HYDROLOGIC MONITORING IN

HOMATHKO RIVER BASIN, 2007

Prepared for the Nature Conservancy of , Regional Office, Victoria

By Sandy Hart, P. Geo., J.S. Hart and Associates Ltd., , BC

February 2008 ii

ACKNOWLEDGEMENTS

This project was undertaken with the funding provided by the …... Their support is gratefully acknowledged. We are also grateful to Chris Swan and Norm Zirnhelt (Environmental Quality Section, Williams Lake) who made available Ministry of Environment field equipment to assist with the research. Lynne Campo of the Water Survey of Canada provided preliminary Homathko station discharge data. Andrew Harcombe contributed research guidance and review of this report as the Nature Conservancy’s Scientific Advisor for this project.

iii

TABLE OF CONTENTS

1.0 INTRODUCTION 1

2.0 DESCRIPTION OF STUDY AREA 2 2.1 Location and area 2 2.2 Physiography 2 2.3 Climate 4 2.4 Streamflow regime 5 2.5 Vegetation 6 2.6 Land use 6 2.6.1 Agriculture 6 2.6.2 Commercial and public recreation 6 2.6.3 Residential use 7 2.6.4 Forestry 7 2.6.5 Mineral exploration and mining 7 2.7 Fish presence 8 2.8 Water use 8 2.9 Sub-basin characteristics 8

3.0 METHODS 11 3.1 Climate 11 3.2 Streamflow 11 3.3 Water quality 12

4.0 RESULTS AND DISCUSSION 13 4.1 Climate 13 4.2 Streamflow 14 4.2.1 Stage-discharge rating curves 14 4.2.2 Flow regime 14 4.3 Water quality 15 4.3.1 Stream temperature variation 15 4.3.2 Stream pH variation 16 4.3.3 Suspended solids transport. 16 4.3.4 Turbidity. 17 4.3.5 Dissolved solids transport. 17 4.3.6 Conductivity 17

5.0 CONCLUSIONS AND RECOMMENDATIONS 19

REFERENCES 21

iv

LIST OF FIGURES

Figure 1. Upper basin land and water use. 2 Figure 2. Lunch Lake temperature and precipitation, 1980-2002. 4 Figure 3. Homathko River monthly hydrograph. 5

LIST OF TABLES

Table 1. Summary of licensed water use in upper Homathko River basin. 9 Table 2. Characteristics of Homathko River basin and sub-basins. 10 Table 3. Homathko basin snowcover data, spring 2007. 13 Table 4. Homathko basin April-October precipitation. 13 Table 5. Discharge total and suspended and dissolved solids yields. 15

APPENDICES.

Appendix A. Stage-discharge rating curves. 23 Appendix B. Lab procedures for suspended and dissolved solids analysis. 29 Appendix C. Hydrographs. 33 Appendix D. Stream temperature variation. 38 Appendix E. Stream pH variation. 40 Appendix F. Suspended solids transport. 42 Appendix G. Turbidity-suspended solids relationships. 48 Appendix H. Dissolved solids transport. 51 Appendix I. Homathko River conductivity-dissolved solids relationship. 57 Appendix J. Discharge and water quality data summaries 59

1.0 INTRODUCTION

This report presents the results of a second year of streamflow and water quality monitoring carried out for the Nature Conservancy of Canada (NCC) in the Homathko River basin upstream of . On its ranch properties in Tatlayoko Valley, NCC is committed to implementing land and water management strategies which protect their diverse terrestrial and aquatic resources. NCC also maintains a broad interest in contributing to environmental stewardship and fostering conservation science research throughout the basin.

The present study is being undertaken to collect baseline information for monitoring of long-term trends in water supply and water quality, to contribute to watershed management activities, and to provide information applicable to aquatic research.

The specific objectives of this year’s program are the following:

• to summarize licensed water use by water source in the upper Homathko River basin; • to describe the characteristics of the sub-basins under study; • to collect baseline discharge and water quality data at representative stations; • to analyze water quality samples at the NCC laboratory in Tatlayoko Valley (established in 2006); and • to present data analyses for the 2007 monitoring period.

2

2.0 DESCRIPTION OF STUDY AREA 1

2.1 LOCATION AND AREA

The upper Homathko River basin is located in the Chilcotin, approximately 200 km west of Williams Lake. Road access is south along Tatlayoko Road from Hwy. 20 at Tatla Lake.

The primary streamflow and water quality monitoring stations, established in 2006, are maintained at Homathko River, Crazy Creek, and upper Skinner Creek (at Chilko Rd.). Additional monitoring was commenced at lower Skinner Creek and Lincoln Creek (flow and limited water quality measurement) and at Cochin Creek (flow only).

Figure 1 illustrates the Homathko study area and the individual sub-basins which were monitored. The Homathko River drainage basin upstream of its inlet to Tatlayoko Lake is 511 km²; and the basin area upstream of the Water Survey of Canada gauge - located 2.2 km north of the lake - is 486 km². The areas of the individual basins are as follows: Cochin Creek basin – 89.50 km²; Crazy Creek basin – 46.95 km²; entire Skinner Creek basin – 94.33 km²; upper Skinner Creek basin – 39.95 km²; and Lincoln Creek basin – 17.40 km².

2.2 PHYSIOGRAPHY

Homathko River, flowing southward to , is the first watercourse north of to cut fully across the to the Pacific coast. In its upstream reaches, the Homathko drains Tatlayoko Lake, the settled Tatlayoko Valley upstream of the lake, the eastern slopes of the , the western flank of the Potato Range, and a lower-relief area of the . The basin drained by Tatlayoko Lake thus encompasses a broad range of physiographic and ecologic settings: from the Fraser Plateau (Ecoregion) to Coast Mountain environments influenced by proximity to the ocean; and from low-elevation valley bottoms to alpine peaks.

Local relief within the upper Homathko basin ranges from 827 m at the lake to 2,080 metres on the northern end of the Potato Range on the east and to the 2,918-metre Niut Mountain in the Niut Range on the west. Elevations on the northern watershed divide at Splinter Ridge reach 1,900 metres.

The bedrock geology of the Homathko basin is complex: the Niut Range includes areas of plutonic, volcanic, and minor sedimentary rock; the Potato Range is underlain by sedimentary rock; Skinner Mountain on the east side of Tatlayoko Valley is plutonic rock; Splinter Ridge (drained by Cochin Creek) is mainly plutonic and metamorphic rock; and Skinner Creek basin is underlain by volcanic rock (Roddick and Okulitch, 1973; Schiarizza et al., 2002).

Tatlayoko Valley, the lower slopes of the Niut Range, Potato Range, and Skinner Mountain, and most of the Plateau portion of the basin are covered by unconsolidated deposits. Glacial till - including prominent valley-scale moraines - is most extensive; fluvio-glacial and alluvial materials are most common in the valley bottom and on lower slopes; and colluvial materials and bedrock exposures are present on steeper

1 Hart (2006) provided a description of the upper Homathko study area, portions of which are updated and included in this section for reference.

4 slopes. There are also lacustrine and organic deposits in isolated low-lying areas and wetlands. At upper elevations, surficial materials are primarily glacial till and colluvial deposits with widespread exposed bedrock.

2.3 CLIMATE

The study area has a cool continental climate moderated somewhat by its proximity to the coast. This maritime influence causes slightly warmer winters and cooler summers than locations at similar elevations further inland. Annual daily temperatures for the 1980-2002 period at the Lunch Lake weather station (1017 m) are 3.0°C, ranging from -8.8°C in December to 13.6°C in July (see Figure 2). For the same period at the Tatlayoko Lake weather station (853 m; 17.5 km to the south), annual daily temperatures are 4.2oC, with a range from -6.5oC in December to 13.7oC in July (Meteorological Service of Canada on-line archive).

Being situated in a ‘rainshadow’ on the leeward side of the Coast Mountains, the study area climate is relatively dry with precipitation decreasing northward with distance from the crest of the Range. Annual precipitation amounts at the Lunch Lake and Tatlayoko Lake stations are 374.8 mm and 465.9 mm respectively; of these totals, the average proportions as snow are 34% at Lunch Lake and 28% at Tatlayoko Lake. At the south end of Tatlayoko Lake, annual valley bottom precipitation is estimated to be

Figure 2. Lunch Lake precipitation and temperature, 1980-2002.

50.0 15.0

45.0 Temperature

40.0 10.0

35.0

30.0 Rainfall (mm) 5.0

25.0 Snowfall (cm) 20.0 0.0

15.0 Mean monthly precipitation. Mean monthly Mean daily temperaturedaily (°C). Mean 10.0 -5.0

5.0

0.0 -10.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

5 twice the valley amounts recorded at the north end of the basin. Similarly, the water equivalent of the accumulated winter snowpack near treeline ranges from a 280 mm average at the Upper station (1650 m) to 572 mm at the Nostetuko River station (1500 m) (Ministry of Environment, on-line archive, 17-19 yr record).

Hawes (1984) mapped the pattern of snowmelt in the Homathko River basin using Landsat imagery. Below treeline and on south-facing alpine slopes snowmelt occurs generally from mid-April to late May. For most alpine areas the snowmelt period is late May, June, and early July. Some of the highest elevation areas, particularly on north-facing slopes, retain snowpatches throughout the summer.

2.4 STREAMFLOW REGIME

The flow regime of streams in the Homathko basin is dominated by meltwater discharge that begins with low elevation snowmelt runoff in late March and peaks between April and July, depending on basin elevation, size, and meltwater source. The smaller, lower-elevation basins have peak flows in April and May. Streams draining high-elevation basins peak in June with snowmelt runoff or during July where alpine glaciers and snowpatches dominate the meltwater supply.

