TFL 35 and FISHTRAP CREEK WATERSHED DETAILED TERRAIN STABI~ITY MAPPING

for

WEYERHAEUSER CANADA LIMITED

by

Anthony Collett, B.Se., G.I.T. and

June Ryder, P.Geo.

April 1999

J. M. Ryder and Associates Terrain Analysis Inc.

J.M. Ryder and Associates, Terrain Analysis Inc.

Ste.# 101, 4336 DWlbar Street, Vancouver, B.C. Mailing Address: Box 45005, Dunbar P.O., Vancouver, B.C. V6S 2M8 Phone: (604) 736-4211 Fax: (604) 736-510 I E-Mail: jrnryder@intergate.bc.ca

April 21 , 1999

Don Brimacombe, R.P.F. Weyerhaeuser Canada Ltd . PO Box 40 1550 Mission Flats Road Kamloops, B.C. V2C 5K3

Dear Don,

Please find enclosed the maps, typed air photos, report, and database (Excel format) for detailed terrain stability mapping ofTFL 35 and Fishtrap Creek.

I have included four bound copies of the report as well as an unbound version of the original report for photocopying purposes. Folded paper copies of all maps are in the back pockets of each bound report. In addition, three flat paper copies of each map are provided. I sent you a complete set of maps (one copy of each map) on April 16, bringing the total number of copies supplied to eight. Atticus Resource Consultants Ltd. sent the digital files to your mapping department on April 19. Although the study area is covered by four map sheets, it is treated in the digital files as one seamless map. Polygons overlapping the TFL boundary have been given separate polygon numbers on each side of the boundary, allowing the TFL data to be manipulated separately from the outlying areas.

Thank you for the opportunity of providing this service and I hope the report and maps meet your expectations. Please contact June or myself if you have any questions.

Sincerely,

J.M. Ryder and Associates, Terrain Analysis Inc.

TFL35lFishtrap Creek Watershed: Detailed Terrain Stability Mapping Project JAM2.99

CONTENTS

(1) INTRODUCTION .............................................................................................. , ........ 2

(2) METHODOLOGy ...................................................................................................... 2 (2.1) Terrain Mapping ............................................... ! .................................................. 2 (2.2) Mapping Reliability ........................................... ! .................................................. 5 (2.3) Interpretations for Slope Stability and Erosion rotential ..................................... 5 (2.4) Interpretations for Sediment Transfer .............. ; .................................................. 9

(3) PHySiOGRAPHy .................................................................................................... 10

(4) SURFICIAL MATERIALS ........................................ : ................................................ 13 (4.1) Till (M) ............................................................................................................... 13 (4.2) Colluvium (C) .................................................................................................... 14 (4.3) Glaciofluvial Materials (FG) .............................. ~ ................................................ 14 (4.4) Glaciolacustrine Materials (LG) ........................ J ................................................ 15 (4.5) Undifferentiated Materials (U) .......................... J.. .............................................. 15 (4.6) Fluvial Materials (F, FA) ................................... ( ............................................... 16 (4.7) Organic Materials {O) ........................................................................................ 16 (4.8) Weathered Bedrock (D) .................................................................................... 16 (4.9) Bedrock (R) ...................................................... J ................................................ 17 (4.10) Volcanic Materials (V) .................................... j ................................................ 17

(5) ACTIVE GEOMORPHOLOGICAL PROCESSES .................................................... 17 (5.1) Slow Mass Movement {-F,-F",-FC,-FU) ............... ! ................................................ 17 (5.2) Rapid Mass Movement (-R", -R, -Rs, -Rd, -Rb, iRr, -R1) .................................. 18 (5.3) Gully Erosion {-V) .............................................. I ................................................ 19 (5.4) Fluvial Pr~cesses (-I, -M) .................................. 1 ................................................ 20 (5.5) Past GlaCial Processes (-E, -H) ......................... I ................................................ 20

(6) DISCUSSION AND RECOMMENDATIONS FOR MfNAGEMENT.. ........................ 20

(7) ACKNOWLEDGEMENTS ........................................ 1' ••••••••••••••••••••••••••••••••••••••••••••••• 23

I (8) BIBLIOGRAPHY ...................................................................................................... 26

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APPENDIX 1: LIST OF AERIAL PHOTOGRAPHS USED FOR D.T.S.M. OF TFL 35*, FISHTRAP CREEK AND "THOMPSON WEST" ......... ..l .................................................. 1

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APPENDIX 2: ASSESSMENT OF EXISTING CLEARCUTS AND ROADS .................... II APPENDIX 3: ANNOTATED PHOTOGRAPHS ............ ~ ................................................ III APPENDIX 4: STANDARD TERRAIN LEGEND ........... f ................................................ IX

Maps in pockets: Terrain Maps and Interpretive Maps

Cover Photo: View southwest over lower Jamieson Creek valley. The photo was taken across I

from the confluence of Rushton and Jamieson creeks. An a ively failing scarp in thick glaciofluvial gravels and till lies on the western valley wall in he photo centre.

