17,1948 13.38 10,100 1926 Apr. 6, 1926 11.5 9,920 1949 May 14,1949 12.70 8,700 1927 Feb. 21,1927 21.5 29, 200 1950 Jan. 23,1950 15.60 14,900 1928 Mar. 25, 1928 35.6 62,000 1951 Nov. 20, 1950 34.7 68,500 1929 June 16,1929 11.3 12,000 1952 Feb. 2, 1952 15.15 13, 900 1930 9 Q 8 ion 1QCO Apr. 27,1953 18.55 22,300 1931 Mar. 18, 1931 10.88 6,110 1954 Mar. 9, 1954 18.65 22,600 1932 May 12,1932 12.40 8,740 1955 May 13,1955 10.87 5,820 1933 May 30,1933 11.6 6,770 1956 Dec. 23,1955 33.9 79,000 1934 Mar. 29, 1934 7 san

NORTH-COASTAL CALIFORNIA The first major flood after the region was settled occurred in De cember 1852, and was especially severe on the Eel River. In Decem ber 1861-January 1862 greater floods occurred which have not since been exceeded in north-coastal California. It is likely, however, that on Eel River at Scotia and on the upper Trinity River the flood of December 1955 was of similar magnitude. Following the relatively minor floods of 1867, 1871, 1878, and 1879 the major floods of 1881 and 1890 occurred. The flood of 1890 was the greater of the two except on the Eel River. Floods of varying magnitude occurred in 1907, 1914, 1915, 1917, 1927, 1937, 1940, 1943, 1950, 1953, and 1955. Some of these were major floods, but none were particularly outstand ing throughout the entire region except the floods of December 1937 and December 1955. In general, it may be stated that the greatest flood known was that of December 1861-January 1862, the second greatest that of December 1955, and the third greatest that of February 1890. On Eel River at Scotia, the peak discharge of February 1915 was probably greater than that of 1890. Annual flood peaks (tables 21-23) on Eel River at Scotia, Trinity River at Lewiston, and Klamath River near Klamath were used to construct a flood frequency curve (fig. 28). The observed record at Klamath River does not fully cover October 1916-September 1956, but is included because it was possible to make fairly reliable estimates of the discharge for the historic floods of 1861-62, 1881, 1890, and 1927. A106 FLOODS IN FAR WESTERN STATES On Eel River, the flood peak of December 1955 was probably of the same order of magnitude as that of January 1862. Because the latter flood exceeded that of December 1852, the peak discharge of Decem ber 1955 was therefore the greatest peak in the 104 years prior to 1956. The peak discharge of February 1915 was the fourth largest for that period. On Trinity River, the flood peak of December 1955 was also probably of the same magnitude as that of 1862.

TABLE 21. Annual peak stages and discharges, Eel River at Scotia, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1911 Jan. 20,1911 136, 000 1934 Mar. 29, 1934 24.8 50,900 1912 Jan. 26,1912 170, 000 1935 Apr. 8, 1935 29.62 79,500 1913 Jan. 18,1913 150, 000 Jan. 16,1936 44.7 216, 000 1914 Jan. 22,1914 52.5 309, 000 1937 Feb. 5, 1937 37.0 134, 000 1915 Feb. 2, 1915 55.5 i 351, 000 1938 Dec. 11,1937 55.1 345, 000 1916 Nc Record 1QOQ Dec. 3, 1938 35.9 133,000 1917- Feb. 25,1917 51. 25 292,000 Feb. 28,1940 52.26 305,000 1918 Feb. 7, 1918 27.7 78,600 1941- Dec. 24,1940 36.4 150,000 1Q1Q Jan. 17,1919 38.3 149, 000 Feb. 6, 1942 42.2 209, 000 1920 Apr. lfi.1920 25.0 62,000 1943 Jan. 21,1943 50. 75 315,000 1921 Nov. 19, 1920 38.2 148, 000 1944. . Mar. 4. 1944 24.60 57,800 Feb. 19,1922 34.5 123, 000 1Q4.C Feb. 3, 1945 30. 55 99, 100 1923.. . Dec. 28,1922 26.9 73, 400 1946 Dec. 27,1945 44.60 239, 000 1924 Feb. 8, 1924 26.9 73, 400 1947 Feb. 12,1947 29.02 86,100 1925 Feb. 6, 1925 35.2 127, 000 1948 Jan. 8, 1948 32.6 114, 000 1926 Feb. 4, 1926 42.2 176, 000 1949 Mar. 18, 1949 35.4 140, 000 1927 Feb. 21,1927 45.2 221, 000 1950 Jan. 18,1950 32.85 117,000 1928 . Mar. 27, 1928 46.3 233,000 1951- - Jan. 22,1951 45.39 249,000 Feb. 4, 1929 21.3 41, 000 1QKO Dec. 27,1951 46.50 262,000 1930 Dec. 15,1929 30.4 120, 000 1953 Jan. 9, 1953 42.98 215, 000 1931 Jan. 23,1931 29.0 87, 000 1954 Jan. 17,1954 45.20 245,000 1932 Dec. 27,1931 36.1 127, 000 1QKC Dec. 31,1954 23.29 52, 400 1933 . Mar. 17, 1933 26.10 58, 100 1956 -. Dec. 22,1955 61.9 " 541, 000

i Probably fourth largest flood since December 1852 (104 years). ' Probably same magnitude as flood of January 1862 (greatest in 104 years).

TABLE 22. Annual peak stages and discharges, Trinity River at Lewiston, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1912 Jan. 25,1912 11, 600 1935 Apr. 15,29, 9.73 8,970 1935 1913 Nov. 9, 1912 1936 - -- Feb. 21,1936 13.0 16,500 1914 Jan. 2, 1914 26,900 1937 Apr. 13,1937 10 E 1915 1 E 0 OQ nnfl 1938 - Dec 11 1937 1 Q QTt 37, 000 1916 Mar. 20, 1916 1 E A 23 500 1 Q3Q Mar. 13, 1939 9.16 4,370 1917 10.1 10 600 90 Q 40, 300 1918 8 9 Q r\zf\ 1941 A/for 1 1 Q41 20.3 32, 500 1919 Feb. 9, 1919 14.7 91 ROfl 1 Q4.9 Dec. 16,1941 18.98 28,900 1920 5.85 1943 TVfar 9Q 1Qd3 12.03 7, 350 1921 13.4 18, 500 1944 Mav 7 1944 11.10 5,560 1922-.-- _ .-- 8. 55 7,700 1 OdK 8,990 1923- TVTav Q 109°. 1946 Dec 29 1945 16.35 21, 4"0 1924 9 20 8 920 1947 Nov. 22, 1946 8,390 1925. Feb. 4,1925 14.00 1948 21.1 39, 700 1926 19 Q 17,100 1949 15, 700 1927 Nov. 30, 1926 1 Q O 31 900 1 Q*\fi 11.08 6,360 1928 - TVTar 9fi 1Q9Q 17 2 9c ?nn 1951 21.00 39, 300 1929 Feb. 4, 1929 7.05 4,690 1 QK9 15.80 19, 500 1930 Dec. 14,1929 15.32 17,900 1931 7 39 5,180 1QE,I Mar. 9,1954 15.89 19, 700 1932 Mar. 19, 1932 9 27 8,840 1 Q55 May 21,1955 11.13 6,880 1933 Mar. 28, 1933 9 44 1956 27.3 i 71, 600 1934 Mar 28 1 1934 11 21 12 ' 400

Probably same magnitude as flood of January 1862 (greatest in 104 years). PART 1. DESCRIPTION A107

TABLE 23. Annual peak stages and discharge, Klamath River near Klamath, Calif.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1862.... __ . 12450,000 1935 April 1935__-._ 6 60, 000 1881... ---_._ 13360,000 1936 8162,000 1890.. ._...__ February 1890. _ i * 425, 000 1937 April 1937- 8121,000 1911_.__._ . Jan. 20, 1911 66,700 1938. December 1937. 8 218, 000 1912... Feb. 17, 1912... 28.5 142,000 1939 6 71, 000 1913..._. . Nov. 6, 1912... _ 74,500 1940 8 237, 000 1914...... Jan. 22, 1914 . 27.0 130, 000 1941 March 1941..... 6124,000 1915...... Feb. 2, 1915... . 33.3 182, 000 1942 8151,000 1916. . Feb. 7, 1916.... 21.5 85, 700 1943 8 162, 000 1917 ... .. Feb. 22, 1917... 20.0 73,700 1944 - March 1944 ..... « 32, 300 1918 . _. Dec. 1, 1917.... 18.8 65, 300 1915 .. February 1945.. 8 102, 000 1919 ...... 27.4 133, 000 1946 8 209, 000 1920...... Apr. 17, 1920... 13.0 27,900 1947 6 73, 900 1921 . Dec. 31, 1920 27.0 130,000 1948 8 202, 000 1922 .... Nov. 30, 1921... 18.0 59,700 1949 March 1949..... 695,000 1923 .... Dec. 28, 1922.. . 18.1 60,400 1950 March 1950..... 6 92, 600 1924. .. - Feb. 2, 1924.... 12.6 25,800 1951 Feb. 5,1951.... 31.6 173,000 1925 Feb. 5, 1925.. . 32.4 175, 000 1952 Feb. 2, 1952.... 33.98 195, 000 1926 102, 000 1953 .. 43.67 297, 000 1927 1 5 300, 000 1954 Jan. 28, 1954 25.53 133, 000 1932 .. March 1932 6 96, 400 1955 .- Dec. 31, 1954. .. 18.90 74,200 1933 ... 6 46, 200 1956. Dec. 22. 1955. - . 49.7 " 425, 000 1934 . _ March 1934..... 8 51, 100

i Computed from floodmarks at Weitchpec and hydraulic properties of channel; routed from Weitchpec Greatest since and greater than floods of 1852-1953 (104 years). 3 Fourth largest in 104 years. 4 Samp, discharge as Dec. 22, 1955. 5 Fifth largest in 104 years. 6 Computed by routing technique, using flood peaks on Klamatb River at Somesbar and on Trinity River near Hoopa. 7 Second largest in 104 years.

WEST-CENTRAL IDAHO In west-central Idaho winter precipitation is generally snow and winter floods rarely occur. On many streams in the Boise and Payette River basins, even the high rates of runoff in December 1955 were exceeded by snowmelt peaks in the spring of 1956. Nevertheless, in other parts of the Boise and Payette River basins, and in the Weiser and Little Salmon River basins, peak discharges of recordbreaking proportions occurred during December 1955. Reservoir storage was effective in reducing peak rates of discharge in the lower reaches of many streams. Little is known concerning floods in west-central Idaho that occurred prior to the inauguration of the stream-gaging program. On Boise River near Twin Springs, where streamflow records have been kept continuously since 1911, the flood peak of December 1955 equalled the previously known maximum that occurred in May 1927, and was exceeded only in the spring flood of May 1956. Other notable peak discharges, listed in order of magnitude, occurred in 1917, 1928, 1952, 1921, and 1953. It is difficult to rank historic floods in order of magni tude in the Payette River basin because of the lack of long-term gaging-station records that are unaffected by storage. It appears, however, that the peak discharge of December 1955 outranked all A108 FLOODS IN FAR WESTERN STATES

300

100

0.5

0.1 1.5 2 2.33 5 10 50 100 RECURRENCE INTERVAL, IN YEARS

FIGURE 29. Flood-frequency curves for selected gaging stations in Idaho, Oregon, and Washington.

1. Boise Rivernear Twin Springs, Idaho 7. Umpqua River near Elkton, Oreg. 2. Little Weiser River near Indian Valley, Idaho 8. Rouge River at Raygold near Central Point, 3. McKenzie River near Vida, Oreg. Oreg. 4. Willamette River at Albany, Oreg. 9. Asotin Creek near Asotin, Wash. 5. Clackamas River near Cazadero, Oreg. 10. John Day River at McDonald Ferry, Oreg. 6. South Fork Coquille River at Powers, Oreg. 11. Wind Rivernear Carson, Wash. peaks since 1921, with the possible exception of that of 1927. Notable floods also occurred in 1922, 1925, 1928, 1938, 1943, 1948, 1949, and 1952. The paucity of long-term records of unregulated flow in other basins in west-central Idaho precludes any generalizing concerning the comparative magnitude of historic floods. PART 1. DESCRIPTION A109

Annual flood peaks (tables 24, 25) and flood-frequency curves (fig. 29) are shown for two representative stations in the region Boise River near Twin Springs and Little Weiser River near Indian Valley.

TABLE 24. Annual peak stages and discharges, Boise River near Twin Springs Idaho

Discharge Gage Discharge Water year Date (cfs) Water year Date height (cfs) (felt) (feet)

1911...... June 13,1911 7.2 7,560 1934.. Mar. 28, 1934 4 OR 3,680 1912 June 13,1912 7.4 7,900 1935 May 24 1935 5.67 4 970 1913. May 28,1913 7.0 7,220 1936 7.70 8,880 1914 May 23,1914 6.0 5,520 1937 May 5,1937 4 Qd 3,610 1915 Apr. 19,1915 4.62 3,140 1938 May 1, 1938 7.63 8,730 1916 June 19,1916 7.37 8,530 1939 Apr. 30,1939 A OQfl 1917 May 15,1917 7.82 9,430 1940 May 12,1940 5.89 5,210 1918 . June 14,1918 7.10 7,990 1941 May 27,1941 5.72 4,830 1919 May 29, 1919 7.50 8,790 1942 May 26,1942 6.21 6,240 1920 May 17, 1920 6.04 5,840 1943 Apr. 17,1943 7.82 8,920 1921 June 12,1921 7.67 9,210 1944. May 15,1944 5.30 3,800 1922 June 7, 1922 7.10 7,860 1945. May 5,1945 6.18 5,600 1923 May 26,1923 6.23 6,080 1946 Apr. 19,1946 7.18 7,560 1924...... May 17,1924 4.51 3,000 1947 May 9,1947 7.16 7,670 1925 . May 20,1925 6.69 7.060 1948 May 28, 1948 7.41 8,210 1926 May 5.1926 5.29 4,250 1949 May 16,1949 6.78 6,990 1927 May 17,1927 8.30 10,300 1950 May 24, 1950 6.64 6,570 1928 May 10, 1928 7 OS 9,400 1951 May 28,1951 6.98 7,290 1929 May 24,1929 5.81 5,320 1952 Apr. 28,1952 7.96 9i210 1930 ____ . May 29,1930 5.00 3,860 1953 June 13,1953 7.81 9,, 090 1931. _ . ___ May 7,1931 4.52 3,020 1954 May 21,1954 7.57 8,560 1932 ..... May 14, 1933 6.87 7,460 1955 June 10,1955 6.49 6,270 1933 June 16,1933 6.91 7,260 1956 Dec. 23,1955 8.31 10,300 Do.. May 24,1956 8.76 11,200

TABLE 25. Annual peak stages and discharges, Little Weiser River near Indian Valley, Idaho

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1923 May 10,1923 550 1945. -. _ . June 5, 1945 4.35 844 1924 . ... May 14,1924 2.01 271 1946 _ ..... Apr. 18,1946 3.95 617 1925 . _ .... Feb. 4, 1925 4.19 1,840 1947...... May 9, 1947 4.30 740 1926. ... Apr. 18,1926 1.99 311 1948 May 27, 1948 4.50 844 1927 ...... May 16,1927 3.98 1,130 1949-...... May 14,1949 3.88 620 1938 May 1,1938 5.15 1,200 1950... ___ .. June 6, 1950 372 1939 Mar. 24, 1939 3.30 419 1951.. _ May 22, 1951 3.45 568 1940 .... Feb. 27,1940 3.80 626 1952 ...... May 8, 1952 5.05 1,280 1941 May 12,1941 3.40 482 1953 June 7, 1953 4.77 1,240 1942 May 25, 1942 3.69 605 1954.... ___ . May 20, 1954 3.48 622 1943 May 31, 1943 4.53 925 1955 _ - Apr. 22,1955 3.32 588 1944 Apr. 5, 1944 3.26 475 1956 _ ..... Dec. 22,1955 4.67 1,200

WILLAMETTE VALLEY Before 1900, major floods are known to have occurred in the Willamette Valley in 1813, 1843, 1844, 1849, 1853, December 1861, January 1881, and February 1890. Quantitative data are lacking for those floods that occurred prior to 1861, but it is known that the stages reached by the flood of 1861 have not since been equaled. The greatest flood since that year occurred in February 1890, and the next greatest was probably that of January 1881. After 1900 several floods had peak discharges of the same general magnitude as that of December 1955, but were greater hi some basins and less in A110 FLOODS IN FAR WESTERN STATES others. These floods occurred in January 1901, January 1903, Novem ber 1909, January 1923, March 1931, January 1943, December 1945, January 1948, and January 1953.

TABLE 26. Annual peak stages and discharges, McKenzie River near Vida, Oreg.

