Nicola River Watershed – Water Use Management Plan Instream Flow Needs for Fish

prepared by: Todd Hatfield Solander Ecological Research Victoria BC

for: Allan Kenney Pacific Salmon Foundation Vancouver BC

October 30, 2006 1. BACKGROUND Instream flows in the Nicola River and its major tributaries have been consistently identified as a substantial environmental concern. The watershed has numerous important fish stocks, and flows are often well below optimal for rearing and spawning, particularly during the summer and fall period. Water is extracted from the mainstem and its tributaries for agricultural, industrial, and domestic use and during low flow periods there appears to be a clear trade-off between these uses and instream environmental benefits. A public decision-making process has been initiated to develop a Water Use Management Plan (WUMP), with an aim to balance water use and instream flow needs. The purpose of this report is to summarize some of the existing information on instream flows and to provide recommendations for further work with respect to understanding and resolving fish-flow issues.

2. STREAMFLOW DATA Water Survey of Canada (WSC) has several gauges in the watershed, with partial records dating back more than 90 years. In all cases, continuous year-round records are less than 50 years old, and in many cases considerably less. The primary gauges in the watershed, as available on the WSC Hydat database, are listed in Table 1.

Table 1. Water Survey of Canada gauging stations in the Nicola River watershed. Note: the last year of available data from Hydat is 2003. Station Name Station ID Period of record Complete years Nicola River near Spences Bridge 08LG006 1911 - 2003 43 years Nicola River near Merritt 08LG007 1911 - 2003 47 years Nicola River at outlet of Nicola Lake 08LG065 1983 - 2003 20 years Nicola River above Nicola Lake 08LG049 1915 - 2003 32 years Coldwater River at Merritt 08LG010 1913 - 1995 33 years Coldwater River at Brookmere 08LG048 1965 - 2003 36 years Spius Creek near Canford 08LG008 1911 - 2003 33 years Guichon Creek near Lower Nicola 08LG004 1911 - 1984 20 years Guichon Creek at Mouth 08LG067 1984 - 2003 19 years Guichon Creek at outlet of Mamit Lake 08LG041 1936 - 2003 18 years Guichon Creek above Tunkwa Lake Diversion 08LG056 1967 - 2003 33 years Pennask Creek near Quilchena 08LG016 1920 - 2003 33 years Beak Creek at Mouth 08LG064 1982 - 2001 18 years Spahomin Creek near Douglas Lake 08LG018 1920 - 1967 0 years Spahomin Creek near the mouth 08LG060 1972 - 1996 23 years

3. WATER USES A description and analysis of water uses in the Nicola watershed is currently underway as part of various studies being undertaken to support the Nicola WUMP. I undertook a brief analysis of water licences on Nicola River mainstem and its major tributaries based on queries of the Provincial water licence database available over the internet at: http://www.elp.gov.bc.ca:8000/pls/wtrwhse/water_licences.input. It should be noted that

1 many details of water licences are not available through this web query process. For example, one cannot conduct queries based on whole basins, sub-basins, or geographic points, nor does it return results based on time of year restrictions on licences. Results from queries do not include licences from tributary systems, necessitating a focus on mainstem systems. All data were converted to the same unit (m3 year-1) before plotting (Figure 1). The intent of this analysis was to examine the cumulative volume in different watersheds and the trends through time in allocating this resource for out-of-stream uses.

Two things are clear from this cursory analysis: the licensed volume of water use in the Nicola watershed is large, and out-of-stream water uses continue to be allocated. This analysis is cursory, since it ignores many factors and other sites in the watershed, such as those on smaller tributaries, but at the same time this also makes the analysis quite conservative. The analysis also ignores groundwater resources. We expect that more robust conclusions will be possible from the analysis of water licences currently underway for the WUMP.

4. NATURAL FLOWS It is customary to begin analyses of instream flow needs by examining the natural availability of water and the temporal patterns in natural streamflows. These patterns provide a baseline that allows determination of impacts associated with past, present and future water uses. Virtually all overview assessment methods utilize natural streamflow data as the benchmark for acceptable limits to water use. (These methods contrast with empirical incremental methods, which analyse existing conditions with data-intensive techniques that are often time-consuming and expensive.)

Licensed water use in the Nicola watershed dates back to the late 1800s, many years before streamflow gauges were installed in the area. Some of these early licences were for considerable volumes, in association with agriculture. Water licences have continued to be granted in various parts of the watershed (Figure 1). Most water uses are not gauged, so obtaining an accurate measure of water use is not a simple task, and requires several assumptions to be made. “Naturalizing” the gauged data is therefore a difficult task, and one that should be performed by those with detailed knowledge of the existing water licences, regional patterns of water use, and regional differences in hydrology.

Spahomin and Pennask Creeks have few licensed water uses and gauged data may be considered approximately natural. All other gauged systems require application of some form of correction to naturalize the recorded flows. The task of naturalizing streamflow data has been completed for very few parts of the Nicola watershed. Ministry of Environment (MoE) hydrologists are undertaking to develop naturalized flow data for several points in the watershed. At present, draft naturalized data are available for only three locations: Spius Creek, Coldwater River at Brookmere, and Coldwater River at Merritt. It should be stressed that even these data are considered preliminary and in draft form only. Additional work is anticipated that will naturalize records for other locations in the watershed, but the delivery date for these data is unknown.

2 Nicola River mainstem Coldwater River mainstem

40 6

20 3

10 Annual Water Allocation Allocation Water Annual Annual Water Allocation 1 (millions ofcubic meters year)per (millions of cubic meters per year) (millions of cubic meters per year)

0 0

1880 1900 1920 1940 1960 1980 2000 1900 1920 1940 1960 1980 2000 Year Year Quilchena Creek mainstem Spius Creek mainstem

0.5 12

0.4 10

8 0.3

6 0.2

4 Annual Water Allocation Annual Water Allocation Allocation Water Annual 0.1 2 (millions of cubic meters per year) (millions ofcubic meters year)per

0 0.0

1880 1900 1920 1940 1960 1980 2000 1940 1960 1980 2000 Year Year Guichon Creek mainstem

Annual Water Allocation Allocation Water Annual 2 (millions ofcubic meters year)per

1880 1900 1920 1940 1960 1980 2000 Year

Figure 1. Cumulative volume of water allocated from five mainstem streams in the Nicola watershed. These amounts do not include licensed out-of-stream uses on tributaries. Data from water licence web query at: http://www.elp.gov.bc.ca:8000/pls/wtrwhse/water_licences.input.

5. GAUGED FLOWS For each of the available datasets (see Table 1) we produced a variety of graphs and tables, to assess the patterns of gauged flows. These are provided in appendix A. Tables include summary statistics on both a monthly and annual time span. Graphs include summary graphs indicating general streamflow patterns, exceedence plots, and time series of summary data. The

3 methods used to produce each graph and the intent of the analyses are described in the text of Appendix A.

The results of graphical analysis of summary streamflow data indicate that all gauged streams in the watershed are snowmelt-driven systems, with peak flows in late spring and early summer. In general, there are two calendar months with high flows, two months with intermediate flows, and all remaining months have low to very low flows. 70 to 80% of days in the year have flows that are less than the mean annual discharge. September is typically the month of lowest flow during the season of active growth for fish. Very low flows also occur in some winter months.

There is considerable geographic variation in the watershed with respect to surface runoff (Table 2). Runoff is a measure of how much surface stream flow is produced by precipitation during the year. In general, sub-basins with streams flowing from south to north have considerably greater runoff than other portions of the Nicola watershed. This presumably reflects general precipitation patterns, especially snowpack. Runoff varies throughout the watershed by more than order of magnitude. Such variation in runoff makes it difficult to extrapolate from one portion of the watershed to another. It should be stressed that these values are calculated from gauged streamflows and do not correct for water use within the watershed. As a result, these values are underestimates of true runoff and the degree of underestimation likely varies among sub-basins. They are nevertheless likely acceptable in reflecting trends in geographic differences in runoff.

Patterns of streamflow at many of the gauge locations show clear indications of climate change over the period of record. This is most apparent as a shift in the timing of freshet to earlier in the year, and in many instances a smaller freshet. This pattern is consistent with a loss of low- to mid-elevation snowpack as more precipitation falls as rain, and an earlier runoff from snowmelt. In some systems, notably the Coldwater River, there is a marked increase in duration of the low flow period during late summer and fall. I interpret these changes as climate change induced, because water use is not likely to be sufficient to affect timing and magnitude of the freshet. In most systems, there was no trend in water levels during the low flow period (i.e., low flows did not become lower through time). I had expected a trend of decreasing low flows, due to water use, climate change or both. For example, one would expect water use to be most noticeable during the low flow period because this is also the period of greatest water extraction. There may be one or more reasons for a lack of obvious trends in low flows: lack of sensitivity of gauging sites for detecting trends in low flows, water use and climate change effects are “noisy” signals that are difficult to detect against a high variance background, improper selection of streamflow metric for trend analysis, or no real trend in water use and climate change impacts. This issue deserves additional analytic effort, and would be informed by the water use study underway for the WUMP.