The hydrograph for the Homathko River gauging station above Tatlayoko Lake illustrates the seasonal flow regime typical of the larger streams (Figure 3). Although meltwater accounts for the maximum annual

Figure 3. Homathko River monthly hydrograph, 1968-2003 (WSC Station 08GD008)

5.0

4.0

3.0

2.0 Mean monthly (m³/s) discharge 1.0

0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

6 discharge volume, the annual peak streamflow is frequently produced by large rainstorms. Through the period of record, 35 percent of the annual peak daily flows have occurred between July and October and are assumed to be associated with rainstorm events.

Many small, low-elevation streams in the study area flow only during snowmelt or decline to very low flows through the summer. Flows of the larger perennial streams have minimum flows during late summer and early fall, often followed by slight flow increases in late fall due to reduced evapotranspiration and increased precipitation.

2.5 VEGETATION

With the study area's variable climate, terrain, and elevation, vegetation zones are diverse: ascending from the lower valley, biogeoclimatic zones range from the Interior Douglas Fir Zone, through Montane Spruce and Engelmann Spruce Subalpine Fir Zones, to Alpine Tundra; and southward along the main valleys there is a transition from the dry Sub-boreal Pine Spruce Zone (Very Dry Cold Subzone) of the Chilcotin Plateau through progressively wetter forest of Dry Cool to Dry Warm Subzones of the Interior Douglas Fir Zone (Steen and Coupé, 1997).

In the alpine and subalpine zones vegetation is less productive than in moister climates; however, areas of meadowland and open subalpine fir, lodgepole pine and whitebark pine forest are common. Treeline elevation is typically in the range 1,800-2,000 metres. Middle elevations are dominated by open lodgepole pine with spruce on moister sites. Lower elevation forest vegetation consists mainly of old and mature Douglas fir, mixed-age lodgepole pine, and localized aspen stands on drier sites and spruce with minor aspen and cottonwood on wetter sites. At the southern end of Tatlayoko Lake scattered western red cedar are encountered and 25 km downstream the Coastal Western Hemlock Zone is present.

2.6 LAND USE

2.6.1 Agriculture

Cattle ranching and hay farming are the main land uses in the settled areas of Tatlayoko and Valley. Most ranches are operated as cow-calf operations with livestock being turned out on Crown range from mid-May to end October while ranch land is used for hay production. Some operators maintain cattle on deeded pasture through the grazing period and others grow hay only, mainly to supply local demand.

In addition to these operations there are numerous smaller operators raising livestock or crops for personal or local use and consumption. Such operations include small mixed farms, a commercial greenhouse, and horse breeders.

2.6.2 Commercial and public recreation

Commercial recreation is a second important land use in the Tatlayoko Valley. Long-established tourism operations rely primarily on the area's outstanding backcountry recreation opportunities. Services and activities offered include tourist accommodation, guide-outfitting, horse trips, hiking, skiing, snowboarding, angling, and mountaineering.

7

Public recreationists are increasingly drawn to the area for the activities listed above as well as other pursuits such as mountain biking, windsurfing, kayaking, and snowmachining. As the range of support services expands and the area becomes better known, the presence of public recreationists will increasingly contribute to the community economy.

2.6.3 Residential use

While ranching and commercial recreation are the most extensive land uses, a majority of residents rely on income from sources that are not directly based on land tenures or large holdings. These sources include carpentry, fine woodworking, general contracting, heavy equipment operation, teaching, health services, retail services, video and website production, bus and truck driving, arts and crafts, logging, environmental consulting, silviculture contracting, and retirement income. Although these activities depend to varying degrees on natural resources, most people who have moved to the area have done so because of the exceptional landscape and recreational opportunities available.

2.6.4 Forestry

In Tatlayoko Valley small-scale logging has been carried on by residents for many decades to supply small, local sawmills, for building and fence construction, and other ranch purposes. This logging was loosely regulated and the dispersed, selectively-logged areas do not appear on forest cover maps.

Industrial logging commenced in 1964 with establishment of a sawmill on the Tatlayoko lakeshore by Lignum Ltd. of Williams Lake. Clearcut logging of Douglas fir forest was carried out mainly along the east side of the lake, but also in small areas on the west lakeside and on the west side of the main valley just upstream of the lake. Logging and milling along Tatlayoko Lake ceased in 1975 when the mill burned down.

Also during this period (mainly from 1969-70) Pinette and Therrien Mills Ltd. was logging Douglas fir in the upper Homathko basin in the vicinity of Lunch Lake. These logs were hauled to their mill at Chilanko Forks.

In the past 20 years a limited amount of logging has been carried out, principally in pine forest in the northern portion of the basin. Clearcut blocks are located in Skinner Creek basin, Cochin Creek basin, and in headwaters of Homathko River on the northern slopes of the Niut Range.

2.6.5 Mineral exploration and mining

Mineral exploration and mining activities have taken place in the Tatlayoko Valley throughout the century. Prospecting for gold commenced in the early 1900's and four small gold mining operations were developed in the 1930's: the Morris Mine on Langara Mtn. at the south end of Tatlayoko Lake being the largest operation; and the Feeney, Rafferty, and Blackhorn Mines in the Niut Range. There is still interest in the mineral potential of the Niut Range and Tatlayoko Valley; although there are no operating mines as yet, Skinner Mountain Mine in Tatlayoko Valley has shipped bulk gold ore samples.

2.7 FISH PRESENCE

Based on available Ministry of Environment and Department of Fisheries and Oceans online records and on a G3 Consulting Ltd. (1999) fish habitat assessment, ‘target’ fish presence has been recorded as

8 follows: , bull trout, and Dolly Varden char in Tatlayoko Lake; rainbow trout, , bull trout, and Dolly Varden in the Homathko River mainstem (above the lake); rainbow trout in Quakie Creek (Homathko headwaters); rainbow trout and bull trout in Cochin Lake and upstream in Cochin (McGhee) Creek; and rainbow trout, cutthroat trout, bull trout, and Dolly Varden in the lowest reach of Skinner Creek as well as rainbow trout in a mid-basin reach at the Chilko Road crossing.

Numerous additional streams tributary to Homathko River, including Lincoln Creek and Crazy Creek, are mapped by G3 Consulting Ltd. as ‘suspected fish-bearing’ based on aerial photo and map measurement of stream gradient; however, formal field surveys of fish presence have not been carried out.

Local observations provide a few additional clues to fish distribution. Rainbow trout are known to ascend the reach of Lincoln Creek within the ranch (Evans, pers. comm.); and local residents report that low, bedrock-controlled falls (or drops) are present in the upstream canyon which would be impassable to fish travelling upstream (Shaughnessy, pers. comm.; Mueller, pers. comm.). Rainbow trout are plentiful in Lincoln Lake, a reservoir upstream of the canyon which was stocked by local residents decades ago. The writer has observed adult fish (species unknown) in the lower reach of Crazy Creek (at the road crossing).

2.8 WATER USE

In the Homathko basin the Ministry of Environment licenses water use for purposes which include irrigation, storage, domestic consumption, stockwater, conservation, and dust control. Because of low growing season precipitation, use of surface water for irrigation is particularly important to the agricultural operations. Water is diverted for irrigation use from Homathko River and its tributary streams during the May-September growing season and it is withdrawn for storage in reservoirs during the period October 1 to June 15 or 30.

Figure 1 shows the licensed points of diversion in the drainage basin and Table 1 summarizes the licensed volumes and uses by water source. Irrigation use accounts for 4,267.24 acre-feet (5,262.51 dam³) and total water storage, which is almost entirely for irrigation purposes, is 1,137 acre-feet (1,402 dam³). As these figures indicate, only 26% of the licensed irrigation use is backed up by storage in reservoirs.

2.9 SUB-BASIN CHARACTERISTICS

Table 2 lists the basin area, elevation range, and land cover characteristics of the Homathko River basin and the individual sub-basins studied.

Upper Skinner Creek basin (upstream of Chilko Rd.) is situated within the Chilcotin Plateau Ecosection (of the Fraser Plateau Ecoregion) 2. The basin is below treeline, with an uppermost elevation at 1900 m. Forest cover is almost entirely lodgepole pine with small areas of leading Engelmann spruce and non-forest wetland. The basin has the highest proportion of recently logged area in the Homathko River basin; of the total 12.9% logged area 7.7% is classified in the Vegetation Resource Inventory as ‘not satisfactorily restocked’ (although this classification may not be current).

The area drained by the lower length of Skinner Creek (downstream of Chilko Rd.) also lies within the Chilcotin Plateau Ecosection. The uppermost elevations in the lower basin are on the northern slopes of

2 www.env.gov.bc.ca/ecology/ecoregions/

9

Table 1. Summary of licensed water use in upper Homathko River basin. (from Water Stewardship Division data summaries at www.env.gov.bc.ca/wsd/)

Water source (including Irrigation Storage Domestic Stock Dust springs and tributaries) (a-f) (a-f) (g/d) (g/d) (g/d) Ailsa Creek 165 Alfred Creek 23 Basket Creek 40 Cassidy Creek 98.7 18 500 500 Charlie Creek 382.5 250 Cochin Creek basin 1,020 415 4,600 1,000 Ethel Spring 1,000 Evans Spring 500 Foxe Spring 500 Francois Spring 500 Homathko River (mainstem) 754 8,000 Ken Moore Creek 40 Lincoln Creek 320 200 1,250 500 Mare Creek 120 120 Poplar Spring 600 Powers Creek 209.64 2,500 500 Quakie Creek 220 Rant Lake 500 Skinner Creek 620 150 Skinner Spring 9 Swamp Mud Creek 160 210 Amanda Spring Wasson Creek 24 24 500 White Sand Creek 60 Williams Spring 1.4 500 Total 4,267.24 1,137 13,450 2,750 8,000

Skinner Mountain (although the 1900 m ridge in upper Skinner Creek basin remains the highest elevation in the entire basin). The lower basin includes cleared land at Skinner Meadows, Moore Lake, and at a ranch downstream along Skinner Creek. The Skinner Meadows wetland complex (encompassed largely by deeded lots held by NCC and Joe Schuk of Tatlayoko Lake) is the largest wetland area in the upper Homathko River basin. Logging in lower Skinner Creek has been almost entirely by selection harvesting methods in Douglas fir stands, thus the logged areas shown in Figure 1 actually remain as forest.

