TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

1.0 INTRODUCTION

2.0 PROCEDURES AND ASSUMPTIONS

3.0 RESULTS

4.0 SUMMARY

5.0 REFERENCES

Appendix A - Detailed Results of CWAP

Appendix B - Round Table Meeting, July 17, 1996

Table 1.1 List of Watersheds and Sub-Basins in the Study Area

Table 2.2 Presence of Fish Species in the Bella Coola River Watershed

Table 2.3 Notable Stream Features within the Bella Coola Watershed

Table 2.1 CWAP Information Sources (Maps and Aerial Photographs)

Table 3.1 Summary of Watershed Indicator Scores

Table 3.2 Equivalent Clearcut Area (ECA) Within Each Sub-Basin

Table 3.3: Summary of Hazard Index Scores for each Sub-Basin

Figure 1.1 Bella Coola Watershed Assessment Study Area.....................................................2

Attachment 1: 1 set of 28 1:20,000 scale hard-copy CWAP base maps covering the study area

Attachment 2: CWAP map of study area

Attachment 3: 1 Colorado tape containing ARC/INFO compatible digital versions of Attachments 1 and 2

Attachment 4: 1 Diskette containing Excel format CWAP spreadsheets and Word format CWAP report

In conjunction with the Watershed Restoration Program (WRP) of Forest Renewal B.C. (FRBC) the Cariboo Regional office of the Ministry of Environment, Lands, and Parks is undertaking a Watershed Assessment for the Bella Coola River Valley. The Level 1 Coastal Watershed Assessment (CWAP), presented here, represents the first stage of this project. The study area includes the Bella Coola River and it’s tributaries including the Talchako River and the lower portion of the Atnarko River (Figure 1.1). The overall purpose of the project is to identify and priorize opportunities for hillside, stream channel, and fish habitat restoration.

Results of the draft CWAP report were discussed at a Round Table meeting held on July 17, 1996 in Hagensborg. Those in attendance included representatives of federal, provincial, and regional district agencies, industry, and local fishing and recreation groups. Comments made at the meeting were used to finalize recommendations contained within this report and guide follow-up field studies planned for late summer 1996. Appendix B contains a list of those present and a summary issues discussed at the meeting.

As employed in the context of a WRP program, the objectives of the Level 1 CWAP are 1) to inventory baseline watershed conditions and basic information relevant to potential watershed impacts associated with forest harvesting, and 2) to identify watersheds and sub-basins at risk of having previously experienced watershed impacts. These potential impacts include changes in peak flows, accelerated surface erosion and changes to riparian buffers as a result of activities associated with forest harvesting.

The results of the office-based Level 1 assessment provide the basis for developing recommendations and priorizing sub-basins for watershed restoration. The results will be used to priorize follow-up field-based detailed assessments to be conducted in late summer 1996.

The Bella Coola River Watershed Assessment study area (Figure 1.1) is located within the Coast Mountains of British Columbia in the Pacific Ranges ecoregion (MOF, 1994). The study area is approximately 2,100 square kilometers in size and encompasses the towns of Bella Coola and Hagensborg. The Bella Coola River flows west into North Bentinck Arm. The project area (Table 1.1) includes two tributaries of the Atnarko River, six tributaries of the Talchako River and thirteen tributaries of the Bella Coola River. Three larger tributaries of the Bella Coola River (Thorsen Creek, Salloomt River, and Nusatsum River) are themselves sub-divided into smaller sub-basins, so that a total of 29 sub-basins are considered in this watershed assessment.

Elevations within the study area range from sea-level to over 3,000 m. Approximately 78% of the project study area lies above 800 m, 13% lies between 300 and 800 m, and 9% lies below 300 m elevation. A significant portion (approximately 7%) of the study area is glacier-covered. Glaciers derived from the Monarch Icefield, situated immediately south of the study area, occupy several sub-basins that drain into the Talchako River.

Climate data from two valley bottom stations within and near the study area (AES-Bella Coola and B.C. Hydro-Falls Creek) indicate that the mean total annual precipitation at valley bottom locations is near 1675 mm, of which about 10% falls as snow (Environment Canada, 1993). Almost 50% of the annual total is recorded between October and December. The mean January and July temperatures recorded at the above-noted climate stations are -1.3^o and 16.7^o Celsius respectively. There are no high elevation climate stations within the study

Table 1.1 List of Watersheds and Sub-Basins in the Study Area

area. However, elevational effects on temperature, precipitation, and the distribution of precipitation between rain and snow are significant. At increasing elevation, temperatures drop, precipitation increases, and a progressively larger fraction of the annual precipitation falls as snow.

The Bella Coola River valley and most lower elevation valleys within the study area lie within the Coastal Mountain Hemlock biogeoclimatic zone. Mid-elevations lie within the Mountain Hemlock biogeoclimatic zone and high elevations lie within the Alpine Tundra zone (MOF, 1994). All of the Bella Coola River and Talchako River tributaries are situated within the Central Coast Mountains hydrologic zone (MELP, 1995). Two tributaries to the Atnarko River within the study area (Tsill Creek and Unnamed Creek 3) are situated within the Chilcotin Ranges hydrologic zone (MELP, 1995).