4 Table 2. Discharge summaries from Water Survey of Canada gauging stations in the Nicola River watershed. Note: the last year of available data from Hydat is 2003. Mean discharge and runoff are calculated on gauged data and do not correct for water uses. Mean Drainage Station annual Runoff Station Name Area -1 ID 2 discharge (cm year ) (km ) (m3 sec-1) Nicola River near Spences Bridge 08LG006 7280 26.7 11.6 Nicola River near Merritt 08LG007 4350 14 10.2 Nicola River at outlet of Nicola Lake 08LG065 2990 5.5 5.5 Nicola River above Nicola Lake 08LG049 1500 4.2 8.8 Coldwater River at Merritt 08LG010 914 8.2 28.4 Coldwater River at Brookmere 08LG048 316 6.9 68.7 Spius Creek near Canford 08LG008 780 10.2 41.4 Guichon Creek near Lower Nicola 08LG004 1230 1.04 2.7 Guichon Creek at Mouth 08LG067 1230 0.74 1.9 Guichon Creek at outlet of Mamit Lake 08LG041 842 0.8 2.9 Guichon Creek above Tunkwa Lake Diversion 08LG056 78.2 0.13 5.1 Pennask Creek near Quilchena 08LG016 87 0.74 26.9 Beak Creek at Mouth 08LG064 85 0.47 17.6 Spahomin Creek near Douglas Lake 08LG018 233 na na Spahomin Creek near the mouth 08LG060 241 0.678 8.7

6. OVERVIEW METHODS FOR INSTREAM FLOW RECOMMENDATIONS

6.1 Previous analyses of fish-flow issues Kosakoski and Hamilton (1982) conducted detailed analyses of fish-flow issues in the Nicola watershed, using repeated measurements at transects at multiple points on the Nicola and Coldwater Rivers. Their analyses led to flow recommendations for several points on the Nicola River, the Coldwater River and several tributaries to the Nicola. Table 3 lists the recommendations based on transect analysis. The report lists flow recommendations of 20% mad on several other tributaries, but since the %mad recommendations are not based on empirical work, they are not discussed here.

Table 3. Flow recommendations made by Kosakoski and Hamilton (1982) for sections of the Nicola and Coldwater Rivers. Fisheries Resource Maintenance Flow (cfs) Stream Point of measurement Aug to Nov Dec to Apr Nicola River (Thompson R to Spius Cr) 200 200 8LG006 Nicola River (Spius Cr to Coldwater R) 110 110 8LG007 Nicola River (Coldwater R to Nicola Lake) 60 40 8LG065 Coldwater River at Merritt 50 50 8LG010

Since the Kosakoski and Hamilton results are now more than 20 years old, the question arises whether the results have any validity today. As with all incremental methods this concern is real since the results are based on channel conditions in a previous time, and changes in channel morphology have likely occurred over the intervening period. Indeed, one of the myriad criticisms levelled at instream flow recommendations based on IFIM and similar approaches is that results reflect the present condition of a stream (Bovee et al. 1998), yet morphology, sediment conditions, and water quality may change when flow becomes regulated, which in

5 turn affects the quantity and quality of available habitat (Church 1995; Bovee et al. 1998; Trush et al. 2000).

There are two primary reasons to think that Kosakoski and Hamilton’s recommendations would be similar if the study were to be repeated today. The first is that water use has increased since their study, but not markedly, and magnitude of flood flows, which are the flows primarily responsible for channel morphology, have changed little over the intervening period. Second, there is evidence that channel morphology is in a form of dynamic equilibrium. That is, channel changes occur through time at any one location, but river-wide patterns in habitat availability remain fairly constant, provided influences like climate, land use, water use, etc., remain similar. Work undertaken by BC Hydro on the Alouette River indicated that instream flow models based on older transect data remained accurate for fisheries-flow planning purposes over at least a 10-year period (Bruce 2005). Transect data at fixed sites changed through time, but when taken as a whole, a group of transects gave similar results through time. It is possible that transects taken at different points in the river, analysis based on additional transects, or updated HSI curves may alter the resulting recommendations, but it seems likely that the original analysis is reasonably robust.

We analysed the Kosakoski and Hamilton results in terms of the availability of flows to meet the recommended minimum flows. In the following tables and figures, we show the patterns of streamflow relative to the recommendations, and tally the number of days in different periods in which the measured flow is below the recommended minimum.

200

150

100 Flow (cms)

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

Figure 2. Nicola River flows at Spences Bridge (08LG006). The red line indicates 200 cfs (5.66 m3 sec- 1), the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river.

6 Table 4. Number of days in which Nicola River flow at Spences Bridge was below 200 cfs in reach N1 for the period August through April. 200 cfs is the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river. Counts are based on gauged flows at 08LG006. Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum 1911 31 28 31 30 0 0 19 19 31 189 1976 0 0 0 0 0 0 0 0 0 0 1912 31 29 31 4 0 24 3 0 21 143 1977 13 0 0 0 27 30 24 5 11 110 1913 31 28 31 30 2 2 6 0 25 155 1978 19 24 6 0 23 2 8 3 24 109 1914 31 28 31 19 27 28 29 27 31 251 1979 14 0 0 0 31 29 27 30 5 136 1915 31 28 31 0 0 6 14 26 31 167 1980 18 17 0 0 12 0 3 0 0 50 1916 31 29 31 0 0 0 7 30 31 159 1981 0 0 0 0 3 11 0 0 1 15 1917 31 28 31 0 5 30 29 3 27 184 1982 7 1 0 0 0 0 0 3 3 14 1918 28 25 15 0 6 30 26 25 28 183 1983 0 0 0 0 0 0 0 0 4 4 1919 31 28 28 17 21 29 31 30 31 246 1984 0 0 0 0 13 23 8 13 31 88 1920 31 29 23 17 25 21 31 30 31 238 1985 31 21 14 0 31 30 15 20 31 193 1957 31 28 31 30 3 27 31 14 1 196 1986 17 16 0 0 0 0 5 3 7 48 1958 0 0 0 0 31 25 10 0 0 66 1987 4 0 0 0 31 30 31 30 31 157 1959 0 0 0 0 0 4 0 0 0 4 1988 31 29 30 2 28 24 10 0 9 163 1960 31 29 14 0 16 28 13 7 23 161 1989 13 7 0 0 0 0 0 0 0 20 1961 24 0 0 0 20 21 0 7 29 101 1990 3 16 0 0 0 10 3 0 2 34 196290000026831741991400000100 5 1963 31 0 0 0 0 24 18 0 0 73 1992 2 0 0 0 21 24 16 3 15 81 1964000000002 219932817400005054 1965000002970743199402002630262716127 1966 7 28 6 0 0 24 16 0 2 83 1995 27 0 0 0 0 27 0 1 0 55 1967 0 0 0 0 13 30 14 0 1 58 1996 0 0 0 0 5 28 10 0 3 46 1968000000005 51997000000000 0 1969 9 1 0 0 14 12 0 0 0 36 1998 0 0 0 0 27 30 31 14 13 115 1970 31 28 5 0 31 30 31 30 31 217 1999 0 0 0 0 0 0 0 0 0 0 1971 12 0 0 0 4 21 3 0 31 71 2000 0 0 0 0 0 2 1 0 13 16 1972 31 11 0 0 0 8 5 6 19 80 2001 10 26 6 0 10 30 24 0 5 111 1973 17 4 5 0 31 30 19 15 14 135 2002 4 2 3 0 4 30 31 13 20 107 1974 14 0 0 0 0 19 31 22 21 107 2003 21 4 10 0 31 30 16 2 10 124 1975 29 28 11 0 0 22 15 0 0 105

100

40 Flow (cms)

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

Figure 3. Nicola River flows at Merritt (08LG007). The red line indicates 110 cfs (3.11 m3 sec-1), the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river.

Table 5. Number of days in which Nicola River flow at Merritt (08LG007) was below 110 cfs (3.11 m3 sec- 1) in reach N2 for the period Jan through Apr and August through Dec. 110 cfs is the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river. Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum 1911 31 28 31 30 0 0 25 22 28 195 1979 23 11 0 0 31 30 28 30 9 162 19121300042030172811219802626006020262 1913311429129181023311771981000001000 1 19148210020303030311701982200000052 9 191531283109303130312211983000000900 9 195731283130313031301625819840000005112945 19585400242110106519853120703130152031185 1959000000000 019862322000002754 196000002130232231127198732002730313031154 1961240001728721281251988312930228241106161 196200000151840371989136000000019 19632010000000211990010000520320 1964000000001 11991400000000 4 1965000003018245419923000016941749 1966079013022057419932714300004048 1967214011301702671994000022121211580 19683000000011141995141000000015 1969313001718001701996000000001212 19702217300303030311631997500000000 5 197124000628244211071998000012303113490 1972312750002130291431999000000000 0 1974140000120126532000000000005 5 1975261320014600612001322000780040 1976000000005 52002200001915132271 1977100003130258141182003237110313013218135 197829287000001377

20 Flow (cms)

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

Figure 4. Nicola River flows at the outlet of Nicola Lake (08LG065). The red line indicates 60 cfs (1.7 m3 sec-1), the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river during the months of August through November, and 40 cfs (1.13 m3 sec-1)

8 Table 6. Number of days in which Nicola River flow at the outlet of Nicola Lake (08LG065) was below 60 cfs (1.7 m3 sec-1) for the period August through November and below 40 cfs (1.13 m3 sec-1) for the period December through April. These values were the minimum flows recommended by Kosakoski and Hamilton (1982) for this portion of the river. Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum 1983 0 0 0 0 00890 17 1984 0 0 0 0 0 11 31 30 31 103 1985 31 28 3 0 25 30 31 30 31 209 1986 31 28 30 30 0 0 22 30 2 173 1987 2 1 0 0 30 15 31 30 31 140 1988 31 29 31 30 31 8 29 30 19 238 1989 31 28 31 14 00000 104 1990 0 0 0 0 0 0 4 24 0 28 1991 0 0 0 0 00000 0 1992 0 0 0 0 0 0 28 30 0 58 1993 0 2 0 0 00000 2 1994 0 0 0 0 0 0 11 26 0 37 1995 0 0 0 0 00000 0 1996 0 0 0 0 00000 0 1997 0 0 0 0 00000 0 1998 0 0 0 0 0 22 31 30 29 112 1999 31 28 18 0 00000 77 2000 0 0 0 0 00000 0 2001 0 0 0 0 0 0 0 10 0 10 2002 0 0 0 0 0 0 23 30 30 83 2003 31 28 31 28 0 10 31 30 28 217

40 Flow (cms)

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

Figure 5. Coldwater River flows at Merritt (08LG010). The lower red line indicates 50 cfs (1.42 m3 sec-1), the “Fisheries Resource Maintenance Flow” recommended by Kosakoski and Hamilton (1982). The upper red line for months of August through November indicates 120 cfs (3.4 m3 sec-1), the optimum spawning flow as calculated by Kosakoski and Hamilton.