Cochin Creek basin (upstream of Tatlayoko Rd.) also drains a Chilcotin Plateau Ecosection area, and shares the 1900 m peak elevation with adjoining Skinner Creek basin. The basin has about the same area as the whole Skinner Creek basin, but has significantly less logging and somewhat more agricultural land clearing. Basin streamflow and water quality are conditioned by Cochin Lake into which two of the three major basin streams discharge.

10

Crazy Creek basin lies entirely within the Central Ecosection (Chilcotin Ranges Ecoregion) of the Coast Mountains. Elevations range from 920 m at Tatlayoko Rd. to the 2918 m summit of Niut Mountain, with 54.8 per cent of the basin area lying above treeline. Two small, alpine glaciers are present on north-facing headwater slopes. The forested area is mainly lodgepole pine with sub-alpine areas of both leading whitebark pine and leading sub-alpine fir and with leading Douglas fir forest on lower slopes. No industrial logging has been carried out within the basin.

Lincoln Creek basin has an elevation range extending from 850 m to a small area of alpine at 2040 m on the north slope of the Potato Range. The basin spans the transition from the Chilcotin Plateau to the Central Chilcotin Ranges Ecosection, with the Potato Range occupying the latter. The basin includes small areas of cleared land (on Lincoln Creek Ranch) and grassland 3, but is otherwise forest plus several small lakes and wetlands. Forest vegetation includes extensive areas of leading lodgepole pine and leading Douglas fir (primarily old growth), plus smaller areas dominated by aspen, Engelmann spruce, and whitebark pine (near treeline). There has been no industrial logging within the basin.

The entire basin of Homathko River has elevations ranging from 827 m at Tatlayoko Lake to 2918 m on Niut Mountain. As Table 2 shows, 10.2 per cent of the basin is alpine, 82.1 per cent is forest, wetland, and lake, and 1.1 per cent is natural grassland and open slope (below treeline). Land clearing for agriculture occupies 3% of the basin (1552 ha) mainly along Tatlayoko Valley and in Cochin and Skinner Creek basins. Logged areas total 3.5 per cent of the Homathko basin area.

Logging within the past 15 years has been carried out in upper Skinner Creek basin and in the northwest headwaters of Homathko basin; elsewhere, the mapped logged areas are former clearcut with regenerated immature forest or selection harvested forest.

Table 2. Characteristics of Homathko River basin and sub-basins. (land cover analysis based on Vegetation Resource Inventory ) Land cover proportion of basin (%) Area Elevation Basin Grassland; Forest, (km²) range (m) Cleared open wetland, Logged NSR Alpine slope and lake Upper Skinner Ck 40.0 1280-1900 0.0 0.0 87.1 12.9 7.7 0.0 entire Skinner Ck 94.3 920-1900 2.1 0.9 91.3 5.7 3.3 0.0 Cochin Ck 89.5 1005-1900 3.4 1.0 93.2 2.4 0.0 0.0 Crazy Ck 47.0 915-2918 0.0 0.0 45.2 0.0 0.0 54.8 Lincoln Ck 17.4 850-2040 0.8 3.6 94.1 0.0 0.0 1.6 Homathko R (abv. lk.) 510.8 827-2918 3.0 1.1 82.1 3.5 1.0 10.2 Notes: - ‘Forest, non-forest wetland, and lake are grouped since they can’t be accurately differentiated in the Vegetation Resource Inventory database. - The logged category includes older logging that is now re-established as immature forest. - Not satisfactorily restocked (‘NSR’) land is also included within the logged category.

3 In Lincoln Creek basin the ‘grassland area’ on the slopes of Skinner Mountain are actually open slope areas with scattered trees, extensive bedrock, and little grass.

11

3.0 METHODS

3.1 CLIMATE

Low-elevation climate data are available from three Meteorological Service of Canada weather stations in the Homathko basin, two of which remain active:

- Tatlayoko Lake (inactive) - manual station at Lincoln Creek Ranch, 51° 40’25”, 124° 24’9”, 875 m; in operation from 1928 to 2004; temperature and precipitation. - Tatlayoko Lake RCS - automated station at Lincoln Creek Ranch, 51° 40’28”, 124° 24’1”, 870 m; in operation since August, 2000; temperature, precipitation, and intermittent record of wind speed and direction. - Lunch Lake , manual station (operated by Helen Schuk) at Lunch Lake, 51°49’30”, 124°27’51”, 1017 m; in operation Nov. 1980 to present; temperature and precipitation.

The BC Ministry of Environment has past and present snowcover data for three upper elevation locations:

- Tatlayoko Lake (inactive) - manual station on the northwest, sub-alpine slope of Potato Mountain; 51°36’, 124°20’, 1710 m; 1952-1998; snow depth and water equivalent. - Upper Mosley Creek - automated snow pillow station in Mosley Creek basin near Homathko headwaters in sub-alpine location; 51°47’, 124°37’, 1650 m; 1989 to present; snow water equivalent. - Nostetuko River - automated snow pillow station in upper Nostetuko River basin in sub-alpine location; 51°15, 124°27, 1500 m; 1989 to present; snow water equivalent.

To supplement the pre-melt snow accumulation data, the following snowcourses were operated during the 2007 field season:

- Hook Creek - manual snowcourse station; 51°47’38”, 124°19’56”, 1525 m; surveyed 30 March 2006 and 17 March 2007; snow depth and water equivalent. - Cochin Lake - manual snowcourse station; 51°48’2”, 124°26’50”, 1000 m; surveyed 16 March 2006 and 12 March 2007; snow depth and water equivalent.

For a second year, during the April-October, open-water season a standard rain gauge was operated near the Cochin Lake snowcourse (51°48’2”; 124°26’30”).

3.2 STREAMFLOW

Streamflow was measured manually at five tributary basins - Crazy Creek, Upper Skinner Creek, Lower Skinner Creek, Cochin Creek, and Lincoln Creek basins – selected to represent the diverse landscapes in the upper Homathko River basin. At Homathko River, discharge is gauged continuously at the Water Survey of Canada station (08GD008) upstream of Tatlayoko Lake. This station has been operated during May to September from 1968 to 1975 and year-round from 1982 to the present.

At four manual stations (not including Cochin Creek), stage was measured from an overhead (bridge or culvert) reference mark and stream velocity was measured by Price 622AA current meter. On two occasions of high flows in Crazy Creek, discharge was measured by dry injection salt dilution gauging

12

(Hudson and Fraser, 2005). At Cochin Creek, streamflow was measured during each visit without reference to a fixed stage. Hydrometric survey procedures were designed to meet Class C standards set out by the Ministry of Environment, Lands and Parks (1998) for manual stations.

Rating curves relating discharge to stage are defined for all manual stations except Cochin Creek (Appendix A). These relationships are applied to all stage measurements to produce the corrected discharge values presented in this report.

The 2007 flow monitoring schedule was once weekly from April 6 to July 20, thence bi-weekly until October 19.

3.3 WATER QUALITY

The water quality parameters selected for measurement are those which are most indicative of impacts upon aquatic habitat and water quality for human use.

At the upper Skinner Creek, Crazy Creek, and Homathko River stations (also sampled in 2006) the following point measurements were made during each site visit: turbidity using a LaMotte 2020E Turbidimeter ; and conductivity, temperature, and pH using a YSI Model 556 MPS meter. Grab samples were also taken in 1000 ml bottles for lab analysis of total suspended and dissolved solids. Replicate samples were taken every 20 samples.

At the Lincoln Creek station and at the lower Skinner Creek station - where the principal objective was discharge monitoring - turbidity, conductivity, temperature and pH were routinely measured. At Lincoln Creek occasional samples were taken through a range of turbidity values in order to provide a first approximation of the turbidity-sediment concentration relationship. No water quality data were collected at the Cochin Creek flow monitoring station.

Suspended and dissolved sediment analyses were conducted in the NCC field lab in Tatlayoko Valley. Lab procedures are outlined in Appendix B.

13

4.0 RESULTS AND DISCUSSION

4.1 CLIMATE

Snowcover data preceding snowmelt for the 2007 season are presented in Table 3. For the 19 and 17 year snow pillow data records at Upper Mosley Creek and Nostetuko stations (respectively), April 1 snow water equivalent amounts were both 1.8 times the record period average, similar to conditions elsewhere in the Coast Mountains (www.env.gov.bc.ca/rfc/). For the second year of measurement the Cochin and Hook Creek snowcourses water equivalents of the snowpack were also higher, especially at the lower elevation Cochin site.

Table 3. Homathko basin snowcover data, spring 2007.

Mean depth Mean water equivalent (mm) Station Date (cm) 2007 Record period Years of record Cochin 12-Mar 60.7 109 85 2 Hook Creek 17-Mar 98.6 133 128 2 Upper Mosley* 1-Apr - 505 280 19 Nostetuko* 1-Apr - 1060 572 17 * Online data source: http://www.env.gov.bc.ca/rfc/archive/

The Homathko basin 2007 precipitation data (consisting almost entirely of rainfall) are summarized in Table 4. Monthly rainfall at the Tatlayoko Lake RCS station were below the Tatlayoko Lake 1970-2000 normals for all months except June and September. The most hydrologically significant storm period was June 5-7 during which the Cochin Lake , Lunch Lake , and Tatlayoko Lake RCS measured 32.5 mm, 34.2 mm, and 16.5 mm respectively.

Table 4. Homathko basin April-October precipitation.