Bedrock geology within the study area consists mostly of intrusive granite and metamorphic schist. Volcanic tuff and andesite comprise large portions of the Noomst, Tsini-Tsini, Nordschow, Gyllenspetz, Unnamed Creek 2 and Jacobsen Creek sub-basins found in the south-eastern part of the study area. A number of sub-basins contain several bedrock types. For example Burnt Bridge Creek contains metamorphic, volcanic and intrusive bands of rock separated by faults (GSC, 1978).

Within the study area the Water Survey of Canada (WSC, a branch of Environment Canada) has monitored stream discharge of Tastsquan Creek, Nusatsum River and Salloomt River. As of 1990, no other creek within the study area has been monitored (Environment Canada 1992). Discharge monitoring of Tastsquan Creek (Station #08FB003) took place between April 1946 and August 1950 (Environment Canada, 1989). Monitoring was continuous using a manual gauge. Average monthly peak flows were recorded in June (4.48 m³/s) and low flows typically occurred in March (0.565 m³/s). Maximum daily discharges occurred in October and November each year, and were much greater than the maximum monthly mean. For example, a maximum daily discharge of 36.5 m³/s was recorded on October 24, 1947 and on November 27, 1949 a discharge of 25.9 m³/s was recorded.

The Nusatsum River (Station #08FB005) has been monitored both continuously and seasonally since 1965. The highest monthly discharges occur in June and July, at almost 35 m³/s. Average monthly flows are lowest from December to April, dropping to 4.4 m³/s in March. The maximum daily discharge recorded between 1965 and 1990 was 190 m³/s (September 27, 1973), and the maximum instantaneous discharge was 318 m³/s (September 29, 1988).

The Salloomt River (Station #08FB004) has been monitored continuously since 1965. Average monthly discharge ranges from 3.7 m³/s in February and March to 18.1 m³/s in June. A maximum daily discharge of 141 m³/s and a maximum instantaneous discharge of 241 m³/s were recorded on December 16, 1980.

These recorded patterns illustrate the nature of the hydrologic regime of the study area. The seasonal cycle of streamflow is governed by two key influences - the predominance of fall rainstorm and rain-on-snow events, and the melting of the winter snowpack in spring and summer. Fall rainstorm and rain-on-snow events generate high but short-duration peak flows. The highest daily and instantaneous flows of the year generally occur in response to this type of flow generating mechanism. However, the highest monthly average flows generally occur in summer. Late summer flows in many study area watersheds are sustained by glacier melt. The lowest flows of the year therefore generally occur in late winter.

Fish resource values within the study area are high. Concern over potentially degraded fish habitat and the search for restoration opportunities are the driving forces behind this assessment. Fifteen different species of fish are found in the study area. Table 1.2 summarizes the known fish presence and Table 1.3 indicates the presence of known obstructions to fish migration and the location of the WSC gauging stations in the area.

Table 1.2 Presence of Fish Species in the Bella Coola River Watershed

Table 1.3 Notable Stream Features within the Bella Coola Watershed

The Level 1 Coastal Watershed Assessment Procedure (CWAP) is a reconnaissance level investigation designed to identify risks that impacts have resulted from the cumulative effects of past forest harvesting.

The Level 1 CWAP completed for the study area followed the steps outlined in the Coastal Watershed Assessment Procedure Guidebook (MOF/MELP, 1995). The procedure involves delineating watersheds and sub-basins, and assessing the hydrologic sensitivity of the sub-basins based on 15 watershed descriptors. Measurements are entered into an Excel spreadsheet, scores are assigned each watershed descriptor, and a Hazard Index Score is calculated for five potential hazard groups for each sub-basin. These hazard groups are:

• Peak Flow Hazard,
• Surface Erosion Hazard,
• Riparian Buffer Hazard,
• Landslide Hazard, and
• Headwaters Hazard

Hazard index scores fall between 0.0 and 1.0. A Hazard Index Score equal to or above 0.5 indicates an area for concern and suggests a need for further watershed assessment; i.e. a Level 2 Channel Assessment. In the present WRP context, the intent of the Level 1 CWAP is to screen out those sub-basins for which all Hazard Indices are low (<0.5) and to focus field studies on sub-basins with a higher risk of prior impacts from forestry-related activities.

Information for the Bella Coola River Level 1 Coastal Watershed Assessment was derived from the information sources listed in Table 2.1. Watershed characteristics are graphically portrayed on the 1:20,000 scale CWAP base maps developed during the study (Attachments 1, 2, and 3).

Measurements and calculations of the watershed descriptors are primarily derived from 1:20,000 TRIM and Forest Cover Maps. Considerations for each watershed parameter are as follows:

Watershed and Sub-Basin Areas:

Watershed and sub-basin areas were calculated from 1:20,000 scale TRIM maps using G.I.S. The total study area covers 2,072.5 square kilometers and is sub-divided into 29 sub-basins (see Figure 1.1 and Table 1.1).

Forest harvesting tends to increase peak flows, which may then causes channel change and sediment movement within the stream channel. Clearcutting affects the hydrologic regime of a watershed by altering interception, transpiration, and snowmelt. As the forest regenerates, the effects on hydrology diminish until clearcuts become "hydrologically recovered". The state of hydrologic recovery of each disturbed polygon found on the 1:20,000 scale Forest Cover Map was determined from projected tree height information contained within the associated map database (.FIP file). Stands are considered to be 0, 25, 50, 75 and 90% recovered for the following respective ranges of tree heights: 0-3 m, 3-5 m, 5-7 m, and >9 m (MOF/MELP, 1995).