Table 7. Number of days in which the Coldwater River flow at Merritt (08LG010) was below 120 cfs (3.4 m3 sec-1) for the period August through November (left portion of table) and below 50 cfs (1.42 m3 sec-1) for the period April through January. 120 cfs is the optimum spawning flow calculated by Kosakoski and Hamilton (1982) and 50 cfs was the recommended “Fisheries Resource Maintenance Flow.” Year Aug Sep Oct Nov Sum Year Jan Feb Mar Apr Aug Sep Oct Nov Dec Sum 1913 29 30 31 30 120 1913 31 28 31 27 24 30 31 30 31 263 1914 31 29 30 8 98 1914 31 28 31 4 31 24 20 8 25 202 1915 31 30 22 16 99 1915 31 28 16 0 28 30 14 2 2 151 1916 14 30 31 30 105 1916 31 29 18 0 0 17 30 21 31 177 1917 26 30 30 30 116 1917 31 28 31 0 4 27 22 30 31 204 1918 31 30 16 20 97 1918 31 28 31 30 3 30 11 2 0 166 1919 18 30 31 30 109 1919 31 28 0 0 0 0 4 16 31 110 1920 31 11 0 6 48 1920 30 29 27 4 20 11 0 0 2 123 1921 27 24 31 30 112 1921 31 28 0 0 3 20 31 30 31 174 1961 31 28 16 25 100 1961 31 28 31 19 28 21 0 4 6 168 1962 29 30 26 16 101 1962 0 0 0 0 0 23 6 0 0 29 1963 28 30 22 15 95 1963 0 0 0 0 0 27 21 0 0 48 1964 20 16 1 22 59 1964 0 0 0 0 0 0 0 1 0 1 1965 31 30 26 15 102 1965 9 0 0 0 18 30 6 0 0 63 1966 31 30 23 26 110 1966 10 28 21 0 17 30 21 0 0 127 1967 31 30 25 1 87 1967 0 0 0 0 19 30 10 0 0 59 1968 31 28 24 15 98 1968 0 0 0 0 19 15 5 0 0 39 1969 31 25 20 19 95 1969 0 0 7 0 31 22 0 0 7 67 1970 31 30 31 30 122 1970 31 23 0 0 31 28 24 29 31 197 1971 25 30 30 29 114 1971 16 0 0 0 7 29 3 0 29 84 1972 12 28 29 30 99 1972 31 8 0 0 0 20 19 25 31 134 1973 31 30 27 30 118 1973 31 28 5 0 31 30 14 0 0 139 1974 16 30 31 29 106 1974 0 0 0 0 0 29 28 19 8 84 1975 31 30 25 1 87 1975 23 28 19 5 8 25 14 0 0 122 1976 0 25 31 28 84 1976 0 0 0 0 0 4 30 11 1 46 1977 31 30 30 18 109 1977 0 0 0 0 31 30 24 5 4 94 1978 31 25 28 20 104 1978 2 0 0 0 25 2 5 0 12 46 1979 31 30 31 30 122 1979 20 19 0 0 31 30 25 22 0 147 1980 31 28 30 10 99 1980 6 0 0 0 0 1 0 0 0 7 1981 30 30 23 16 99 1981 0 0 0 0 20 30 1 0 16 67 1982 28 30 28 30 116 1982 16 7 0 0 11 30 9 14 10 97 1983 31 30 31 8 100 1983 1 0 0 0 20 22 22 0 13 78 1984 31 30 27 30 118 1984 0 0 0 0 16 18 8 6 30 78 1985 31 30 15 21 97 1985 29 11 15 0 31 30 15 10 31 172 1986 31 30 29 20 110 1986 14 12 0 0 24 29 21 2 4 106 1987 31 30 31 30 122 1987 3 2 0 0 31 30 31 30 31 158 1988 31 30 26 14 101 1988 31 29 10 0 28 27 14 0 3 142 1989 26 30 22 4 82 1989 0 1 0 0 12 23 11 0 0 47 1990 31 30 6 0 67 1990 5 17 4 0 27 26 4 0 0 83 1991 18 29 31 9 87 1991 0 0 0 0 0 11 24 4 2 41 1992 31 30 26 28 115 1992 2 0 0 0 31 26 19 5 10 93 1993 27 30 31 30 118 1993 27 17 4 0 1 26 25 22 21 143 1994 31 30 31 30 122 1994 3 17 0 0 31 30 27 27 12 147 1995 31 30 31 30 122 1995 10 0 0 0 31 30 31 30 31 163

10 In general, the Kosakoski and Hamilton recommendations seem to be streamflow targets that are reachable in most years, with the exception of Coldwater River. There is no striking evidence that recent years have more days below the flow targets than do earlier years, and there is no striking evidence that some months are more flow-limited now than they were in the past. It should be noted that the measure of limitation I have used here is simply the number of days below the threshold, and it is possible that a more detailed analysis (e.g., using magnitude of flow) would detect trends not evident in the current analysis. Nevertheless, this result underscores the notion that the Kosakoski and Hamilton recommendations are “reasonable” in that they are reachable, and that they are as reachable today as they were when they were made.

The Coldwater River appears to present a somewhat special case, in that low flows are usually well below the flow targets, particularly in the late summer and fall (Figure 6). Water use appears to have an effect on fish habitat availability, but in most years water use itself is not responsible for reducing flows to critical levels. Rather, natural availability is consistently below the target flow threshold, often for extended periods during fish migration and spawning.

Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov 2000 2001 2002 2003 5 4 3

2 1

0 1996 1997 1998 1999 5

4 3

2 1 0 1992 1993 1994 1995 5

Flow (cms) 3 2 1 0 1988 1989 1990 1991 5 4 3 2 1 0 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov

Figure 6. Coldwater River flows at Merritt. The blue lines indicate observed flows at 08LG010 for the years 1988 through 2003, the most recent 16 years on record. Naturalized flows (i.e., observed flows plus assumed water uses) are indicated in green, based on modeling undertaken by MoE hydrologists. Red lines indicate the optimum spawning flow for chinook (120 cfs, upper line) and the Fisheries Resource Maintenance Flow (50 cfs, lower line) as calculated by Kosakoski and Hamilton. Note: the y- axis is limited to flows below 5 cms to show detail during low flows.

6.2 BC Instream Flow Guidelines for Fish The Ministry of Water, Land and Air Protection (MWLAP), Ministry of Sustainable Resource Management (MSRM), Land and Water BC Inc. (LWBC), and Fisheries and Oceans Canada (DFO) developed the British Columbia Instream Flow Guidelines for Fish to aid in the process of setting instream flows in British Columbia streams. These Guidelines deal specifically with instream flow requirements to support aquatic ecosystem values. The Guidelines are made up of two main components, Flow Thresholds (Hatfield et al. 2003) and Assessment Methods (Lewis et al. 2003), to support a two-tiered review process for proposed water uses on BC streams. The first tier is a scoping level process that provides thresholds for alterations to natural stream flows that are expected to result in low risk to fish, fish habitat, and productive capacity. These thresholds are meant to act as a “coarse filter” during the review of proposed water uses on BC streams when there is little or no biological or physical data available. The second tier applies to projects that propose to exceed these flow thresholds. Such projects must collect additional data, using the Assessment Methods to support a more detailed review.

In this section we calculate the flow threshold for five sites in the Nicola watershed for which natural or naturalized flows are currently available. Spahomin and Pennask Creeks are two gauged systems that have relatively little water use, and we treat them as natural. Flow records for Spius Creek and Coldwater River (2 sites: Brookmere and Merritt) have been naturalized by MoE staff and we have used these records. The flow thresholds for these systems are plotted in Figure 7 through Figure 11.

Each system is similar in that flows are snowmelt-driven, have relatively low flows during non- freshet times of the year, and exhibit considerable among-year variance in flow magnitude and timing. The calculated flow thresholds underscore two main points: these systems are “water- rich” only during the spring freshet, and have low flows that are potentially limiting to fish for much of the year, including late summer, fall, and winter. The thresholds indicate that water extraction during the low flow periods should be permitted only after studies are undertaken to examine how such water use would interact with instream fisheries needs.

12 5

Flow (cms) 2

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

Figure 7. Spahomin Creek flows (08LG060). Light blue lines indicate daily flows, overlaid for the years 1972 through 1996. The green line indicates flows in the year 1995, a relatively wet year. The red line indicates flows in 1977, a relatively dry year. The dark blue lines indicate calculated minimum and maximum flow thresholds, based on the BC Instream Flow Guidelines.