Precipitation amount (mm), 2007 Tatlayoko Lake Period Cochin Lake Lunch Lake Tatlayoko Lake 1970-2000 normal Apr 9.6 6.4 5.6 16.8 May 27.2 28.0 22.4 27.3 Jun 50.9 53.6 34.6 35.5 Jul 15.1 13.2 9.0 36.6 Aug 31.6 52.6 26.0 34.5 Sep 27.1 35.8 27.8 27.2 Oct 23.6 28.1 41.4 50.0 Period 185.1 217.7 166.8 227.9 Note: Scattered days missing from Tatlayoko Lake RCS 2007 precipitation record. Lunch Lake and Tatlayoko Lake RCS stations operated by the Meteorological Service of Canada (www.climate.weatheroffice.ec.gc.ca).

14

4.2 STREAMFLOW

4.2.1 Stage-discharge rating curves

Stage-discharge rating curves defined for Upper Skinner Creek, Lower Skinner Creek, Crazy Creek, and Lincoln Creek are shown in Appendix A. At the Lower Skinner Creek station, two rating curves were required due to the passage of a large flood wave – likely due to a sudden, upstream pond release - which altered the channel cross-section. The rating curves were defined by polynomials rather than being fit by eye to facilitate accurate discharge prediction. All rating curve relationships were strong, with regression coefficients of 0.99.

An additional rating curve (not appended) has been constructed for the interior culvert cross-section at Skinner Creek. This curve also has a regression coefficient of 0.99. It has been defined for use in the event of a change of water level at the culvert outlet.

4.2.2 Flow regime

The Homathko River hydrograph (Figure C1, Appendix C) is from preliminary data provided by the Water Survey of Canada (Campo, pers. comm.). Low-elevation snowmelt proceeded slowly through late March and April and rose gradually in May with the onset of high-elevation melt. Considering the above-average mountain snowpack, this protracted melt likely spared the valley substantial flooding. Nevertheless, the June 5-7 rainstorm event, coupled with snowmelt, produced widespread, overbank flooding. The June 7 maximum daily discharge was the third highest of the 33 year record, although all three peaks are similar at 15.8, 15.9, and 16.0 m³/s. This daily peak discharge thus has a recurrence interval of 11 years. A secondary hydrograph peak of 7.13 m³/s in mid July is due to snow and glacier meltwater discharge following a week-long period of warm summer weather4. This lower peak still exceeded the 5.54 m³/s peak daily flow in 2006. Following this event streamflow declined through late summer and fall without significant stormflow occurring.

As Table 5 indicates, the total Homathko River discharge for the April 6-October 19 period is 51,310 dam³, which is equivalent to a unit discharge (or total discharge per unit area) of 105.6 dam³/km².

Figure C2 (Appendix C) shows streamflow at the upper and lower Skinner Creek gauging stations. At both stations the principal snowmelt runoff period takes place during May. The higher May flows measured upstream are assumed due to intervening withdrawals for irrigation use and storage. In contrast, the prominent June 7 stormflow peak is higher at the downstream station. As it happened, the lower Skinner Creek stormflow was greatly supplemented by an (ungauged) overbank flood wave which passed during the preceding night; this event is presumed to be related to a sudden release from upstream storage, either from a beaver dam or reservoir. After early July Skinner Creek streamflow remained low, with slightly lower flows at the upper station.

The calculated total discharge volumes at upper and lower Skinner Creek for the measurement period are 1770 and 1599 dam³ (Table 5) respectively; by these measures the upstream flow exceeded downstream flow by 171 dam³ (139 acre-feet). The lower downstream discharge would be accounted for by irrigation withdrawals and wetland and lake storage changes. The licensed irrigation use in the basin is 620 acre-

4 Mean daily temperature of 18.5°C for July 9-15 period at Tatlayoko Lake RCS station.

15 feet (765 dam³). For upper Skinner Creek (located above the irrigation diversion points) the unit discharge for the April 6 to October 19 monitoring period is 44.3 dam³/km².

The Crazy Creek hydrograph (Figure C3) has a pattern similar to Homathko River, a 3.6 m³/s June 7 stormflow peak and a secondary, 3.4 m³/s mid July peak related to snow and glacier meltwater discharge. These peaks exceeded the 2.1 m³/s peak flow in June 2006; however, they were not overbank flows and are not considered infrequent. Long-time residents will attest to occasional, overbank flooding on the alluvial fan, hence its name. April 6 to October 19 unit discharge for the basin is 447 dam³/km²; at 10 times that of Skinner Creek, the basin’s much greater major snow and glacier meltwater supply is evident. Crazy Creek discharge for the monitoring period produced 41 per cent of the total flow measured at the Homathko River WSC station.

Cochin Creek discharge (Figure C4) rose through May to early June with high-elevation snowmelt, then declined to seasonal low flow by mid July. Total discharge for the measurement period is 873 dam³. Major factors affecting the basin water balance include withdrawals and releases from licensed storage, water use for irrigation (Table 3), and evaporation losses and storage changes in Cochin Lake. At the monitoring station the April 6-October 19, 2007 unit discharge was a low 9.75 dam³/km ².

As at other stations, the Lincoln Creek peak flow occurred in response to the early June rainstorm. Streamflow had already climbed through May to a seasonal high due to snowmelt runoff. Following the early June peak, streamflow declined sharply through the month, thence gradually through July and August to low flows in late summer and fall. Lincoln Creek unit discharge for April 6-October 19 is 220 dam³/km², a relatively high rate related to the basin’s extent of high elevation, Chilcotin Mountains terrain.

Table 5. Discharge total and suspended and dissolved solids yields.

Watercourse Period Discharge TSS yield TDS yield total (dam³) (tonnes) (tonnes) Cochin Ck 6 Apr-19 Oct 873 Crazy Ck 6 Apr-19 Oct 20,972 34 739 Homathko River 11 Mar-5 Apr 2,498 55 295 Homathko River 6 Apr-19 Oct 51,310 614 3,395 Lincoln Creek* 6 Apr-19 Oct 3,832 150 437 Lower Skinner Ck 6 Apr-19 Oct 1,599 Upper Skinner Ck 6 Apr-19 Oct 1,770 6 182 *Lincoln Creek values are first estimates only, being based on less frequent sampling and correlations with turbidity and specific conductivity.

4.3 WATER QUALITY

4.3.1 Stream temperature variation

Figure D1 (Appendix D) shows the variation of temperature in study area streams through the April- October, 2007 season. It is important to note that the graphed values are based only on periodic

16 measurements and provide only a first indication of the range of temperature. Actual values would fluctuate significantly, both diurnally and between the measured points.

The summer temperatures in Homathko River, Lincoln Creek, and Crazy Creek 5 warrant continued monitoring, since they approach or exceed the 15°C threshold for bull trout (Oliver and Fidler, 2001), the most temperature-sensitive species in the basin.

4.3.2 Stream pH variation

Figure E1 (Appendix E) shows the variation of pH (hydrogen ion activity) from May to October, 2007. pH values were highest in Skinner Creek and Lincoln Creek and lowest in Crazy Creek and Homathko River which drain the more acidic surficial materials of the Coast Mountains. All pH values are within ranges typical of natural stream systems in these environments.

4.3.3 Suspended solids transport.

Figure F1 (Appendix F) illustrates the variation of total suspended solids concentrations in Homathko River, Crazy Creek, upper Skinner Creek, and Lincoln Creek6 during 2007. For the snowmelt period, as was found in 2006, sediment concentrations in Homathko River were generally an order of magnitude higher than in Skinner and Crazy Creeks. Hart (2006) considered the higher downstream concentrations to be most likely related to land use effects, although no sediment source investigations have been carried out.

Suspended sediment concentrations in Lincoln Creek during the snowmelt period were close to, and during the early June storm period were higher than, those in Homathko River. This sediment may derive from natural sources along the steep-walled canyon between the main Lincoln Creek Ranch and the Lincoln Pass property.

Figures F2-F5 show the suspended sediment yields at the three principal monitoring stations – upper Skinner Creek, Crazy Creek, and Homathko River - plus the estimated yield for Lincoln Creek; and Table 5 lists the quantities calculated for the monitoring periods.

The upper Skinner Creek suspended sediment yield for 2007 of 6 tonnes was transported almost entirely during the snowmelt and early June stormflow periods. This yield is less than 1% of the Homathko River load and the basin total discharge is 3.4% of the Homathko basin total. In 2006, the Skinner Creek yield at 2.9 tonnes was 1.1% of the basin total.

Crazy Creek suspended sediment yield for the 2007 monitoring period totaled 34 tonnes, equivalent to 5.5% of the total Homathko River load, although Crazy Creek provided 41% of total basin discharge. As Figure F3 illustrates, most of the monitoring period suspended sediment yield occurred during the two high flow periods of early June and mid July. In 2006, Crazy Creek yield was 23 tonnes and represented 8.7% of total Homathko yield (Hart, 2006).

5 The 15.6°C July 14 temperature measurement in Crazy Creek seems anomalously high. 6 Lincoln Creek suspended solids concentrations after mid June are based on turbidity readings which remained low throughout the period.

17

In contrast to Upper Skinner Creek and Crazy Creek, the approximated Lincoln Creek suspended sediment yields represented 24.4% of the Homathko basin total, although the basin seasonal discharge was only 7.4% of the Homathko total discharge. In Lincoln Creek, 80% of the suspended sediment load was transported during the early June stormflow period and almost all the balance was during April and May snowmelt discharge (see Figure F4).

As Figure F5 shows, Homathko River suspended yield was highest during the snowmelt period and early June storm flow period. During this initial snowmelt runoff period, sediment concentrations relative to discharge were higher than occurred later in the monitoring period – a “hysteresis” effect typical of both seasonal yields and individual storm runoff events.

In the Homathko basin it’s also important to note that the early June storm runoff which accounted for significant proportions of the annual sediment yield was produced mainly by upper elevation rain and snowmelt runoff. At lower elevations, runoff was produced by the rainstorm alone which was not large at 34.2 mm at Lunch Lake and 16.5 mm at Tatlayoko Lake RCS for the June 5-7 period. Higher rainfall amounts in the valley bottom may result in significantly differing rates of suspended sediment production.