Table 2.1 CWAP Information Sources (Maps and Aerial Photographs)

The peak flow index is determined from the equivalent clearcut area (ECA) found within three elevation bands (<300 m, 300-800 m and >800 m) within each sub-basin. The equivalent clearcut area (ECA) of each clearcut polygon is equal to its area reduced by the amount of hydrologic recovery. ECA’s of each polygon are summed within each sub-basin and each elevation band. In coastal areas of B.C., at elevations less than 300 m, peak runoff is generally found to be due to rainfall (i.e. the effects of harvesting on peak runoff are minimal). The zone between 300 and 800 m produces the high rain-on-snow events typical of the fall season. Runoff from elevations greater than 800 m is produced mostly during the spring and summer. For these reasons, equivalent clearcut areas within the 300 - 800 m elevation band are weighted by 1.5 (MOF/MELP, 1995) in the calculation of a peak flow index.

All roads mapped on the Forest Cover Maps were used for the road inventory. This information was supplemented by the 1:20,000 scale TRIM maps and aerial photographs. Forest roads, secondary roads and old overgrown roads are included in the CWAP analysis but Highway #20 and many paved roads within the townsites are not included.

The riparian buffer index is calculated from the portion of stream logged and the portion of fish-bearing stream logged. A stream was considered to be logged if either the cutblock straddled the stream, or its boundary was adjacent to the stream, per MOF/MELP (1995). Information on the distribution of fish within the watershed was derived from 1:50,000 scale FHIIP maps, Nicholson & Moore (1988) and a UBC library search. In addition, Mr. Mike Ramsay of the Ministry of Environment, Lands and Parks in Bella Coola provided information from local DFO staff and MELP files.

Erodible Soils:

Information on erodible soils was available to be interpreted from terrain maps prepared for the Salloomt River watershed (Pedology Consultants, 1980). No other soils mapping was available for the study area. According to the CWAP guidebook (MOF/MELP, 1995) erodible soils are assoicated with landforms having fine-textured soils (i.e. lacustrine, fluvio-glacial) and from slopes greater than 60% (other than rock). Using 1:15,000 scale air photos, soil textures were interpreted, very generally, from surface expression and associated landforms. Areas of fine-textures soils and steeply-sloping medium textured soils are more likely to be gullied and eroded. These areas of erodible soils are transferred from airphotos to the TRIM base map. This interpretation is considered to be reconnaissance-level and is meant to give rudimentary information for use in the CWAP only.

Landslides were identified on 1:15,000 scale colour 1995 aerial photographs for most of the study area and on a combination of 1977 and 1979 1:20,000 (approximately) scale black and white aerial photographs.

Unstable terrain for a portion of the Salloomt River watershed was obtained from mapping completed by Pedology Consultants (1980). No other terrain maps or slope stability maps are available. Therefore, unstable terrain was also interpreted from aerial photographs fro the purpose of the CWAP. Unstable terrain was interpreted very generally as those slopes with evidence of instability or other mass movement activity (i.e. landslide scars, talus slope development, slump scarps). Again, this interpretation is general and is meant to provide information for the CWAP only.

For each sub-basin, spreadsheets provided by the Ministry of Forests were used to convert raw measurements into 15 "indicator scores" and to combine the scores into 5 "hazard indices". The CWAP spreadsheets are provided in Appendix A. Table 3.1 summarizes the 15 watershed indicator scores for each sub-basin. The scores and the resultant Hazard Indices are discussed for each sub-basin below.

Equivalent clearcut areas (ECA’s) are summarized in Table 3.2. The table indicates the percentage equivalent clearcut area within each elevation band and is summarized for each sub-basin. No sub-basin within the project study area has an ECA greater than 10%. Operability within the project area is likely severely constrained by the topography.

Calculated Hazard Indices for each sub-basin are summarized in Table 3.3. The intent of the CWAP procedure is to focus additional study on those areas having hazard scores greater than 0.5. Accordingly, hazard scores greater than or equal to 0.5 are highlighted in the table. This table is used to guide the recommendations for detailed field-based assessments to be conducted in the summer of 1996.

Table 3.1 Summary of Watershed Indicator Scores

Table 3.2 Equivalent Clearcut Area (ECA) Within Each Sub-Basin

Table 3.3: Summary of Hazard Index Scores for each Sub-Basin

Tastsquan Creek has a drainage area of 28.2 km². The creek provides waterworks and domestic water supply to the Regional District and Bella Coola Municipality as well as to the Nuxalk First Nation (MELP, 1996). There is no logging and less than a kilometer of road within the watershed.

All hazard indices are between 0 and 0.02 except for the landslide hazard index. Nine landslides, all of which impacted the mainstem due to the steep and narrow geometry of the valley, result in a landslide hazard index of 1.0. Because of the absence of prior logging, no further watershed assessment under the WRP program appears to be warranted. However, because of the local importance of the creek, a reconnaissance overview is suggested, with the objective of identifying slide mitigation opportunities.