10 Flow (cms) 5

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

Figure 8. Pennask Creek flows (08LG016). Light blue lines indicate daily flows, overlaid for the years 1920 through 2003. The green line indicates flows in the year 1997, a relatively wet year. The red line indicates flows in 1977, a relatively dry year. The dark blue lines indicate calculated minimum and maximum flow thresholds, based on the BC Instream Flow Guidelines.

13 120

100

60 Flow (cms) 40

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

Figure 9. Spius Creek flows based on naturalized data from MoE. Light blue lines indicate daily flows, overlaid for the years 1970 through 2003. The green line indicates flows in the year 1997, a relatively wet year. The red line indicates flows in 1977, a relatively dry year. The dark blue lines indicate calculated minimum and maximum flow thresholds, based on the BC Instream Flow Guidelines.

40 Flow (cms)

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

Figure 10. Coldwater River flows at Brookmere, based on naturalized data from MoE. Light blue lines indicate daily flows, overlaid for the years 1965 through 2003. The green line indicates flows in the year 1999, a relatively wet year. The red line indicates flows in 1994, a relatively dry year. The dark blue lines indicate calculated minimum and maximum flow thresholds, based on the BC Instream Flow Guidelines.

14 100

40 Flow (cms)

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

Figure 11. Coldwater River flows at Merritt, based on naturalized data from MoE. Light blue lines indicate daily flows, overlaid for the years 1965 through 2003. The green line indicates flows in the year 1999, a relatively wet year. The red line indicates flows in 1994, a relatively dry year. The dark blue lines indicate calculated minimum and maximum flow thresholds, based on the BC Instream Flow Guidelines.

6.3 Other Overview Methods Several methods exist for providing office-based recommendations of streamflow targets for the protection of fish resources (e.g., Tennant Method, BC Modified-Tennant Method, Meta- analysis regression equations, etc.). Virtually all of these rely natural or naturalized flow records and are therefore not currently available for most stream sections in the Nicola watershed.

7. CONCLUSIONS AND RECOMMENDATIONS Patterns of streamflow and an overview of fisheries concerns in the Nicola watershed indicate that natural patterns of streamflow are critically low during important life history periods for local fish stocks. All systems have snowmelt-driven hydrographs, with low flow periods in late summer, fall and winter. In many years low flow periods are well-below recommended minimum flows for maintenance of instream values such as fish habitat.

Climate change impacts are apparent in systems with long flow records, and likely reflect patterns occurring throughout the larger watershed, as similar trends have been observed elsewhere in this portion of the province (e.g., Leith and Whitfield 1998). These changes include an earlier snowmelt season and longer duration of low flows, particularly in late summer and fall. Such changes are likely to remain or worsen as global warming and climate change continue to affect patterns of precipitation in the interior of BC (Ministry of Environment 2006). These changes may be exacerbated over the next decade as hydrology is further altered by increases in forest harvest related to the ongoing mountain pine beetle outbreak. My analysis

15 did not detect trends in low flows (that is, there was no evidence of low flows becoming lower through time), however, it is possible that these trends exist but are not detectable with available data.

A cursory analysis of water licences in the Nicola watershed shows licenced water use to be of considerable magnitude. A detailed analysis of water use is being undertaken in a separate study as part of the Nicola WUMP. Until this study is complete it is difficult to quantitatively assess the effect of water use on fish habitat, other than to say that it is likely to negatively influence the quality and quantity of available fish habitat.

Kosakoski and Hamilton (1982) made a number of recommendations to protect fish and fish habitat from the effects of excessive water use. Their first recommendation was stated as follows: “To ensure that the salmonid production potential of the Nicola River system is maintained, it is recommended that: There be no increase in water diversion from the Nicola mainstem, Spius Creek, and Coldwater River during low flow periods, and no new water diversion licences unless they are supported by storage.” This recommendation is reiterated here, and would likely be reiterated by any examination of fish-flow issues in the area. Nevertheless, it appears that water allocation is continuing in the area and it is not clear why water management staff are allowing further allocation of this resource. It will be necessary to address this issue directly during the Nicola WUMP.

Kosakoski and Hamilton undertook a detailed study of the Nicola mainstem and the Coldwater River. Based on their study they were able to provide recommendations for flows to protect instream fish habitat. These recommendations are likely valid today, although it may be useful to re-analyse the data if they are available. Re-analysis could include use of updated HSI curves, calculation of confidence intervals, and application of analytic techniques discussed in Lewis et al. (2003). It seems unlikely that resources are available to repeat this study or to add to the number of transects used. It may be preferable to expend effort establishing flow targets for other portions of the watershed. To the extent possible, all flow targets should be based on empirical work using methods described in Lewis et al. (2003). Overview methods may be required to establish flow targets in some parts of the watershed.

There have been a variety of discussions regarding the use of Nicola Lake to provide additional water storage to support both water use and instream fish needs, and there continues to be interest in pursuing this option. Figure 12 shows recent patterns of outflow from Nicola Lake, and provides a visual sense of the potential for water storage. The red lines in the figure represent the minimum flows recommended by Kosakoski and Hamilton (1982). Observed flows (blue lines) above the red lines indicate storage potential to meet minimum instream flows and other demands. It is apparent that considerable storage potential exists, but it is also apparent that inflow to the lake is very low in some years (e.g., 1988, 1992 and 2003). In years such as these the lake is barely refilling, and additional water use may prevent it from completely refilling. It should also be noted that storage in the lake would come at a cost of increased fluctuations in water levels and reduced flushing rates, and there can be severe ecological costs, including effects on fish distribution and abundance (Cohen and Radomski 1993; Paller 1997; Turner et al. 2005). There should be some assessment of the ecological trade- offs between lake and stream ecosystems.

16 Many of the issues raised here and elsewhere have been slated for discussion and analysis within the Nicola WUMP, as it strives for a balance between instream (environmental) and out- of-stream (human) benefits of water allocation. There appear to be fundamental trade-offs between these two uses in that increased allocation for one, will de facto imply a loss for the other. It is unlikely that a “win-win” situation exists for water allocation across most of this watershed. The process of decision-making with respect to water allocation therefore needs to be carefully planned to ensure that one user group does not dominate another and that the trade-offs are made in a defensible and transparent manner, and reflect the values of society as a whole and not those of a single user group.

Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov 1999 2000 2001 2002 2003 25 20 15

10 5

0 1994 1995 1996 1997 1998 25 20 15

5 0 1989 1990 1991 1992 1993 25 20

Flow (cms) 15 10 5 0 1983 1984 1985 1987 1988 25 20

15 10 5 0 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov

Figure 12. Outflow from Nicola Lake as recorded at 08LG65. The red line indicates 60 cfs (1.7 m3 sec-1), the minimum flow recommended by Kosakoski and Hamilton (1982) for this portion of the river during the months of August through November, and 40 cfs (1.13 m3 sec-1) for December through April.

8. SUMMARY OF RECOMMENDATIONS 1. produce defensible time series of naturalized flows for Nicola River and its tributaries 2. conduct a quantitative analysis of water use and its effects on fish habitat 3. establish instream flow targets for fisheries, based on empirical and overview methods, including temperature modeling 4. conduct trade-off analyses in the WUMP using a third party experienced decision analyst and facilitator 5. develop tools to manage water resources in the face of conflicting needs, including development of rules under different flow scenarios such as wet and dry years

17 6. incorporate climate change projections into water management decisions 7. establish and maintain gauging stations at key points in the watershed 8. avoid further water allocation for out-of-stream uses

9. REFERENCES Bovee, K. D., B. L. Lamb, J. M. Bartholow, C. B. Stalnaker, J. Taylor, and J. Henriksen. 1998. Stream habitat analysis using the instream flow incremental methodology. Biological Resources Division Information and Technology Report United States Geological Survey, Fort Collins, Colorado, USA. British Columbia Ministry of Environment. 2006. Indicators of climate change for British Columbia 2002. Available at http://www.eng.gov.bc.ca/air/climate Bruce, J. 2005. Alouette River fish habitat monitor: a test of the dynamic equilibrium hypothesis. Research report for BC Hydro. Church, M. 1995. Geomorphic response to river flow regulation: case studies and time-scales. Regulated Rivers: Research and Management 11: 3-22. Cohen, Y., and P. Radomski. 1993. Water level regulations and fisheries in Rainy Lake and the Namakan Reservoir. Canadian Journal of Fisheries and Aquatic Sciences 50:1934-1945. Hatfield, T., A. Lewis and D. Ohlson. 2003. Development of instream flow thresholds as guidelines for reviewing proposed water uses. prepared for British Columbia Ministry of Sustainable Resource Management, and British Columbia Ministry of Water, Land, and Air Protection Kosakoski, G.T . and R.E. Hamilton. 1982. Water requirements for the fisheries resource of the Nicola River, B.C. Canadian Manuscript Report of Fisheries and Aquatic Sciences 1680. 127 pp. Leith, R. and P. Whitfield. 1998. Evidence of climate change effects on the hydrology of streams in south-central BC. Canadian Water Resources Journal 23: 219-230. Lewis, A., T. Hatfield, B. Chilibeck and C. Robert. 2003. Assessment methods for fish, fish habitat and instream flow characteristics in support of applications to dam, divert, or extract water from streams in British Columbia. prepared for Ministry of Water, Land & Air Protection and Ministry of Sustainable Resource Development. Paller, M.H. 1997. Recovery of a reservoir fish community from drawdown related impacts. North American Journal of Fisheries Management 17:726-733. Trush, W. J., S. M. McBain, and L. B. Leopold. 2000. Attributes of an alluvial river and their relation to water policy and management. Proceedings of the National Academy of Sciences USA 97: 11858-11863. Turner, M.A., D.B. Huebert, D.L. Findlay, L.L. Hendzel, W.A. Jansen, R.A. Bodaly, L.M. Armstrong and S.E.M. Kasian. 2005. Divergent impacts of experimental lake-level drawdown on planktonic and benthic plant communities in a boreal forest lake. Can. J. Fish. Aquat. Sci. 62: 991–1003.