4.3.4 Turbidity

Turbidity-suspended solids relationships were defined for the two monitoring stations – Lincoln Creek and Homathko River - at which a range of values were measured (Figures G1 and G2, Appendix G). The two relationships have similar patterns: significant data scatter in the lower ranges where resolution of meters and laboratory method is most significant; and improved alignment of points in the upper ranges. The predictive value of these relationships will strengthen with additional points along the range.

4.3.5 Dissolved solids transport

Figure H1 (Appendix H) illustrates the variation of total dissolved solids concentrations in Homathko River, Crazy Creek, upper Skinner Creek, and Lincoln Creek7 during 2007. Dissolved solids concentrations were high in Skinner Creek and Lincoln Creek, intermediate in Homathko River, and lowest in Crazy Creek basin.

Table 5 lists the dissolved solids yields calculated for each station. Dissolved solids yields for the monitoring period for Crazy Creek, upper Skinner Creek, and Lincoln Creek were respectively 21.8%, 5.4%, and 12.9% of total dissolved solids yield measured in Homathko River.

4.3.7 Conductivity

Figure I1 (Appendix I) shows specific conductivity values measured at all stations except Cochin Creek. As for the dissolved solids analyses, upper Skinner Creek and Lincoln Creek have relatively high values, Homathko River has intermediate values, and Crazy Creek has the lowest. Lower Skinner Creek, for which no dissolved solids data were analyzed, has the highest conductivity values recorded. It’s probable that the apparently greater solute load at this station derives from the Skinner Meadows wetland complex.

7 Lincoln Creek dissolved solids concentrations after mid June are first estimates only based on the specific conductivity values.

18

The ratio of specific conductivity to dissolved solids concentration can be calculated for individual streams and used to predict dissolved solids yields based on conductivity probe measurements. For Crazy Creek, upper Skinner Creek, Lincoln Creek, and Homathko River the ratios in 2007 were found to be 0.79, 0.70, 0.66, and 0.62. Figure I2 shows the conductivity-dissolved solids relationship for Homathko River. As for the turbidity-suspended solids relationships, this relation is expected to improve with additional data.

19

5.0 CONCLUSIONS AND RECOMMENDATIONS

For a second year, a network of streamflow and water quality monitoring stations has been operated in the Homathko River basin upstream of Tatlayoko Lake. The monitoring program is designed to achieve two principal objectives: to identify long-term trends related to changing climate, land and water uses, and restoration measures; and to provide a basis for related scientific studies, such as investigations of water supply variation across the watershed and studies of habitat suitability for fish. In order to provide a local capability for water quality research and related studies, a laboratory has been established in the valley for analysis of suspended and dissolved solids concentrations in water.

In addition to the water monitoring components, the study this year included more detailed description of basin conditions relating to water supply and quality. A 1: 100 000 scale map of basin land and water use cover was prepared; water licences were tabulated by source; and sub-basin topography and land cover characteristics were analyzed.

This year’s principal streamflow and water quality monitoring observations are summarized as follows: • snow water equivalent preceding snowmelt at the Ministry of Environment high-elevation automated stations was 1.8 times the record period average; • precipitation during the April-October monitoring period was below average with only one rainstorm occurring which produced significant storm runoff; • total discharge for the monitoring period from Crazy Creek, upper Skinner Creek, lower Skinner Creek, Cochin Creek, and Lincoln Creek were respectively 41%, 3.4%, 3.1%, 1.7%, and 7.5% of the Homathko River outflow; • the peak daily discharge measured on Homathko River was the third highest of the 33-year record, (i.e., equivalent to a peak flow with an 11-year recurrence interval); • Homathko River and Lincoln Creek temperatures approached or exceeded the 15°C temperature threshold for bull trout, the most temperature-sensitive species in the river; • as measured in 2006, Homathko River suspended solids concentrations were generally an order of magnitude higher than those Skinner Creek and Crazy Creek; • Lincoln Creek suspended solids concentrations were generally lower than concentrations in Homathko River, but were significantly higher during the early June storm runoff event; • suspended solids yields for the monitoring period for Crazy Creek, upper Skinner Creek, and Lincoln Creek were respectively 5.5%, 1.1%, and 24.4% of total suspended solids yield measured in Homathko River; in Lincoln Creek, the high sediment yield during early June storm discharge accounted for its disproportional contribution; • dissolved solids concentrations were highest in Skinner Creek and Lincoln Creek, intermediate in Homathko River, and lowest in Crazy Creek; and • dissolved solids yields for the monitoring period for Crazy Creek, upper Skinner Creek, and Lincoln Creek were respectively 21.8%, 5.4%, and 12.9% of total dissolved solids yield measured in Homathko River.

As noted, the peak daily discharge in Homathko River in 2007, although equivalent to an 11-year recurrence interval flood event, was produced by a relatively modest rainstorm in combination with snowmelt discharge. For all streams, this event accounted for the peak suspended sediment yields. It’s expected that, due to land use effects, a higher intensity rainstorm at lower elevations might cause significantly differing rates of sediment delivery at a given discharge. As noted by Hart (2006), monitoring

20 of the sediment yield during events of differing magnitude, frequency, and source area is important to an understanding of basin hydrology. For logistical reasons this storm response information is often not collected during routine watershed monitoring projects.

With respect to NCC’s research and stewardship interests in the Homathko basin, the following recommendations for further work are provided:

• continue baseline monitoring of snow accumulation, rainfall, streamflow, and water quality at established stations; • establish a permanent flow gauging station at Lincoln Creek near the NCC’s Lincoln Creek Ranch research station (a temporary station was established for 2007, subject to final determination of the location of irrigation water withdrawals); • monitor stormflow water quality and quantity at upper Skinner Creek, Crazy Creek, Lincoln Creek, and Homathko River stations with a focus on the variation of suspended sediment yield; • install probes at the Homathko River station to continuously record temperature, pH, conductivity, and turbidity; and • assess in-stream habitat conditions for fish, including summer baseflow, stream temperature regime, stream sedimentation, bed material characteristics, and riparian vegetation condition.

21

REFERENCES

G3 Consulting Ltd. 1999. Homathko River and Mosley Creek Level 1 Fish Habitat Assessment and Riparian Assessment. Watershed Restoration Program. Prepared for the Tatlayoko Woodlot Association, Tatlayoko Lake.

Hart, S. 2006. Water Supply and Water Quality Monitoring in Homathko River Basin . Prepared for the Nature Conservancy of Canada. J. S. Hart and Associates Ltd., Tatla Lake.

Hawes, D.B. 1984. LANDSAT-based mapping of snow cover and vegetation cover. B.C. Hydro Homathko Development Generation. Prepared for B.C. Hydro by Pegasus Earth Sensing Corp.

Hudson, R. and J. Fraser. 2005. Introduction to Salt Dilution Gauging for Streamflow Measurement Part IV: The Mass Balance (or Dry Injection) Method. Streamline Watershed Management Bulletin, 9(1): 6-12. http://www.forrex.org/streamline/streamline.asp

Leith, R.M.M. and P.H. Whitfield. 1998. Evidence of climate change effects on the hydrology of streams in south-central B.C. Canadian Water Resources Journal 23(3): 219-230.

Meteorological Service of Canada. On-line climate data and normals. http://www.climate.weatheroffice.ec.gc.ca/Welcome_e.html .

Ministry of Environment. Snow Survey Bulletins and Snow Pillow Data on-line. http://www.env.gov.bc.ca/rfc/ .

Ministry of Environment and Department of Fisheries and Oceans. Fish Inventory Data Queries, http://srmapps.gov.bc.ca/apps/fidq .

Oliver, G. and L.E. Fidler. 2001. Ambient Water Quality Guidelines for Temperature: Overview. Ministry of Water, Land and Air Protection. http://www.env.gov.bc.ca/wat/wq/ BCguidelines/temptech/temperature.html.

Roddick, J.A., J.E. Muller, and A.V. Okulitch. 1973. Open File 165. Geological map of parts of British Columbia and Washington. Geological Survey of Canada. http://geoscan.ess.nrcan.gc.ca/cgi-bin/starfinder/7277/geoscan_e.txt .

Schiarizza, P. J. Riddell, R.G. Gaba, D.M. Melville, P.J. Umhoefer, M.J. Robinson, B.K. Jennings and D. Hick. 2002. Geology of the Beece Creek-Niut Mountain Area, British Columbia (NTS 92N/8,9,10; 92O/5,6,12). Geoscience Map 2002-3. BC Geological Survey, Ministry of Energy, Mines and Petroleum Resources. http://www.em.gov.bc.ca/Mining/Geolsurv/bedrock/mapsonline/dwfs/GM2002-3.htm .

Steen, O.A. and R.A. Coupé. 1997 . A field guide to forest site identification and interpretation for the Forest Region. Ministry of Forests, Williams Lake. (Mapping revised in 1998).

22

PERSONAL COMMUNICATIONS

Campo, L. Water Survey of Canada, Environment Canada, .

Evans, S. Former Lincoln Creek Ranch owner, Tatla Lake.

Shaughnessy, P. West Chilcotin Project Manager, Nature Conservancy of Canada, Tatlayoko Lake.

Mueller, S. Tatlayoko Valley resident.

23

APPENDIX A. STAGE-DISCHARGE RATING CURVES.

24

Figure A1. Upper Skinner Creek stage-discharge rating curve, 2007.

0.90

0.80

0.70

0.60 y = 2680.5x 5 - 16486x 4 + 40441x 3 - 49448x 2 + 30125x - 7312.8 R2 = 0.9952 0.50

0.40 Discharge (m³/s)

0.30

0.20

0.10

0.00 1.35 1.30 1.25 1.20 1.15 1.10 1.05 1.00 Stage (m)

25

Figure A2. Lower Skinner Creek stage-dischargeing rat curve A, 2007.