J.M. Ryder and Associates, Terrain Analysis Inc. 1

TFL351Fishtrap Creek Watershed: Detailed Terrain StabUity Mapping Project JAM2.99

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(1) INTRODUCTI01

The objective of this project was to complete detailed ~errain stability mapping at TSIL C for TFL 35, Fishtrap Creek watershed, and several srryall adjoining areas surrounding the TFL, about 52 673 ha, for Weyerhaeuser Canada I Ltd. The small areas include the headwaters of creeks that flow into the TFL, and the east-facing slopes bounded by TFL 35 to the west and south, Fishtrap Creek to the nbrth, and North Thompson River floodplain to the east, herein referred to as "Thompso~ West" (Figure 1.1). The study area lies west and southwest of Barriere, and about 1 p-25 km north of Kamloops. All but approximately 700 ha are operable forest; there are no alpine areas. Existing terrain mapping for the TFL, completed by J.M. RYder\and Associates, Terrain Analysis Inc. in 1997 as part of a terrestrial ecosystem mapping project with Larkspur Biological Consultants Ltd. for Weyerhaeuser Canada Ltd., was ~ransformed into detailed terrain stability mapping at TSIL C concurrently with mapping of the additional areas.

This report describes the methods and results of terrain mapping with interpretations for slope stability, erosion potential and sediment transfe~. Two map themes were prepared at 1 :20 000 scale for the study area: terrain ~nd interpretive maps. The terrain maps provide basic information about terrain, soil drai~age and slope steepness. The interpretive maps show ratings for slope stability, eros~on potential and sediment transfer. This report augments the information shown on the maps. It provides descriptions of terrain mapping methodology, reliability, and the criteria used for slope stability, erosion potential and sediment transfer inter~retations (Section 2). It also includes a general overview of the physiography of the study area (Section 3) and additional information about surficial materials and pr~cesses (Sections 4 and 5). Implications and recommendations for forest land management are discussed in

Section 6. J (2) METHODOLOG .

(2.1) Terrain Mapping

Terrain mapping followed the standard British Columbia procedures for terrain classification (Howes and Kenk, version 2.0, 1997; Re~ources Inventory Committee (RIC), 1996), mapping methodology (RIC, 1995) and d,'etailed terrain stability mapping (Forest Practices Code, 1995).

Preliminary terrain mapping for areas outside the TFL was carried out by interpretation of 1:15 OOO-scale colour air photos (see Appendix 1). Ten field days with two field crews (Le., 20 crew days) were spent in the area during August 18 to 27, 1998. The objectives of field work were to ground check 35°A, of ~II polygons, which falls within the range of terrain survey intensity level (TSIL) C, and to fine tune criteria to be used for slope stability and erosion potential interpretations by aking observations of existing unstable and eroding areas.

J.M. Ryder and Associates, Terrain Analysis Inc. 2

TFL351Fishtrap Creek Watershed: Detailed Terrain Stability Mapping Project JAM2.99

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Roads provide access to all of the study area, and we~e used as vehicle traverse routes and as access for foot traverses. Vehicle and foot traJerses carried out during both 1997 (bioterrain mapping) and 1998 are shown in Fig~re 1.1. Road conditions gave an indication of the potential for road-related instability, a d road cuts provided useful exposures of surficial materials, soils, and bedrock. F ot traverses were made through representative polygons of different surficial materials land slope steepness, with attention focused on those relatively steep slopes likely to be designated as stability class IV or V. All field observation sites are shown on the terrain maps. "Ground check sites" were visited, and are distinguished from "visuallt inspected sites" where reliable visual observations were made from a distance. At ground check sites, soil pits were dug where natural exposures such as slide scars, treeLthrow hollows, or road-cut exposures were not available for examination. A field ~ata form or field notes were completed at each site, and these are available upon request.

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Following fieldwork, terrain mapping on air photos was corrected in light of field observations. Mapping previously completed within th~ TFL was reviewed and slope classes were added. For areas outside the TFL, soil drainage and slope steepness classes were added, the latter based partly on field m$asurements and partly on 1 :20 000 scale TRIM maps (20 m contour interval). Comparisons between map and field measurements of slope steepness suggests that the tbpographic maps provide reliable estimates for long, uniform slopes, but slope morpholdgy is so highly generalized that small, locally steeper or gentler areas and narrow gullibs are not clearly represented by contours. Next, interpretations for slope stability, erosibn potential, and sediment

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transfer were made for the entire study area according to criteria discussed in Sections 2.3 and 2.4. Polygons outside the TFL were then numbered, continuing from the existing polygon numbers. A database was compiled for all polygon attributes. The terrain polygon boundary lines outside the TFL were r~ctified by monorestitution (to compensate for air photo distortion) and digitized by Atticus Resource Consultants Ltd. The linework was then combined with the database to I produce terrain and interpretive maps.

The study area has been divided into four unconventiqnally sized, overlapping map sheets as requested by Weyerhaeuser Canada Ltd. They are wider than the standard TRIM sheet but have approximately the same "height"!(N-S distance) as a TRIM sheet. The maps are presented on a mylar, 50% screened, 1 t20 000 scale topographic (TRIM) base map and as digital files in IGDS and ARCINFO formats. Paper "presentation maps" are included in the back of this report. The digit~1 files present the data as a continuous coverage of the study area. Polygons overlapping the TFL boundary have been given a separate polygon number on each side qf the boundary, thus allowing the TFL digital file to be manipulated separately from the outlying areas.

J.M. Ryder and Associates, Terrain Analysis Inc. 3

TFL 35 Fishtrap Creek Watershed Detailed Terrain Stability Mapping (submitted to Tolko)Pages from MAPS UPs 25 March 2013-2.pdf