Gage Discharge Gage Discharge Water year Date heieht (cfs) Water year Date heieht (cfs) (feet) (feet)

1925 Feb. 4, 1925 9.1 26, 700 1941- Nov. 29, 1940 4.71 10,700 1926 Feb. 6, 1926 8.5 24,400 1942 Nov. 15,1941 8.40 24,100 1927 Feb. 20,1927 14.2 47,200 1943 Jan. 1, 1943 14.6 48,900 1928 .. . Nov. 28, 1927 0 ft OQ ftftA 1944 Nov. 4,1943 7.65 20, 800 1929 Mar. 21, 1929 7 05 18,900 1945 Feb. 13,1945 9.09 26,600 1930 Dec. 18,1929 9.97 30,100 1946. Dec. 28,1945 17.70 64,400 1931...... Apr. 1, 1931 11.99 38,000 1947 Dec. 14,1946 12.20 39,400 1932. .. -. Mar. 18, 1932 11.77 37,400 1948 Jan. 7, 1948 12.16 39,200 1933. June 9, 1933 8.60 24,900 1949... .. Dec. 12,1948 11.47 36,300 1934 Jan. 23, 1934 8.80 25,600 1950...... Feb. 24,1950 8.85 25,600 1935 Dec. 20,1934 8.22 23,400 1951 Oct. 29,1950 11.30 35,600 1936, .-. Jan. 4, 1936 8.28 23, 700 1952...... Oct. 23,1951 7.98 22,100 1937 Apr. 14,1937 8.66 25,300 1953 Jan. 18,1953 15.03 51, 800 1938...... Jan. 22,1938 9.39 28,000 1954...... Nov. 23, 1953 12.22 39,400 1939 Dec. 2, 1938 5.88 14,700 1955-.... . Dec. 31,1954 7.08 18,500 1940...... Feb. 10,1940 4.85 11,200 1956 15.00 51, 700

TABLE 27. Annual peak stages and discharges, Willamette River at Albany, Oreg.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1862...... Dec. 4, 1861 36.0 i 34Q OQO 1922 Nov. 23, 1921 23.2 122,000 1879... . Mar. 27. 1879 114,000 1923 Jan. 8, 1923 30.0 206,000 1880 Dec. 7, 1879 23.5 116,000 1924 Feb. 3, 1924 13.2 52,000 1881...... Jan. 14. 1881 00 Q Ofifi Ann Feb. 6, 1925 23.5 130,000 1882. Mar. 2, 1882 91 Q m nnn 1926 Feb. 8, 1926 24.7 143.000 1884 Feb. 22,1884 21.5 101,000 1927 Feb. 22,1927 29.2 191,000 1890 Feb. 4, 1890 33.9 2 9Q1 nnn 1928 Mar. 13, 1928 17.6 74,000 1893...... Feb. 13,1893 18.4 79 700 1929 Mar. 23. 1929 13.30 50,800 1894 Jan. 16, 1894 28.2 1930 Dec. 21,1929 20.4 91,500 1895... Jan. 14, 1895 19.4 DC Ann 1931 Apr. 3, 1931 22.9 109,000 1896.. _ Jan. 23, 1896 25.0 198 nnn 1932...... Mar. 21. 1932 25.5 134,000 1897.. Nov. 18, 1896 28.5 170 nnn 1933 Jar. 4,1933 20.8 94,500 1898... Dec. 15, 1897 19.2 85,100 1934 Jan. 25,1934 18.2 76,300 1899 OQ n i 10 nnn 1935...... 17.70 73,200 1900 Jan. 15, 1900 25.1 ion nnn IQOfi Jan. 13.1936 24.3 125,000 1901 Jan. 15, 1901 31.2 231,000 1937 Apr. 16,1937 24.5 127,000 1902 Dec. 10,1901 1Q 9 85,100 1QQO Mar. 20, 1938 21.24 96,800 1903 .Tan. 26,1903 31.3 OQO fiAA 1QOQ Feb. 17.1939 61,000 1904 Feb. 17,1904 24.7 126,000 1940 Mar. 1, 1940 15.56 59,000 19Q5-.- , Dec. 31,1904 18.5 fin mn 1941 Dec. 28,1940 11.86 41,200 1906 Feb. 25,1900 15.1 en onn 1942 Nov. 18, 1941 19.97 8*88,000 1907 Feb. 6, 1907 30.7 220,000 1943...... Jan. 2, 1943 30.6 3< 236, 000 1908 OQ 7 1QO AAA 1944 12.97 3 47,000 1909 - OQ D 110 nnn IQAK Feb. 15,1945 10 Q£ 3 78, 000 1910.. Nov. 24. 1909 31.0 226,000 1946 Dec. 30 1945 30.0 '220,000 1911 10 4 70 nnn 10« 1C 1Q/lft 25.82 3141,000 1912...... Jan. 14,1912 26.2 145,000 1948 Jan. 8,1948 28.87 3196,000 1913 Apr. 1,1913 01 0 91.500 1949 Dec. 14,1948 25.75 3 142,000 1914... Jan. 26,1914 17.6 67, 100 1950 Jan. 24,1950 22.00 3*109,000 1915 Jap. 15. 1915 14.9 53,000 lo>;1 Oct. 31,1950 26.01 3 167, 000 1916... . . Feb. 8, 1916 27.7 165,000 1952 Dec. 6. 1951 18.62 385,000 W7 Apr. 9, 1917 14.2 49,500 1953 Jan. 20,1953 28.03 3200,000 1918 Dec. 25 1917 20.5 91,200 1954 Nov. 25, 1953 22.42 3*168,000 1919 Jan. 24 1919 20.0 07 cnn 1955... . - 14.62 3 69, 000 1920 Jan. 28,1920 17.1 CQ f\f\f\ 1956 Dec. 23.1955 26.70 3 231, 000 1921.. 23.5 i is nnn

1 Greatest in 95 years. 2 Second largest flood in 95 years. 3 Adjusted for storage; figures furnished by Corps of Engineers. 4 Storage began Fern Ridge Reservoir, Nov. 13, 1941; Cottage Grove Reservoir, Oct. 31, 1942; Dorena Reservoir, Oct. 11,1949; and Lookout Point Reservoir, November 1953. PART 1. DESCRIPTION Alll

Annual flood peaks (tables 26-28) and flood-frequency curves (fig. 29) are shown for 3 representative stations in the region McKenzie River near Vida, Willamette River at Albany, and Clackamas River near Cazadero. For Willamette River at Albany the annual flood peaks have been adjusted for the effect of storage since regulation began in 1941. This station was included in the tabulation because of the historic data available for the site.

TABLE 28. Annual peak stages and discharges, Clackamas River near Cazadero, Oreg.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date heieht (cfs) (feet) (feet)

1809 Jan. 20,1909 538.0 27,900 1933. 543. 90 18,300 1910..-.- ... Nov. 22. 1909 543. 70 43,100 1934 Dec. 22,1933 550. 65 38,700 1911 VU. 1 1935 542.56 15,600 1912 Jan. 12,1912 537. 93 23,900 1936 Jan. 4, 1936 545.9 24.200 1913 Mar. 30, 1913 536.80 20,700 1937 Apr. 14,1937 545.65 23,400 1914. Jan. 5, 1914 534.6 14,400 1938 Dec. 30,1937 549. 24 34,300 1915. Jan. 14,1915 530.45 6,590 1939 541. 15 12,000 1916 28,300 Feb. 6, 1940 544.03 19,000 1917 June 9, 1917 531. 77 9,260 1941 Nov. 29, 1940 542.18 14,400 1918 Dec. 19,1917 195.2 44.800 1942 Dec. 2, 1941 545.48 23,000 1919 536. 55 99 df\(\ 1943 Nov. 23, 1942 551. 79 42.600 1920.. _ ------Nov. 4,1919 cjfi K 35,800 1944 Nov. 4,1943 540. 07 9,150 1921 Dec. 30,1920 539.0 29,900 1945 Feb. 8, 1946 544.60 20,300 1922 . 546.0 44 300 1946 Dec. 28,1945 553.5 48,400 1923 - Jan. 6, 1923 60,000 1947 552.8 46,000 1924 Dec. 6, 1923 545. 65 23,800 1QXQ Ctf.i Q 53,400 1925 Nov. 21, 1924 547. 25 28,500 1949 May 2, 1949 546.24 24,900 1926 Feb. 6,1926 545. 70 21.900 1950. Feb. 25,1960 546.01 23,600 1927 Nov. 29, 1926 547. 90 28 300 1951 Nov. 2,1950 545. 96 23,500 Feb. 20,1927 547. 90 28,300 1952... __ ---- Oct. 23,1951 542.74 14,500 1928 Nov. 25, 1927 547.8 29.900 1953 Jan. 18, 1953 552. 16 40,700 1929 Mar. 21, 1929 540.43 10,200 J954 Dec. 20,1953 550.00 33,700 1930 Dec. 14,1929 542.60 15,000 1QCC Dec. 31,1954 10.83 14,400 1931 _ . _ ---. Mar. 31, 1931 fin Rflfl 1QCA 21.15 48,000 1932 Mar. 18, 1932 546.34 25,100

i Staff gage in forebay at River Mill dam.

COASTAL OREGON The earliest flood in coastal Oregon for which quantitative data are available is the flood of December 1861. The peak discharge for this flood has not been exceeded since, although it was equaled at Elkton on the Umpqua River in December 1955. Generally speaking, however, the greatest flood since 1861 in the coastal region occurred in February 1890. Subsequent floods of great magnitude were those of November 1909, February 1927, December 1945, October 1950, January 1953, and December 1955. Annual flood peaks (tables 29-31) and flood-frequency curves (fig. 29) are shown for 3 representative stations in the region South Fork Coquille River at Powers, Umpqua River near Elkton, and Rogue River at Raygold near Central Point. On the Coquille River the highest flood known occurred in February 1890, although it is presumed that the flood of December 1861 was A112 FLOODS IN FAR WESTERN STATES greater. Between 1890 and 1917, just prior to the beginning of gaging on the South Fork at Powers, notable floods are known to have occurred in January 1901, January 1903, February 1907, Decem ber 1907, November 1909, and February 1916. During the period of record at this station, 1917-26, 1929-56, the flood peak of December 1955 was exceeded only by that of December 1945. The greatest discharge known on Umpqua River at Elkton, that of December 1861, was equaled in the flood of December 1955. From table 30 it will be noted that the four highest observed peaks at this gaging station occurred during the last 6 years. On South Umpqua River at Brockway, it is presumed that the flood of 1861 was the greatest known. The four highest floods there since that date, in order of magnitude, are those of February 1890, October 1950, February 1927, and December 1955. On North Umpqua River at Glide the greatest known flood occurred in November 1909. This flood was greater than that of December 1955 and probably exceeded that of February 1927. No information regarding the floods of 1861 or 1890 is available. It has been established that on the Rogue River the two greatest floods known occurred in 1861 and 1890. Since the establishment of a gaging station at Raygold in 1906, the six highest peak discharges, in order of magnitude occurred in February 1927, December 1955 (equaled 1927 flood), November 1909, January 1953, February 1907, and November 1953.

TABLE 29. Annual peak stages and discharges, South Fork Coquille River at Powers, Oreg.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1917 . ... Dec. 3, 1916 8.2 5,040 1938 Nov. 19, 1937 17.4 23,300 1Q1S Feb. 6, 1918 10 8 10,000 1939 Dec. 2, 1938 12.06 11,100 1919 ICO 1Q 7nn 1Q4O 12.76 12, 100 n o 10 900 1941 1Q Oft 1921 _ . __ Feb. 20,1921 11.0 iciioo 1Q49 14. 50 15,500 1922 Nov. 21, 1921 8,440 1943 Dec. 8, 1942 15. 05 16,500 1923 __ - 9 9fifl 1Q44. 10.78 1924... Dec. 6, 1923 10.4 Q -\A 1QOQ 12.10 19 70ft 1Q4Q 1Q 19 1931 ... Mar. 12, 1931 8 9ft 5,870 1950_ n AQ 11,000 1932 - ___ Dec. 31,1931 13.1 14,700 1951 Oct. 28,1950 18.14 24,400 1933 Jan. 2, 1933 15.0 1952 12.04 12,000 1934 _ Dec. 18,1933 12. 05 11,500 1953 Jan. 18,1953 17.64 24,900 1935 .. __ - 10.55 7,230 1954 17.49 24,500 1936...... _ .. Jan. 12,1936 17.50 23,600 1955 Dec. 31,1954 10.35 9,600 1O37 Apr. 13,1937 15.6 15,200 1QKA Dec. 21,1955 1 n 7c 28,000 PART 1. DESCRIPTION A113

TABLE 30. Annual peak stages and discharges, Umpqua River near Elkton, Oreg.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1862 i 218, 000 1932 _____ Mar. 19, 1932. 1906 Jan. 17, 1906.. 18.33 61,400 1933 __ __ Jan. 3, 1933____ 28 101, 000 1908 _____ Dec. 26, 1907--. 29. 106, 000 1934 _____ Jan. 24, 1934., __ 18.1 53,200 1909... 97 °00 1935 _____ Dec. 20, 1934. 23.1 76,600 1910--. Nov. 23, 1909- 38 144, noo 1936 ____ Jan. 13, 1936 30 111, 000 1911 -. Nov. 29, 1910__ 26 94,300 1937 --.-.. Apr. 14, 1937. . _ 26.60 94,000 1912 __ . Jan. 13, 1912 29 1938.. .-__-_ Feb. 7, 1938- - 31.0 1913 Jan. 18, 1913- 22.0 75,800 1939 ______Mar. 13, 1939___ 19.00 57, 300 1914...... Jan. 26, 1914 20.0 67, 000 1940 _____ Feb. 29, 1940_._ 24.50 83, 500 1915... ______Feb. 3, 1915. ... 12.0 33, 100 1941 ______Dec. 27, 1940. __ 21.8 70, 400 1916 ______Feb. 7, 1916.... 30.0 116, 000 1942 ______Dec. 19, 1941... 22.6 74, 200 1917 ___ Mar. 25, 1917- _ 13.8 40,300 1943 ______Dec. 31, 1942.-- 41.1 186,000 1918 .__.. 20.0 67,000 Nov. 5, 1943.. 18.0 1919 ______Jan. 19, 1919 25.0 91, 000 1945 _____ Feb. 14, 1945. __ 23.12 76, 500 1920 _____ Dec. 9, 1919. _ 17.0 53,500 1946 ______Dec. 29, 1945. _ _ 40.1 179, 000 1921 ______23.0 81, 000 1947 --- Dec. 14, 1946. 22.60 74, 000 1922 _ Nov. 30, 1921. . 22.0 76, 000 1948 _____ Jan. 7, 1948- ___ 37.8 154, 000 1923 ______Jan. 6, 1923.. __ 26.0 96,000 1949 --- Dec. 12, 1948. . _ 29.5 109,000 1924. _ Dec. 7, 1923.. __ 13.5 39,100 1950 ______Jan. 22, 1950.. __ 23.36 78, 000 1925... Dec. 30, 1924. __ 30.0 116, 000 1951_. ______Oct. 30, 1950 44.2 208, 000 1926 ... Feb. 5, 1926.... 20.0 67, 000 1952 _____ Feb. 2, 1952.... 22.30 72, 500 1927 _____ Feb. 21, 1927--. 40.0 1953 ______Jan. 19, 1953____ 43.0 199, 000 1928 _____ 20.0 67,000 1954 _____ Nov. 23, 1953- 42.40 195, 000 1929 ______Apr. 15, 1929. _. 15.2 45,400 1955 ______Dec. 31, 1954, __ 19.8 60,400 1930... ______Dec. 20, 1929. .- 19.90 62, 000 1956 __ ___ Dec. 22, 1955,. _ 45.6 2 218, 000 1931 Apr. 1, 1931____ 17.40 51,000

1 Equaled on Dec. 22, 1955 but not exceeded in 95 years. 2 Same magnitude as flood of December 1861.

TABLE 31. Annual peak stages and discharges, Rogue River at Ray gold, near Centra Point, Oreg.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1906 ______10 7 Mar. 19, 1932 12.2 31,900 1907 . . ___- Feb. 4, 1907 1933 ______Jan. 2, 1933 8.45 17, 800 1908 ______Dec. 26,1907 15.3 44,800 1934 ._.____ Jan. 23,1934 6.06 10, 600 1909 ______12.0 Dec. 20,1934 6.85 12,700 1910.. ______Nov. 23, 1909 oo K 79,500 1936 ______Jan. 15, 1936 10.24 24,200 1911 ------Nov. 28, 1910 13.0 35, 100 1937 - Apr. 13,1937 10.70 26,100 1912 ______Feb. 17,1912 14.2 40,100 1938 -.__-.__ Dec. 11,1937 10.97 27,200 1913 ______7 ^ 1939 Mar. 12,1939 7.62 15,200 1914 ___ _ Jan. 22.1914 10.0 1940 ______Feb. 28,1940 10.2 24,200 1915 ______Feb. 1, 1915 7.4 15,400 1941 ______Jan. 25,1941 7.28 14, 100 1916... ______10.45 25, 200 1917_-_-_- Feb. 25,1917 6.68 12,300 1943 ______Dec. 31,1942 14.30 40,500 1918 .._ ___ Jan. 12.1918 10.9 25,800 1944 _ ____ Nov. 5,1943 5.06 8,060 1919 ______9 0 1945 ______Feb. 14,1945 10.98 27, 100 1920 __ ... Dec. 25,1919 5.52 8,980 1946 __._ Dec. 28,1945 16.0 48, 000 1921 . __ 10.52 24,400 1947. ______Nov. 19,1946 6.37 11,500 1922 ______Nov. 30, 1921 9.10 19, 600 1948 ______Jan. 7, 1948 15.6 46, 200 1923... _____ 8.78 1949 ____._. Feb. 22,1949 9.15 20,400 1924______Feb. 7, 1924 7.3 14,400 1950 ______Mar. 19,1950 9.34 21, 100 1925 ______1 K OO 44 400 14.91 43, 100 1926______... Feb. 4, 1926 5.94 lo| ooo 1952... ______Feb. 2, 1952 11.43 28,900 1927 . _ ____ Feb. 21,1927 24.8 110, 000 1953______Jan. 18,1953 17.83 56,500 1928 ______26,100 1954 . _____ Nov. 23, 1953 16.93 52, 300 1929 ______Jan. 3, 1929 5.81 9,730 1955 ______Dec. 31,1954 5.49 9,210 1930 .. _ __ Dec. 19,1929 7.50 14,800 1956______Dec. 22,1955 23.4 110, 000 1931 ___ _ 5.30 A114 FLOODS IN FAR WESTERN STATES

AREAS OF MINOR FLOODING IN OREGON, WASHINGTON, AND IDAHO Peak discharges during the floods of December 1955 in the tristate area of Oregon, Washington, and Idaho, while noteworthy, were not of record-breaking proportions. In general, the dearth of long-term streamflow records makes it difficult to establish a ranking of major floods. On the John Day River in Oregon, where records have been collected at McDonald Ferry since 1905, the flood peak of February- 1907 ranked second only to the historic peak of 1894. The peak dis charge of December 1955, while exceeded during the snowmelt flood of May 1956, was the sixth highest annual peak for the station. Annual flood peaks (tables 32-34) and flood-frequency curves (fig. 29) are shown for 3 representative stations in the region Asotin Creek near Asotin, Wash., John Day River at McDonald Ferry, Oreg., and Wind River near Carson, Wash. TABLE 32. Annual peak stages and discharges, Asotin Creek near Asotin, Wash.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1904.... . Apr. 15,1904 4 0 1,180 1943 Apr. 16,1943 2 in 373 1929..- . May 24, 1929 1.67 107 1Q44 1 K4 142 1930 May 3, 1930 1.67 160 1945 May 26, 1945 1.57 152 1931 Apr. 1, 1931 2.28 KA(\ 1946 Dec. 29,1945 2.08 303 1932 May 13,1932 1.78 340 1947 Dec. 15,1946 2.70 562 1933 June 10,1933 1.82 323 1948 Jan. 7, 1948 2.85 674 1934 Dec. 23,1933 500 1949 May 15.1949 2.70 378 19351-.. Apr. 16,1935 1.48 174 1950 Feb. 27,1950 2.20 277 1936 Apr. 18,1936 372 1951. Feb. 11,1951 2.80 490 1937...... Apr. 15,1937 1.75 220 1952 Apr. 28,1952 2.30 360 1938 Apr. 19,1938 2.17 345 1953 Apr. 28,1953 2.00 270 1939.. Mar. 20, 1939 2.00 343 1954 Feb. 13,1954 2.18 315 1940 Feb. 29,1940 1.82 236 1955 June 11.1955 1.76 215 1941 May 1, 1941 1.37 128 1956 Dec. 22,1955 3.94 1,040 1942... Dec. 3, 1941 2.32 416 i Prior to 1935, gage at different site and datum. TABLE 33. Annual peak stages and discharges, John Day River at McDonald Ferry, Oreg.

Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1894 12.8 1 OQ lAfl 1923____._ __ Apr. 19,1923 6.6 10,500 1905. May 10,1905 A OK 1Q94. Feb. 9, 1924 6.25 9,180 1906 May 31, 1906 7.90 14,000 1925 Feb. 6, 1925 7.92 15,000 1907 Feb. 6, 1907 in ft '27,800 1926 Feb. 8, 1926 5.9 8,180 1908 Mar. 17,1908 7.20 11,700 1927...- Apr. 28,1927 7.12 12,900 1910 Mar. 3,1910 0 Cft 1Q9S. Jan. 14,15, 7.04 12,500 1911 __ _ Mar. 24, 1911 5 QA 8 9ftA 1928 1912 . May 11, 16, 7.9 14,300 1929 Mar. 23, 1929 5.8 8,270 1912 1930- Feb. 161930 4.10 3.420 1913 Apr. 21,1913 7.7 13,700 1931...----.--. Apr. 2, 1931 6.84 11,800 1914 Apr. 17,1914 6.95 11,100 1932 ------Mar. 20, 1932 10.60 326,800 1915 Apr. 4, 1915 5.1 5,870 1933 Apr. 29,1933 5.97 8,060 1916 Feb. 11,1916 9.2 is onn 1934 Dec. 28,1933 4.37 3,760 1917 Apr. 27,1917 9 « 99 Ann 1935 - Apr. 17,1935 5.90 7,760 1918 Feb. 8, 1918 6.8 11 200 1936 - Apr. 19,1936 6.58 9,900 1919 Apr. 5, 1919 8 C 17 200 1937 Apr. 16,1937 7.65 13,300 1920 Apr. 14, 1920 7.15 19 finn 1938 Apr. 20,1938 7.64 13,700 1921 Feb. 15,1921 8 0 18 400 Mar. 25, 1939 7.68 14,000 1922 Apr. 23,1922 8.3 16 400 iQdn Mar. 1, 1940 7.28 12,500 Footnotes at end of table. PART 1. DESCRIPTION A115

TABLE 33. Annual peak stages and discharges, John Day River at McDonald Ferry, Oreg. Continued

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1941 June 9, 1941 5.32 6,290 1949....---.... Mar. 20, 1949 7.33 12,500 1942 . 7.11 11 900 1950 Mar. 19, 1950 6.08 8,310 1943 Mar. 29, 1943 8.14 15,300 1951 Feb. 12,1951 7.70 13,900 1944 Mar. 11,1944 5.50 6,610 1952 Mar. 27, 1952 9.8 22,900 1945 May 5, 18, 8 71ft Apr. 29,1953 8.17 15,800 1945 1954 - Apr. 15,1954 5.68 7,120 1946 8.67 17,300 1955. . .. May 22, 1955 5.91 7,800 1947 Apr. 19,1947 5.59 6,860 1956. Dec. 23,1955 9.78 22,800 1948 May 23, 1948 9.83 1956 May 9,1956 10.22 24,900

' Greatest since 1894. 2 Probably second largest since 1894. 3 Second largest since 1905.

TABLE 34. Annual peak stages and discharges, Wind River near Carson, Wash.

Gage Discharge Gage Discharge Water year Date height (cfs) Water year Date height (cfs) (feet) (feet)

1935- -. Dec. 21, 1934 14.6 12,200 1946 Dec. 28, 1945 16.02 15,800 1936. _.__.._ Jan. 12, 1936 13.96 10,900 1947 Dec. 13, 1946 15.92 15,000 1937 . Apr. 14, 1937 15.72 14,900 1948 Jan. 7, 1948 15.26 13,500 1938 _____ Dec. 29, 1937 17.30 20,000 1949. Feb. 17, 1949 13.43 9,460 1939 -. Feb. 15, 1939 11.90 7,300 1950 .- _. Nov. 27, 1949 14.07 10,800 1940.. ... Feb. 6, 1940 13.7 10, 100 1951 Dec. 23, 1950 13.38 9,460 1941.... . Nov. 23, 1940 10.94 5,860 1952 Feb. 4, 1952 15.28 13,800 1942... _.____._ Dec. 19, 1941 15.99 15,800 1953... ____._._ Jan. 9, 1953 16.02 15,500 1943. .. . Nov. 23, 1942 16.58 17,600 1954 _____ Dec. 9, 1953 15.42 14,600 1944 ______Feb. 6, 1944 10.18 4,910 1955 .-_._.__ Dec. 31, 1954 12.67 8,330 1945 ______Feb. 8, 1945 16.62 17, 600 1956 _._____. Dec. 21, 1955 16.70 18,500

DETERMINATION OF FLOOD DISCHARGE The standard method employed by the Geological Survey for deter mining peak discharge at gaging stations by means of current-meter measurements and stage-discharge relation curves has been described in detail in several water-supply papers. Basically, the method involves computing a stage-discharge relation from current-meter measurements of discharge at various stages and applying this re lation to records of stage. The reliability of the stage-discharge relation depends upon how adequately the measurements define the complete range in stage. Short extensions of the stage-discharge relation curve are made on basis of slope-conveyance studies, from velocity-area studies, by logarithmic plotting, or by the use of other hydraulic or hydrologic principles. Because of the great area and record-breaking magnitude of the December 1955-January 1956 floods, it was impossible to obtain current-meter discharge measurements at or near peak stage at many of the gaging stations. In some instances, measuring facilities were destroyed; in others, access roads and bridges were flooded or washed out; for some of the smaller streams, the durations of the flood peaks A116 FLOODS IN FAR WESTERN STATES, were too short to permit measurement. However, the main dif ficulty was that the number of sites requiring flood measurements was far too great for the available trained personnel to measure by current-meter. For many of the gaging stations at which no high-water current- meter measurements were made and for ungaged sites where peak discharge data were desired, the peak discharge has been obtained by slope-area, contracted-opening, or other types of indirect discharge measurements. These indirect measurements are based on channel geometry and high-water profiles obtained by a field survey and are computed by established hydraulic principles. They are indirect only in the sense that the data are collected subsequent to the passage of the peak discharge. A general description of the indirect measurement methods used by the Geological Survey is given in Water-Supply Papers 773-E, 798, 816, and 843, and more detailed information concerning the latest techniques is available in recent publications and reports of the Geological Survey, such as Circulars 284 and 376. Indirect measurements were made at over 300 sites throughout the area covered by this report. Collection of the field data for these measurements was hampered severely by inclement weather during the months following the flood. Continuing heavy rains in January over much of the area washed away high-water marks left by the peak flow, and made the high-water profile more difficult to define. Also, streams were at or near bankfull stage during most of the period, and hampered the surveys of channel geometry. The difficul ties were surmounted by the application of skills acquired through previous flood experiences, and the peak discharges determined by indirect methods are believed to be reliable.

SUMMARY OF FLOOD STAGES AND DISCHARGES Maximum stages and discharges at the 788 gaging stations, partial- record stations, miscellaneous sites, and reservoir stations are summarized in table 35. The station numbers in the table correspond to those on the location maps and to the numbers used for identification in Water-Supply Paper 1650-B. The derivation of the maxima data has been explained in the station descriptions for each site. For streamflow sites the peak- discharge values are given in table 35 as actually determined; that is, no adjustments for storage, regulation, or diversion have been made. PART 1. DESCRIPTION A117

For reservoir stations the maximum stage and contents are given. For some of the reservoir stations the computed peak inflow and occasionally the computed outflow are given (see station 593, table 35). At stations where the peak discharge did not occur simultaneously with the peak stage, the maxima are given on separate lines (see station 81, table 35). Under the heading "Maximum flood previously known" the first line gives the maximums during the period of gaging- station operation, and a second line gives data on floods outside this period, where such information is available (see station 26, table 35). Peak discharges in cubic feet per second per square mile have been tabulated for all sites except those significantly affected by regulation or diversions and those for which the drainage-area figures were not available. TABLE 35. Summary of flood stages and discharges

Maximum flood previously known Maximum during December 1955-January 1956 00 Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfsper (feet) Cfsper Cfs square Cfs square mile mile

The Great Basin

Walker Lake basin: 1 Q9ft f\f\ Mar. 13, 1928 4,051.8 3,990 Sept. 27, 1908 4, 078. 0 2 Virginia Creek near Bridgeport, Calif ... 64 1953-55 Apr. 14, 1954.. - 3.13 74 1.15 Dec. 23, 3:45 a.m. . 8.40 1,300 20.2 3 19.4 -...do...... June 10, 1955. ... 2.88 1228 11.8 Dec. 23, 9:30 a.m ... 3.39 1307 15.8 4 12.6 do.__ Mar. 9, 1954 2.83 42 3.3 Dec. 23, 2 a.m ..... 5.95 690 54.8 34.7 . .do...... May 21, 1954 3.56 1225 2.37 167 June 21, 1911 .... 5.2 12660 6 Swager Creek near Bridgeport, Calif 53 1911-15, 1953-55- June 16, 1911 '4.1 151 2.8 Dec. 23, 4:30 a.m ... 6.24 585 11.0 7 Buckeye Creek near Bridgeport, Calif. . 45 1910-14, 1953-55- June 21, 1911 '4.8 "~<44,~580 Dec. 23, 7:30 a.m.. 4.00 700 15.6 8 362 June 12, 1938 6,460.7 Jan. 31 6,456.85 * 33, 730 Calif. 9 362 1921-55.... Jan. 22, 1943 4.95 U.240 1.16 1134 Calif. 10 1,100 1 QJ.7 tt July 14, 1952 6.21 U,400 6.87 1 1, 640 ditch near Mason, Nev. 11 East Fork West Walker River near 63 1910, 1944-55 Feb. 2, 1945. 2.69 660 10.5 Dec. 23, 3:40 a.m.. 2.80 994 15.8 Bridgeport, Calif. 12 West Walker Elver below East Fork 182 1938-55 Nov. 20, 1950 8.10 6,220 34.2 Dec. 23, 7 a.m __ 7.41 5,180 28.5 near Coleville, Calif. 13 1931-55 June 30, 1941 5, 005. 35 460,240 Jan. 31...... 4, 994. 13 436,420 14 OfU 1914-25,1947-55- June 7, 1922 '6.35 12,530 7.42 12,700 Carson River basin: 15 Silver Creek below Pennsylvania 20 1946-55 Nov. 20, 1950 '7.95 1,260 63.0 Dec. 23, 3 a.m ..... 6.09 1,520 76.0 Creek, near Markleeville, Calif. 16 14 -do ...... do_ '8.49 1,740 124 Dec. 23 7.36 900 64.3 Springs near Markleeville, Calif. 17 East Fork Carson River near Gardner- 344 1890-93, 1900- Nov. 21, 1950 9.66 12, 100 35.2 Dec. 23, 9:30 a.m.. 11.88 17,600 51.2 ville, Nev. 1906, 1908-10, 1917, 1924-29, 1935-37, 1939- 55. 18 West Fork Carson River at Woodfords, 66 1900-20,1938-55- Nov. 20,1950 .... 8.35 4,730 71.7 Dec. 23, 5:45 a.m.. 8.86 4,810 72.9 Calif. 19 15 1948-55 Dec. 3, 1950.. ... 1.95 106 7.07 Dec. 23, 5:30 p.m.. 2.03 117 7.80 20 Carson River near Carson City, Nev.. 876 1939-55 Nov. 22, 1950 11.4 15,500 17.7 Dec. 24, 4-6 a.m.. - 15.0 30,000 34.2 PART 1. DESCRIPTION A119

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668521 O 63- TABLE 35. Summary of flood stages and discharges Continued

Maximum flood previously known Maximum during December 1955-January 1956 Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfsper (feet) Cfsper Cfs square Cfs square mile mile

Central-coastal California

Arroyo de la Cruz basin: 48 41.4 1950-55... Jan. 14, 1952 10.80 11,600 280 Dec. 23, 8a.m ..... 12.40 17,700 428 Calif. Sur River basin: 49 46.9 .. do. ... Nov. 19, 1950. ... »11.0 7,000 149 11.05 5,220 111 Carmel River basin: 50 188 Dec. 23...... 36.9 Calif. Salinas River basin: 72.5 1942-55...... Jan. 21, 1943 13.35 5,800 80.0 10.65 3,920 54.1 52 111 1941-55 Mar. 15, 1952____ 1,304.26 « 28, 600 Jan. 27, 12 p.m .... 1, 302. 48 * 27, 200 53 112 1942-55 ..do-...... 4.99 12,200 Jan. 27, 3:30 p.m_. 2.90 1625 Santa Margarita, Calif. 54 25.4 1949-55 - Jan. 15, 1952..... 7.81 2,690 106 Jan. 25, 8:30 a jn___ 9.56 5,040 198 55 IRQ 1939-55 Mar. 9, 1943. - 16.2 i 14, 200 16.73 Feb. 10-13, 1938.. 16.9 5fi 922 1954-55 Feb. 27, 1955-... 250 .27 3.92 1,310 1.42 57 140 1955 Dec. 23, 6a.m ..... 24.63 30,300 216 58 354 1939-55 Jan. 15, 1952-. ... 12.57 53,100 150 13.15 166 Calif. 59 282 1929-55...... Feb. 2, 1945..... 5.85 13,500 47.9 Dec. 23, 12m...... 5.84 14,500 51.4 60 2,522 1948-55 - Jan. 15, 1952..... 12.35 26,800 10.6 12.01 9.91 fil 262 1942-45 Feb. 2, 1945..... 11.15 3,460 13.2 Dec. 23..- 13.91 3,100 11.8 62 241 1901-55 Feb. 21, 1917, 816. 5 22,000 91.3 14.30 27,700 115 Nov. 25, 1926. 63 4,231 1900-1, 1929-55 Feb. 12, 1938. ... 75,000 17.7 24.52 23,600 5.58 Jan. 16, 1952..... 26.85 Pajaro River basin: 64 146 1940-55 Feb. 2,1945 17.8 17,200 18.6 112,600 65 19.6 1951-55 Jan. 12, 1952.. ... 8.18 2,760 141 Dec. 23, 2p.m.. ... 3.39 1334 66 30.2 1930-55 Dec. 11, 1937..-. 13.70 8,630 286 Dec. 23 ...... 14.3 10,300 341 67 108 1949-53 Jan. 14, 1952.. ... 7.5 2,640 24.4 Dec. 24., ...... 7.03 3,140 29.1 near Hernandez, Calif. 68 San Benito River near Willow Creek 250 1939-55 Apr. 4, 1941.. ... 7.8 6,200 24.8 Dec. 24, 2a.m ..... 5.2 3,790 15.2 School. Calif. 1937-38 9.0 Tres Pinos Creek near Tres Pinos, 209 1940-55...... Apr. 4, 1941... __ 7.75 8,060 38.6 Dec. 23, 10 p.m_ 6.90 4,750 22.7 Calif. February 1938 ... 9.0 586 1949-55...-.--... Mar. 15, 1952 10.80 5,490 12 55 7 460 1,188 1939-55 Apr. 4 or 5, 1941. 26.2 11,100 9.34 09 AjR 24 * ggo 20.2 February 1938 _ 31.3 27.8 Dec. 22..-.... . 3 t> Y\ 1OA Sequel Creek basin: 40.4 1951-55 Jan. 12, 14, 1952J. 11.63 4,910 122 22.33 15,800 OQ1 San Lorenzo Kiver basin: 110 1937-55 Feb. 27, 1940.... 21.1 24,000 218 Qf\ Af)f\ 276 Calif. 115 1952-55. _ .. Dec. 7, 1952 9,400 81.7 Dec. 23, 3 a.m ..... 23.10 30,400 264 Branciforte Creek at Santa Cruz, Calif- 18.5 1940-43, 1952-55- Feb. 9, 1941.... . '15.1 3,910 211 Dec. 22, 11 p.m .... 22.04 8,100 438 Scott Creek basin: 13.6 Dec. 23 ...... 6,430 473 Pescadero Creek basin: 46.2 1951-55 . Dec. 7, 1952..... 15.61 4,030 87.2 21.27 9,420 204 Purisima Creek basin: 6.11 Dec. 22 ...... 683 112 Calif. San Francisquito Creek basin: San Francisquito Creek at Stanford 37.7 1931-41, 1950-55- Nov. 18, 1950 10.4 3,650 96.8 Dec. 22, 12 p.m __ 13.60 5,560 147 University, Calif. Matadero Creek basin: 8.10 1952-55 .. Dec. 6, 1952.... . 7.1 535 66.0 1854 Dec. 23, la.m. .... 9.88 Stevens Creek basin: 18.0 1930-55. _ ...... Feb. 28, 1940. ... 7.05 U.090 8.25 11,420 Guadalupe River basin: Alamitos Creek near Edenvale, Calif. .. 35.0 .... -do...... Dec. 27, 1931.... 36.60 12,670 Dec. 23, 2:30 a.m.. 6.6 14,140 12.7 . -do. .... Jan. 12, 1952 4.22 U.330 Dec. 22, 12 p.m .... 4.20 i 1, 320 38.9 1930-44, 1953-55.. .Feb. 27, 1940.... 3 14. 71 7,110 183 Jan. 1, 9:30 a.m .... 6.74 1715 131 1930-55 do...... 11.88 18,680 Dec. 23, 4:30 a.m. . 13.94 i 5, 570 8.97 1933-55.. .-...... do ...... , 2,540 283 Dec. 22, 12 p.m .... 6.40 2,730 304 Mar. 1, 1940 ._ 5.90 Coyote Creek basin: 194 1902-12, 1916-55- Mar. 7, 1911.. ... 25,000 129 2.24 128 229 1916-55 . . Feb. 10, 1922... . 12.8 10,000 43.7 5.02 i 1, 610 Alameda Creek basin: 58.4 1912-28- ... Jan. 3, 1916..... M,460 Dec. 23...... 5,810 99.5 36.7 .....do...... Feb. 20, 1914.... ?700 ..... do ..... 1,880 51.2 149 ..... do .. . Jan. 25, 1914.. ... 7 5, 930 do...... 18,200 122 406 r.do ...... do .... '9,810 . do...... 24,800 61.1 Calif. 94 633 1916-55 . Jan. 12, 1952 13.92 124,300 Dec. 23, 4 p.m ..... 14.9 129,000 San Lorenzo Creek basin: San Lorenzo Creek at Hay ward, Calif.. 38.0 1940,1946-55..... Feb. 27, 1940 13.13 2,990 78.7 Dec. 22, 12 p.m .... 20.82 4,790 126 Jan. 24, 1942 15.7 4,200 111 See footnotes at end of table. TABLE 35. Summary of flood stages and discharges Continued

Maximum flood previously known Maximum during December 1955-January 1956 10 fcO Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile Central-coastal California Continued