The total area of the Thorsen Creek watershed is 85.5 km², and the watershed is sub-divided into a Lower, an Upper West, and an Upper East sub-basin. Thorsen Creek provides domestic water to the Nuxalk First Nation (MELP, 1996). High rates of bedload deposition at the highway bridge and flooding of private land are problems identified on Lower Thorsen Creek.

The area of the Lower Thorsen Creek sub-basin is 14.2 km². Logging within the sub-basin is limited to 10% of the area below 300 m elevation and 10% of the area between 300 and 800 m elevation. The resulting Peak Flow Hazard index is low (0.18).

Due to the length of roads within 100 m of a stream (6.12 km) the Surface Erosion Hazard Index is moderate (0.59). The Riparian Buffer Hazard index is high (1.0) due to logging adjacent to approximately 1.0 km of fish-bearing stream and adjacent to the mainstem. The sub-basin is relatively stable with only 4% of the area classified as unstable. The resulting Landslide Hazard Index is 0.

The Surface Erosion and Riparian Buffer Hazard Indices indicate the need for field-based assessments in the Lower Thorsen Creek sub-basin.

Streamflow in Upper West Thorsen Creek (area = 21 km²) is dominated by snow and glacier melt. Elevations in the upper watershed are as high as 2100 m. Limited forest harvest within the sub-basin means that all Hazard Indices are 0 except the Landslide Hazard Index. The Landslide Hazard Index is 0.83 due to 4 landslides which impacted the mainstem of the creek.

The CWAP Level 1 study suggests that no further assessment is needed.

The Upper East Thorsen sub-basin (50.3 km²) is also glacier-fed. There is very little logging or forest road development in the sub-basin which results in a low Peak Flow Hazard Index (0), Surface Erosion Hazard Index (0.02) and Riparian Buffer Hazard Index (0). Six naturally occurring landslides, 2 of which hit the mainstem, result in a moderate Landslide Hazard Index (0.5). About 56% of the sub-basin is classified as unstable terrain.

The CWAP Level 1 study suggests that no further assessment is needed.

Water from small icefields flows into a series of three lakes before entering Snooka Creek. This relatively small watershed (12.1 km²) has high relief with elevations up to 2000 m.

There is little logging within the watershed and the Peak Flow Hazard Index is low (0.03). A total of 1.2 km of forest road and 2 road crossings results in a low Surface Erosion Hazard Index (0.07). However, the logging is adjacent to about 1.0 km of stream, of which 0.8 km is fish-bearing. This results in a moderately high Riparian Buffer Hazard Index (0.68). It is noteworthy that the logging adjacent to the stream is now 90% hydrologically recovered. The sub-basin is relatively stable, having a Landslide Hazard Index of 0.25.

Additional field-based assessments are recommended due to high fisheries values in Snooka Creek.

This relatively small watershed is 39 km² in size. There is some logging in the lower to mid-elevation areas and this accounts for 3.8% of the total sub-basin area. The Peak Flow Hazard Index is low (0.03). The Surface Erosion Hazard Index is also low (0.08). The Riparian Buffer Hazard Index is moderately high (0.65) due to logging adjacent to more than 4.0 km of the stream (0.60 km of which is fish-bearing). Fish resource values are high as there is a DFO fish hatchery on Snootli Creek.

Field based assessments are recommended.

Nooklikonnik Creek is a glacier-fed creek whose watershed is 97.5 km² in area. There is a water license for irrigation located on the creek. Approximately 27% of the sub-basin area below 300 m has been logged. In total, however, all of the logging within the watershed accounts for only 1.2% of the sub-basin area. The resulting Peak Flow Hazard Index is low (0.03). There are 3.3 km of forest road, about half of which is within 100 m of a stream. The Surface Erosion Hazard Index is correspondingly low (0.06). The Riparian Buffer Hazard Index is low to moderate (0.49) due to logging along 49% of the mainstem length. Bedload problems have been identified on the fan of Nooklikonnik Creek.

Eleven landslides, 2 of which hit the mainstem, result in a moderate Landslide Hazard Index (0.50). About 40% of the total watershed area is classified as unstable and 17% of the total area is classified as having erodible soils.

Field based assessments are recommended for the Nooklikonnik Creek sub-basin.

Sawmill Creek is a tributary to the Bella Coola River located on the north side of the River near the estuary. Its watershed area is 16.6 km². The creek enters the Bella Coola River just downstream from the town of Hagensborg. Logging is limited to the low elevations within the Bella Coola River valley so all Indices but the Landslide Hazard Index are less than 0.11. Unstable terrain and landslides are primarily limited to the upper elevations within the watershed.

The CWAP Level 1 does not suggest that further watershed assessment is needed.

The total area of the Salloomt River watershed is 168.9 km², and it is sub-divided into an Upper and Lower sub-basin.

Terrain mapping was prepared by Pedology Consultants for Crown Zellerbach Canada Ltd. in 1980. These maps were interpreted and used to supplement the identification of unstable terrain and erodible soils for the CWAP.

The size of the Lower Salloomt River sub-basin is 80.6 km². Most of the logging within the Salloomt River watershed occurs within the Lower sub-basin and most is within the < 300 m elevation band. Because the ECA and the road densities are small compared with the total sub-basin area, the Peak Flow Hazard Index is small (0.20). However, the Lower Salloomt River sub-basin has the highest percentage of its area logged (8.7%) of all the sub-basins in the project area.