0.70

0.60

y = 3.9464x 2 - 5.5712x + 1.9836 R2 = 0.9927 0.50

0.40

0.30 Discharge(m³/s)

0.20

0.10

0.00 0.75 0.70 0.65 0.60 0.55 0.50 0.45 0.40 0.35 0.30 Stage (m)

26

Figure A3. Lower Skinner Creek stage-discharge ingrat curve B, 2007.

0.20

0.18

0.16

0.14 y = 1.7855x 2 - 2.8479x + 1.1275 R2 = 0.999 0.12

0.10

Discharge (m³/s) 0.08

0.06

0.04

0.02

0.00 0.75 0.70 0.65 0.60 0.55 0.50 0.45 Stage (m)

27

Figure A4. Crazy Creek stage-discharge rating curve, 2007.

4.00

3.50

3.00 y = 7.623x 2 - 44.260x + 64.304 R2 = 0.992 2.50

2.00 Discharge (m³/s) 1.50

1.00

0.50

0.00 2.90 2.80 2.70 2.60 2.50 2.40 2.30 2.20 2.10 Stage (m)

28

Figure A5. Lincoln Creek stage-discharge rating rve,cu 2007.

0.80

0.70

0.60 y = 3.312x 2 - 9.578x + 6.800 R2 = 0.990 0.50

0.40 Discharge (m³/s) 0.30

0.20

0.10

0.00 1.30 1.25 1.20 1.15 1.10 1.05 1.00 0.95 0.90 Stage (m)

29

APPENDIX B. LAB PROCEDURES FOR SUSPENDED AND DISSOLVED SOLIDS ANALYSIS.

30

TABLE B1. LABORATORY PROCEDURE FOR ANALYSIS OF TOTAL SUSPENDED SOLIDS (NONFILTERABLE RESIDUE)

Introduction:

In this analysis the total suspended solids (TSS) fraction is determined as the particulate mineral and organic material retained by a glass microfibre filter of 1.0 µm pore size.

Apparatus:

- 1.0 µm pore size, 907 mm diameter glass microfibre filters (Whatman GF/B) - 100 ml porcelain Buchner funnel with rubber stopper - 1000 ml glass filter flask - Nalgene 36 cc hand vacuum pump with gauge - 1000 ml graduated cylinder - aluminum sample pans - Acculab ALC 210.4 balance (0.1 mg resolution) - Fisher Scientific 3511FS gravity convection drying oven - 0-250°C oven thermometer - Sanplatec Drykeeper cabinet desiccator (with hygrometer) - reagent grade distilled water

Method:

A 1.0 µm filter paper is dried on an aluminum sample pan in the lab oven at 103-105°C for at least one hour. The filter and pan are cooled to ambient temperature in the desiccator, weighed, and the filter then placed in the Buchner funnel/filter flask filtration apparatus. Suction is applied to the filter by a hand-held vacuum pump as the filter is rinsed with 60 ml of reagent- grade distilled water in successive 20 ml applications; the filtrate is then discarded. The (approximately 1000 ml) sample volume is measured in a graduated cylinder then drawn through the filter. Upon completion of sample filtration, the filter is rinsed with a final 60 ml of distilled water in successive 20 ml applications. The filter is dried at 103-105°C on the aluminum pan for at least one hour, cooled to ambient temperature in the desiccator, and then weighed to calculate suspended solid quantity. The filtrate in the filter flask is used for total dissolved solids (filterable residue) analysis.

Accuracy:

Standard Methods reports studies by two analysts which determined a 5.2 mg/L standard deviation at 15 mg/L and 24 mg/L at 242 mg/L, as well as an analysis demonstrating a standard deviation of differences of 2.8 mg/L.

31

TABLE B2. LABORATORY PROCEDURE FOR ANALYSIS OF TOTAL DISSOLVED SOLIDS (FILTERABLE RESIDUE)

Introduction:

In this analysis the total dissolved solids (TDS) fraction is determined as the mineral and organic solute which will pass through a glass microfibre filter of 1.0 µm pore size.

Apparatus:

- 1.0 µm pore size, 907 mm diameter glass microfibre filters (Whatman GF/B) - 100 ml porcelain Buchner funnel with rubber stopper - 1000 ml glass filter flask - Nalgene 36 cc hand vacuum pump with gauge - 1000 ml graduated cylinder - Acculab ALC 210.4 balance (0.1 mg resolution) - Fisher Scientific 3511FS gravity convection drying oven - 0-250°C oven thermometer - 100 ml porcelain evaporating dishes - Scholar PC171 magnetic stirrer - Sanplatec Drykeeper cabinet desiccator (with hygrometer) - reagent grade distilled water - 100 ml glass pipette

Method:

A 100 ml porcelain evaporating dish is heated in the drying oven at 180°C for one hour, cooled to ambient temperature in a desiccator, and then weighed. A 1.0 µm filter paper is placed in the Buchner funnel/filter flask filtration apparatus; the filter is rinsed with 60 ml of reagent-grade distilled water in successive 20 ml applications; suction is applied by a hand-held vacuum pump; and the distilled water filtrate in the filter flask is then discarded. The (approximately 1000 ml) sample volume is measured in a graduated cylinder then drawn through the filter. Upon completion of sample filtration, the filter is rinsed with a final 60 ml of distilled water in successive 20 ml applications. While in the filter flask the filtrate is well stirred by magnetic stirrer while a 100 ml volume is withdrawn by pipette and transferred to the evaporating dish. The 100 ml volume is evaporated in a drying oven and the dish is then heated at 180°C for one hour. The dish is cooled to ambient temperature in a desiccator and then weighed. The dish weight increase is used to calculate the total dissolved solids concentration in the sample.

Accuracy:

Standard Methods reports one study which determined a standard deviation of differences of 21.2 mg/L for 77 samples of a known 293 mg/L concentration.

Lab procedure references:

32

British Columbia Environmental Laboratory Manual . 2005. Water and Air Monitoring and Reporting Section. Ministry of Environment, British Columbia.

Standard Methods for the Examination of Water and Wastewater . 1998. American Public Health Assoc., American Water Works Assoc., Water Environment Federation. Washington, DC. 20 th edition.

33

APPENDIX C. HYDROGRAPHS.

34

Figure C1. Upper and lower Skinner Creek hydrographs, 2007.

0.90

0.80

0.70

0.60

0.50 Lower Skinner Ck. Upper Skinner Ck. 0.40 Discharge (m³/s)

0.30

0.20

0.10

0.00

r n l l p p pr ay n n u u g u u u -J -J ug e -A -A -M -J -J -J 3 -Au -A 6 4 8-May 1 1 27 0 4 7-S 20 1 15 29 1 2 21-Sep

35

Figure C2. Crazy Creek hydrograph, 2007.

4.00

3.50

3.00

2.50

2.00 Discharge (m³/s) 1.50

1.00

0.50

0.00

r y l g p a ay ct A Jun Jun Jun -Jul -Ju Oct O M M - - - 3 7 -Aug -Sep Sep - 6-Apr 4- 8- 1 1 2 4 7 1- 5 9- 20- 1 15 29 10-Au 2 2 1

36

Figure C3. Lincoln Creek hydrograph, 2007.

0.80

0.70

0.60

0.50

0.40 Discharge (m³/s) 0.30

0.20

0.10

0.00

r t p ay un un ep -Apr -J -J -Jul -Jul S Oc -Oct 6-A 4-May 1-Jun 13 27 7-Sep 5- 20 15 29 10-Aug 24-Aug 21- 19 18-M

37

Figure C4. Cochin Creek hydrograph, 2007.

0.160

0.140

0.120

0.100

0.080 Discharge (m³/s) 0.060

0.040

0.020

0.000

r y n l p u e Jun Ju -J 7- -Aug S 9- 21-Jul 4-Aug 1-Sep 14-Ap 28-Apr 23 18 15-Sep 29- 13-Oct 12-May 26-Ma

38

APPENDIX D. STREAM TEMPERATURE VARIATION.

39

Figure D1. Temperature variation in Homathko basin streams, 2007.

18.0 Homathko R. Lincoln Ck. 16.0 Crazy Ck. Lower Skinner Ck. 14.0 Skinner Ck.

12.0

10.0

8.0 Temperature (°C)

6.0

4.0

2.0

0.0

t pr ay ay c A M -M -Jun -Jun -Aug 5- 2 0-Jun 14-Jul 28-Jul 8-Sep 6-Oct 21- 19 16 3 11-Aug 25 22-Sep 20-O

40

APPENDIX E. STREAM pH VARIATION.

41

Figure E1. pH variation in Homathko basin streams, 2007.

9.0

8.8

8.6

8.4

8.2

8.0 pH

7.8

7.6 Homathko R. 7.4 Lincoln Ck. Crazy Ck.

7.2 Lower Skinner Ck. Skinner Ck.

7.0

t un un ul ul c -May -May -J 5-J 7 19-J 2-Aug 10 24 21-J 16-Aug 30-Aug 13-Sep 27-Sep 11-O

42

APPENDIX F. SUSPENDED SOLIDS TRANSPORT.

43

Figure F1. Suspended solids concentrations of Homathko basin streams, 2007.

1000.0

Homathko R. Lincoln Ck. Crazy Ck. Skinner Ck. 100.0

10.0

1.0 Total solids(mg/L) suspendedconcentration

0.1

t pr ul p A Jul J ug e Oc Oct Mar -A -Aug Sep -S 7-Apr 5-May 2-Jun 14- 28- 8- 6- 10-Mar 24- 21- 19-May 16-Jun 30-Jun 11 25 22 20-

44

Figure F2. Upper Skinner Creek suspended solids ad,lo 2007.