Pacheco Creek basin: 96 5.89 1952-55.... _ ... Dec. 7, 1952. . ... 3.72 212 36.0 14 2 i °>*n 229 97 50.7 do...... do... . 7.60 1,880 37.1 14.55 Calif. QQ 78.1 . .do...... do. ... . 11.15 3,660 46.9 00 00 141 99 6.16 1954-55...... Jan. 18, 1955..... 1.56 9 1.48 3 AK OftO 49 9 100 27.0 1952-55--...... 6.40 14.7 9 OK QQO 1.94 1954-55. Feb. 27, 1955.... 1.60 29 14.9 4.72 416 217 in9 4.35 . . do...... 10.24 604 IOQ San Joaquin Valley Kern Kiver basin: i 09. 1912-55. Nov 19 1950 27,000 32.0 17.55 97 900 qo o 104 1,026 1905-12, 1953-55.. 10,400 10.1 16.20 9O 4-00 105 South Fork Kern River near Onyx, 530 1911-14, 1919- .Mar. 2, 1938 6.69 3,450 6.51 Dec. 24, 2a.m ..... 5.73 2,050 3.87 Calif. 42, 1947-55. 2,093 1953-55. 2, 543. 60 4 85, 380 * 119, 700 Dec. 23, 12m .. 825,000 107 1945-55 Nov 19 1950 39, 000 6.11 1374 2,264 1950-55 do 30.7 40, 000 17.7 9.60 1 1 390 Calif. 2,327 1893-1955 do...... 314.2 36,000 9 35 i 2, 130 109 house, Calif. Tulare Lake basin: 110 1906-55 June 27, 28, 1941. 196.8 Jan. 31..-... . 187. 40 111 North Fork of Middle Fork Tule River 39.5 1939-55 Nov. 19, 1950 . 13.06 11,000 278 12.47 12,400 314 near Springville, Calif. 112 261 1901-55 __ ...... do...... 13.75 25,500 97.7 11.80 24,200 92.7 113 105 1930-54 do...... 3 11. 36 7,100 67.6 9.04 3,110 29.6 Calif. 114 395 1953-55 Jan. 25, 1954 16.35 3,110 7.87 21.65 27,000 68.4 terville, Calif. 115 100 1949-55- Nov. 19, 1950.... 15.70 17,500 175 Dec. 23 29 46,800 468 wisha Camp, Calif. 116 50.6 1950-55 - Nov. 18, 1950 . 10.1 ,ooo 79.1 Dec. 23, 5:30 a.m. . 13.4 12,500 247 wisha Camp, Calif. North Fork Kaweah River at Kaweah, 128 1910-55 _____ - Dec. 11, 1937-.. 11.0 11,200 87.5 Dec. 23 14.1 21,500 168 Calif. 118 Kaweah River near Three Rivers, Calif. 520 1903-55.- . . Nov 19 ' 1950 1Q e 52,000 100 22 24 80, 700 155 119 Lime Kiln Creek (Dry Creek) near 75.5 Dec. 23, 6-7 a.m ... 6,070 80.4 Lemon Cove, Calif. 120 Sand Creek near Orange Cove, Calif_. 32 1944-54 Jan. 24, 1952 4.12 446 13.9 4.81 749 23.4 121 South Fork Kings River near Cedar 4DQ 1950-55 Nov. 19, 1950 10,000 24.4 Dec. 23l 4-5 a.m ... 16.30 13,900 34.0 Grove, Calif. 122 Kings River near Hume, Calif.__..... 838 1921-36, 1951-55- June 5, 1952. .... 11.12 12,100 14.4 Dec. 23, 4 a.m ..... 15.53 38,000 45.3 123 Kings River above North Fork, Calif- 956 1927-28, 1931-55- Nov. 19, 1950 .... 13.23 36,200 37.9 Dec. 23, 5 a.m __ 16.26 59,100 61.8 124 North Fork Kings River near Cliff 174 1921-55 Dec. 11, 1937.... 18.0 14,000 80.5 Dec. 23, 3 a.m ___.. 16.8 11,900 68.4 Camp, Calif. 125 North Fork Kings River below Ran- 225 1926-50 do 23 21,000 93.3 Dec. 23 24,600 109 cheria Creek, Calif. 126 Kings River below North Fork, Calif... 1,350 1951-55 May 30, 1952 12.22 20,300 15.0 23.08 85,200 63.1 Nov. 19, 1950 21.6 74,200 55.0 127 Big Creek above Pine Flat Reservoir, fiQ 9 Feb. 13, 1954--- 4 60 1,400 20.2 9.21 10,400 150 Calif. 128 Sycamore Creek above Pine Flat Reser 56.5 -do Feb. 14, 1954- . 4.20 1,000 17.7 Dec. 24, 1 a.m __ 9.78 6,760 120 voir, Calif. 129 Pine Flat Reservoir near Piedra, Calif.. 1,542 1951-55 June 13, 1955- 835.10 « 439, 000 Jan. 31, 12 p.m .... 890.18 « 674, 300 Dec. 23, 7 a.m __ »112,000 130 Kings River below Pine Flat Dam, 1,542 1954-55 July 9, 1954 6.58 16,260 Jan. 29, 11 p.m to 2.57 1248 Calif. 131 Kings River at Piedra, Calif____... 1,694 1895-1955 Nov. 19, I960 21.0 91,000 53.7 8.89 19,380 132 Warthan Creek near Coalinga, Calif-.~ 783 6.99 133 Los Qatos Creek above Nunez Canyon 1949-55 3.70 1,250 13.1 3.19 681 7.13 near Coalinga, Calif. San Joaquin River basin: 134 North Fork San Joaquin River below 38.0 1920-28, 1951-55- June 27, 1922..- 7.24 2,000 52.6 Dec. 23, 5:30 a.m.. 7.48 2,400 63.2 Iron Creek, Calif. 135 San Joaquin River at Miller Crossing, 254 1921-28, 1951-65- June 4, 1922 17.68 6,200 24.4 Dec. 23, 8a.m.. ... 21.28 16,600 65.4 Calif. 136 Florence Lake near Big Creek, Calif . 171 July 16, Ifi35 . 7, 328. 8 * 65, 700 7,269.39 « 17, 400 137 South Fork San Joaquin River near 171 1921-55 15.38 '4,320 9.23 112 Florence Lake, Calif. 138 Bear Creek near Lake Thomas A. 53.5 -...do. .... July 21, 1936 - 6.90 1,530 28.6 Dec. 23,4:30 a.m.. 6.62 1,330 24.8 Edison, Calif. 139 Lake Thomas A. Edison near Big QQ Q 7 603 7 * 59, 100 7, 597. 5 « 50. 300 Creek, Calif. 140 Mono Creek below Lake Thomas A. o9 n 1 Q91 tt Q ftO 1,760 19.1 6.25 1372 Edison, Calif. 141 Jackass Creek near Jackass Meadow, 12.8 1921-28, 1951-55- Apr. 27, 1953.. .. 9.81 435 34.0 Dec. 23, 5 a.m. .... 11.37 786 61.4 Calif. 142 Chiquito Creek near Arnold Meadow, 59.6 ..do. - - May 27, 1952-.-. 9.13 1,470 24.7 Dec. 23, 4:30 a.m.. 16.38 8,630 145 Calif. 143 San Joaquin River above Big Creek, 1 042 1922-55 Dec. 11, 1937..-. 24.05 52,500

Maximum flood previously known Maximum during December 1955-January 1956 Drainage Sta area Discharge Discharge tion Stre'am and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfsper (feet) Cfs per Cfs square Cfs square mile mile

San Joaquin Valley Continued

San Joaquin River basin Continued 146 22.7 1927-55...... Nov. 19, 1950____ 10.77 3,220 142 11.20 3,670 162 Calif. 147 29.7 ..do...... July 4, 5, 1946, 5, 370. 2 « 135, 700 5, 339. 77 « 76, 400 Aug. 2, 3, 1952. 148 1,299 1951-55 Dec. 29, 1951-... 22.67 1 15, 100 54.2 i 73, 200 Creek, near Auberry, Calif. 149 50.8 1940-55 Feb. 11, 1941. 5.85 '847 5.28 i860 Lake, Calif. 150 130 1952-55 Jan. 25, 1952 . 10.45 U,380 28.5 112,000 Calif. 151 1,480 1910-14, 1936-37, Dec. 11, 1937-... 4fi K i 75, 000 Dec. 23 1 Q9 900 powerhouse, Calif. 1942-55. 152 92.8 1936-55 10,300 17 94 7,450 sn 4 153 1,633 1941-55 May 21, 1954 177 Id < 517, 300 567.41 « 470, 100 '91,900 12m. 154 1,675 1907-55 Dec. 11, 1937... »23.8 i 77, 200 9.00 17,120 155 Little Dry Creek near Friant, Calif _ .- 58 1941-55 Jan. 25, 1952 5.63 1,810 31.2 6.70 1,766 30.3 156 1,805 6.58 i 2, 240 Dec. 27 17,240 157 Panoche Creek below Silver Creek near 299 1949-53 Jan. 12, 1952- 7.05 3,160 10.6 Dec. 23-- ... . 5.52 1,890 6.32 Panoche, Calif. 158 132 1911-13, 1915-55.. Nov. 19, 1950 9.31 8,540 Kd 7 11.52 13,300 101 159 270 1941-55 do.... __ 10.36 10,700 39.6 11.64 17, 500 64.8 160 Chowchilla River at Buchanan dam- 238 1921-23, 1930-55- Nov. 18, 1950 15.06 22,500 94.5 Dec. 23, 6:30 a.m.. 16.50 30,000 126 site, Calif. 161 1940-55.- - ___ Mar. 9, 1941 _ i 7 2, 420 Jan. 30, 31 - 6.60 620 162 8,090 1944-55 i I" 4, 470 69.78 i 1° 4, 420 Bridge, Calif. 69.67 163 Los Banos Creek near Los Banos, Calif- 156 Dec. 23 11, 400 73.1 164 San Luis Creek near Los Banos, Calif.. 84.7 1949-53 Nov. 19, 1950 5.60 2,760 32.6 do . 7.07 2,640 31.2 165 181 1915-55 - Nov. 18, 1950- ... 11.55 9,260 51.2 12.73 9,860 54.5 near Yosemite, Calif. 166 Tenaya Creek near Yosemite, Calif __ 47 1904-09, 1912-55- Dec. 11, 1937 10.00 6,800 145 Dec. 23, 4 a.m ..... 8.14 4,730 101 167 Merced River at Pohono Bridge near 321 1916-55 Nov. 19, 1950 20.98 23,000 71.7 Dec. 23, 6 a.m __ . 21.52 23,400 72.9 Yosemite, Calif. 168 South Fork Merced River near El 239 1950-55 ..do ...... 17.63 37,600 . 157 Dec. 23, 5:30 a.m.. 18.70 46,500 195 169 Merced River at Bagby, Calif .. . 912 1922-55 ... ..do. .... 26.96 83,000 91.0 Dec. 23, 10 a.m .... 26.80 92,500 101 170 Lake McClure at Exchequer, Calif..... 020 1926-55 Dec. 4, 1950... - 710. 5 * 290, 800 Dec. 27, 12 m.-7 706.4 4 279, 700 p.m. 8103,000 171 Merced River at Exchequer, Calif__. 035 1915-55 .do .... 22.6 146,200 ...... Dec. 27, 6 a.m ..... 11.00 i 10, 400 172 Merced River near Stevinson, Calif-_- 274 1940-55 Dec. 5, 1950. -. 19.05 i 13, 600 Dec. 28, 4 a.m ..... 18.10 111,200 173 Merced River Slough near Newman, 1941-55 .do 11.29 i 6, 410 Dec. 28, 9 a.m-2 10.90 14,240 Calif. p.m. 174 San Joaquin River near Newman, Calif- 990 1912-55 . Mar. 7, 1938 18.50 8 133,000 Dec. 29, 5-12 p.m.. 17.05 '16,800 175 Orestimba Creek near Newman, Calif.. 135 1932-55 Jan. 21, 1943- 5.95 6,450 47.8 Dec. 23, 10 a.m_ 5.18 5,620 41.6 176 Falls Creek near Hetch Hetchy, Calif 45.2 1915-55 Nov. 19, I960 9.0 6,660 147 9.00 6,660 147 177 Hetch Hetchy Reservoir at Hetch 160 1923-55 Dec. 3, 1950- 3, 810. 4 4 369, 100 Jan. 28, 12 p.m.... 3, 735. 3 4231,000 Hetchy, Calif 178 Tuolumnc River near Hetch Hetchy 162 1915-55 _____ . June 1, 1943- __ 13.90 112,900 Dec. 22, 8:30 a.m.. 6.57 1918 179 Lake Eleanor near Hetch Hetchy, Calif. 79 1919-55 L Dec. 11,1937-- 4,663.4 « 31, 010 "l46"~ Dec. 23, 8 a.m. . 4, 663. 5 4 29, 600 t_4 180 Eleanor Creek near Hetch Hetchy, Calif- 80 1909-55 Nov. 19, 1950 .... 14.95 11,700 .do 14.80 11,500 144 181 South Fork Tuolumne River near Oak 87.6 Dec. 11,1937 10.00 9,000 103 Dec. 23, 6 a.m. . 10.9 11,900 136 land Recreation Camp, Calif. 182 Middle Tuolumne River at Oakland 71.0 1922-55- Nov. 19, 1950. ... 10.45 3,450 48.6 Dec. 23 . 11.75 4,920 69.3 Recreation Camp, Calif. 1 ' 183 North Fork Tuolumne River near Long 21.6 do 2,590 120 Barn, Calif- O 184 Woods Creek near Jacksonville, Calif. 98.4 1925-55 Feb. 9, 1938..-- 13,500 137 Dec. 23, 2 a.m ..... 14.66 14,400 146 H 185 Don Pedro Reservoir near La Grange, 539 1924-55 __ -.. JunelS, 1937 606.1 4 292, 100 604.8 4 288, 000 CO Calif. O 186 Tuolumne River above La Grange 540 1895-1955 Dec. 8, 1950- ... 43.8 i 61, 000 ..do . 34.00 i 41, 700 Dam, near La Grange, Calif. 187 Tuolumne River at Modesto, Calif... ~49~5~ 1943-55 Dec. 9, I960. 69.19 157,000 Dec. 25, 4 a.m... 66.43 137,600 188 Middle Fork Stanislaus River at Ken 1938-55 Nov. 20, 1950..- 6.66 1 1,700 6.51 11,480 H nedy Meadows, Calif. O 189 Clark Fork Stanislaus River near Dar- 65.7 1950-55 do 11.88 4,350 66.2 Dec. 23, 4:30 a.m.. 10.54 3, 340 50.8 danelle, Calif. 190 Middle Fork Stanislaus River at Hells 280 Dec. 23 . 17.72 26,600 95 Half Acre Bridge, Calif. 191 Middle Fork Stanislaus River at Sand J18 1905-55 Dec. 11, 1937... . 21.0 » 24, 000 75.5 .do ...... 20.2 26,000 81.8 Bar Flat, near Avery, Calif. 192 North Fork Stanislaus River below 29.2 1952-55 Apr. 27, 1953.... 7.58 654 22.4 Dec. 23, 2 a.m 9.17 1,370 46.9 Silver Creek, Calif. 193 Highland Creek below Spicer Meadows 43 .do ...... Mar. 9, 1954 8.00 2,350 54.7 Dec. 23, 5:30 a.m.. 11.50 8,800 205 Reservoir, Calif. Nov. 20, 1950.... 11.50 8,800 205 194 North Fork Stanislaus River near 63 1914-22, 1928-55.- Dec. 11,1937 14.1 31,100 191 Dec. 23, 5 a.m..--. 14.23 32,000 196 Avery, Calif. 195 South Fork Stanislaus River at Straw 45.5 1911-17, 1938-55-. Nov. 21, 1950--- - 9.25 '3,900 Dec. 23, 3a.m -- 7.00 i 2, 130 berry. Calif. 196 South Fork Stanislaus River near Long 67.2 1937-55-.------.do---.-- - 9.3 14,900 8.00 i 3, 160 Barn, Calif. See footnotes at end of table. to 01 TABLE 35. Summary of flood stages and discharges Continued

(feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile i_i San Joaquin Valley 'Continued Q /-> O San Joaquin River basin Continued OJ 197 Melones Reservoir at Melones Dam, 897 May 27, 1951.... 736.7 4 115, 800 733.0 4 108, 900 Calif. hH 198 Stanislaus River below Melones power 898 1931-55 ----- Nov. 21,1950 - 25.18 i 49, 500 Dec. 23, 4 p.m. 29.0 i 62, 800 house, Calif. 199 Stanislaus River at Goodwin Dam, near 973 326.0 60,000 61.7 62,900 64.6 ^ Knights Ferry, Calif. 200 Nov. 21,1950 . 62.78 48, 500 Dec. 24,9a.m. .- 63.25 62, 500 Feb. 12, 1938---. 64.4. 201 San Joaquin River near Vernalis, Calif.. 14, 010 27.75 79,000 26.89 50,900 ^ 202 Duck Creek near Farmington, Calif. . . . 8.25 Dec. 22, 12p.m.-.. 6.60 940 114 H 203 San Domingo Cieek near San Andreas, 27.1 1950-55.- Feb. 4, 1950. - 928 34.2 Dec. 23, 2:30 a.m. . 8.24 2.830 104 03 Calif. Jan. 15, 1952 4.68 204 San Antonio Creek near San Andieas, 46.4 .do... Feb. 4, 1950, Nov. 4.50 1,220 26.3 Dec. 23, 4 a.m.. 5.66 2,500 53.9 H Calif. 18, 1950. P3 205 South Fork Calaveras River near San 118 .do...... do .... 6.40 5, 620 47.6 Dec. 23, 1.-30a.m. 10.29 17,600 149 3 Andreas, Calif. 206 Calaveritas Cieek near San Andreas, 53.3 -...do do 6.2 3,420 64.2 Dec. 23, 3a.m.. 6.33 3,600 67.5 CO Calif. 207 Esperanza Creek near Mokelumne Hill, 16.7 1951-55.. -- Jan. 15,1952 4.56 1,160 69.5 Dec. 23, 5 p.m. 6.78 3,060 183 > Calif. SI Nov. 18, 1950 6.5 2,030 122 208 Jesus Maria Creek near Mokelumne 34.7 - .do ----- 7.1 4,380 126 7.63 5,490 158 ^ Hill, Calif. 209 North Fork Calaveras River near San 85.7 -.-.do..--. .. -- do.-.-- 8.5 3,420 39.9 Dec. 23, 8:30 p.m. . 12.52 6,200 72.3 Andreas, Calif. 2)0 Murray Cieek near San Andreas, Calif.. 23.5 . .do------..-.do ----- 34.8 960 40.9 Dec. 23, 7p.m. - 6.62 1,700 72.3 211 Cosgrove Creek near Valley Springs, 20.6 8.38 3,180 154 8.96 3,240 157 Calif. 212 Hogan Reservoir near Valley Springs, Dec. 24, 11:30 a.m. 625. 40 4 55, 500 Calif. 213 395 1907-55 . Jan. 31, 1911 21.0 £0,000 127 15.44 1 14, 200 214 48.4 1930-33, 1943-55.. Feb. 2, 1945 .. -- 14.45 2,260 46.7 Dec. 23,8p.m. 13.48 1,840 38.0 215 Salt Springs Reservoir near West Point, 160 June or July, 3, 958. 0 * 140, 000 Jan. 24... _..-.._. 3,921.3 4 106, 500 Calif. 1948-54. 216 North Fork Mokelumne River below 160 1926-55----...... Nov. 21, 1950- . 17.20 '16,000 4 99 Salt Springs Dam, Calif. 217 Cold Creek near Mokelumne Peak, 23 1927-55- - 9.69 239 Dec. 23, 2a.m... 9 o/\ 4,670 203 Calif. 218 Bear River near Salt Springs Dam, Calif. 48 4.12 1 1 Rdt\ Dec. 23, 3a.m. __ 4 00 11, 400 . H O 219 Middle Fork Mokelumne River at West 07.2 1911-55- - Nov. 18, 1950 - 7.70 2,820 42.0 Dec. 23, 5:30 p.m_- 8.98 4,320 Point, Calif. 220 South Fork Mokelumne River near 73.8 1933-55- . Feb. 2, 1945-- 9 CC Dec. 23... ----- 14.8 6,920 West Point, Calif. 221 Mokelumne River near Mokelumne 538 1927-55--___ __ 1 23,500 Hill, Calif. 222 Mokelumne River at Lancha Plana, 584 1926-55- -- - Nov. 21, 1950 - 20.1 i 26, 700 -- -- Dec. 23, 10 p.m.... 19.15 i 25,500 . Calif. 223 Mokelumne River near Clements, Calif. 630 1904-51, 1955 ..--.do ----- 24.40 OQ QC i 27,300 . 224 Mokelumne River at Woodbridge, Calif. 644 1924-55------Nov. 22, 1950 29.58 i 27, 000 "167" Dec. 24, 2p.m _ 29.00 1 23,000 225 North Fork Cosumnes River at Cos- 36.9 1948-53-- 9 KA Dec. 23 ----- 11.53 6,160 167 umnes Mine, Calif. 226 Camp Creek near Camino, Calif------33.0 1948-55------. Nov. 20. 1950 5.65 2,560 77.6 .do... -- 6.24 3,260 98.8 227 Camp Creek near Somerset, Calif.. . 62.7 1924, 1954-55 Feb. 8, 1924. '195 12.48 6,020 96.0 228 North Fork Cosumnes River near El 202 1911-41, 1948-55 . Nov. 18, 1950 12.06 10,900 Dec. 23.. H O 15,800 78.2 Dorado, Calif. 229 Cosumnes River near Plymouth, Calif.. 429 1951-55- Jan. 12, 1952 12.32 7,380 17.2 ....-do ------20.96 33,500 78.1 Nov. 18, 1950 20.5 20,900 48.7 230 Cosumnes River at Michigan Bar, Calif- 537 1907-55------_do_ ___-... 11.85 27,600 51.4 42,000 78.2 16.3 231 Deer Creek above Little Deer Creek 46.4 4,460 96.1 near Sloughhouse, Calif. 232 Carson Creek near Sloughhouse, Calif- - 23. 7 2,480 105 233 Cosumnes River at McConnell, Calif-.. 730 1943-55 - 44.89 21,900 30.0 46.26 54,000 74.0 Feb. 23, 24, 1936- 45 94 234 Dry Creek near Gait, Calif------325 1926-33, 1944-55- Feb. 2, 1945-. 13.84 13,200 40.6 Dec. 24, 8a.m _ - 14.55 17,000 52.3 235 Marsh Creek near Byron, Calif------42.5 4.48 86 3,800 89.4 236 Kellogg Creek near Byron, Calif-. - 24.1 Dec. 23- 1,310 54.4

