GEOLOGIC HAZARDS of PARTS of NORTHERN HOOD RIVER, WASCO, and SHERMAN COUNTIES, OREGON
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BULLETIN 91 TEXT STATE OF OREGON OF GEOLOGY AND INDUSTRIES DEPARTMENT MINERAL GEOLOGIC HAZARDS OF PARTS of NORTHERN HOOD RIVER, WASCO, and SHERMAN COUNTIES, OREGON 1977 STATE OF OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES f069 STATE OFFICE BUILDING, PORTLAND, OREGON 97201 BULLETIN 91 GEOLOGIC HAZARDS OF PARTS of NORTHERN HOOD RIVER, WASCO, and SHERMAN COUNTIES, OREGON by John D. Beaulieu Oregon Department of Geology and Mineral Industries Conducted in compliance with ORS 516.030. Funded in part with a grant from the Land Conservation and Development Commission to the Mid-Columbia Economic District. GOVE-RNING BOARD STATE GEOLOGIST R. W. deWEESE, CHAIRMAN, PORTLAND R. S. MASON LEEANNE MAcCOLL PORTLAND 1977 ROBERT W. DOTY TALENT Before completion of the Dalles Dam, the Columbia River flowed over Columbia River Basalt at Celilo Falls near The Dalles, Oregon. Indians, shown here spearing and netting fish from the rocks, were granted sole fishing rights at the falls by government treaty dating from 1855. (Photo courtesy Oregon State Highway Commission) CONT ENTS INTRODUCTION----- 1 Purpose 1 How to Use 1 General - 1 Site evaluations- ---- ------ 1 Land use capobility onalyses ----- 2 Projection of data - ------- ------ 2 Policy formulation - ------- 2 Map Scale and Detail - ------------ Acknowledgments -- --- ----- - --- - 2 4 GEOGRAPHY------------ -- 5 Location and Extent 5 Climate and Vegetation ---- --- 5 Topography -------- - -- 7 Population and Land Use - � - ------ 7 GEOLOGIC UNITS ---- 9 Genera I - ----- 9 Bedrock Geologic Units ------- ------ 9 Eocene volcanic rock- Ohanopecosh Formation (T eo) -- - 9 Early Miocene volcaniclastic rock - Eagle Creek Formation (Tme) --- 9 Miocene flood basalts- Columbia River Basalt (Tcr) ------- 10 Pliocene Columbia River deposits- Troutdale Formation (Tpt) -- --- 12 Pliocene volcanic rocks ------------- 12 Rhododendron Formation (Tpr) -- ---------- 14 The Dalles Formation (Tpd) -------- ---- - 14 High Cascades volcanic rock- Cascades Formation (QTv) (Qba, Qdf, Qvw1, Qvw2 , Qvu, Qvp) ---- --- 16 Quaternary and Pliocene intrusive rock (QTi) - - - - - ---- 17 Surficial Geologic Units ----------------- 17 Pleistocene lake deposits- gravel and sand (Qgs) and silt (QI) 17 Stream deposits (Qooh, Qoa, Qaf, Qal)- ------ 18 Quaternary older alluvium of the Hood River Volley (Qoah) --- 18 Quaternary older alluvium (Qoa) ----------- 20 Quaternary alluvium (Qal) ------- - ----- 20 Quaternary alluvial fan deposits (Qof) --- 20 Slide deposits- Quaternary thick talus (Qt)- ---- --- 22 Wind deposits - Quaternary eolian sand- (Qs) ------- 22 Structure - ----- ----------- 24 General --- - 24 Folds ------ 24 Faults----- 25 GEOlOGIC HAZARDS - 26 General- --- 26 Mass Movement - - - 26 General -- 26 Causes ---------- 26 Downslope gravity component - ------- 26 Shear resistance ---- -------- 26 iii Mass Movement (Cont.) Deep bedrock slides - - Slides in the Eag le Creek Formation 28 Slides in the Columbia River Basalt 28 Slides in the Dalles Formation 30 Slides in the Casc ades Formation 30 Shallow earthflow and slu mp topography - 30 Steep-slope mass movement - 32 Soi I creep- 32 Potential future mass movemen t- --- 34 Sl ope Erosion 34 Defini tion and causes 35 Me th ods of study --- 35 Distribution - 36 Impacts and recommendations - Stream F loadi ng 38 General - 38 Cau ses- 38 Distribution an d magnitude - 39 Impacts 41 Recommendati ens 41 Stream Erosion and Deposition 46 Ge neral - 49 Distribu tion and impacts 49 Recommen datiens - 49 Earthquakes - - --- 53 General ---- 53 Earthquake potential 53 Impacts and recommendations 54 Volcanism Ge neral - 58 Recent activity - 58 Future activi ty 58 Impacts and recommendations - 58 59 GEOLOGIC HAZARD S OF COMMUNITIES General - 60 Communities of the Columbia River Gorge 60 Cascade Leeks 60 Hood River 60 Mosier 62 The Dalles 62 Rufus - 62 Communities of the Deschutes River Drainage 67 Tygh Valley - 67 Maupin 67 Communities of the Deschutes Plateau 70 Dufur - - -- 70 Ke nt - 70 Wasco- - 70 Moro - 73 Grass Valley - 75 75 iv SUMMARY- - 78 Use of This Bulletin 78 Geography -- 78 Geology- 78 Geologic Hazards - ---- 79 Mass movement - 79 Slope erosion 79 Stream flooding- - - --- - - 79 Stream erosion and deposition- 79 Earthquakes - - - - 79 Volcanism 80 Geologic Hazards of Communities 80 BIBLIOGRAPHY - 81 APPENDIXES - 89 A. The formation and classification of soils 91 B. Guide for the textural classification of soils - 92 C. Unified soil classification system 93 D. American Association of State Highway Officials (AASHO) soi Is classification 94 E. Comparison of three systems of particle-size classification --- 95 ILL USTRATI ONS Frontispiece. Indians fishing at Celilo Falls of