The Surface Erosion Hazard Index is moderate (0.55) due to a combination of the density of roads within the sub-basin, the density of roads on erodible soils, roads within 100 m of a stream, and the number of stream crossings. Logging adjacent to the stream and especially adjacent to fish-bearing stream reaches results in a high Riparian Buffer Hazard Index (1.0). The Landslide Hazard Index is high (0.83) due to ten landslides, of which 4 hit the mainstem. These four slides are small failures along the stream bank but may be logging related due to the proximity of roads and cutblocks.

Additional field-based assessments are recommended.

Headwaters of the Upper Salloomt River sub-basin originate from somewhat low gradient slopes, small icefields and lakes. The area of the sub-basin is 88.3 km². There are copper and silver mineral occurrences in the Upper Salloomt River sub-basin (GSC, 1972).

There is almost no logging (the ECA is 0.1%) nor are there many roads (0.56 km) within the sub-basin. The Peak Flow, Surface Erosion, and Riparian Buffer Hazard Indices are all less than 0.10. The Landslide Hazard Index is high (1.0) due to 31 landslides, 6 of which hit the mainstem. However, terrain mapping was completed on 1:10,000 scale maps (Pedology Consultants, 1980), and there may be a higher rate of landslide identification compared with the use of 1:15,000 scale air photos.

The CWAP Level 1 does not indicate the need for further assessment.

The total area of the Nusatsum River watershed is 274.6 km², and it is sub-divided into a Lower, Upper West and Upper East sub-basin. A road connects the Bella Coola River valley to the Noeick River valley and South Bentinck Arm via the Lower and Upper East Nusatsum River valleys.

The area of the Lower Nusatsum River sub-basin is 112.0 km². The Peak Flow Hazard Index for the sub-basin is low (0.11). ECA’s range from 13.0% below 300 m, to 11.5% between 300 and 800 m, to 0.8% above 800 m (4.1% overall).

The Surface Erosion Hazard Index is low (0.30) because the length of roads is small compared to the total sub-basin area. The Riparian Buffer Hazard Index is high (0.90) due to logging adjacent to streams and adjacent to fish-bearing streams. The Landslide Hazard Index is low (0.25).

Additional field-based assessments are recommended for this sub-basin.

There is very little forest development within the Upper West Nusatsum River sub-basin (55.59 km²). The equivalent clearcut area is 1.3 km² (19.8%) between the 300 and 800 m elevation, but only 2.3% overall. This results in a low Peak Flow Hazard Index (0.06). The Surface Erosion Hazard Index is also low (0.10). The Riparian Buffer Hazard Index is high (1.0) due to the portion of mainstem logged. It is noteworthy that "mainstem" here refers to the river within the Upper West sub-basin of the Nusatsum watershed. Slopes are relatively stable (Landslide Hazard Index = 0.25).

Additional field-based assessments are recommended.

The Upper East Nusatsum River is glacier fed and its area is 107.0 km². Over 90% of the total sub-basin area lies above 800 m elevation. There are 21.5 km of logging road, including the road to South Bentinck Arm. Due to low overall road densities the Surface Erosion Hazard remains low (0.24). Logging adjacent to the stream and adjacent to fish-bearing stream results in a high Riparian Buffer Hazard Index (1.0). The Upper East tributary of the Nusatsum River is fish-bearing up to approximately 800 m elevation.

Only one out of 13 landslides have reached the mainstem which contributes to a low Landslide Hazard Index (0.25).

Additional field-based assessments are recommended.

Tseapseahoolz Creek drains into the north side of the Bella Coola River. The watershed is 29.8 km² in area and an icefield and lake comprise its headwaters. There is very little forest development within the sub-basin (ECA only 2.2% of total sub-basin area). Most of this forest harvest occurs between 300 and 800 m elevation.

A low (0.32) Surface Erosion Hazard Index can be attributed to a low density of roads (despite the fact that 6 km of road come within 100 m of the stream). Logging adjacent to the stream, including 1.4 km of fish-bearing stream, results in a high Riparian Buffer Hazard Index (1.0). The Landslide Hazard Index is low (0.10) as no landslides impact the mainstem.

Additional field-based assessments are recommended.

A total of 6.2 km² of clearcut logging is spread between the three elevation bands within the 150.7 km² watershed. The Peak Flow Hazard Index is low (0.09). Thirty-one kilometers of road, almost half of which is within 100 m of the creek, still nets a low Surface Erosion Hazard Index (0.17). The Riparian Buffer Hazard Index is 1.0 due to the portion of fish-bearing stream logged and the portion of mainstem logged. Only 16% of the sub-basin is classified as unstable and the Landslide Hazard Index is correspondingly low (0.25).

Additional field-based assessments are recommended.

The Cacoohtin Creek sub-basin is a small (51.6 km²) and relatively steep drainage flowing into the south side of the Bella Coola River. Elevations within the sub-basin are as high as 2600 m (Space Point Peak). What little logging occurs within the sub-basin is all below 300 m elevation. The Peak Flow Hazard Index (0.03) reflects the small amount of forest development. The Surface Erosion Hazard Index is also low (0.12). The Riparian Buffer Hazard Index is moderate (0.65) because 33% of the length of fish-bearing stream and 27% of the mainstem length has been logged. The Landslide Hazard Index is also high (0.83) due to four slides that hit the mainstem.