Sacramento Valley

Goose Lake basin: 9Q7 1909-55------A/Tor 1 9 IQIft 3,000 14.2 4.08 1483 938 30 1908-19,1924-55.. 11 500- 4.20 1200 Oreg. 1927. 1,000 Sacramento River basin : ?39 427 1944-55--- --. 16.61 26,900 19.50 37,000 86.7 248 Apr. 27, 1932.-. 5.55 11,060 3.30 '228 241 51,430 1 QAl ft^ 1 Q9Q C; f( A/Tar ft IQfM. 117,000 8.39 ?4? » 2, 970 16 4 10.78 1 11, 700 1921-26, 1928- 31, 1951-55. See footnotes at end of table. 10 TABLE 35. Summary of flood stages and discharges Continued

Maximum flood previously known Maximum during December 1955-January 1956 OO Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage miles) Date height Date and hour height (feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile

Sacramento Valley Continued

Sacramento River basin Continued 243 Hat Creek near Hat Creek, Calif .. 122 1926-55 ------. Dec. 11, 1937...- 7.75 3,320 27.2 Dec. 23, 1 p.m. 5.06 1,050 8.61 244 6 4 860 1927-55 - Dec. 12, 1937. . - 17.90 14.39 '17,200 5 4 Q9fi ....do-.- -- 16.26 134,200 Dec. 23 5 5, 170 Tan Q 1 OUT. 10.95 14.12 ' 37, 100 Calif. 247 65.3 --._do _-.. Mar. 9, 1954 18.90 11,200 172 Dec. 21, 10:30 p.m. 21.90 17,800 273 1955 ------.do.-. -- - 6.80 10,100 29.7 McCloud, Calif. 249 16.8 .-...do-- - 6.27 2,000 119 Calif. 250 McCloud River near McCloud, Calif 382 1931-55 Feb. 28, 1940 ..- 8.9 10,800 28.3 Dec. 21, 11:30 p.m. 9.42 11,800 30.9 251 420 1955 Dec. 22, 12:30 a.m. 15.4 12,800 30.5 near McCloud, Calif. 252 McCloud River above Shasta Lake, 606 1944-55 ------Jan. 9, 1953.-- _ 22.55 21.400 35.3 Dec. 22, 2:30 a.m.. 28.20 45,200 74.6 Calif. 253 *6,665 1Q^O_ce May 17, 18, 1952- 1,065.40 «4, 504, 600 Dec. 26 1,033.28 43,617,100 Dec. 22, 3-5 a.m.- "~26.~90 "201,000 ...... 254 « 6, 710 1938-55 - Feb. 28, 1940- - »47.2 186,000 27.7 Jan. 17, 4:30 a.m.. 151,200 255 Clear Creek at French Gulch, Calif- _ 115 1950-55 Feb. 1, 1952 8.27 4,140 36.0 Dec. 22, 6:30 a.m.. 10.49 7,050 61.3 256 228 Mar. 1, 1941 12.2 19,200 84.2 13.75 24,500 107 257 145 1Q11 14. Nov 6 1912 4 4.RA 30.9 Jan. 15- 13,700 94.5 Dec. 31, 1913 .... 13.5 258 427 1949-55. 21.55 45,200 106 19.06 33,000 77.3 259 36.8 Dec. 21...... 12,100 329 Ono, Calif. 260 130 8,180 62.9 261 945 1940-55 Mar. 1, 1941 15.4 52,300 55.3 Dec. 22, 8 a.m. _ 15.23 49,000 51.9 Calif. 262 362 1940-55 Feb. 6, 1942 11.85 12,800 35.4 10.32 8.540 23.6 Dec. 11, 1937 15.8 35,000 96.7 263 Paynes Creek near Red Bluff, Calif__ 92.5 1949-55 Dec. 27, 1951 - 8.10 4.060 43.9 Dec. 19, 5 p.m __ 8.77 5,130 55.5 ORJ. 6 O Q/W "Fob 9ft 1Q4ft 00 Q oQi nnn 01 0 oo QO i 115,000 265 40 4 2,990 74.0 Creek near Red Bluff, Calif. PART 1. DESCRIPTION A129

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Sacramento Valley Continued

Sacramento River basin Continued 299 Indian Creek near Crescent Mills, Calif. 746 1906-09, 191t-18, Feb. 28, 1940. ..- 16.07 14,000 18.8 Dec. 24, 12:30 a.m. 17.80 31,500 42.2 1930-55. 300 Spanish Creek above Blackhawk Creek, 184 1933-55 Dec. 11, 1937-.-- 12.43 12,400 67.4 Dec. 23, 3:30 p.m... 12.47 13,100 71.2 at Keddie, Calif. 301 East Branch of North Fork Feather 1.035 1950-55 Jan. 9, 1953 .... 11.68 18,500 17.9 Dec. 23, 8 p.m..... 16.52 48,000 46.4 River near Rich Bar, Calif. 302 28 1928-55 June 23, 1938- - 5, 157. 1 4 in** son Jan. 27-29... _.... 5, 138. 7 473,800 1 Q4fi 1911-37,1939-55.. Dec. 11, 1937-... 29 7 1 aa QAA 30 60 Calif. 304 14.7 1927-52 Feb. 1,1952. - 5.75 2,260 154 Dec. 23...... 2,300 156 305 145 1Qon_i!i! Dec. 11, 1937. on ^ 91 4AO 148 Qfl 9 21,300 147 Yankee Hill, Calif. 306 3,611 1902-55 Mar. 19, 1907 328.2 230,000 63.7 Dec. 23, 12:30 p.m. 76.77 203,000 56.2 30.5 1950-55 Nov. 20, 1950 8.68 3.170 iru Dec. 23, 1 p.m. 11.15 6,340 208 Calif. 308 Middle Yuba River at Milton, Calif .... 39.5 1925-34, 1935-55.. Dec. 11, 1937..-- 4.18 6,800 172 Dec. 23, 4 a.m.. _ 4.15 6,680 169 309 Middle Yuba River above Oregon 162 1941-55 Nov. 21, 1950 - 15.25 19,500 120 Dec. 22,9a.m.. ... 17.25 26, 400 163 Creek, Calif. 310 Oregon Cieek near North San Juan, 34.4 1910-55 do «____ 9.8 3,240 94.2 Dec. 22, 7 a.m ..... 11.90 5,390 157 Calif. 311 North Yuba River near Sierra City, 91.8 1911-13, 1923-44.. Dec. 11,1937...- 10.0 9,800 107 Dec. 23, 10a.m..-. 9.63 11,400 124 Calif. 312 4.83 1,570 325 313 4.12 786 191 Calif. 314 North Yuba River below Goodyears 245 1930-37, 1938-55.- Nov. 20, 1950 19.15 26,400 108 Dec. 23, 1 p.m. . 19.30 26,800 109 Bar, Calif. 315 482 1940-56 Nov. 21, 1950 - 31.3 47,100 97 7 Dec. 23... -- 39.0 70.000 145 Dam. Calif. 31« South Yuba River near Cisco, Calif. _ _ 51.5 1942-55 - Nov. 20, I960 - 15.82 11, 700 227 Dec. 23, 7 a.m.- 14.84 10, 200 198 317 9Q A 1926-55 1Q^7 1Q4^l IQ^O 4 70,500 5,558.0 4 64, 200 1951, 1953, 1954. 01 0 30.4 1 Q97 ^ * 6 9ft 1 9 ^9fi 3 in Calif. 01Q 198 24,700 125 Dec. 23 ------24.8 26.300 133 Calif. 320 Yuba River at Englebright Dam, Calif. 1,104 1941-55 - Nov. 21, 1950- 109,000 98.7 ----.do. ------148,000 134 3?1 84.6 11 300 134 13.60 11.300 134 20.4 1948-55------Feb. 1,1952.. ... 6.65 1.190 58.3 Dec. 22, 2a.m. - 7.48 1,890 92.6 ooq 71.3 -----do ...... -- Nov. 20, 1950- 9 1 *1 7,400 in4 9.85 9,120 128 324 1,33? 1943-44,1954-55- 79 fU Dec. 23 ------88.85 1 136, 000 325 140 1940-55 . Jan. 21,1943 16.45 1C, 300 138 Dec. 22, 9:30 a.m 16.56 19,700 141 326 295 1628-55------do. .---- 31,300 33,000 112 327 79.4 Dec. 23--. ------13,900 175 328 QQ *1 1Qifi_KK TQTI 19 1Q^9 11.54 5,610 Kfi 4 13. 45 8,760 88.3 329 2,200 OQn 1943-55- 47.80 1145,000 51.60 331 41.20 1 7Q 9ftft 39.81 i 71 400 qoo _do_. A/TQT 9fi 1Q9ft 1 1 ft flftn Dec 24 7 4g goo Calif. Nov. 21, 1950. 32.92 ~~~ 46~6bb 333 North Pork American River at North 343 1941 -55------Nov. 20, 1950- - 9.96 "l36 Dec. 23, 3 p.m. - 10.22 49,100 143 Fork Dam, Calif. 334 Middle Fork American River at 46.7 1951-55------Apr. 27, 1953--.. 8.84 3,310 70.9 Dec. 23, 4 a.m.- 14.95 16,300 349 French Meadows, Calif. OQe 56.9 i Qfto_i 1 Jan. 30, 1911 30.1 Dec. 23 15 19. 2 11,700 206 near Georgetown, Calif. 336 Rubicon River near Georgetown, Calif- 198 1909-14,1943-55- Nov. 18, 1950- 18.10 44,600 225 Dec. 23, 11 a.m. 18.76 51,000 258 QQ7 15.1 1946-55------. -----do ----- no. 84 3 f\Af\ 201 Dec 23 8.06 201 338 Middle Fork American River near Au 619 1911-55- - Nov. 20, 1950 34.7 68,500 111 Dec. 23, 6a.m.---- 33.9 79,000 128 burn, Calif. 339 1 Q99 ^ Nov 21 1950 6.03 1676 4.72 1 143 Calif. 340 196 ..do...... --..do------9.40 1 14, 500 9.25 113.800 Kyburz, Calif. 341 Alder Creek near White Hall, Calif. . 22.8 .---do------Mar. '25, 1928.-- 7.1 3,700 162 Dec. 23, 2:30 a.m. - 8.40 5,500 241 040 6.8 1Q99 3d . .do.. ----- 4 10 635 93 1,400 206 343 Nov 20 1950 12,100 146 18.85 15,800 191 044 28.4 -~.do - Nov. 18,1950 6.69 3,900 137 Dec. 23, ba.ni - 6.71 3,640 139 House, Calif. 345 176 ...... do ------14.25 25,800 147 14. £0 27,500 156 346 497 1922-55 -- 29.4 146,000 Dec. 23, 11 a.m.--. 32.6 149,800 mino, Calif. 347 678 1951-55 - Mar. 9, 1954 - 10.51 10,000 14.7 Dec. 23, 5 p.m 21.37 71,800 106 Calif. Nov. 21, 1950 20.4 64,500 95.1 348 Weber Creek near Salmon Falls, Calif- - 100 1943-55- - Nov. 18, 1950 - 14.2 6,740 67.4 Dec. 23, 5:30 p.m-. 15.92 11,800 118 349 1,875 1QKK 455. 16 * 889, 600 8219,000 350 1,921 1904-55 Nov. 21, 1950 31.85 180,000 93.7 20.35 i 71, 500 1921, 1929-32, .. do ...... 45.73 1176,000 Dec. 26, 12 p.m 38.93 i 72, 100 1943-55. 1893-1948, 1949- .. do ...... 30.14 1104,000 28.67 195,300 55. 353 15.8 Dec. 22 ...... 806 51.0 See footnotes at end of table. TABLE 35. Summary of flood stages and discharges Continued Maximum flood previously known Maximum during December 1955-January 1956 COto Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile

Sacramento Valley Continued

Sacramento Kiver basin Continued 354 46 1948-55 __ ...... Dec. 3, 1950 ..... 8.17 3,880 84.3 9.65 5,600 122 Dec. 10-11, 1937. 11,000 239 355 14 .....do ... .. Dec. 3, 1950 8.0 1,600 114 ... ..do...... 9.45 2,280 163 Dec. 10-11, 1937. 3,400 243 356 54 do. 16.05 7,300 135 17.0 7,660 142 Dec. 10-11, 1937. 11,000 204 OKT 6.39 1954-55...... Nov. 15, 1954- ... 6.32 416 65.1 Dec. 21, 10 p.m .... 8.72 1,250 196 OCQ 12.7 ..... do ...... do...... 6.4 408 32.1 Dec. 19, 12m ... 10.92 1,820 143 359 37.2 1946-55...... Jan. 17, 1954.. ... 314.8 8,150 219 Dec. 21, 11:30 pjn. 12.80 8,800 237 ocn 528 1913-55 _ ...... 11.12 8.59 361 528 1944-55 8.85 15,750 8.30 i 4, 710 362 198 1930-55 Dec. 11, 1937 . 13.98 20,300 103 Dec. 22, 2:30 a.m.. 12.56 15,900 80.3 Lake, Calif. 363 1,052 1942-55...... Jan. 21, 1943- ... 17.54 135,000 Dec. 22, 8:30 a.m.- 17.54 131,800 tDA 1,137 Feb. 28, 1940.... i 38, 700 28.63 i 22, 500 Mar. 10, 1904.... 34.2 iQ4n_ *& "EVK 8 1 Qd.9 32.00 272,000 31.60 253,000 366 112 1904-06, 1930-55__ Dec. 11, 1937.- 22.7 32,000 286 Dec. 22, 2 a.m. _ . 21.80 29,200 261 367 T*lltali froAlr TIART* TOT^Tltpra (~\&Hf 577 1930-55 . 30.5 81,000 140 Dec. 22, 11 a.m _ 26.73 155,400 368 636 1948-55 Dec. 7, 1952 21.50 39,000 61.3 Dec. 22, 1 p.m __ 24.36 i 46, 600 369 4.29 Dec. 22.-..... - 972 227

North-coastal California

Napa River basin: 370 81.3 1929-32, 1939-55.. Feb. 6, 1942---. 14.6 11,800 145 Dec. 22, 5a.m_ .... 15.17 12,600 155 371 52.3 Feb. 27, 1940- '11.80 7,700 147 Dec. 23, 12m ___ 3.70 13,600 372 Dry Creek near Napa, Calif... _____ 17.4 1951-55 Dec. 6, 1952- . 7.05 2,380 137 Dec. 19, 12:15 p.m. 7.25 2,600 149 Sonoma Creek basin: 373 1955 Dec. 22, 1 a.m_ _ - 17.1 8,880 142 Calif. PART 1. DESCRIPTION A133

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North-coastal California Continued f Big River basin: o 398 Big River near Mend ocino, Calif.-. _. - 152 1951-55 Dec. 27, 1952. ... 28.99 24,900 164 Dec. 22... ___ ... 31.9 31, 300 206 o Noyo River basin: o QQQ 105 -_do...... - 24.56 16, 000 152 9>; fid 99 noft 210 GO Pudding Creek basin: 400 Pudding Creek near Fort Bragg. Calif.. 11.8 1,940 164 Mattole River basin: 242 1911-13, 1950-55- Jan. 25, 1912 '27.1 48,000 90,0. 29.60 90, 400 374 402 North Fork Mattole River at Petrolia, 37.6 1951-55. Dec. 30, 1954-.. . 9.60 5,760 153 Dec. 21, 11 p.m .... 10.6 9,600 255 Calif. Eel River basin: 403 288 1922-55 - < 95, 600 1, 909. 2 4 01 onn 404 Eel River below Scott Dam , near Potter 290 _ .do...... Dec. 11,1937..- 22.9 1 41, 100 ... ..do...... 21.85 "40,000 Valley, Calif. H 405 347 1909-55..-.-. .... Mar. 26,1928 i 40, 000 Dec. 22 31.4 i 48, 600 Potter Valley, Calif. Dec. 11, 1937. 30.9 406 101 23,100 229 703 1950-55 Tan Q 1Q1^ OQ QA 70 o TlAf* 99 R o m AC A 175 408 161 Dec. 21 35.8 25,000 155 409 Middle Fork Eel River below Black 367 1951-55 -- Jan. 9, 1953- ... . 16.85 41, 100 112 Dec. 21, 12 p.m _ 25.0 89, 100 243 Butte River, near Covelo, Calif. 410 15.4 3,780 245 411 1,481 1911-13,1951-55- 123, 000 83.1 49.86 283, 000 191 412 North Fork Eel River near Mina, Calif.. 251 1953-55-.-- _ .. Jan. 17, 1954.. ... '25.4 23, 200 92.4 Dec. 22, 3:30 a.m.. 24.00 58,400 233 413 Eel River at Alderpoint, Calif...... 2,079 1955...... __ . 72.5 376, 000 181 OP 414 43.9 1946-55.. --. Jan. 21,1951 11. 1 8,740 199 Dec. 22, 2:30 a.m. . 16.20 20,100 458 Calif. 415 50.3 Dec. 22 16, 300 324 416 South Fork Eel River near Miranda, 537 1940^55- Dec. 27, 1945--.- 27.73 73, 200 136 Dec. 22, 5a.m ..... 42.7 173, 000 322 Calif. 417 Eel River at Scotia, Calif...... 3,113 1910-15, 1916-55 Dec. 11. 1937.-.. 345, 000 111 61.90 541, 000 174 Feb. 2, 1915-.-.. 55.5 418 80.2 1953-55. 14.60 14,000 175 19.25 21, 400 267 Calif. 419 South Fork Van Duzen River near 36.2 Dec. 22 ...... 11.91 8,990 248 Bridgeville, Calif. PART 1. DESCRIPTION A135

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DuzenRiverBridgeville,Vannear CreekJacobyFreshwater,Califnear.... Glen,MadRiverForestCalif.near..-. CreekLake,BlueCalif.Redwoodnear_ CreekTennant,Calif.Antelopenear... LinkFalls,RiverKlamathOregat..... MadCalifNorthForkRiverKorbel,at CreekOrick,Calif.Redwoodat..__ Macdoel,Calif.ButteCreeknear__.. SpragueRiverChiloquin,Oreg.near... FallCreekCopco,atCalif...... EastForkScottRiverCallahan,at ScottRiverCalif...... FortJones,near Klamath RiverSeiadValley,Calif.near MadArcata,CalifRivernear_.-... Crannell,Calif.LittleRiverat___ WilliamsonRiverKlamathnear WilliamsonRiverbelowSpragueRiver, KlamathUpperLakenear KlamathRiverbelowFallCreek,near LittleShastaRiverShasta,near BeaverWalker,CreekCalifnear__. SouthForkScottRiverCallahan,near CreekCarlotta,CalifYagernear_ Oreg.....SpragueRiverBeatty,near KceneCreekIlyattPrairie,Ashatnear ShastaRiverMontague.Calif.near.. ShastaRiverYreka,Calif.near... RiverOregKlamathatKeno,

KlamathLakebasin:Dwer Chiloquin,Oreg.near Creekbasin:edwood lamathRiverbasin: Creekbasin:icoby Agency,Oreg. Calif.Copco, basin:tadRiver Riverbasin:ittle Oreg.Falls, land,Oreg. Calif. Calif. Calif. Calif.