0.40

0.35

0.30

0.25

0.20

0.15

0.10 Total suspended solids load (tonnes/day)

0.05

0.00

r n n n pr p ay u u u A A J J J Jul Oct - M - 3- -Aug -Sep -Oct 6- 4-May 1 9- 1 27-Jul 0-Aug 4 7 5 9- 20 18- 15- 2 1 2 21-Sep 1

45

Figure F3. Crazy Creek suspended solids load,. 2007

7.00

6.00

5.00

4.00

3.00

2.00 Total suspended solids load (tonnes/day)

1.00

0.00

r y g g p a un un ul u u -J -A -J -J -A -A 6 4-May 1 13-Jul 27 7-Sep 5-Oct 9-Oct 20-Apr 18-M 15-Jun 29 10 24 21-Sep 1

46

Figure F4. Lincoln Creek suspended solids load,07. 20

12.00

10.00

8.00

6.00

4.00 Total suspended solids load(tonnes/day)

2.00

0.00

n g g p t un ul u ep May May Jun J Oc 6-Apr 4- 1-Ju 13-Jul 27-J 7-S 5- 20-Apr 18- 15- 29- 10-Au 24-A 21-Se 19-Oct

47

Figure F5. Homathko River suspended solids load,007. 2

30.00

25.00

20.00

15.00

10.00 Total suspended solids load(tonnes/day)

5.00

0.00

n g g p t pr un ul ul u u ep e May J A Oc 7-Apr 5-May 2-Ju 14-J 28-J 8-S 6- 10-Mar 24-Mar 21-A 19- 16-Jun 30- 11- 25-A 22-S 20-Oct

48

APPENDIX G. TURBIDITY-SUSPENDED SOLIDS RELATIONSHIPS.

49

Figure G1. Lincoln Creek turbidity-suspended solids relationship, 2007.

200.0

180.0

160.0

140.0

120.0

100.0

80.0 y = 2.304x R2 = 0.969 60.0

Total concentrationsolids suspended (mg/L) 40.0

20.0

0.0 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 Turbidity (NTU)

50

Figure G2. Homathko River turbidity-suspended solids relationship, 2007.

35.0

30.0

25.0

20.0

15.0 y = 1.873x R2 = 0.731 10.0 Total concentrationsolids suspended (mg/L)

5.0

0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 Turbidity (NTU)

51

APPENDIX H. DISSOLVED SOLIDS TRANSPORT.

52

Figure H1. Dissolved solids concentrations of Homathko basin streams, 2007.

160

140

120

100

80

60

40 Total dissolvedsolids concentration (mg/L) Homathko R.

20 Lincoln Ck. Crazy Ck. Skinner Ck. 0

r r y g p un un ul u ep 8-J -S -Oct 7-Apr 1-A 5-May 2-Jun 14-Jul 2 5-A 8 6 10-Mar 24-Ma 2 19-Ma 16-J 30-J 11-Aug 2 22-Sep 20-Oct

53

Figure H2. Skinner Creek dissolved solids load, 07.20

7.0

6.0

5.0

4.0

3.0

2.0 Total dissolvedsolids load (tonnes/day)

1.0

0.0

ay un un un ug ug ep ep J J J May -M A S 6-Apr 4- 1- 13-Jul 27-Jul 7-S 5-Oct 20-Apr 18 15- 29- 10- 24-A 21- 19-Oct

54

Figure H3. Crazy Creek dissolved solids load, 2007.

16.0

14.0

12.0

10.0

8.0

6.0

4.0 Total dissolvedsolids load (tonnes/day)

2.0

0.0

y t pr ay un un un ug ep ep ct J J O 7-Jul A -Oc 6-Apr 4-Ma 1-J 9- 13-Jul 2 7-S 5 20-A 18-M 15- 2 10- 24-Aug 21-S 19-

55

Figure H4. Lincoln Creek dissolved solids load, 07.20

8.0

7.0

6.0

5.0

4.0

3.0

2.0 Total dissolvedsolids load (tonnes/day)

1.0

0.0

ay un un un ug ug ep ep J J J May -M A S 6-Apr 4- 1- 13-Jul 27-Jul 7-S 5-Oct 20-Apr 18 15- 29- 10- 24-A 21- 19-Oct

56

Figure H5. Homathko River dissolved solids load,007. 2

90.0

80.0

70.0

60.0

50.0

40.0

30.0

Totaldissolved solids load(tonnes/day) 20.0

10.0

0.0

p ar ar ay un un ul ul ug ug ep J J J J -M -M -Apr 1-Jul -A 8-Apr 6-May 3- 15- 29- 6-A 9-Se 7-Oct 11 25 22 20-M 17- 12 2 23-S 21-Oct

57

APPENDIX I. HOMATHKO RIVER CONDUCTIVITY -DISSOLVED SOLIDS RELATIONSHIP.

58

Figure I1. Homathko River conductivity-dissolvedolids s relationship, 2007.

120.0

100.0

80.0

y = 0.447x + 16.266 R2 = 0.824

60.0

40.0 Total dissolvedsolids concentration (mg/L)

20.0

0.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 Specific conductivity (µS/cm)

59

APPENDIX J. DISCHARGE AND WATER QUALITY DATA SUMMARY.

60

Table J1. Skinner Creek discharge and water quality data.

Discharge TSS TDS Turbidity Temp. Conductivity Spec. cond. TSS load TDS load Date Time pH (m³/s) (mg/L) (mg/L) (NTU) (°C) (µS/cm) (µS/cm) (t/day) (t/day) 6-Apr 9:40 0.028 2.0 99.5 0.00 0.005 0.236 14-Apr 10:50 0.067 2.0 111.6 0.00 0.012 0.648 21-Apr 10:55 0.047 2.0 111.8 0.00 0.00 0.008 0.455 29-Apr 11:30 0.115 8.4 102.5 0.55 0.00 0.084 1.017 6-May 13:20 0.084 7.7 139.0 0.00 3.30 0.056 1.011 11-May 10:30 0.568 0.2 95.0 1.09 1.11 55 102 7.97 0.011 4.662 17-May 11:10 0.779 3.6 98.3 0.81 5.15 57 92 8.12 0.239 6.617 23-May 12:45 0.373 7.4 104.0 0.26 6.72 70 108 8.03 0.237 3.349 2-Jun 12:20 0.164 0.0 70.5 0.43 9.51 91 129 8.15 0.000 1.000 6-Jun 16:30 0.644 6.4 115.4 1.73 8.54 83 121 8.12 0.358 6.424 7-Jun 6:20 0.717 1.6 99.2 1.49 7.85 64 95 8.01 0.096 6.143 7-Jun 17:45 0.745 0.7 94.0 0.98 0.044 6.055 10-Jun 8:00 0.183 0.0 111.1 0.77 7.18 81 123 8.07 0.000 1.761 15-Jun 9:55 0.068 0.0 110.5 0.90 6.92 97 148 8.17 0.000 0.648 22-Jun 10:10 0.130 0.0 112.1 0.90 7.16 93 141 8.36 0.000 1.258 29-Jun 11:30 0.033 0.5 117.4 0.98 8.10 117 173 8.21 0.001 0.338 7-Jul 8:45 0.015 0.0 127.0 0.20 6.82 126 192 8.39 0.000 0.170 13-Jul 8:15 0.012 0.0 95.4 0.00 10.28 146 203 8.13 0.000 0.098 20-Jul 10:40 0.012 0.0 129.5 0.00 8.81 141 204 8.28 0.000 0.133 4-Aug 10:15 0.008 0.0 132.3 0.00 8.56 141 206 8.28 0.000 0.090 16-Aug 20:15 0.001 3.5 80.1 0.00 9.47 149 212 8.43 0.000 0.004 31-Aug 13:50 0.007 3.0 107.2 0.08 9.09 148 213 8.43 0.002 0.068 14-Sep 10:30 0.006 0.0 106.3 0.00 6.17 140 219 8.52 0.000 0.056 20-Sep 5:10 0.014 0.1 126.5 0.14 5.51 128 204 8.49 0.000 0.152 2-Oct 9:10 0.013 27.0 109.0 1.00 3.78 130 218 8.54 0.030 0.121 19-Oct 14:10 0.013 10.1 119.4 0.40 2.90 124 214 8.39 0.011 0.133

61

Table J2. Lower Skinner Creek discharge and water quality data, 2007.

Discharge Turbidity Conductivity Spec. cond. Temp. Date Time pH (m³/s) (NTU) (µS/cm) (µS/cm) (°C) 6-Apr 15:00 0.0563 NM 14-Apr 11:45 0.0330 0.00 21-Apr 15:00 0.0924 0.70 4.0 29-Apr 14:30 0.0968 0.15 6.0 6-May 16:00 0.0659 0.41 8.0 11-May 14:00 0.3558 3.24 217 306 9.8 8.4 17-May 15:10 0.5898 1.66 206 275 11.8 8.5 23-May 17:45 0.1566 0.32 196 262 11.8 8.5 2-Jun 15:15 0.0196 0.00 284 371 12.7 8.5 6-Jun 20:25 0.0891 2.30 226 321 9.5 8.5 7-Jun 21:55 0.8032 4.50 15-Jun 10:45 0.1282 0.72 219 300 10.9 8.6 22-Jun 10:50 0.1778 0.32 213 286 11.6 8.6 29-Jun 15:30 0.0575 0.48 242 316 12.7 8.6 7-Jul 9:15 0.0198 0.29 247 367 7.9 8.5 13-Jul 9:00 0.0541 0.00 262 343 12.6 8.6 20-Jul 11:35 0.0171 0.00 272 376 10.5 8.4 4-Aug 10:45 0.0096 0.00 271 389 9.1 8.4 17-Aug 8:00 0.0157 0.00 258 375 8.8 8.5 2-Sep 18:00 0.0085 0.63 274 397 8.8 8.6 14-Sep 11:10 0.0085 0.00 250 402 5.8 8.8 2-Oct 10:00 0.0157 0.00 250 402 5.1 8.6 19-Oct 15:00 0.0153 0.23 250 402 4.6 8.4

62

Table J3. Crazy Creek discharge and water quality data, 2007.