Additional field-based assessments are recommended.

Noomst Creek is a glacier-fed stream. At least a third of the total sub-basin area (97.5 km²) is covered by ice and rock and 88% of the entire sub-basin lies above 800 m elevation. Both the Peak Flow and Surface Erosion Hazard Indices are low (0.06 and 0.17, respectfully). The Riparian Buffer Hazard Index is high (0.73) due to the length of fish-bearing and mainstem stream logged. The Landslide Hazard Index is low (0.25) with only 1 landslide which impacted the mainstem of Noomst Creek.

Additional field-based assessments are recommended.

The study area boundary follows two east-west tributaries of Burnt Bridge Creek. This corresponds with the Tweedsmuir Provincial Park boundary. The area included in the project is 53.3 km². There is a stock watering license on Burnt Bridge Creek.

All Hazard Indices are low. The Peak Flow and Surface Erosion Hazard Indices are both 0 and the Riparian Buffer Hazard Index is 0.45 due to some logging (90% hydrologically recovered) adjacent to the mainstem. The sub-basin is relatively stable, with only 2% of sub-basin area classified as unstable.

The Level 1 CWAP does not indicate a need for detailed assessment. However, because the Riparian Buffer Hazard Index is close to the 0.5 threshold, an overview assessment in the field is suggested.

The total area of all watersheds contributing to the Bella Coola River drainage is 1,316.9 km², or approximately 60% of the total project study area. Bella Coola River Residual sub-basin areas consist of the valley bottom and those areas not accounted for by the other 13 sub-basins within the Bella Coola River drainage.

Forty-two percent (42%) of the area considered Bella Coola River residual lies below 300 m elevation. Within this elevation band 14.25 km² have been clearcut. This generates the largest total ECA of any sub-basin in the study area. However, this is only 5.8% of the total basin area. The resulting Peak Flow Hazard Index is low (0.10).

Development within the Bella Coola River valley accounts for 86 km of forest road. The length of Highway 20 and other paved residential roads are not considered in the CWAP analysis. Despite the length of roads and the 61 stream crossings, the Surface Erosion Hazard Index is low (0.17).

The Riparian Buffer Hazard Index is high (0.69) due to logging adjacent to the stream channel. The residual areas are particularly sensitive to streamside logging due to high fish resource values.

Slopes within the Bella Coola River valley are relatively stable. Only 14% of the area is classified as unstable. Twenty-one landslides were identified on the air photos but impacts on the mainstem are minimized due to the wide valley bottom.

Due to high public interest and high fisheries values within the Bella Coola River valley, there is a high priority for assessment work. It is recommended that field assessments be conducted for all areas within the sub-basin, including those on private land, that may have stream impacts.

Unnamed 3 Creek (drainage area = 13 km²) flows into the north side of the Atnarko River. The creek is one of two sub-basins located within the Chilcotin Ranges hydrologic zone. The sub-basin is characterized by stable, rocky slopes. There is no logging and there are no roads within the sub-basin. All Hazard Indices are 0.

No further assessment is suggested by the Level 1 analysis.

Tsill Creek flows into the south side of the Atnarko River. This small (17 km²) sub-basin is also within the Chilcotin Ranges hydrologic zone. The sub-basin is rocky and stable. There is no logging nor any forest road within the sub-basin, and all Hazard Indices are 0.

The Level 1 analysis does not suggest a need for further watershed assessment.

The total area of all watersheds contributing to the portion of the Atnarko River drainage included in the study area is 39.2 km², or 3.2% of the total project area. Only 2 sub-basins of the Atnarko River drainage are included in the project area. These are Tsill Creek and Unnamed Creek 3. The Atnarko Residual sub-basin accounts for all valley bottom and residual areas between the Bella Coola River drainage and the Talchako River drainage.

The town of Stuie is situated adjacent to the Atnarko River close to the junction of the Talchako River and the Bella Coola River. There is limited forest development within the residual areas of the Atnarko River. All hazard indices are low.

The results do not suggest a need for further assessment for the small portion of the Atnarko River included in this project.

Tsini-Tsini Creek flows into the Talchako River at the junction with the Atnarko River. The sub-basin, 141 km² in area, is glacier-fed. There is little forest development within the sub-basin and the Peak Flow Hazard Index is correspondingly low (0.02). The Surface Erosion Hazard Index is also low (0.04).

Logging adjacent to 2.5 km of stream, 1.9 km of which is mainstem, results in a moderate Riparian Buffer Hazard Index (0.51). The Landslide Hazard Index is high (1.0) due to the nature of the valley geometry. Six out of nine slides hit the mainstem of Tsini-Tsini Creek.

Additional field-based assessment is recommended for this sub-basin.

The Nordschow Creek sub-basin is 99.8 km² in area, and the creek drains into the Talchako River. Ninety-three percent (93%) of the sub-basin lies above 800 m elevation. Only 0.65 km² ECA (10.1%) between 300 and 800 m results in a low Peak Flow Hazard Index (0.02). Only 5.4 km of forest road results in a low Surface Erosion Hazard Index (0.05). There is a limited amount of logging adjacent to the stream and the Riparian Buffer Hazard Index is accordingly low (0.47). There are twenty-four slides, 8 of which hit the mainstem, resulting in a high Landslide Hazard Index (1.0). The slides are naturally occurring on steep slopes (31% of the total sub-basin area is classified as unstable).