IN COTtOO CO f~OO

068521 O 6*3- -10 TABLE 35. Summary of flood stages and discharges Continued

Maximum flood previously known Maximum during December 1955-January 1956 CO O5 Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile

North-coastal California Continued

Klamath River basin Continued 44Q 118 1911-15...... Feb. 17, 1912..- 810.6 8,430 71.4 23,000 450 91.1 Dec. 21...... 8.35 14, 400 158 451 251 Dec. 22, 9 p.m ..... 12.2 24, 200 96.4 Salmon, Calif. 4W 135 Dec. 22 ...... 18.15 19, 200 142 Bar, Calif. 453 746 1911-15, 1927-55.. Jan. 18, 1953 19.23 45, 900 61.5 Dec. 22, 6:30 a.m.. 28.80 84,000 113 February 1927 ... 224.8 49, 000 65.7 454 8,480 -do ...... Jan. 18, 1953 . 49.7 137, 000 16.2 Dec. 22, 7 a.m. _ 59.4 202,000 23.8 Feb. 21, 1927- 50.8 141, 000 16.6 455 74.6 Dec. 21, 12p.m _ - 25.6 20, 200 271 456 727 1911-55.-...-... Jan. 7, 1948 21.1 Dec. 22, 2a.m ..... 27.3 71, 600 98.5 Feb. 28, 1940---- 40,300 55.4 457 105 Dec. 21 ...... 21,600 206 Calif. 458 1,429 1931-40...... , Feb. 28, 1940. 33.8 80, 700 56.5 Dec. 22...... 172, 000 120 342 Dec. 21, 12 p.m .... 22.2 39, 400 115 pom, Calif. 460 87.2 Dec. 22. -...... 15.15 3,880 44.5 461 379 1953-55.. .. Jan. 17, 1954..... 15.37 17,900 47.2 Dec. 22, 3 a.m. .... 18.00 25,300 66.8 4«o 899 1950-55- _do_-. ._ 27.80 38,900 43.3 Dec. 22 . 39.4 74,700 83.1 Calif. 463 2,846 1911-14, 1916-18, Feb. 28, 1940..-. 31.2 124,000 43.6 Dec. 22, 12m ...... 36.90 190,000 66.8 1931-55. 464 Klamath River near Klamath, Calif- _ 12,100 1910-26, 1950-55- Jan. 18, 1953-.-. 43.67 297,000 24.5 Dec. 22, 1:30 p.m_. 49.7 425,000 35.1 Smith River basin: 465 130 11.5 26,000 200 Calif. 466 158 Dec. 22 .- 20.9 50,600 320 Calif. 467 South Fork Smith River near Crescent 295 1911-13, 1954-55.. Feb. 17, 1912-.. . 328.6 Dec. 22, 2:30 a.m_. 36.95 108, 000 366 City, Calif. 468 613 1931-55 Oct. 29, 1950 39.51 152,000 248 41.20 165, 000 269 35.0 Dec. 22-- ____ - 4,760 136 PART 1. DESCRIPTION A137

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Maximum flood previously known Maximum during December 1955-January 1956 CO 00 Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfs per (feet) Cfs per Cfs square Cfs square mile mile

West-central Idaho Continued

Boise River basin Continued 489 830 1911-55...... May 17, 1927 8.30 10,300 12.4 Dec. 23, 6 p.m__ 8.31 10, 300 12.4 490 21.4 1914-1S, 1939-41.. Apr. 26, 1917... . 32.30 166 8.34 Dec. 23 4.76 330 15.4 Reservoir, Idaho. 491 1945-55...... Apr. 28, 1952.-.. 7.47 5,530 8.71 .... .do...... 4.53 2,000 3.15 ville. Idaho. 492 131 -....do...... Apr. 19, 1946, 1,180 9.01 Dec. 23, 3 a.m ..... 4.97 660 5.04 Apr. 27, 1952. Feb. 15, 1949... . 16 8. 02 493 55.3 -do.-..-..... Apr. 27, 1952.... 6.25 948 17.1 Dec. 23, 3 p.m ..... 438 7.92 is 4. 89 AQA -do ..... Timi* 97 1Q14 4, 197. 37 * 470, 700 4, 142. 36 4 253, 600 Dec. 23 8 4, 600 4.69 495 A - 17 i QJQ 10.06 9,100 9.27 4.63 i 1, 560 Ranch Dam, Idaho. 4.QC 2 910 1Q17 tt Mn\r 9Q 1QJ.R 3, 219. 1 * 301, 200 3, 217. 5 * 291, 200 8 16, 700 7.56 497 Bannock Creek near Idaho City, Idaho. 4.5 1939-41, 1950-55- Apr. 26, 1952.... "i«~2.~63 39 8.67 Dec. 23, 3 p.m ..... 1.91 31 6.89 498 119 1939-41 4.38 725 6.09 Dec. 23... . 6.70 1,650 13.9 Idaho City, Idaho. 499 399 1950-55 Apr. 27, 1952. ... 8.23 3,620 9.07 Dec. 23, 8 p.m ..... 9.55 5,440 13.6 Arrowrock, Idaho. 500 15.8 . dO...- ... Jan. 18, 1953..... 2.43 118 7.56 Dec. 23, 4 p.m. .... 2.67 163 10.3 1QK4_ee June 25, 1955.... 3 ftKQ QO « 305, 100 * 260, 90C s 5, 800 2,680 1895-1916, 1954- 35, 500 13.2 Jan. 31 ...... i 1, 100 55. 503 2,, 760 Apr. 20, 1943..- 8 10. 00 i 21, 000 do...... i, 7 1,080 504 20.9 1954-55. _ ...... Apr. 22, 1955..- 2.19 60 2.87 Dec. 23, 5 p.m ..... 2.18 54 2.58 505 59.4 .--do ...... 3.14 149 2.51 Dec. 23, 7 p.m ..... 3.7? 156 2.63 506 66.4 ..... do do...... 4.12 136 2.05 Dec. 23, 9 p.m ..... 4.20 14< 2.24 K(V7 3,820 1920-55 A . On I QJQ 10 43 i 20, 500 4.4] i 2, 10( Payette River basin: 508 456 1941-55 May 21, 1954 6.83 5,450 12.0 Dec. 22, 5 p.m ..... 5.59 3,170 6.95 Idaho. PART 1. DESCRIPTION A139

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~~10 tO to to to TABLE 35. Summary of flood stages and discharges Continued~~

~~West-central Idaho Continued~~

Weiser River basin Continued 539 107 1937-43 ___ . _ Feb. 28, 1940... . 36.90 1,180 11.0 19 5 540 390 1937-53 ___ ..-. Mar. 16 or 17, 87. 6 6,700 17.2 -do- .... - 9.86 16.9 1938. 86.5 1910-13, 1919-21, May 27, 1913 36.3 1,440 16.6 ..do 1,710 19.8 Idaho. 1937-49. 605 1939-55...... Mar. 31, 1940, 8.30 6,670 11.0 do 13.9 10, 100 16.7 CJQ 32 1938-43- - Mar. 16, 1938 6.07 582 18.2 .... .do...... 469 14.7 54 1938-55- May 27, 1948 33.60 1^505 9.35 3.65 420 29 Dec. 22...... 499 17.2 bridge, Idaho. 81.9 1920-21, 1923-27, Feb. 4, 1925 1,840 22.5 4.67 1,200 14.7 Idaho. 1938-55. 547 206 Dec. 22. ... 4,800 23.3 Cambridge, Idaho. 548 Weiser River below Little Weiser River, 952 ..-.do ...... 16,600 17.4 near Cambridge, Idaho. 549 Crane Creek above Crane Creek Res 120 ..... do._ ...... - 4,120 34.3 ervoir, near Crane, Idaho. 25 - do ... .. 339 13.6 551 10 ..... do ...... - 305 30.5 552 South Fork Crane Creek near Crane, 52 do 1,060 20.4 Idaho. 553 242 1923-55 Feb. 22, 1927,-- 47.31 * 34, 800 Idaho. 3 S Q 1706 242288" Fiof» ^ iQin 4,240 4.76 555 1920-55 6.80 12,350 5.26 1 1, 780 Idaho. 556 1,460 1890-91, 1894- Mar. 8, 1904 310.5 16,900 11.6 Dec. 23, 1:30 a.m_- 11.06 19,900 13.6 1904, 1910-14, Mar. 19, 1932 . 17,500 12.0 1952-55. 557 56 1911-13, 1920, Mar. 27, 1940 35.45 1,540 27.5 Dec. 22, 2p.m___ 3.00 550 9.82 1937-55. 558 32 1945-49 Mar. 18, 19, 1946- 2.40 Dec. 22 3.9 271 8.47 near Weiser, Idaho. PART 1. DESCRIPTION A141

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Heath,IdaCreekBrownleenear IdahoJoseph,RiverSnakenear PollockSalmonRiverLittlenear Idaho...Weiser,RiveratSnake ButteaboveWildHorseCreek ButtebelowHorseCreekWild Ore.RiverOxbow,Snakeat Riggins,RiverSalmonatLittle Idaho.WildHorse,near Idaho,WildHorse,near stem:Rivermainke Creekbasin:wnlee HorseCreekbasin:d Rivermainstem:ke g D Sg . . S -fe -g -g *> ^§« aQS «--| s- basinRiver:non \ i j S ! S 1 0 1 J i| i!il Hi si Ii! Illfl!! if SlI & « £ & & 4? 0 <§ £ £ P PS ^ OS O *** OI M 1 g§ I 1 § IS g E- Sl g s § f- TABLE 35. Summary of flood stages and discharges Continued

Maximum flood previously known Maximum during December 1955-January 1956 Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Ofs per (feet) Cfs per Cfs square Cfs square mile mile

Areas of ntinor flooding in Washington and Oregon Continued f1 0 O Deschutes River basin: o 581 Deschutes River at Moody, near Biggs, 10,500 1897-99, 1906-55.. Jan. 7, 1923 310.2 43,600 4.15 Dec. 22, 8-10 p.m__ 7.91 128,900 Oreg. Columbia River main stem: 582 Columbia River near The Dalles, Oreg. 237,000 1858-ia55 _ ..... June 6, 1894. .... 160.1 1,240,000 5.23 Dec. 24, 12m___ 137. 01 1320,000 § Klickitat River basin: 583 Little Klickitat River near Wahkiacus, 280 1944-55 Jan. 7, 1948-.... 9.4 7,000 25.0 Dec. 21, 6 p.m ..... 8.63 5,500 19.6 j> Wash. w Hood River basin: 584 Hood River near Hood River, Oreg ..... 329 1913-55 Jan. 6, 1923 311.1 34,000 103 Dec. 12, 12:30 a.m. 15,000 45.7 ^ Wind River basin: 585 Wind River above Trout Creek near 108 1944-55 - Feb. 8,1945. 15.5 8,880 82.2 Dec. 21, 9 p.m . 13.35 6,480 60.0 » Carson, Wash. 586 5225 1934-55 Dec. 29, 1937-.. . 17.30 20,000 88.9 Dec. 21, 10 p.m . 16.70 18, 500 82.2 y Sandy River basin : 587 Sandy River below Bull Run River, 440 1910-14,1929-55- Mar. 31, 1931 20.6 58,000 132 Dec. 12, 4 a.m _ - 14.97 30, 900 70.2 § near Bull Run, Oreg. GQ Willamette Valley > H Willamette River basin: GO 588 Middle Fork Willamette River above 392 1913-14,1935-55- Dec. 28, 1945..- 12.06 34,000 86.7 Dec. 22, 8 a.m 12.71 33,300 84.9 Salt Creek, near Oakridge, Oreg. 589 117 1913-19, 1933-55...... do...... 8.40 8,040 68.7 do .. - 8.20 7,640 65.3 590 North Fork of Middle Fork Willamette 246 1909-16,1935-55.. .do...... 16.60 17,000 69.1 Dec. 22, 6:30 a.m.. 14.60 13,400 54.5 River near Oakridge, Oreg. 591 924 1911-12,1923-55-. _ _ do ...... 318.8 81, 800 88.5 Dec. 22, 9 a.m __ 13.36 72,900 78.9 North Fork, near Oakridge, Oreg. 592 .44 1952-55 ____ ... Nov. 23, 1953.. .. 5.17 22 50.0 Dec. 21 _ --- ... 5.45 30 68.2 593 991 1953-55 June 14, 1955. ... 927. 23 « 448, 400 Dec. 26, 12 p.m ... . 922. 06 < 426, 500 8 76, 000 76.7 Dec. 28, 10 a.m 1815,200 594 1,001 1955 . _ .. Jan. 26, 6 p.m. .... 8.30 '16,900 Dexter, Oreg. 595 Fall Creek below Winberry Creek, near 186 1935-55 Dec. 28, 1945-... 18.0 22,500 121 13.74 1 9 Rftft 68.8 Fall Creek, Oreg. 596 Middle Fork Willamette River at Jas 1,340 1905-12, 1913-17, Nov. 23, 1909 317.4 94,000 70.1 Dec. 22, 8 a.m., 8.86 i 21, 100 per, Oreg. 1952-55. Jan. 22, 6 p.m. 597 Coast Fork Willamette River at Lon 69 1935-55 Dec. 28, 1945- ..- 13.25 8,800 128 Dec. 23, 5 a.m __ 10.88 6,210 on n don, Oreg. 598 Cottage Grove Reservoir near Cottage 104 1942-55 May3, 1949 792.42 « 34, 750 791.38 « 33, 380 Grove, Oreg. 88,000 76 9 Dec. 30, 8:30 a.m. . 183, 220 599 Coast Fork Willamette River below 104 1939-55. ___ ... May 4, 1949-. 9.75 13,460 . .do .. - 9.36 13,220 Cottage Grove Dam, Oreg. 600 Prather Creek near Disston, Oreg_____. 5.69 1952-55 Nov. 22, 1953- - 5.73 286 50.3 Dec. 21.. ------5.65 264 46 4 601 Row River above Pitcher Creek, near 211 1935-55 Dec. 28, 1945-. 14.33 19,600 92.9 Dec. 22, 4 a.m .... . 13.62 19,200 91.0 Dorena, Oreg. 602 Dorena Reservoir near Cottage Grove, 265 1949-55 May 27, 1953-.-- 834.31 * 76, 210 Dec. 23, 10:30 a.m. 838.37 « 84, 060 Oreg. 87.5 Dec. 22, 5:30 p.m. . is 8, 500 603 Row River near Cottage Grove, Oreg-. 970 1939-55 18.20 21,400 79.3 -do ...... 11.02 i 9 060 604 Mosby Creek at mouth, near Cottage Qfi 1946-55 Oct. 28, 1950 - 10.82 7,160 74.6 10.66 6,920 Grove, Oreg. 605 Coast Fork Willamette River near 1905-12, 1950-55-. Nov. 22, 1909 - U9.5 58,500 91.1 16.44 Goshen, Oreg. 606 Willamette River at Springfield, Oreg-- 2,030 1911-13,1919-55.. Dec. 29, 1945..-. 20.9 i 140, 000 "267""" Dec. 26, 4-6 p.m... 9.94 i 48, 500 607 Hackleman Creek near Upper Soda, .21 1952-55 Nov. 22, 1953- 4.04 56 Jan. 15 . 4.23 62 Oreg. McKenzie River at outlet of Clear Lake, 101 1912-15,1947-55.. Jan. 18, 1953 7.21 2,600 25.7 Dec. 22, 5:30 a.m. . 7.66 2,970 29.4 Oreg. 609 McKenzie River at McKenzie Bridge, Jan. 6, 1923 38.3 16,500 47.8 7.79 13,000 37.7 Oreg. 610 South Fork McKenzie River near Rain 91 1 1947-55 8.34 16,400 77.7 bow, Oreg. Dec. 28, 1945.--. 9.3 24,500 116 " 8. 90 611 Lookout Greek tributary No. 3 near .34 1952-55 Jan. 18, 1953 2.80 47 138 2.57 36 106 Blue River, Oreg. 612 Lookout Creek tributary near Blue .41 1953-55 Nov. 22, 1953 2.80 44 107 Dec. 21 2.73 41 100 River, Oreg. 613 Blue River near Blue River, Oreg--- 75 1935-55 Dec. 28, 1945---. 9.80 13,300 177 7.70 9,500 127 614 McKenzie River near Vida, Oreg...... 930 1924-55 ... -.do.. 17.70 64,400 69.3 Dec. 22, 6a.m __ 15.00 51, 700 55.6 615 Gate Creek at Vida, Oreg 47.6 1951-55. Jan. 18, 1953 9.38 5,510 116 8.38 3,680 77.3 616 Mohawk River near Springfield, Oreg-- 180 Dee. 28, 1945- - 22.1 8,600 47.8 22.9 9,200 51.1 617 McKenzie River near Coburg, Oreg 1,310 1944-55 Dec. 29, 1945-..- 17.36 88,200 67.3 Dec. 22, 2:30 p.m.. 16.25 73,500 56.1 618 Willamette River at Harrisburg, Oreg__ 3 J.9O do--. - do.- 1Q fiQ 1 210, 000 16.25 i 114, 000 1861 21 619 Long Tom River near Noti, Oreg . 88 1935-55- _ --.... Jan. 28, 1954 18.56 5,400 61.4 Dec. 22, 12:30 a.m- 20.17 6,990 79.4 620 Coyote Creek near Crow, Oreg-- --- 94 1940-55 14.13 9,260 98.5 Dec. 21, 9 p.m __ 14.32 10,100 107 621 Fern Ridge Reservoir near Elmira, Oreg »252 1941-55. Jan. 1, 1943 373. 94 105,400 Dec. 27, 7:30 a.m.. 375.83 « 124, 500 » 24, 000 95.2 is 10, 400 Long Tom River below Fern Ridge «252 1QQQ_KK .....do--...... i a ' 500 ..... do.- 13.97 i 10, 400 Dam, Near Smithfield, Oreg. See footnotes at end of table. TABLE 35. Summary of flood stages and discharges Continued Maximum flood previously known Maximum during December 1955- January 1956 fc Drainage Sta area Discharge Discharge tion Stream and place of determination (square Period of record Gage Gage miles) Date height Date and hour height (feet) Cfsper (feet) Cfs per Cfs square Cfs square mile mile