the Columbia River near The Dalles, Oregon. Figures 1. Suggested use of this bulletin in site evaluations - 3 2. Index map of study area - - 3. Time distribution of stratigraphic and surficial geologic units 6 4. Columbia River Basalt exposed in quarry in middle reaches of China Hollow north ll of Wasco- -- - 13 5. Bench eroded into Columbia River Basalt by Missoula Flood- 13 6. River-deposited andesitic debris of the Dalles Formation exposed near the mouth of Chenoweth Creek - -- --- 14 7. Scablands developed on the Columbia River Basalt immediately northwest of The Dalles - -- 19 8. Scab lands developed on Columbia River Basalt along the north side of Fulton Ridge - 19 9. Flood-prone bottomland underlain by Quaternary alluvium (Qal) in Grass Valley canyon north of the community of Grass Valley - 21 10. Massive, poorly sorted deposits of angular rock debris perched along the sides of Gherkin (Girkling) Canyon 21 11. Quaternary thick talus deposits on the north slope of Shellrock Mountain - 23 12. Small Pliocene fault in the Dalles Formation exposed near the mouth ofChenoweth Creek-- - - - 23 13. The Bonnevilie landslide, site of the legendary Bridge of the Gods- 29 14. Active bedrock failure in Columbia River Basalt in middle reaches of Chenoweth Creek- 29 Government Flat landslide, largest bedrock failure in study area - -- 31 15.16. Highway I-BON, which passes over toe of large slump3 miles west of Wyeth - 31 17. Shallow slump in gully near Wasco ----- 33 18. Massive earthflows in talus extend upslope to exposed bed rock of Wind River Mountain- - - - - --- 33 19. Large rockfall immediately east of Mosier- 37 v 20. Slide-free slopes in gently sloping terrain east of The Dalles- --- 37 21. Numerous gullies and channels in flat bottomland in middle reaches of China Creek - 40 22. Barn protected from smaller floods by small levee ---- 40 23. Downtown area of The Dalles during 18 94 flood - -- 42 24. Flooding of Tygh Valley area in 1964 - - - 45 25. East Fork of Hood River during 1964 flood - 45 26. Floodwaters at Dee in 1964 which were aggravated and diverted by a debris jam - 46 27. lower Fifteenmile Creek in 1974 flood - 47 28. Flooding of Fifteenmile Creek immediately downstream from Dufur during 1974 flood - 47 29. Extensive flooding and erosion of the upper reaches of Fifteenmile Creek upstream from Dufur- - - - ------ 48 30. lower Eightmile Creek during 1974 flood 48 31. Torrential flood deposits at Viento Park after 1964 flood - 50 32. Critical stream -bank erosion in middle reaches of Fulton Canyon after 1964 flood-- 51 33. Stream-bank erosion in the steep lower reaches of Fulton Canyon 51 34. Large culvert used in repair of Fulton Canyon Road after 1964 flood- - 52 35. Rufus, constructed on alluvial fan deposits, suffered extensive torrential flood damage and deposition in 1964- 52 36. Geologic hazards of Cascade Locks and vicinity --- 61 37. Geologic hazards of Hood River and vicinity 63 38. Geologic hazards of Mosier and vicinity 64 39. Geologic hazards of The Dalles and vicinity (folded, in envelope) 40. House in The Dalles placed on tracks to minimize ongoing structural damage due to sliding- --- 66 41. Ongoing slide activity has damaged driveway of house shown in Figure 40 -- 66 42. Geologic hazards of RtJfus and vicinity - 68 43. Geologic hazards of Tygh Valley and vicinity - - - - - - - - - 69 44. Geologic hazards of Maupin and vicinity 71 45. Geologic hazards of Dufur and vicinity - --- 72 46. Geologic hazards of Kent and vicinity - 72 47. Kent, situated on flat terrain away from streams 73 48. Geologic hazards of Wasco and vicinity- -- - -- -- ---- 74 49. Poor maintenance of creek channel through Wasco that may add to flood potential- - 75 50 . Geologic hazards of Moro and vicinity -- --- 76 51 . Geologic hazards of Grass Valley and vicinity- --- ---- 77 TABLES 1. Climatic data for selected communities to 1974- --- 5 2. Population of communities and counties- 8 3. Classification of mass movement in northern Hood River, Wasco, and Sherman Counties, Oregon ---- 27 4. Maximum floods for streams of northern Hood River, Wasco, and Sherman Counties, Oregon 43 5. Scale of earthquake intensities and magnitudes- ---- 55 6. Historic earthquakes of northern Hood River, Wasco, and Sherman Counties, Oregon- 56 7. Distant historic earthquakes affecting the study area ---- 57 vi MA PS IN ENVE LO PE Geo logic maps covering parts of the fo llowing quadrang les: Bon nevi lie Dam and Wasco Hood River The Dal les White Salmon Wishram Geologic ha�ards maps covering parts of the fo llowing quadrangles: Bonnevi lie Dam and Wasco Hood River The Dal les White Salmon Wishram Geo logic hazards map of The Dal les and vicinity vii GEOLOGIC HAZARDS PARTS NORTHERN HOODof RIVER, WASCO,of SHERMAN COUNTIES, and OREGON INTRODUCTION Purpose Effective land use planning and land management require