The result does not suggest that further assessment work is warranted.

The Gyllenspetz Creek sub-basin is 139.8 km² in area. The creek flows into the Talchako River. The headwaters of Gyllenspetz Creek are large icefields, one of which is the Borealis Glacier.

All Hazard Indices are low (0.01 - 0.03) within this sub-basin except the Landslide Hazard Index (0.67). There are 15 landslides, all of which are natural and 3 of which hit the mainstem. Over 40% of the total area of the sub-basin is classified as unstable and about a third of the sub-basin is covered in glacier and rock.

The results do not suggest a need for further assessment.

The area of the Ape Creek sub-basin is 66.2 km². Mt. Jacobsen is the highest point within the watershed at over 3000 m a.s.l. Water flows into Ape Creek from surrounding icefields and from Ape Lake over a divide (1395 m a.s.l.) as long as natural flow to the Noeick River is blocked by ice. Ape Lake was formed by the Late Neoglacial advance of Fyles Glacier, which blocks its drainage down the Noeick River.

A report by Jones et al. (1985) describes a glacier outburst flood (jokulhlaup) that occurred about October 19, 1984 when subglacial leakage from Ape Lake beneath the glacier increased rapidly, melting a tunnel beneath the glacier. A flood of water subsequently caused the breach of a climax end moraine and approximately 45.8 x 10⁶ m³ of water flowed down the Noeick River. Peak discharges at the tunnel exit during the event are estimated to be between 985 and 1500 m³/s. Within the Noeick River valley the flood "destroyed several kilometers of logging road, severely damaged two bridges, razed over 200,000 recently planted trees and probably destroyed a large proportion of the salmon eggs deposited in the river gravel earlier in the year". The report concludes that major floods will continue until the thickness of the ice damming the valley is 20-30 m lower than ice thickness in 1984 and that the lake is expected to drain every 1-2 years for at least the next 8 years and possibly as long as 100 years unless management options are considered.

There is no logging within the Ape Creek sub-basin, nor are there any roads. Hazard Indices are all 0 except the Landslide Hazard Index (1.0). The sub-basin is steep, volcanic, and generally unstable. Approximately 26% of the sub-basin is classified as unstable and another large proportion of the area is ice and rock. Nine slides were identified and they all hit the mainstem.

No further watershed assessment is recommended.

Unnamed Creek 2 (drainage area = 16.6 km²) is located between Ape Creek and Jacobsen Creek along the Talchako River. There is no logging, nor any roads within the sub-basin and all Hazard Indices are between 0 and 0.02, including the Landslide Hazard Index. Slopes within the Unnamed Creek 2 sub-basin are relatively stable.

No further watershed assessment is indicated.

About half of the Jacobsen Creek sub-basin (area = 175.9 km²) is glacier and rock. Water from the Jacobsen Glacier and the Monarch Icefield flows into the creek. There is no logging nor are there any roads within the sub-basin. Therefore, all Hazard Indices, with the exception of the Landslide Hazard Index, are 0.0. The Landslide Hazard Index is moderate (0.50) due to the large amount of ice and steep rock.

No further watershed assessment is indicated.

The total area of the Talchako River drainage within the study area is 785.8 km². This accounts for 36.2% of the total project area. Six sub-basins drain into the Talchako River and the residual area between these drainages is 135.0 km². The Talchako River stems from the Talchako Glacier and Monarch Icefield.

International Forest Products Ltd. has a land improvement water license for the Talchako River (MELP, 1996). There is some logging within the valley (6.87 km² or 5.9% of the residual sub-basin area) but the Peak Flow Hazard Index is low (0.11). The Surface Erosion Hazard Index is 0.32 due to the portion of road length within 100 m of the stream and 63 stream crossings. The Riparian Buffer Hazard Index is 0.32 and the Landslide Hazard Index is 0.25. A small amount of logging on first or second order tributaries (headwaters) to the Talchako River results in a Headwaters Hazard Index of 0.04.

The Level 1 study does not indicate a need for further assessment of the Talchako River valley but concerns from the Round Table have resulted in a recommendation for further field assessment work. Reasons for this recommendation include possible riparian impacts, recent logging and road building, and a recent slide which impacted the river.

Neither the Peak Flow Hazard Index nor the Headwaters Hazard Index exceeds 0.5 in any sub-basin within the project area. The Surface Erosion Hazard Index is greater than 0.5 in only 2 sub-basins (Lower Thorsen Creek and Lower Salloomt River). The Riparian Buffer Hazard index is high (> 0.5) in thirteen sub-basins and the Landslide Hazard Index is high (>0.5) in fourteen sub-basins (although many landslides appear natural in origin). The Level 1 analysis points to a need for further assessment mainly as a result of high indices for the Surface Erosion Hazard Index and the Riparian Buffer Hazard Index. Further assessment of sub-basins having only a high Landslide Hazard Index and for which all slides appear natural in origin, does not appear to be necessary.