TDS Date Time Discharge TSS TDS Turbidity Conductivity Spec. cond. Temp. pH TSS load load (m³/s) (mg/L) (mg/L) (NTU) (µS/cm) (µS/cm) (°C) (t/day) (t/day) 6-Apr 13:30 0.139 3.1 43 0.0 0.038 0.521 14-Apr 12:30 0.173 0.0 50 0.5 0.000 0.754 21-Apr 14:15 0.192 4.8 36 1.2 1.0 0.080 0.599 29-Apr 15:40 0.166 0.6 47 0.0 2.0 0.009 0.680 6-May 14:15 0.194 0.1 45 0.0 3.5 0.002 0.754 11-May 13:30 0.439 0.9 46 0.0 35 61 3.1 7.8 0.034 1.740 17-May 14:45 0.783 0.0 54 0.3 31 53 3.6 7.8 0.000 3.686 23-May 14:05 0.567 1.0 38 0.2 34 55 4.7 7.8 0.047 1.877 2-Jun 12:55 1.988 1.4 35 1.7 29 45 6.1 7.9 0.238 6.062 6-Jun 17:10 3.310 22.6 19 9.1 25 39 6.1 7.9 6.463 5.301 7-Jun 10:10 3.616 8.6 26 4.7 27 42 5.4 7.8 2.690 8.123 8-Jun 14:05 3.513 6.0 42 29 43 6.4 7.9 1.821 12.707 10-Jun 8:45 2.924 1.0 38 2.2 27 43 5.2 7.9 0.244 9.485 15-Jun 11:20 1.765 0.0 41 1.6 30 45 7.1 8.5 0.000 6.219 22-Jun 11:30 1.913 0.0 34 2.0 30 46 7.3 8.2 0.000 5.638 29-Jun 12:05 1.988 0.7 26 1.2 34 48 10.1 7.8 0.112 4.392 7-Jul 9:55 2.391 0.8 35 1.3 33 47 9.4 8.3 0.165 7.267 12-Jul 15:45 2.924 1.3 57 2.1 38 47 15.6 8.3 0.319 14.315 13-Jul 9:40 3.411 1.5 31 0.442 9.278 20-Jul 12:15 2.391 0.3 32 0.7 34 45 11.6 7.6 0.072 6.630 4-Aug 11:15 1.694 0.1 35 0.7 33 46 10.7 7.8 0.017 5.162 17-Aug 8:30 1.178 0.0 35 1.8 34 47 10.9 8.1 0.000 3.585 2-Sep 17:30 1.092 0.0 34 0.9 33 46 9.7 8.1 0.000 3.228 14-Sep 11:40 0.783 0.0 42 0.0 34 49 8.7 8.4 0.000 2.828 20-Sep 6:00 0.855 0.1 41 1.2 32 49 7.2 8.2 0.009 3.015 2-Oct 10:10 0.628 2.6 41 0.3 32 52 4.7 8.2 0.139 2.198 19-Oct 15:20 0.439 0.0 42 0.3 32 55 2.9 0.000 1.582

63

Table J4. Lincoln Creek discharge and water quality data, 2007.

Discharge TSS TDS Turbidity Conductivity Spec. cond. Temp. TSS load TDS load Date Time pH (m³/s) (mg/L) (mg/L) (NTU) (µS/cm) (µS/cm) (°C) (t/day) (t/day) 6-Apr 11:40 0.1541 28.5 111 0.20 0.379 1.478 14-Apr 13:25 0.2480 28.6 128 3.42 0.612 2.752 21-Apr 12:50 0.2647 3.6 115 1.55 3.0 0.081 2.630 29-Apr 14:15 0.3986 13.8 115 6.02 5.0 0.476 3.960 6-May 15:15 0.3202 15.7 108 3.84 8.0 0.434 2.985 11-May 12:30 0.5517 32.4 111 9.13 118 174 8.3 8.18 1.543 5.277 17-May 13:50 0.5339 15.2 121 2.74 128 179 10.2 8.27 0.701 5.573 23-May 16:00 0.5339 5.7 121 2.47 136 184 11.5 8.34 0.261 5.602 2-Jun 14:10 0.7064 143.2 120 59.80 147 182 15.1 8.32 8.740 7.331 6-Jun 18:15 0.7064 171.9 112 75.00 135 173 13.4 8.31 10.490 6.828 7-Jun 11:30 0.7064 121.4 119 56.20 130 170 12.7 8.33 7.408 7.264 10-Jun 9:00 21.0 115 11.10 124 166 12.0 8.31 15-Jun 12:30 0.3508 1.4 105 3.64 127 167 12.5 8.34 0.043 3.181 22-Jun 12:30 0.3559 4.1 106 1.78 123 160 12.9 8.35 0.126 3.247 29-Jun 13:20 0.2490 3.9 105 1.70 125 159 14.0 8.33 0.084 2.257 7-Jul 11:00 0.2490 1.7 100 0.74 118 152 13.5 8.32 0.037 2.158 13-Jul 10:30 0.1995 1.4 102 0.60 130 154 17.0 8.32 0.024 1.752 20-Jul 13:20 0.1954 1.2 100 0.52 124 152 15.6 8.23 0.020 1.694 4-Aug 12:15 0.0788 0.0 110 0.00 127 166 12.9 8.32 0.000 0.745 17-Aug 9:00 0.0427 3.7 117 1.62 133 178 11.6 8.36 0.014 0.434 2-Sep 15:50 0.0156 1.1 123 0.50 134 186 10.5 8.42 0.002 0.165 14-Sep 12:45 0.0023 2.1 128 0.90 137 194 9.6 8.40 0.000 0.025 2-Oct 11:15 0.0200 6.0 126 2.60 126 191 7.0 8.43 0.010 0.218 19-Oct 16:05 0.0177 0.8 124 0.36 117 188 5.4 8.50 0.001 0.190 Note: All TSS and TDS data following 22 June are based turbidity and specific conductivity data respectively.

64

Table J5. Homathko River discharge and water quality data, 2007.

Discharge TSS TDS Turbidity Conductivity Spec. cond. Temp. TSS load TDS load Date Time pH (m³/s) (mg/L) (mg/L) (NTU) (µS/cm) (µS/cm) (°C) (t/day) (t/day) 11-Mar 14:58 1.11 28.4 57 2.726 5.437 28-Mar 13:35 1.24 18.4 132 1.967 14.167 6-Apr 12:20 0.88 22.2 127 1.685 9.667 14-Apr 14:00 1.41 18.6 122 2.264 14.868 21-Apr 12:10 1.22 25.5 109 4.0 2.692 11.528 29-Apr 14:45 1.30 21.5 113 6.0 2.414 12.727 6-May 14:45 0.96 21.0 96 6.5 1.742 7.965 11-May 11:55 2.41 26.0 106 123 189 6.8 8.1 5.408 21.987 17-May 13:10 3.89 22.5 85 9.8 102 154 7.3 8.0 7.548 28.582 23-May 15:30 2.79 17.6 73 3.0 108 152 9.8 8.1 4.242 17.538 2-Jun 13:45 7.41 29.3 63 14.4 73 101 10.5 7.9 18.781 40.465 6-Jun 18:00 14.10 23.5 55 11.6 60 86 8.8 7.7 28.639 66.579 7-Jun 12:15 15.80 21.6 56 12.0 61 89 8.4 7.6 29.474 76.364 10-Jun 9:25 10.60 4.1 76 5.4 67 99 8.3 7.7 3.790 69.509 15-Jun 11:55 4.57 6.9 63 5.0 76 109 9.5 7.9 2.739 24.912 22-Jun 12:00 4.83 7.5 65 5.4 68 98 8.9 7.9 3.110 27.155 29-Jun 12:45 3.65 7.6 64 4.3 70 95 11.4 7.9 2.382 20.129 7-Jul 10:20 4.15 5.7 49 3.4 56 78 10.3 7.9 2.060 17.547 13-Jul 10:00 5.81 9.3 48 6.5 59 75 14.0 7.8 4.643 23.844 20-Jul 12:50 5.06 4.6 51 3.4 56 74 12.0 7.7 2.024 22.078 4-Aug 11:45 2.69 3.3 49 2.7 56 77 11.1 7.9 0.766 11.420 17-Aug 8:45 1.76 7.3 46 5.4 62 85 10.7 7.9 1.102 6.919 2-Sep 15:10 1.84 5.8 51 1.7 58 82 9.5 8.2 0.922 8.184 14-Sep 12:10 1.31 0.0 53 2.9 60 88 8.2 8.1 0.000 5.942 20-Sep 6:30 1.53 0.6 65 1.3 65 97 7.6 8.2 0.083 8.526 2-Oct 12:30 1.23 3.5 62 2.8 66 104 6.2 8.1 0.371 6.609 19-Oct 15:45 1.20 9.6 61 0.7 67 112 4.1 8.2 0.999 6.316

65

Table J6. Cochin Creek discharge data, 2007.

Discharge Date Time (m³/s) 14-Apr 15:30 0.0578 21-Apr 15:30 0.0596 29-Apr 13:15 0.0541 11-May 14:50 0.1009 23-May 18:15 0.1499 2-Jun 15:50 0.1474 15-Jun 14:00 0.1416 29-Jun 16:20 0.0699 13-Jul 11:45 0.0108 20-Jul 15:20 0.0137 4-Aug 15:00 0.0124 16-Aug 20:45 0.0026 2-Sep 18:30 0.0094 14-Sep 14:10 0.0086 3-Oct 16:15 0.0148 19-Oct 13:30 0.0120

66

Respectfully submitted by Sandy Hart, P. Geo., J. S. Hart and Associates Ltd.

Signature Date