Detailed Terrain Stability Mapping In the Ellis Creek Community Watershed and the Steward Creek Watershed, Penticton Forest District, BC

Transcription

1 Detailed Terrain Stability Mapping In the Ellis Creek Community Watershed and the Steward Creek Watershed, Penticton Forest District, BC Prepared for: Ministry of Forests Penticton Forest District Small Business Forest Enterprise Program 102 Industri ~ 1 Place Penticton, Bit V2A 7G8 Prepared by: Pottinger G,aherty Environmental Consultants Ltd. # !j West Georgia Street Vancouver, Be V6E 4E6 I PGL File #6!l November 2000 I E. Pottinger Gaherty EnJironmental Consultants Ltd.

2 Detailed Terrain Stability Mapping In the Ellis Cre~k Community Watershed and the Steward Creek Watershed, Penticton Forest District, BC Prepared for: Ministry of Forests Penticton Forest District Small Business Forest Enterprise Program 102 Industrial Place Penticton, BC V2A 7G8 Prepared by: Pottinger Gaherty Environmental Consultants Ltd. # West Georgia Street Vancouver, BC V6E 4E6 PGL File # November 2000

3 I ACKNOWLEDGEMEjTS The following people have contributed to the co~pletion of this project: I Ray Crampton, R.P.F., Penticton Forest District, SBFEP Planning Forester, was the Contract Officer. I Tim Giles, P.Geo., Kamloops Forest District, Regional Geomorphologist, provided expert technical eview. Fieldwork, photo interpretation, report pre aration and QAlQC were conducted by Dave Tupper, Barbara Sle and Susan Wilkins, of Pottinger Gaherty Environmental Consultan Ltd (PGL). Daria Dube, M.Sc., an,independent consult" g geologist from Naramata, BC, provided field assistance. Map construction involved the efforts of I Blandford from PGL, with support from Andrew Neale of Digital Mapp gin Victona.

4 TABLE OF CONTENTS ACKNOWLEDGEMENTS... i TABLE OF CONTE~rS... ii 1.0 Introduction Objectives Previous \Vork Description of the Area...: Physiography Climate...: Bedrock Geolog)T Geomorphic I-listory...' Soils Methodolog)T General Description Denvatlves...: Terrain Stability Likelihood of Landslide-Induced Debris Entering Streams Soil Erosion Potential Sediment Delivery Potential..., Methods... ~ Reliability ofmapping... ~ Surficial Materials... J Moraine (iv1) Glaciofluvial (F'G) Glaciolacustrine ~G) Colluvium (C) Fluvial Materials (F' A, F) Eolian Materials (E) Organic Materials (0) Bedrock (R..) Arlthropogenic (A) Results and Interpretation Ellis Canyon Highlands Conclusions and Recommendations Ellis Canyon I-fighlands References ii

5 Figures - Follows page: Figure 1 - Location of the Ellis Creek AIea in British Coliunbia... 2 Figure 2 - Index Map showing Location of Field Checks... 2 Figure 3 - Bedrock Geolog)" Tables - Table 1 - Criteria for Terrain Stability Interpretations Table 2 - Criteria for Assessing Likelihood of Landslide- nduced Debris Entering Streams 10 Table 3 - Criteria for Soil Erosion Potential Interpretatio s Table 4 - Criteria for Sediment Delivery Potentiallnterp etations Attachments - Appendix 1- Site Photographs Appendix 2 - List of Aerial Photographs Used Appendix 3 - Field Data Forms Terrain and Terrain Stability Maps for: Interpretative Maps for: Ellis Creek Watershed and Steward Cree Watershed, North half Ellis Creek Watershed and Steward Cree Watershed, South half Ellis Creek Watershed and Steward CreeK. Watershed, North half Ellis Creek Watershed and Steward Cree Watershed, South half iii

6 Detailed Terrain Stability Mapping in the Ellis Creek Community and Steward Creek Watersheds November 2000 File: Introduction Small forestry operations within the Ellis Creek and Steward Creek watersheds are contracted by the Penticton Forest District Small Business Forest Enterprise Program (SBFEP). Regulations under the Forest Practices Code of BC (FPC) encourage operators to copduct terrain mapping and terrain stability hazard assessments within their harvest areas to avoid potential erosion problems that might arise as a result of forest operations. This detailed terrain stability mapping project of the Ellis Creek and Steward Creek watershed areas was completed for thj Penticton Forest District SBFEP at Terrain Survey Intensity Level C ~SIL C). The project was completed to provincial Resources Inventory <1ommittee (RIC) standards. Field work, air photo interpretation and map pr6duction were conducted by Pottinger Gaherty Environmental Consultants L~d. (pgl). Users of this report/these maps unfamiliar with terrain maps may wish to consult Terrain Information: A User's Guide to :Terrain Maps in BC (Ryder & Howes, 1986). ' 2.0 Objectives The objectives of this project were to: I 1. Produce 1:20,000 scale maps that present degailed terrain, terrain stability, likelihood of landslide-induced debris enrering streams, soil erosion potential, and sediment delivery potential ofi the Ellis Creek and Steward Creek watersheds based on roughly 1:15,000!scale photos; 2. Carry out field checking at TSIL C over the ~ntire study area; and 3. Prepare a report that describes how the i maps were made, surficial materials present, physiography of the area,! and terrain hazards present, with recommendations regarding forest harv~sting and land management. 3.0 Previous Work Regional surficial geological mapping to date has been limited to the Okanagan Valley (Nasmith, 1962). Terrain stability mapping has been conducted on the adjoining Penticton Creek (Agra, 1998) and Shuttleworth and Vaseaux Creek (Maynard, 1999) watershedsl for the Okanagan Falls Unit of Weyerhaeuser Canada Ltd. Pottinger Gaherty Group 1

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58