Appendix A Analysis of WSC Gauge Data

The following pages contain a variety of graphical analyses of streamflow data. All data are from the Hydat database available from the Water Survey of Canada (WSC). Over the years WSC has operated several streamflow gauges in the Nicola watershed, some of which are no longer maintained.

For each streamflow gauge I have provided two sheets of graphs and tables. The graphs and tables do not have captions, as the analysis has been repeated across all available gauges. The following text describes each graph and table.

Page 1, Row 1, left. This table lists the name of the gauge, period of record, description of the watershed, and basic descriptors of flow.

Page 1, Row 1, middle. The plot shows the Nicola watershed, the major streams, and maps the location of the gauge.

Page 1, Row 1, right. This table lists the basic streamflow statistics for the available gauge data on a monthly basis, and over the period of record (PoR).

Page 1, Row 2, left. This graph indicates the general pattern of streamflow through the year on a monthly basis. The two lines indicate mean monthly flows (upper) and median monthly flows (lower). The mean annual flow and median annual flow are both indicated as horizontal lines.

Page 1, Row 2, middle. Exceedence graphs indicate the probability of flows of different magnitude. Exceedences are plotted on both a monthly basis, and over the period of record. The mean annual flow is shown as a reference point.

Page 1, Row 2, right. Trends in annual streamflow metrics through the period of record. Trends are shown for mean, median, 10th percentile and minimum.

Page 1, Row 3, left. General pattern of streamflow. Light blue lines are super-imposed traces of daily average flow across all years in the period of record. Dark blue, red and green lines are 90th, 50th and 10th percentiles respectively.

Page 1, Row 3, middle. This graph displays super-imposed traces of daily average flow across all years in the period of record (light blue). The streamflow record is split into two equal periods and the median daily flow in each period is plotted as a red and green line. The comparison of the two periods provides a rough indication of trends induced by climate change.

Page 1, Row 3, right. Trends in streamflow metrics for the month of September, which is typically the month of lowest flow during the growing period for fish in this watershed. Trends are shown for mean flow and minimum flow for all Septembers in the period of record.

Page 2, Row 1, left. This table is repeated from this location on page 1. It lists the name of the gauge, period of record, description of the watershed, and basic descriptors of flow.

Page 2, Row 1, middle. This image is repeated from this location on page 1. It shows the Nicola watershed, the major streams, and maps the location of the gauge.

Page 2, Row 1, right. This graph shows the trend in the duration of low flows during the growing season of fish (defined as April through October). Low flows are defined as flow less than the median September flow (calculated over the period of record). A trend line is shown in red, and is calculated using a locally-weighted regression (loess), which can be thought of as similar to a rolling average. Trends in duration of low flows can be brought about by changes in water use, climate, or both.

Page 2, Row 2, left. This image presents a trend analysis by month, using minimum flow in each of twelve calendar months. The trends of greatest interest for the purpose of this analysis were low flows during the fish growing season, so the y-axis scale has been limited to the typical magnitude of low flows. For this reason, observations in April through July are often missing, as they are greater than the maximum indicated on the scale. Trends are indicated with a locally-weighted regression (loess) line. The primary purpose of this analysis is to ascertain trends in low flows across the period of record.

Page 2, Row 2, middle. This image is similar to Page 2, Row 2, left, except that the flow metric is mean monthly flow. The primary purpose of this analysis is to ascertain trends in mean flows across the period of record.

Page 2, Row 3, left. This image is similar to Page 2, Row 2, left, except that the flow metric is 10th percentile of monthly flow. The primary purpose of this analysis is to ascertain trends in low flows across the period of record.

Page 2, Row 2, middle. This image is similar to Page 2, Row 2, left, except that the flow metric is the 90th percentile of monthly flow. The primary purpose of this analysis is to ascertain trends in high flows across the period of record.

Page 2, Row 2, right. This image is an attempt to analyse trends in flow patterns using a slightly different metric. For each month during the period of record a mean flow was calculated. Deviations were then calculated for each month for each year on record. A positive residual indicates a higher flow than average, while a negative residual indicates a lower flow than the long term average. Thus, an upward trend would indicate an increasing streamflow during that month across the period of record. Trends are indicated with a locally-weighted regression (loess) line. The primary purpose of this analysis is to ascertain trends in mean water availability by month across the period of record.

Knutsford percentiles Bestw ick Monte Lake month mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Station Name: Nicola River near Spences Bridge Logan Lake Jan 9.2 7.2 1.0 156.0 3.7 4.5 5.4 6.3 7.2 8.3 9.6 11.0 15.0 Jan

Stump Lake Station ID: 08LG006 Spences Bridge Feb 10.2 8.4 2.2 111.0 4.3 5.2 6.4 7.2 8.4 9.5 11.1 12.9 16.2 Feb

e Period of record: 1911-2003 N r Mar 13.1 10.2 3.6 60.6 6.0 7.2 8.0 9.0 10.2 11.3 13.9 16.5 25.1 Mar C ic o n l a o

R h

i c Complete records: 43 years v i Apr 29.8 24.5 4.4 151.0 10.0 13.3 16.3 20.5 24.5 28.3 33.4 41.7 58.0 Apr e r u

G 2 Lytton Ni Douglas Lake Drainage area: 7280 km col Nicola a May 94.0 83.1 14.7 378.0 37.3 48.9 57.9 69.9 83.1 96.1 112.0 133.0 169.0 May R. Low er Nicola Coyle 3 -1 Merr itt Mean Annual Discharge: 26.7 m sec Merritt Collettville Jun 87.7 74.5 12.2 320.0 29.1 38.8 51.0 61.1 74.5 90.6 108.3 130.2 167.0 Jun -2 -1 Runoff: 120.4 L m year k e Jul 28.8 20.5 4.2 159.0 8.2 10.8 14.3 16.8 20.5 26.4 32.3 44.0 62.5 Jul e r k C ree ena C s uilch u Q i Aug 9.0 7.1 2.2 38.1 3.6 4.3 5.2 6.1 7.1 8.4 9.8 12.0 17.1 Aug p

Canyon Alpine Sep 6.2 5.4 2.3 29.2 3.3 3.7 4.3 4.8 5.4 6.2 7.0 7.8 9.6 Sep r North Bend e Trépanier Boston Bar iv R Pe

r Oct 8.7 6.8 2.6 180.0 3.8 4.5 5.5 6.0 6.8 7.7 8.9 10.7 14.7 Oct e t a w ld Osprey Lake Bankeir o Nov 13.0 9.2 1.6 226.0 4.4 5.8 6.8 8.0 9.2 10.7 12.6 15.3 22.2 Nov C Dec 9.9 7.2 1.5 236.0 3.8 4.8 5.6 6.4 7.2 8.3 9.9 12.3 17.3 Dec Streamflow Gauge PoR 26.7 10.4 1.0 378.0 4.3 5.7 7.0 8.4 10.4 13.8 20.7 36.2 75.2 PoR

150 all flow s Jan mean 100 Feb median Mar 10th Apr min May Jun 40 Jul 80 Au g Se p Oct Nov 100 Dec MAD 30 60

40 20 Flow (cms) Flow (cms) 50 Flow (cms) MAD 20 10

Median

0 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 Quantiles of observed flow s

median before 1975 20 September mean median after 1975 September min

150 15 150

100 10 100 Flow (cms) Flow Flow (cms) Flow (cms) Flow 5 50 50

0 0 1 0 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestw ick Monte Lake

Brigade Lake Westw old Station Name: Nicola River near Spences Bridge Logan Lake

Stump Lake Station ID: 08LG006 Spences Bridge

e Period of record: 1911-2003 N r C ic o n l a o 80

R h

i c Complete records: 43 years v i e r u

G 2 Lytton Nic Douglas Lake Drainage area: 7280 km ola Nicola R. Low er Nicola Coyle 3 -1 Merr itt Mean Annual Discharge: 26.7 m sec Merritt Collettville -2 -1 Runoff: 120.4 L m year k e 60 e r k C ree ena C s uilch u Q i p

Canyon Alpine

r North Bend e Trépanier Boston Bar iv R Pe

r e t 40 a w ld Osprey Lake Bankeir o C

Streamflow Gauge 20 Number of Days Apr to Oct

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000

Jan Feb Mar Apr 30 Jan Feb Mar Apr 10

with Less Than September Median Flow 0 25 8 20 6 1960 1970 1980 1990 2000 15 4 10

2 5 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000

0 0 Jan Feb Mar Apr 6 May Jun Jul Aug May Jun Jul Aug 30 10 4 25 8 2 20 6 0 15

4 -2 10

2 5 -4

0 0

Mean Flow (cms) May Jun Jul Aug 6 Sep Oct Nov Dec 30 Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 10 4 25 8 20 2 6 15 0 4 10 -2