~~Willamette Valley Continued~~

Willamette Kiver basin Continued 21.3 1954-55----.-.. Nov. 19, 1955--. 6.14 38.3 9 OC 2 720 19ft fi9d 391 1920-55..-- _ ... Jan. 2, 1943----. 3 17. 14 10.26 '11,000 14.6 1945-55 Jan. 6, 1948 ... 5.78 1,650 113 6 Of) 2 1 on 1 t\f\ 1940-55 Dec. 15, 1946 _ 20.67 8,250 51.9 OA QQ M e 627 1935-55. ___ .... Dec. 28, 1945-.-, 14.1 12.67 102 coo 5.06 1954-55 Nov. 17, 1954 14.11 143 28.3 Dec 21 58.1 629 1940-55- Jan. 8, 1948 24,900 66 9 OO 19 87 9 Jan. 2, 1943 .. 16 25. 5 630 4,840 1878-82, 1892- Jan. 14, 1881 32.8 55.0 26.70 1955. Dec. 4, 1861-- 36.0 70.2 631 15.2 1953-55- Jan. 28, 1954 12.23 716 47.1 10 94 765 50.3 632 North Santiam River below Boulder 216 1907-9, 1928-55 Dec. 28, 1945. ... 311.24 20,300 94.0 Dec. 22, 3 a.m_ ... . 8.98 15,200 70.4 Creek, near Detroit, Oreg. 633 1.03 1953-55 Dec. 20, 1953. 11.30 109 11.17 101 634 106 1932-55- _ ----- Dec. 28, 1945. ... 3 11. 86 109 10.80 87.0 Creek, near Detroit, Oreg. 635 437 1953-55 1, 566. 02 * 390, 700 Jan. 10, 8 a.m.. ... is 15, 000 636 453 1908-19, 1938-55- Nov. 22, 1909 316.4 63,200 140 Jan. 11, 8-30 a.m ... 9.15 1 15, 100 637 1.97 17.44 86 43.7 n 9Q ftl 41.1 Gates, Oreg. 638 110 Dec 28 1945 15.20 19,900 181 10 7ftn hama, Oreg. 665 1905-07, 1910- do... 15.37 115 9 "51 14, 1921-55. 640 .94 1952-55 Dec. 4, 1953.---. 14.90 72 76.6 13.21 44 46.8 174 Dec. 28, 1945.-.- 18.65 134 16.64 120 Oreg. 642 287 19.67 134 18.35 113 Dec. 28, 1945- 154 643 52 1947-55 Jan. 7, 1948 ...... 7.52 5,410 104 8.42 6,290 121 644 South Santiam River at Waterloo, Oreg. 640 1905-07, 1910-11, Dec. 28, 1945- 22.85 74,200 116 Dec. 21, 11 p.m .... 19.95 62,800 98.1 1923-55. 645 1,790 1905-06, 1907-16, Nov. 22, 1909 318. 2 89.9 21.11 115,000 1939-55. Nov. 21, 1921 24.4 202,000 113 646 34 1934-55 Dec. 14, 1946, 13.22 5,560 164 10.35 3 ?sn 111 Feb. 17, 1949. 647 115 1940-55. _____ - .do ...... 18.46 13,500 117 15.96 q IJ40 QO A 648 3.46 Feb. 12, 1954-... 14.49 304 87.9 Dec. 21 16.33 522 151 649 Luckiamute River near Suver, Oreg .. 240 1905-11, 1940-55- Feb. 18, 1949-.- 33.10 23,800 99.2 Jan. 4, 9:30 p.m... 30.46 16,200 67.5 Dec. 29, 1937.-.. 33.5 25,000 104 650 .57 1952-55 Feb. 17, 1953..., 4.10 63 111 Dec. 21 4.53 80 140 651 43.4 -do ...... 7,120 164 652 Willamette River at Salem, Oreg- ...... 7,280 1909-16, 1927-55.. Nov. 25, 1909 30.5 315,000 43.3 Dec. 23, 6:30 a.m.. 25.46 1240,000 Dec. 4, 1861..... 39 7 500,000 68.7 653 Mill Creek at penitentiary annex, near 104 1938-55- . _ .. Feb. 18, 1949.. 7.6 5,140 49.5 Dec. 21, 7 p.m ..... 8.28 4,810 46.2 Dec. 29, 1937... . 8,320 654 110 -do Jan. 28, 1954 - 7.07 11,350 6.53 '1,150 655 2.72 1951-55 . Jan. 20, 1953- ... 13.28 156 57.4 Dec. 21 ...... i« 14. 26 172 63.2 656 4.83 do do 16.53 238 49.3 16.4 190 QQ Q lege, near Salem, Oreg. 657 133 1934-55----...... Feb. 10, 1949.-- 14.80 15,200 114 W AA 15,000 Oreg. 658 1.81 1953-55 Feb. 12, 1954.... 11.48 179 98.6 Dec. 21 ______21.00 420 232 Willamina, Oreg. 659 65 1934-55 Feb. 17, 1949-- 10.25 6,380 98 2 7,760 119 Oreg. Mar. 31, 1931 12 8,200 126 660 1940-55 Feb. 11, 1949. 43.39 28,900 57.6 AK OK 36,800 7Q Q Oreg. 661 Haskins Creek below reservoir near 7.1 1951-55 ___ - ... Apr. 9, 1952--... «558 Dec. 21, 8:30 p.m.. 3.52 '446 McMinville, Oreg. 662 66.8 1948-55 Feb. 10, 1949-.- 9.98 6,280 94.0 19 J.9 9,530 143 663 3.19 1952-55...... Feb. 12,1954-..- 13.77 212 66.4 Dec. 21.... ___ .. 492 154 664 1948-55 Jan. 21, 1953 87 i 248, 000 1 235, 000 Dec. 4, 1861 -- ... 105 665 96 1935-55- ... Jan. 7, 1948 ... 12,200 127 16.04 Wilhoit, Oreg. Jan. 9, 1943- .... 14.92 "~77y 666 1928-55 Jan. 7, 1948 15.6 14 42 62.5 667 204 1939-55. Feb. 17, 1949. ... 15,000 73.5 7,620 37.4 Oreg. Feb. 18,1949.-. 30.38 ""5376" Dec. 22, 9 a.m __ 27.83 479 1928-55 Dec. 30, 1937... . 94. *\ 01 1C 19 30O 91 7 Jan. 7, 1923 25.0 97 QOft KQ 0 669 51 1940-55 Feb. 17,1949-... 19 OQ 4,820 Qd t\ 1O 1 0 8,170 670 44.0 -.do-. . . do.. - 315.53 3,460 78.6 -.do.. 1 K QA 5,320 671 133 ..do.. . do.-.. ... 13.89 9,460 71.0 13, 200 99.3 672 4.70 1951-55 Dec. 9, 1953- - ... 48 7 Jan. 4...... 17.17 OfiK 56.4 673 1.34 1951-55 Feb. 12, 1954. ... 13.88 115 85.8 Dec. 21-- _ 16.0 145 108 674 66 1940-55 Feb. 17, 1949-___ 310,90 6,410 97.1 6,300 95.5 675 McKay Creek near North Plains, Oreg. 27.6 1940-43,1948-55-. do-.-. - 11.23 2,100 76.1 Dec. 21, 8:30 p.m.. 11.35 1,000 36.2 676 568 1939-55 Feb. 18, 1949. ... > 17, 400 30.6 QC AQ Dec. 22 or 23, 37 1933. 677 710 1928-55 Dec. 23, 1933- ... 16.7 i« 29, 300 41.2 19 21, 400 30.2 678 Mar. 31, 1931, 6,750 An G 8.96 5,650 41.5 Dec. 15, 1946. Jan. 18, 1953..... 8.63 See footnotes at end of table. Oi TABLE 35. Summary offload stages and discharges Continued

~~Willamette Valley Continued~~

Willamette River basin Continued 679 Oak Grove Fork above powerplant 126 1909-55 __ ... Jan. 7, 1923 85.45 5,000 39.7 Dec. 22, 11 a.m..~ 4.46 2,280 18.1 intake, Oreg. 680 Clackamas River above Three Lynx 479 1909-13, 1921-£5- Mar. 31, 1931..- 15.5 34,800 72.7 Dec. 21, 10 p.m._-_ 15.06 34,100 71.2 Creek, Oreg. 681 657 1908-55 _ .do.... 24.5 60,800 92.5 Dec. 21, 11:30 p.m. 22.62 42,600 64.8 682 28.2 1940-55 _ .. Feb. 10, 1949.... 13.77 2,110 74.8 13.23 1,820 64.5 683 1.46 1951-55 _____ - Jan. 22, 1954 223 153 Dec. 21. 13.33 306 210 Oreg.

~~Coastal Oregon~~

Youngs River basin: 40.1 1927-55. 36.52 6,300 157 U on 3,580 89.3 Necanicum River basin: 685 North Fork Necanicum River near 5.70 1951-55 Nov. 26, 1955- 7.25 680 119 ..do. - 7.08 610 107 Seaside, Oreg. 686 7.99 1952-55 Jan. 22, 1954..-. is 8. 52 2,320 290 i«8.85 Seaside, Ore?. Asbury Creek basin: 687 1.97 1951-55- dO-- - 8-97 260 132 do- 8.96 260 132 Oreg. Nehalem River basin: 688 667 1939-55 Feb. 17,1949 19.04 36,900 55.3 Dec. 21, 9-10 p.m~ 19.67 39,300 58.9 Pacific Ocean tributary: 689 1.87 1951-55 Nov. 26, 1955- ... 13.08 207 111 Dec. 21_ 12.85 188 101 Wilson River basin: 690 Wilson River near Tillamook, Oreg .. 159 1914-16,1931-55- Dec. 21, 1933 ' 19. 28 30,000 189 Dec. 21, 12p.m 15.28 21,100 133 Trask River basin: 691 143 1931-55 Dec. 22, 1933. 13.00 20,000 140 13.09 20,200 141 Nov. 1921, 17 30,000 209 Mar. 31, 1931. PART 1. DESCRIPTION A147

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~~00 O»< S SS TABLE 35. Summary of flood stages and discharges Continued~~

~~Coastal Oregon Continued~~

Umpqua River basin Continued 721 97.4 1955 - -.-do 14.83 12,300 126 56.9 -do ...... Dec. 26, 1 a.m _ ,. 7.5 4,930 86. f 723 177 1954-55 Dec. 30, 1954... . 11.72 8,340 47.1 Dec. 22, 3 a.m __ 16.55 15,800 89. r Nov. 22, 23, 1953. 20.6 22,700 128 724 1,210 1915-20, 1921-22- 17.3 59, 500 49.2 21.7 90,000 74.4 Oreg. 1927-38 Nov. 22, 1909..- 22.6 94, 000 77.7 725 16.4 1955. Dec. 26, 6 a.m .... . 7.77 1,350 82. r 726 Sutherlin Creek at Wilbur, Oreg 22.6 Dec. 22-_ _ 3,830 169 727 North Umpqua River at Winchester, 1,344 1908-13, 1923-29, Nov. 23, 1909.... 328.1 100, 000 74.4 Dec. 22, 9a.m__ - 29.14 92,500 68.! Oreg. 1954-55 728 49.4 Dec. 21, 22..-.. 4,980 101 near Nonpareil, Oreg. 729 Dec. 26, 7 a.m ..... 20.47 20, 300 96. 730 3,683 1905-55 Oct. 30, 1950 4.42 208,000 56.5 Dec. 22, 7 p.m.. ... 45.6 218, 000 59. 1861- 4.55 218, 000 59.2 731 37.6 Dec. 21 ...... 2,700 71. Yonealla, Oreg. 732 26.0 Dec. 26, 10 a.m .... 14.48 1,480 56. 733 104 -do. Dec. 26, 10:30 a.m. 19.06 9,100 87. 734 K\ Q .. do . 13.57 5,410 87. 735 Ton 97 1 Q^d 15.07 412 80.3 Dec. 21... .. -- 15.59 452 88. Coos River basin: 736 H e 10.26 89.0 ...-do . 10.7 1,800 124 737 West Fork Millicoma River near Alle- 46. 5 1954-55 Dee. 30, 1954. . - 15.70 13,800 293 Dee. 21, 7:30 a.m.. 12.06 7,990 172 gany, Oreg. Coquille River basin: 738 South Fork Coquille River at Powers, 169 1916-26, 1928-55- Dee. 28, 194R-___ 20.57 30,500 180 Dee. 21, 10 p.m .... 19.75 28,000 166 Oreg. 739 CKQ Dee. 26, 7 a.m ..... 124, 000 224 Middle Fork, near Myrtle Point, Oreg. 740 276 1929-46 . Dec. 28, 1945... 39.3 26,900 97.5 Dee. 26.- ...... 37.0 20,000 72. Point. Oree. 1909-10.. ... 41.2 741 Oettys Creek near Myrtle Point, Oreg- 1.45 1952-55.. . _ 14.34 176 121 Dec. 21...... 16.33 223 154 742 Geiger Creek near Bandon, Oreg .... 1.36 1953-55 22.10 101 74.3 ... do_.__ 24.10 131 Brush Creek basin: 743 Dry Run Creek near Port Orford, Oreg. sfi 17.82 151 176 16.90 133 155 Rogue River basin: 744 Rogue River above Prospect, Oreg_ .. 332 1908-12, 1923-55__ Dec. 28, 1945-.. 8.4 11,900 35.9 Dec. 22, 2 a.m. __ 10.01 16,600 50.0 745 South Fork Rogue River near Prospect, 79 1924-31, 1949-55.. Nov. 23, 1953. .. 7.34 2,540 32.2 Dec. 22, 9a.m_ __ 8.3 3,180 40.3 Oreg. 746 Middle Fork Rogue River near Pros 57 1925-55-...... do..__ 3,120 54.7 Dec. 22... 5.65 3,230 pect, Oreg. 747 Red Blanket Creek near Prospect, Oreg. 40 1925-55 . Nov. 29, 1942 35.1 1,630 40.8 Dec. 22, 4 a.m. .... 7.30 1,840 46.1 748 Rogue River below South Fork Rogue 643 1929-55 Jan. 18, 1953- 12.50 20,500 31.9 Dec. 22, 6 a.m. ... 17.3 34,000 52.9 River, near Prospect, Oreg. 749 South Fork Big Butte Creek near Butte 135 1910-11, 1915, Feb. 20, 1927-.- 4.05 2,470 18.3 Dec. 22, 5a.m. ... . 4.50 2,770 20.5 Falls, Oreg. 1917-22, 1925- 55. 750 Big Butte Creek near McLeod, Oreg__. 249 11.1 6,390 25.7 Dec. 22, 3 a.m. ... _ 12.75 8,950 35.9 751 Elk Creek near Trail, Oreg-..____. 133 -do .. do____ 3 13. 32 10,000 75.2 Dec. 22, 2a.m. .... 14.34 13, 700 103 752 Rogue River at Dodge Bridge, near 1,210 1938-55--. _ ---. do 11.08 44,600 36.9 12.9 75,000 62.0 Eagle Point, Oreg. 753 South Fork Little Butte Creek near 138 1921-55 Jan. 7, 1948 6.48 3,920 28.4 Dec. 22, 5 a.m. .... 6.84 3,410 24.7 Lake Creek, Oreg. 754 North Fork Little Butte Creek at Fish 18 6940 Jan. 22-31 1.14 US Lake, near Lake Creek, Oreg. 755 North Fork Little Butte Creek near 38 1911-13, 1922-28, Dec. 30, 1924.-- 3.30 680 17.9 Dec. 22, 1 a.m. __ 2.51 1281 Lake Creek, Oreg. 1931-55. 756 Dry Creek near Eagle Point, Oreg_ . 13.4 Dec. 22_ 1,020 76.2 757 Emigrant Creek above Hill Creek, near 51.6 do 2,580 50.0 Ashland, Oreg. 758 Emigrant Creek near Ashland, Oreg-... 64.3 1920-55 Feb. 20, 1927- - - 15,260 Dec. 21, 12 p.m.___ 8.55 U,600 759 West Fork Ashland Creek near Ashland, 10.5 1924-32, 1953-55- ..do. . - 33.15 281 26.8 Dec. 21_ ..... 14.85 »208 Ore?. 760 East Fork Ashland Creek near Ashland, 8.14 .do. . do - 33.50 292 35.9 do...... _- 5.22 Oreg. 761 Meyer Creek near Ashland, Oreg.--.... 5.90 1953-55-__ __ .-- Oct. 10, 1953 11.55 111 18.8 - -do. ___._ 11.89 154 26.1 762 Bear Creek at Medford, Oreg___.... 279 1915-55 - Feb. 20, 1927- 11.0 8,300 29.7 Dec. 22, 5 a.m. ... 7.50 9,400 33.7 763 Griffin Creek near Medford, Oreg__.. 5.41 Jan. 27, 1954- . 13.92 117 21.6 12.25 74 13.7 764 Rogue River at Raygold, near Central 2,020 1905-55 Feb. 21, 1927. 24.8 110, 000 54.5 Dec. 22, 9 a.m. .... 23.1 110,000 54.5 Point, Oreg. 1861-62-., ..... 32 Evans Creek above West Fork, at 33.7 1941-53----- __ . Dec. 28. 1945--- 6.60 2,630 78.0 Dec. 22 7.14 4,520 134 Meadows Bridge, Oreg. Evans Creek at Bybee Springs, near 116 1925-27, 1940-53- Feb.20, 1927.-- 312.5 11, 100 95.8 do..... 12.1 9,150 78.8 Rouge River, Oreg. Jones Creek near Grants Pass, Oreg - 7.41 1951-55 Jan. 27, 1954 - 14.70 502 67.7 Dec. 21 13.12 228 37.5 Rouge River at Grants Pass, Oreg 2,420 1939-55.---. _ -- Jan. 18, 1953 23.9 77, 000 31.8 29.60 135, OOC 55.8 1861-62 39 Applegate River near Copper, Oreg_ 220 1938-55 Jan. 18, 1953 19.48 15, 300 69.6 Dec. 21, 9 p.m. . 23. 47 20,30( 92.3 Appleeate River near App'egate, Oreg 480 -do.... ~ ... .-do.--. . 15.60 29, 100 60.6 Dec. 21, 10 p.m .... 18.00 47,60C 99.2 Powell Creek near Williams, Oreg- __ 8.6 1946-55 do...... 5.36 1,110 129 Dec. 22, 2a.m. .... 5.37 972 113 Applegate River near Wilderville, Oreg. 694 1938-55 do.-.. . 18.3 47, 500 68.4 Dec. 22 _--...-- 20.3 66, 50C 95.8 Butcherknife Creek near Wonder, Oreg. 3.07 1953-55 Jan. 27. 1954- 16.82 367 120 Dec. 21 ...... 16.84 369 120 TABLE 35. Summary of flood stages and discharges Continued