The results of the level 1 CWAP, in conjunction with discussions at a Round Table meeting on July 17, 1996, will guide field-based studies to be conducted during the summer of 1996. The level 1 CWAP analysis suggests that level 2 field work is needed in 14 sub-basins in the study area. Following a July 17, 1996 meeting of the Bella Coola Round Table, the field plan was expanded to include the Talchako River residual (Table 4.1). In addition, because the CWAP process is relatively new and untested, it is recommended that brief overview-level inspections be conducted in all other sub-basins in which prior logging has occurred.

Table 4.1 Suggestions for Field-Based Assessment Resulting from the CWAP Level 1 Analysis and the Round Table Meeting

Energy Mines and Resources Canada. 1975. NTS Map Sheet, 1: 50 000 scale (92N/13).

Energy Mines and Resources Canada. 1980. NTS Map Sheet, 1: 50 000 scale (92M/16, 93D/1 & 93D/2).

Energy Mines and Resources Canada. 1984. NTS Map Sheet, 1: 50 000 scale (93C/4, 93C/5, 93D/7, 93D/8, 93D/9 & 93D/10).

Energy Mines and Resources Canada. 1986. NTS Map Sheet, 1: 250 000 scale (92M & 92N).

Energy Mines and Resources Canada. 1989. NTS Map Sheet, 1: 250 000 scale (93C & 93D).

Environment Canada. 1989. Historical Streamflow Summary British Columbia 1988. Minister of Supply and Services Canada. Ottawa.

Environment Canada. 1990. Surface Water Data British Columbia 1989. Minister of Supply and Services Canada. Ottawa.

Environment Canada. 1991. Surface Water Data British Columbia 1990. Minister of Supply and Services Canada. Ottawa.

Environment Canada. Atmospheric Environment Service. 1993. Canadian Climate Normals 1961-90 British Columbia. Minister of Supply and Services Canada. Ottawa.

Geological Survey of Canada. 1969. Geology-Anahim Lake. 1: 250 000 scale (Map 1202A). Energy, Mines and Resources. Ottawa.

Geological Survey of Canada. 1971. Surficial Geology-Anahim Lake. 1: 250 000 scale (Map 1289A). Energy, Mines and Resources. Ottawa.

Geological Survey of Canada. 1973. Surficial Geology-Bella Coola. 1: 250 000 scale (Map 1329A). Energy, Mines and Resources. Ottawa.

Geological Survey of Canada. 1972. Geology - Bella Coola. 1: 250 000 scale (Map 1327A). Energy, Mines and Resources. Ottawa.

Jones, D.P., K.E. Ricker, J.R. Desloges, and M. Maxwell. 1985. Glacier Outburst Flood on the Noeick River: The Draining of Ape Lake, B.C. October 20, 1984. Open File Report 1139. Geological Survey of Canada.

Ministry of Environment, Lands and Parks. 1995. Hydrologic Zone Map. 1: 2 000 000 scale. Water Management Division, Hydrology Branch. Victoria.

Ministry of Environment Lands and Parks. 1996a. Water License Database accessed from the Internet at wtrwww.env.gov.bc.ca

Ministry of Environment, Lands and Parks. 1996b. TRIM Topographic Map Sheet,

1: 20 000 scale (92M 100; 92N 091; 93C 001, 011, 021, 031; 93D 009, 010, 019, 020, 026-030, 036-040, 047-050, 057-059, 068). Surveys and Resource Mapping Branch. Victoria.

Ministry of Forests and Ministry of Environment, Lands and Parks. 1995. Coastal Watershed Assessment Procedure Guidebook (CWAP). Victoria.

Ministry of Forests. 1989. Forest Cover Map Sheet, 1: 20 000 scale (92M 100; 92N 091; 93C 001, 011, 021, 031; 93D 009, 010, 019, 020, 026-030, 036-040, 047-050, 057-059, 068). Inventory Branch. Victoria.

Ministry of Forests. 1994. Biogeoclimatic Units of the Vancouver Forest Region. Map Sheet 2 of 6. Central British Columbia Coast, 1: 250 000 scale. Research Branch. Victoria.

Nicholson, H.F. and J.E. Moore. 1988. Bibliography of Canadian Freshwaters. Can. Tech. Rep. of Fish. and Aquat. Sci. No. 1600.

Pedology Consultants. 1980. Terrain Analysis of Salloomt Watershed. Prepared for Crown Zellerbach Canada Ltd. - Bella Coola Operations. 1: 10 000 scale.

Province of British Columbia. 1954. Aerial Photographs. BC1700 (33-25), BC1819 (72-74), BC1820 (30-40, 79-91), BC1821 (2-14, 51-58, 60-70, 105-116), BC1822 (1, 4-11, 52-59, 62), BC1833 (70-71, 73-82), BC1834 (28-35, 38-39, 41-49) BC1845 (47-48, 51-56), BC1846 (82-87, 89-104), BC1847 (10-42, 64-90, 113- 118), BC1848 (1-18, 49-64, 95-100).

Province of British Columbia. 1979. Aerial Photographs, 1: 20 000 scale. 30BC77105 (105-114, 118-130), 30BC78124 (220-237), 30BC78125 (5-22, 170-200), 30BC78126 (69-93), 30BC79148 (238-246), 30BC79149 (022-027).

Province of British Columbia. 1995. Aerial Photographs, 1: 15 000 scale. 30BCC95081 (226-266), 30BCC95082 (1-283), 30BCC95083 (1-313).