2 5 -4

0 0 Sep Oct Nov Dec 6

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 Residual monthly flow

-2 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr -4

25 15 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 20

10 15

10 5 5

0 0 May Jun Jul Aug May Jun Jul Aug

25 15 20

10 15

10 5 5

0 0 Sep Oct Nov Dec Sep Oct Nov Dec

25 15

10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 20

10 15

10 5 5 2 0 0

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 percentiles Knutsford th th th th th th th th th Bestwick month mean median min max 10 20 30 40 50 60 70 80 90 month Monte Lake

Brigade Lake Westw old Jan 4.7 4.0 0.6 83.3 2.0 2.5 2.9 3.3 4.0 4.6 5.2 6.0 7.8 Jan Logan Lake Station Name: Nicola River near Merritt Feb 5.7 4.6 0.8 48.7 2.5 3.1 3.6 4.1 4.6 5.1 5.8 6.9 9.9 Feb Station ID: 08LG007 Stump Lake Spences Bridge Mar 6.7 5.1 1.3 35.7 3.3 3.8 4.2 4.6 5.1 6.0 7.1 8.6 11.6 Mar

Period of record: 1911-2003 e

e N r Apr 14.3 11.6 1.3 78.3 5.3 6.8 8.2 9.9 11.6 13.2 16.0 20.1 26.4 Apr C ic

o n Complete records: 47 years l a o R May 44.9 40.5 6.5 145.0 16.7 23.7 28.7 34.5 40.5 46.0 53.8 64.2 78.8 May i ch v i e 2 r u

Drainage area: 4350 km G Lytton Nic Douglas Lake ola Jun 47.8 40.7 6.1 161.0 16.4 22.0 29.9 34.6 40.7 49.3 61.2 72.6 86.6 Jun 3 -1 Nic ola R. Mean Annual Discharge: 14.0 m sec Low er Nicola Coy le Merr itt Jul 17.1 12.6 2.8 72.8 5.6 7.2 8.9 10.5 12.6 15.8 19.6 25.4 34.8 Jul -2 -1 Merritt Runoff: 105.8 L m year Collettville Aug 6.0 4.7 1.0 32.0 2.4 3.0 3.6 4.3 4.7 5.4 6.5 7.9 10.9 Aug k e e r k C ree ena C Sep 3.9 3.5 1.1 18.0 2.0 2.4 2.7 3.1 3.5 4.1 4.5 5.1 6.1 Sep s uilch u Q i p S Oct 4.9 4.0 0.6 62.1 2.1 2.7 3.0 3.4 4.0 4.5 5.3 6.1 7.9 Oct Canyon Alpine

r North Bend e Trépanier Nov 6.5 4.8 0.8 115.0 2.0 2.8 3.6 4.3 4.8 5.2 6.1 7.9 11.5 Nov Boston Bar iv R Pe

r e t Dec 5.3 3.8 0.1 136.0 1.6 2.5 3.1 3.5 3.8 4.4 5.4 7.0 9.5 Dec a w ld Osprey Lake Bankeir o C PoR 14.0 5.8 0.1 161.0 2.5 3.3 4.0 4.8 5.8 7.6 11.2 19.1 38.8 PoR

Streamflow Gauge

all flow s mean Jan median 50 Feb 10th Mar min Ap r May 40 Jun Jul 60 Au g 40 Se p Oct Nov Dec 30 MAD 30 40

20 20 Flow (cms) Flow (cms) Flow (cms)

MAD 20 10 10

Median

0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 Quantiles of observed flow s

20 80 100 median before 1975 mean median after 1975 September min

80 15 60

60 10 40

Flow (cms) Flow (cms) Flow 40 Flow (cms)

5 20 20

0 0 0 3 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Nicola River near Merritt 100 Station ID: 08LG007 Stump Lake Spences Bridge

Period of record: 1911-2003 e

e N r C ic

o n Complete records: 47 years l a o R

i ch v i e 80 2 r u

Drainage area: 4350 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 14.0 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 105.8 L m year Collettville

k e 60 e r k C ree ena C s uilch u Q i p

Canyon Alpine

r North Bend e Trépanier Boston Bar iv R Pe

r 40 e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 20 Number of Days Apr to Oct

with Less Than September Median Flow 0 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr 1960 1970 1980 1990 2000 12 20 10 15 8

10 6 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000

4 Jan Feb Mar Apr 5 3 2 2 0 0 May Jun Jul Aug May Jun Jul Aug 1 12 20 0 10 15 -1 8 -2 10 6 -3 4 May Jun Jul Aug 5 2 3

0 0 2 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 1 12 20 0 10 15 -1 8 -2 10 6 -3 4 Sep Oct Nov Dec 5

2 Residual monthly flow 3

0 0 2

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1

0 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 -1 Jan Feb Mar Apr Jan Feb Mar Apr -2 8 8 -3 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 6 6

4 4

2 2

0 0 May Jun Jul Aug May Jun Jul Aug

8 8

6 6

4 4

2 2

0 0 Sep Oct Nov Dec Sep Oct Nov Dec

8 8 10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms)

6 6

4 4

2 2 4

0 0

1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 percentiles Knutsford

Bestwick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month

Brigade Lake Westw old Station Name: Nicola River at Logan Lake Jan 1.7 1.4 0.0 4.7 0.9 1.0 1.2 1.3 1.4 1.9 2.1 2.4 3.0 Jan outlet of Nicola Lake Stump Lake Feb 1.8 1.4 0.1 4.5 0.8 0.9 1.2 1.3 1.4 1.8 2.1 2.5 3.2 Feb Spences Bridge

Station ID: 08LG065 e

e N r Mar 2.4 1.5 0.4 13.5 1.0 1.2 1.2 1.4 1.5 1.9 2.1 3.1 3.9 Mar C ic

o n Period of record: 1983-2003 l a o R

i ch v i e u Apr 4.1 2.6 0.5 26.6 1.0 1.3 1.5 2.0 2.6 3.1 4.0 6.2 9.5 Apr r

Complete records: 20 years G Lytton Ni Douglas Lake col 2 Nic ola a R . May 16.3 16.6 0.7 53.8 2.3 4.6 6.5 12.5 16.6 19.0 21.2 24.4 30.9 May Drainage area: 2990 km Low er Nicola Coy le Merr itt 3 -1 Merritt Mean Annual Discharge: 5.2 m sec Collettville Jun 17.1 14.3 1.5 58.2 2.2 4.1 7.4 11.2 14.3 17.0 20.8 29.3 39.2 Jun -2 -1 k e Runoff: 57.66 L m year e r k C ree ena C Jul 7.4 5.4 1.4 26.4 2.3 3.3 3.8 4.8 5.4 6.4 9.1 12.8 16.1 Jul s uilch u Q i p S Aug 4.0 3.1 0.6 23.8 1.5 2.2 2.7 2.9 3.1 3.3 3.8 4.6 6.1 Aug Canyon Alpine

r North Bend e Trépanier Boston Bar iv R Pe Sep 2.4 2.2 0.6 6.1 1.5 1.8 1.9 2.1 2.2 2.5 2.7 3.0 3.6 Sep

r e t a w d Osprey Lake l Bankeir Oct 1.9 1.8 0.4 4.3 1.2 1.4 1.6 1.7 1.8 2.0 2.4 2.5 3.1 Oct o C Nov 1.9 1.7 0.3 4.5 1.1 1.2 1.4 1.5 1.7 2.0 2.3 2.4 3.0 Nov Streamflow Gauge Dec 1.7 1.4 0.1 5.3 0.8 1.0 1.0 1.3 1.4 2.0 2.0 2.3 3.0 Dec PoR 5.2 2.3 0.0 58.2 1.0 1.4 1.6 2.0 2.3 2.8 3.6 5.7 15.4 PoR

30 all flows mean Jan median Feb 10th Mar min Apr May 10 25 Jun Jul 15 Aug Sep Oct Nov 8 20 Dec MAD

10 6 15 Flow (cms) Flow (cms) 10 Flow (cms) 4 5 MAD

5 2 Median

0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 Quantiles of observed flow s

mean September min

30 3

20 2 Flow (cms) Flow Flow (cms)

10 1

0 0 5 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Station Name: Nicola River at Logan Lake outlet of Nicola Lake Stump Lake 200 Spences Bridge

Station ID: 08LG065 e

e N r C ic

o n Period of record: 1983-2003 l a o R

i ch v i e r u

Complete records: 20 years G Lytton Nic Douglas Lake ola 2 Nic ola R. Drainage area: 2990 km Low er Nicola Coy le 150 Merr itt 3 -1 Merritt Mean Annual Discharge: 5.2 m sec Collettville

-2 -1 k e Runoff: 57.66 L m year e r k C ree ena C s uilch u Q i p

Canyon Alpine 100 r North Bend e Trépanier Boston Bar iv R Pe

r e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 50 Number of Days Apr to Oct

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000

with Less Than September Median Flow 0 Jan Feb Mar Apr Jan Feb Mar Apr 6 4 1985 1990 1995 2000 5 3 4 1985 1990 1995 2000 1985 1990 1995 2000 3 2 Jan Feb Mar Apr 1.5 2 1 1 1.0

0 0 0.5 May Jun Jul Aug May Jun Jul Aug 6 0.0 4

5 -0.5 3 4 -1.0 3 2 May Jun Jul Aug 2 1.5 1 1 1.0

0 0 Mean Flow (cms) 0.5 Sep Oct Nov Dec Sep Oct Nov Dec Minimum Flow (cms) Minimum Flow 6 4 0.0 5 -0.5 3 4 -1.0 3 2 Sep Oct Nov Dec 2 1.5

1 Residual monthly flow 1 1.0 0 0 0.5 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 0.0

-0.5 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr Jan Feb Mar Apr -1.0 10 10 1985 1990 1995 2000 1985 1990 1995 2000 8 8