~~Coastal Oregon Continued~~

Kouge River basin Continued 774 30.9 1913, 1943-55..... Oct. 29, 1950 9.72 4,020 130 9 fin 197 3.16 1953-55 __ ...... Jan. 27, 1964 6.73 305 96.5 Dec. 21 ...... 6.30 262 82.9 Oreg. 776 28. 1922, 1929-30, Oct. 29, 1950 9.8 3,300 118 -do.... Q n 9 70ft 1932-55. 777 76.7 Dec. 22 . 114 778 22 1940-55. Oct. 29, 1950 '. 36.95 3,550 161 9. 6fi 4,610 210 Placer, Oreg. 779 1941-55-. .-.. ... -do . 8.75 158 10.05 8,230 1QO Oreg. 780 23.8 1944-45, 1946-53- Jan. 18,1953. _ . 6.50 2,680 113 Dec. 22... __ .... 6.5 2,680 113 781 76 1941-55 ..... do ...... 7.75 6,580 86.6 7.95 7,150 94.1 782 42.4 1954-55 Dec. 30, 1954... . 11.50 5,200 123 Dec. 22, 3a.m ..... 14.79 12, 100 285 Creek, near O'Brien, Oreg. Oct. 28, 1950 .. 12.96 2 14, 200 292 783 364 1926-55. _ Feb. 20, 1927.--. 319.6 52, 000 143 14.4 56,800 156 ' 23 1941-55 .- Jan.18,1953 5 {\f\f\ 917 4,400 191 Oct. 29, I960 7.92 785 1.62 Dec. 21 ... 278 172 78fi 579 Dec. 22...... 85, 000 147 near Selma, Oreg. 787 Rogue River below Illinois River 4,890 ..do...... 20 414, 000 84.7 near Agness, Oreg. Eiler Creek basin: 788 .74 1953-55 - Jan. 17, 1953 24.8 300 405 Dec. 21 ..... 23.06 211 285

1 Affected by storage and (or) diversion; see station description. " Natural flow estimated as 170 cfs; augmented by water escaping through break 2 At different site; see station description. in reservoir outlet conduit. 3 Site and datum then in use. 12 Two-hour average maximum inflow, in cfs. 4 Contents, in acre-feet. is Exceeded by floods of Dec. 31, 1913; Feb. 20,1927; and Mar. 25,1928. 5 Based'on net contributing area; see station description. 14 Does not include flow bypassing through Best Slough. 6 Affected by failure of dam or dam appurtenance; see station description. ls At gage established July 1956. 16 Affected by backwater; see station description. 7 Mean daily discharge, in cfs. 17 May have been more when gage was overtopped June 3,1948. 8 Maximum inflow, in cfs. 18 Maximum outflow, in cfs. 9 Four-hour average maximum inflow, in cfs. w Includes flow in bypassing canal; see station description. 1° Does not include water bypassing through Mud Slough. 20 Equal to or greater than any in last 65 years. PART 1. DESCRIPTION A151

STATION DATA The station data of discharge and stage for the 788 stations in the flood area are assembled in Water-Supply Paper 1650-B. The data consist of records of stage and discharge at gaging stations and peak-stage and peak-discharge for numerous miscellaneous sites and partial-record stations in or on the fringe of the area of intensive flooding. The records are in more detail than those in the regular annual reports so as to be more useful in the many hydraulic and hydrologic studies relative to flood phenomena. The basic data collected at stream-gaging stations consist of records of stage, measurements of discharge, and general information useful in determining the daily flow. The records of stage are obtained either from the continuous trace of a water-stage recorder or from periodic direct readings on a nonrecording gage. Discharge measurements are generally made by use of a current meter; however indirect methods are used at times. In general, the information presented for each gaging station is: a description of the station, a tabulation of daily mean discharges for December 1955 and January 1956, a tabulation of stages and discharges at selected intervals during each day of the flood rise and recession for the two or three highest peaks during the 2-month period, and a list of peak discharges above a designated base. For the miscellaneous sites and partial-record stations, only the station description is presented. The station description gives information relative to the: location of the gage; size of the drainage area above the gage; nature of the gage-height record obtained during the period covered by this report and datum of gage; definition of the stage-discharge relation; maximum stage and discharge during the 1955-56 floods; previous maximum during the period of record; available maxima data for floods outside the period of record; effect of regulation and diversion; and other pertinent general information. Daily mean discharges during the months of December 1955 and January 1956 follow the station description for each gaging station. In general, this 2-month period includes the flows reflecting antecedent conditions, the flood flows, and enough of the flood-recession records to allow adequate study of the flood hydrology. Also shown in these tables are the monthly mean discharge in cubic feet per second and the volume of monthlv runoff in acre-feet and in inches. The monthly runoff is not given for stations where regulation or diversion affect the runoff significantly or where the drainage area has not been determined.

~~668521 O 63 11 A152 FLOODS IN FAR WESTERN STATES~~

The tables of stage and discharge at selected times, where such detailed information is warranted, follow the daily mean discharge tables. Enough detail is presented so that the hydrographs of the two or three highest flood peaks may be accurately constructed. Because these flood peaks did not occur on the sume days throughout the entire area, the periods of detailed record do not necessarily coincide for all the stations. INDEX

Page Page A C Acknowledgments______.....____ A 4-5 Cache Slough...... _.. A46 Adobe Creek..______45 Calaveras River basin______..__ 36 Alameda Creek___.__..____.__... 27 California, central-coastal, December storms.. 7-8 Alhambra Creek...______27 description of floods...______r .__ 20-28 American River basin..._____..__...... 45 central-coastal flood damage....__ 77,78,79 Anatone, Wash., weather station at...___ 13 flood-data sites in. ______21 Anderson Banch Reservoir__..._____. 59 flood frequencies.______.. 98-100 Anderson Reservoir.______.___ 27 flood stages and discharges, summary 120-122 Annual flood peak stages and discharges, magnitude of floods..______20 Arroyo Seco near Soledad, Calif._ 100 precipitation in..______.______7-8 Asotin Creek near Asotin, Wash....._. 114 previous floods.______98,100 Boise River near Twin Springs, Idaho__ 109 reservoir storage______90-91 Clackamas River near Cazadero, Oreg__ 111 north-coastal, description of floods... __ 46-56 Eel River at Scotia, Calif...... 106 flood damage______.. 81,82 Feather River at Bid well Bar, Calif.--.-. 103 flood-data sites...______.. 47 John Day River at McDonald Ferry, flood frequencies..______.. 105-107 Oreg....--.-....-...... -... . 114 flood stages and discharges, sum Kaweah River near Three Rivers, Calif.. 102 mary....-...... 132-136 Kern River near Kernville, Calif.. ___ 101 precipitation....______--.- 10 Klamath River near Klamath, Calif._.. 107 previous floods..______105-106 Little Weiser River near Indian Valley, reservoir storage.._.-.--.___-... 94 Idaho...... 109 Cameron Creek.._. ____ ._ __ --- - 31 McKenzie River near Vida, Oreg_____ 110 Carmel River basin...... 21,22 Merced River at Pohono Bridge near Carnadero Creek...__..__...___...... 22 Yosemite, Calif...... 102 Carson River, peak discharge_.. -... 19 Middle Fork American River near Carson River basin, description of floods..... 15,17 Auburn, Calif...... 105 Cascade Mountains, December storms in._... 12 Rogue River at Raygold, near Central Cascade Reservoir..____------59 Point, Oreg...... 113 Cazadero in Russian River basin...... _ -... 10,50 South Fork Coquille River at Powers, Cherry Valley Reservoir__------35 Oreg...... 112 Chewaucan River near Paisley, Oreg-.. _ 20 Trinity River at Lewiston, Calif...... 106 Chowchilla Creek..____.______-.-. 34 Umpqua River near Elkton, Oreg__ __ 113 Coeur d'Alene River basin...... _-...-. 56 Willamette River at Albany, Oreg...... 110 Conn Creek___.______... _. 48 Wind River near Carson, Wash...... __ 115 Coos River basin______.-... 72-73 Aptos Creek__...... __..___._ 25 Coquille River basin.- . 72-73 Arrowrock Reservoir..__...____..... 59 Corralitos Creek basin...______.. 22 Arroyo Seco.______22,100 Corte Madera Creek.______-- .. 49 Asotin Creek...... 56,114 Cosumnes River..-...------.-.__- . 37 Coyote Creek-.. 26,27 Coyote Reservoir__--...._...... -.------. 27 B Crane Creek Reservoir..------60 Bear Creek...... 35,37,44 Cross Creek...... 31,33 Bear Reservoir.______35 Big Chico Creek...... 41 D Black Canyon Dam______59,60 Deadwood Dam....._..__ . 57 Black Rock Desert basin, description of floods December floods, peak discharge Eel River in...... 19 basin.. 52 Boca Reservoir._____._____._____ 18,19 Deep Creek above Adel, Oreg...... ------20 Boise River basin....-...... -.-- 56,59,82,109 Deer Creek. 43,44 Borel CanaL ______29 Discharge measurements.. __ 115-116 Boulder Creek....______8,24 Bridgeport Reservoir...... __...... 15 Don Pedro Reservoir..__... ----- 35 Burns Creek.....______35,37 Downie River...... _ .------..-- 44 Burns Reservoir______...... -...-.-. 35 Dry Creek.... 37,48 Butte Creek__.______41 Duck Creek.. ... - 36 A153 A154 INDEX

Page Page E Hog Flat Reservoir..______A20 East Fork Quinn River, peak discharges,.. _. A19 Honcut Creek __.______41 East Walker River above Bridgeport, Calif... 15 Humboldt River basin. ______19 Eel River basin.-.------..--. 48,50,52-53,106 Hydrographs------16,23,30,40,51,58,64,70, 76 Elder Creek----..-_...... 38 Elk Bayou...------.---...... --.---. 31 Englebright Dam______44 Idaho, west-central, description of floods. . 56-62 west-central, flood damage_ -_-_.-. 82 flood-data sites...------____.---.- 57 Feather River at Nicolaus, Calif, ______43,44 flood frequencies--.,-.______108-109 Feather River basin, description of floods. 41-44,103 flood stages and discharges, sum Fernbridge, Calif., flood damage______53 mary....- ...... 137-141 Flood-crest stages, Eel River basin______89 minor storms in.-..-.-.------_ .. 10-11 north-coastal California_____... 89 precipitation--_-.___--____ 10-11 Sacramento Valley, Calif.---.._...... 87-88 previous floods...-_._-..._-.... 107 San Joaquin Valley, Calif------...... _ 85-86 reservoir storage-_-____----_-- 94-95 Flood-data sites, Idaho. ______75 Isabella Reservoir. _____. _ - _____ 28 location of....__.______3 Oregon . ____ 75 Washington______75 Flood discharge, determination._ ... ___ 115-116 January floods, total damage..--. 49 Flood-frequency curves, central-coastal Cali John Day River______- _- 56,114 fornia__..______... 99 north-coastal California______104 K Flood stages and discharges, central-coastal Kaweah River, December flood--- . 31,33 California summary.._____ 120-127 Kaweah River basin, flood damage___- __ 28,33 coastal Oregon__ .-..._.____ 146-149 precipitation-.,. 9 Great Basin....._._-.----.----.-..- 118-119 Kelsey Creek . 45 north-coastal California..______132-136 Kern River basin, peak discharge.--__. 28,101 Oregon, minor floods...... ______141-142 Klamath, Calif., flood damage. 54-55 Sacramento Valley...-.------.----.. 127-132 Klamath River basin...... 46,48,54-55,107 San Joaquin Valley.______79-80 Washington, minor floods In...... 137,141,142 west-central Idaho- __.______137-141 Willamette Valley...... 142-146 Lahonton Reservoir.--...... -. 15,17,89 Folsom Reservoir__..__.______45 Little Chico Creek... -- -- 41 Franktown Creek. _ _.______19 Little Creek, tributary to Scott Creek-...--- 25 Friant-Kern Canal...______.__ 32 Little Salmon River basin . .. . . 56,61,82 Friant Reservoir.______._ 33 Little Truckee River, peak discharge. 18,19 Littlejohn Creek.-.-.. - 36 Q Livestock losses.. ____ 14-15,44 Qardnerville, Nev., flood-damage near_._ 17 Llagas Creek Reservoir 22 Giant Forest, precipitation in..-... ___ 9 Lone Tree Creek... 36 Gold Beach Ranger Station, near mouth of Lookout Point Reservoir- .. 63 Roque River...... __... 12-13 Los Banos Creek 34 Goose Lake basin______38 Lost Valley Reservoir-.-.-.----.------60 Great Basin, description of floods in.____ 13-15 Lucky Peak Reservoir ... . 59 flood damage. . ..______77,78 M flood-data sites....______14 frequencies_ _....______98 McCoy Flat Reservoir.._. 20 stages and discharges, summary.... 118-119 McDermitt Creek...... 19 hydrographs at gaging stations in___ 16 Mad River basin. 54 minor floods______..____ 5-6 Manning Creek-- - 45 precipitation in__.__..__.____ 6-7,13 Marin County, Calif., small stream basins in. 49 previous floods...- _ .______98 Mariposa Creek.. . ------35 reservoir storage... .---.-.--__.-... 89-90 Marsh Creek.- - - - 34 Gregorio Creek______25 Martin Creek--. - - 19-20 Guadalupe River, peak discharge_--.--.---. 26 Marysville, Calif., flood damage.- 41,42,43,44 Matadero Creek ------26 H Mattole River basin------52 Happy Isle gaging station. Mendota Dam...---.------33 Hetch Hetchy Reservoir... Merced River, peak discharges ------34,35,102 Hobart Dam....____. Mill Creek-.. - 31 INDEX A155

Page Page Minor storms, Great Basin___ _._____ A5-6 S San Joaquin Valley ______.__ 8-9 Mokelumne River.-___._____....._ 37 Sacramento River basin be low Feather River. A44-46 Monterey B ay area, flood damage in.... __ 20 Sacramento Valley, drainage area.. _ --.-. _ 38 Mormon Slough._____.______36 flood-crest stages ______.. ___ 87-88 Mud Creek ______41 flood damage ______38,80-81 flood-data sites. .. __ ... ______39 N flood-frequency curves ______104 Napa River basin..__.______._..__ 46,48 flood frequencies ______102-103 Novato Creek...... _____._..__. 49 flood stages and discharges, summary 127-132 Novato Reservoir.--.-----____---__--.--- 49 precipitation. __ . _ . ______9-10 previous floods.. ______102-103 O reservoir storage ... . ------93 Onyx station on South Fork Kern River__ 28 St. John River-- 31,33 Oregon, coastal, December storms.__-..__ 12-13 Salinas River basin ___ - ______21 coastal, description of floods______67-77 Salus Creek.--. ______56 flood damage.------.-.------___ 84 San Antonio River, peak discharge _____ . . 22 flood-data sites...______.....__ 67,68 San Bruno Creek _____ . ______- ___ 25,26 flood frequencies..-..-______111-113 San Clemente Dam____... _ . 21 flood stages and discharges, sum San Francisco Bay area, flood damage. .. 20-28 mary.------...141-142,146-150 San Francisco Peninsular streams. _._... __ 25,26 previous floods...__.______. 111-112 San Francisquito Creek- . . ... 26 storage regulation__-- ..____ 96-97 San Joaquin River basin, description of floods. 33-37 north-coastal streams.__...__.___. 69 peak discharge. 33 Orestimba Creek.______...... 34 San Joaquin Valley, December storms in..--. 28-33 Oroville, Calif., flood damage_....___.. 41 flood-crest stages __ - 85-86 Owens Creek.______._____._ 35,37 flood-data sites.. - . 29 Owens Reservoir...._____..._.__._. 35 flood damage. __ ------79,80 Owyhee River basin_..____-----_._ 20 flood frequencies __ 100-102 flood-frequency curves. __ 99 P precipitation.. _____ ._.. 8-9 Packwood Creek..._.--___-_.__.__..... 31 previous floods------100-101 Pajaro River basin...__....._____.. 22,24 reservoir storage ------.-. 91-93 Palouse River..-.-..._...... _..__ 56 San Lorenzo River basin..-. __ . _ _ ... 24-25,27 Paradise Valley...__.___.__._____ 19 San Mateo Creek------25,26 Pardee Reservoir..._.___--.-._------37 San Pablo Creek-. __ . __ .. . 27 Payette River basin______.____ 56,59-60,82 San Pablo Reservoir... ------... --- 28 Paynes Creek..__..._...... ______38 Santa Clara Valley, description of floods. .. 26-27 Peavine Creek _.__._..______18 Santa Cruz, Calif., flood damage. ... . 20,24,25 Petaluma Creek..._....._....._____ 48 Scott Creek- - 25,45 Pilarcitos Creek______25 Scott River---.-----.------55 Pine Creek__...... 20,41 Shasta Dam.. _____ . _____ ------38 Pine Flat Reservoir--..-- - . - - 33 Shasta Lake 38 Pinole Creek...... ______.__..____ 27 Silver Creek. ___ . _ . ___ .. __ ------15 Pohono Bridge gaging station__.. ... 35 Smith River basin. ------46,55-56 Precipitation, amount in December.....__. 12 Snake River.. _ .... 61 Putah Creek..--..--.--..------46 Sonoma Creek _ . . ------48 Q Sequel Creek.. ______. __ ------25 Sprague River basin _ _-_- ___ - _ 55 Quinn River near McDermitt - 19 Stanislaus River. __ - ._ ------34,36 R Stockton, Calif., flood damage. ______36 Redwood Creek basin...._._.-.--..--..-- 48,54 Sur River basin... __ . _____ .... 21 Reno-Sparks area, flood damage....._._.. 18 Susan River, peak discharge. ___- - 20 Reservoir storage, north coastal California.... 94 Susie Creek.... 20 Sacramento Valley, Calif_ ___ 93 San Joaquin Valley, Calif 91 Thomes Creek ------38 west-central Idaho..-.__..._.___ 94 Topaz Reservoir-..-. _ ------15 Willamette Valley.-..------95,96 Trinity River... - 55,106 Rock Creek...... 20,41 Truckee River basin, description of floods in.. 17-19 Rodeo Creek... . 27 peak discharge...------17,18 Rogue River basin, flood stages and discharges, summary.-.- .. 150 Tulare Lake basin...-_. ... 31-33 precipitation in-__.______. 12,13,73-74 Tule River station near Porterville... 31 Russian River basin, description of floods-... 50 Tunitas Cieek.._. - 25 precipitation.______._ 10,47,50 Tuolumne River. - 34.35 A156 tNDEX

Page Page U Willamette Valley Continued flood damage______A83 Umpqua River basin, December storms in. A12,71 flood-data sites...______.__ 82 flood frequencies______.. 109-111 W flood stages and discharges, summary... 142-146 precipitation...______11-12 Walker River basin, description of floods..... 15 previous floods..-.__-- _--- 109,110,111 Walnut Creek basin, flood damage_.... __. 27 Weiser River basin...... 56,60-61,82 reduction of flood discharge by storage Wildcat Creek...... 27 regulation.____.____...-. 96 Willamette City, Oreg., flood damage.-.. - 63 reservoir storage. ___...._. 95-96 Willamette River, eastside tributaries.. ___ 65-66 Wind River weather station__ __ _...... 13 westside tributaries______._ 66 Willamette River basin, Coast Fork.._..... 65 Y Middle Fork...... 63 Yankee Slough______... 45 Willamette Valley, December storms____. 11-12 Yuba City, flood damage.. . 38,42,43 descriptions of floods... ______62-67 Yuba River, peak discharge.______41,43 o