6 6

4 4

2 2

0 0 May Jun Jul Aug May Jun Jul Aug 10 10

8 8

6 6

4 4

2 2

0 0 Sep Oct Nov Dec Sep Oct Nov Dec 10 10

10th Percentile Flow (cms) 10th Percentile 8 90th Percentile Flow (cms) 8

6 6

4 4 2 2 6 0 0

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Knutsford percentiles Bestwick Monte Lake month mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Logan Lake Station Name: Nicola River above Nicola Lake Jan 0.8 0.8 0.0 3.3 0.2 0.4 0.5 0.6 0.8 0.9 1.1 1.3 1.6 Jan

Stump Lake Station ID: 08LG049 Spences Bridge Feb 1.0 0.9 0.0 3.6 0.4 0.5 0.7 0.8 0.9 0.9 1.1 1.3 1.7 Feb

e Period of record: 1915-2003 N r Mar 1.2 1.0 0.1 4.9 0.4 0.6 0.8 0.9 1.0 1.1 1.3 1.7 2.3 Mar C ic

o n l a o R Complete records: 32 years i ch v i e Apr 3.8 2.0 0.1 34.8 0.7 1.0 1.2 1.5 2.0 2.9 3.9 5.5 8.8 Apr r u 2 G Lytton Nic Douglas Lake Drainage area: 1500 km ola Nic ola R. May 18.2 16.3 1.1 64.7 5.8 8.9 11.0 13.2 16.3 19.0 22.8 27.2 33.4 May 3 -1 Low er Nicola Coy le Mean Annual Discharge: 4.2 m sec Merr itt Merritt Collettville Jun 14.3 11.9 1.9 49.3 4.3 5.6 7.4 9.5 11.9 13.6 16.3 21.6 30.2 Jun Runoff: 92.15 L m-2 year-1 k e e r Jul 5.3 4.3 0.3 22.1 1.3 2.2 2.9 3.5 4.3 5.2 6.3 7.8 10.7 Jul k C ree ena C s uilch u Q i p Aug 1.9 1.3 0.0 20.4 0.2 0.4 0.7 1.0 1.3 1.7 2.1 2.7 4.2 Aug S

Canyon Alpine r Sep 1.1 0.7 0.0 10.1 0.1 0.2 0.2 0.5 0.7 1.1 1.3 1.7 2.4 Sep North Bend e Trépanier Boston Bar iv R Pe

r e t Oct 0.8 0.5 0.0 5.9 0.1 0.1 0.2 0.3 0.5 0.7 1.0 1.3 1.8 Oct a w ld Osprey Lake Bankeir o C Nov 1.0 0.7 0.0 5.4 0.1 0.2 0.4 0.5 0.7 0.9 1.3 1.6 2.1 Nov

Streamflow Gauge Dec 0.9 0.7 0.0 3.3 0.1 0.3 0.4 0.6 0.7 1.0 1.3 1.6 1.9 Dec PoR 4.2 1.3 0.0 64.7 0.2 0.5 0.7 1.0 1.3 1.7 2.6 5.4 12.8 PoR

all flow s mean 20 Jan median Feb 10th Mar 8 min Apr 25 May Jun Jul Aug 15 Sep Oct 20 Nov 6 Dec MAD

15 10 4 Flow (cms) Flow (cms) Flow (cms) 10

5 2 MAD 5

Median 0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Quantiles of observed flow s

40 median before 1987 mean median after 1987 September min 30 5

30 25 4

20 3 20 15

Flow (cms) Flow (cms) Flow 2 Flow (cms)

10 10 1 5

0 0 0 7 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Nicola River above Nicola Lake

Stump Lake Station ID: 08LG049 Spences Bridge

e Period of record: 1915-2003 N r C ic 100

o n l a o R Complete records: 32 years i ch v i e r u 2 G Lytton Nic Douglas Lake Drainage area: 1500 km ola Nic ola R. 3 -1 Low er Nicola Coy le Mean Annual Discharge: 4.2 m sec Merr itt Merritt Collettville 80 Runoff: 92.15 L m-2 year-1 k e e r k C ree ena C s uilch u Q i p S 60 Canyon Alpine

r North Bend e Trépanier Boston Bar iv R Pe

r e t a w ld Osprey Lake Bankeir o C 40

Streamflow Gauge

20 Number of Days Apr to Oct

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr

with Less Than September Median Flow 0 1.5 3.0 2.5 1970 1980 1990 2000 1.0 2.0

1.5 1970 1980 1990 2000 1970 1980 1990 2000 0.5 1.0 Jan Feb Mar Apr 1.0 0.5

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.5 1.5 3.0

2.5 0.0 1.0 2.0

1.5 -0.5 0.5 1.0 May Jun Jul Aug 0.5 1.0

0.0 0.0 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 1.5 3.0 0.5

2.5 0.0 1.0 2.0

1.5 -0.5 0.5 1.0

0.5 1.0 Sep Oct Nov Dec

0.0 0.0 Residual monthly flow

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 0.5

0.0 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr 1.5 -0.5 8

6 1.0 1970 1980 1990 2000 1970 1980 1990 2000

0.5 2

0.0 0 May Jun Jul Aug May Jun Jul Aug 1.5 8

6 1.0

0.5 2

0.0 0 Sep Oct Nov Dec Sep Oct Nov Dec 1.5 8 10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 6 1.0

0.5 2 8 0.0 0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 percentiles Knutsford

Bestw ick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month

Brigade Lake Westw old Station Name: Coldwater River at Merritt Logan Lake Jan 3.3 1.9 0.3 81.4 0.8 1.2 1.4 1.7 1.9 2.3 2.8 3.9 5.7 Jan Station ID: 08LG010 Feb 3.6 2.4 0.3 39.6 1.0 1.2 1.6 1.9 2.4 2.8 3.4 4.5 6.8 Feb Stump Lake Spences Bridge

k Period of record: 1913-1995 e Mar 4.2 2.9 1.0 28.0 1.5 1.9 2.2 2.5 2.9 3.5 4.6 5.7 8.5 Mar e N r C ic

o n Complete records: 33 years l a o R Apr 10.5 8.4 1.3 62.6 3.1 4.3 5.4 6.7 8.4 9.8 11.8 15.1 21.4 Apr i ch v i e 2 r u

Drainage area: 914 km G Lytton Nic Douglas Lake ola May 29.3 25.2 4.7 115.0 11.4 14.6 18.2 21.3 25.2 29.8 34.9 40.8 53.2 May 3 -1 Nic ola R. Mean Annual Discharge: 8.2 m sec Low er Nicola Coy le Merritt -2 -1 Merritt Jun 26.3 22.7 3.2 102.0 8.8 11.8 15.5 19.3 22.7 26.1 30.9 38.5 49.3 Jun Runoff: 295.4 L m year Collettville

k e Jul 8.3 5.3 0.6 54.4 1.7 2.5 3.4 4.3 5.3 6.8 8.7 13.1 19.3 Jul e r k C ree ena C s uilch u Q i Aug 1.7 1.3 0.2 12.1 0.4 0.6 0.8 1.0 1.3 1.6 1.9 2.4 3.5 Aug p

S Canyon Alpine Sep 1.1 0.9 0.1 9.0 0.3 0.5 0.7 0.8 0.9 1.1 1.3 1.5 2.1 Sep r North Bend e Boston Bar iv Trépanier R Pe

r e Oct 2.3 1.5 0.1 56.4 0.6 0.8 0.9 1.2 1.5 1.8 2.2 3.1 4.5 Oct t a w ld Osprey Lake Bankeir o C Nov 4.1 2.5 0.4 107.0 0.9 1.3 1.7 2.1 2.5 3.0 3.7 4.8 6.8 Nov Dec 3.6 2.0 0.1 122.0 0.8 1.1 1.4 1.7 2.0 2.6 3.4 4.6 7.1 Dec Streamflow Gauge PoR 8.2 2.9 0.1 122.0 0.8 1.2 1.6 2.2 2.9 4.2 6.6 12.0 24.1 PoR

all flow s 15 mean Jan median Feb 10th 30 Mar min Ap r 40 May Jun Jul 25 Au g Se p Oct Nov 10 30 Dec 20 MAD

15 20 Flow (cms) Flow (cms) Flow (cms) 5 10 MAD 10 5 Median

0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 Quantiles of observed flow s

median before 1978 mean 60 median after 1978 September min 3 60 50

40 2 40 30 Flow (cms) Flow (cms) Flow Flow (cms) 20 1 20

0 0 0 9 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knuts f ord

Bestw ick Monte Lake

Brigade Lake Westw old Station Name: Coldwater River at Merritt Logan Lake

Station ID: 08LG010 Stump Lake Spences Bridge 80

k Period of record: 1913-1995 e N e ic r C ol a n R o Complete records: 33 years iv h e c r i u 2 G Lytton Ni Douglas Lake Drainage area: 914 km cola Nic ola R. 60 3 -1 Low er Nicola Coyle Merritt Mean Annual Discharge: 8.2 m sec Merritt Collettv ille Runoff: 295.4 L m-2 year-1 k e e r reek C a C chen s Quil 40 u i p S

Canyon Alpine

North Bend r Boston Bar e Trépanier iv Pe R r te a 20 w Osprey Lake ld Bankeir o C Number of Days Apr to Oct

Streamflow Gauge

with Less Than September Median Flow 0

1965 1970 1975 1980 1985 1990 1995

1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 Jan Feb Mar Apr Jan Feb Mar Apr 5 Jan Feb Mar Apr 2.5 4 2 2.0 3 1.5 1

2 1.0 0 0.5 1 -1 0.0 0 May Jun Jul Aug May Jun Jul Aug 5 May Jun Jul Aug 2.5 4 2 2.0 3 1.5 1

2 1.0 0 0.5 1 -1 0.0 0 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 5 Sep Oct Nov Dec 2.5 Residual monthly flow 4 2 2.0 3 1.5 1

2 1.0 0 0.5 1 -1 0.0 0

1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995

1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 Jan Feb Mar Apr Jan Feb Mar Apr 5 3.0

2.5 4

2.0 3 1.5 2 1.0 1 0.5

0.0 0 May Jun Jul Aug May Jun Jul Aug 5 3.0

2.5 4

2.0 3 1.5 2 1.0 1 0.5

0.0 0 Sep Oct Nov Dec Sep Oct Nov Dec 5 3.0

10th Percentile Flow (cms) 10th Percentile 2.5 90th Percentile Flow (cms)

2.0 3 1.5 2 1.0 1 10 0.5

0.0 0

1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 1965 1975 1985 1995 Knutsford percentiles Bestw ick Monte Lake th th th th th th th th th

Brigade Lake month mean median min max 10 20 30 40 50 60 70 80 90 month Westw old Logan Lake Station Name: Coldwater River at Brookmere Jan 2.4 1.5 0.2 96.2 0.6 0.8 1.0 1.3 1.5 1.7 2.0 2.6 4.5 Jan

Stump Lake Station ID: 08LG048 Spences Bridge

k Feb 2.4 1.7 0.2 32.0 0.7 0.9 1.2 1.5 1.7 2.0 2.4 3.1 4.4 Feb

e Period of record: 1965-2003 N r C ic

o n l a o Mar 3.0 2.1 0.4 22.2 1.0 1.3 1.6 1.8 2.1 2.6 3.4 4.2 6.3 Mar R Complete records: 36 years i ch v i e r u 2 G Lytton Nic Douglas Lake Apr 7.9 5.6 1.1 46.5 2.2 2.9 3.7 4.6 5.6 7.1 9.3 12.1 17.5 Apr Drainage area: 316 km ola Nic ola R. 3 -1 Low er Nicola Coy le Mean Annual Discharge: 6.9 m sec Merritt May 23.9 20.3 2.6 91.2 9.4 11.6 14.9 17.3 20.3 23.8 28.6 34.3 43.8 May Merritt Collettville Runoff: 715.3 L m-2 year-1 k Jun 22.7 19.4 3.0 84.7 8.0 10.7 13.4 16.7 19.4 23.1 27.5 33.6 41.4 Jun e e r k C ree ena C s uilch u Q i Jul 7.8 4.7 0.8 42.1 1.7 2.2 3.0 3.8 4.7 6.0 8.0 12.5 19.7 Jul p

S Canyon Alpine Aug 1.7 1.2 0.4 12.0 0.6 0.7 0.9 1.0 1.2 1.4 1.8 2.3 3.2 Aug r North Bend e Boston Bar iv Trépanier R Pe

r e t Sep 1.2 0.9 0.2 7.2 0.5 0.6 0.7 0.8 0.9 1.1 1.3 1.6 2.1 Sep a w ld Osprey Lake Bankeir o C Oct 2.3 1.5 0.3 69.0 0.6 0.7 0.9 1.2 1.5 1.8 2.3 3.0 4.2 Oct

Streamflow Gauge Nov 4.3 2.3 0.3 104.0 0.9 1.2 1.5 1.9 2.3 2.7 3.4 4.7 8.1 Nov Dec 2.7 1.5 0.1 92.6 0.7 0.9 1.1 1.3 1.5 1.8 2.0 2.9 5.2 Dec PoR 6.9 2.3 0.1 104.0 0.7 1.0 1.4 1.8 2.3 3.3 5.3 10.1 20.3 PoR

40 all flow s mean Jan median 25 Feb 10th Mar min Ap r 10 May Jun Jul Au g 20 30 Se p Oct 8 Nov Dec MAD 15 6 20

Flow (cms) 4 Flow (cms) Flow (cms)

MAD 10 5 2

Median

0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Quantiles of observed flow s

median before 1986 mean 60 50 median after 1986 2.5 September min

50 40 2.0

40 1.5 30

30 1.0 Flow (cms) Flow (cms) Flow

20 Flow (cms) 20

0.5 10 10

0.0 0 0 11 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestw ick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Coldwater River at Brookmere

Stump Lake Station ID: 08LG048 Spences Bridge

e r 80 Period of record: 1965-2003 N C ic

o n l a o R Complete records: 36 years i ch v i e r u 2 G Lytton Nic Douglas Lake Drainage area: 316 km ola Nic ola R. 3 -1 Low er Nicola Coy le Mean Annual Discharge: 6.9 m sec Merritt Merritt Collettville Runoff: 715.3 L m-2 year-1 60 k e e r k C ree ena C s uilch u Q i p

Canyon Alpine

r North Bend e Trépanier Boston Bar iv 40 R Pe

r e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 20 Number of Days Apr to Oct

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000

with Less Than September Median Flow 0 Jan Feb Mar Apr 4 Jan Feb Mar Apr

2.0 1970 1980 1990 2000 3

1.5 2 1970 1980 1990 2000 1970 1980 1990 2000 1.0 Jan Feb Mar Apr 2 1 0.5

0.0 0 1 May Jun Jul Aug May Jun Jul Aug 4

2.0 0 3

1.5 -1 2 1.0 May Jun Jul Aug 2 1 0.5

0.0 0 1 Mean Flow (cms) Sep Oct Nov Dec 4 Sep Oct Nov Dec Minimum Flow (cms) Minimum Flow

2.0 0 3

1.5 2 -1 1.0 Sep Oct Nov Dec 2 1 Residual monthly flow 0.5

0.0 0 1 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 -1 Jan Feb Mar Apr Jan Feb Mar Apr 2.5 1970 1980 1990 2000 1970 1980 1990 2000 4 2.0

3 1.5

2 1.0

0.5 1

0.0 0 May Jun Jul Aug May Jun Jul Aug 2.5 4 2.0

3 1.5

2 1.0

0.5 1

0.0 0 Sep Oct Nov Dec Sep Oct Nov Dec 2.5 4 2.0 10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 3 1.5

2 1.0

0.5 1 12

0.0 0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Knutsford percentiles Bestwick Monte Lake month mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Logan Lake Station Name: Spius Creek near Canford Jan 3.2 2.4 0.3 65.4 1.0 1.3 1.5 1.8 2.4 2.8 3.3 4.0 6.2 Jan

Stump Lake Station ID: 08LG008 Spences Bridge Feb 3.8 2.5 0.5 65.0 1.1 1.5 1.9 2.2 2.5 2.8 3.5 4.9 7.0 Feb

e Period of record: 1911-2003 N r C Mar 5.0 3.5 0.9 25.2 1.6 2.0 2.4 2.9 3.5 4.5 5.8 7.4 10.7 Mar ic

o n l a o R

i ch Complete records: 33 years v i e r u Apr 14.9 12.4 1.3 81.9 3.9 5.6 7.7 10.2 12.4 15.1 18.2 22.0 30.0 Apr 2 G Lytton Nic Douglas Lake Drainage area: 780 km ola Nic ola R. May 38.6 31.4 7.0 181.0 16.3 20.0 23.4 26.6 31.4 36.2 42.4 52.7 72.3 May 3 -1 Low er Nicola Coy le Merr itt Mean Annual Discharge: 10.2 m sec Merritt Collettville Runoff: 430.9 L m-2 year-1 Jun 31.6 25.7 4.5 149.0 11.1 14.8 18.3 21.8 25.7 30.0 35.0 44.3 60.4 Jun k e e r k Jul 9.7 6.4 0.9 54.4 2.1 3.1 4.1 5.3 6.4 7.7 10.4 15.2 23.7 Jul C ree ena C s uilch u Q i p S Aug 2.4 1.6 0.3 16.3 0.7 1.0 1.2 1.3 1.6 1.9 2.5 3.3 4.8 Aug Canyon Alpine

r North Bend e v Trépanier Sep 1.4 1.2 0.3 8.1 0.6 0.8 0.9 1.0 1.2 1.3 1.5 1.8 2.4 Sep Boston Bar i R Pe

r e t a Oct 2.8 1.7 0.3 56.8 0.7 1.0 1.2 1.4 1.7 2.0 2.7 3.8 5.3 Oct w ld Osprey Lake Bankeir o C Nov 5.5 2.8 0.4 115.0 1.0 1.4 1.9 2.3 2.8 3.5 4.6 7.0 11.4 Nov

Streamflow Gauge Dec 3.7 2.2 0.3 102.0 1.0 1.4 1.7 1.9 2.2 2.6 3.1 4.0 6.8 Dec PoR 10.2 3.4 0.3 181.0 1.0 1.4 1.9 2.5 3.4 5.0 8.2 16.0 28.6 PoR

all flow s mean Jan median 40 Feb 10th Mar min Apr 50 May 15 Jun Jul Aug Sep 30 Oct 40 Nov Dec MAD 10 30 20 Flow (cms) Flow (cms) Flow (cms) 20 5 10 MAD

10 Median

0 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Quantiles of observed flow s

median before 1987 mean median after 1987 September min 100 3.0 80

2.5 80 60 2.0

60 1.5 40 Flow (cms) Flow (cms) Flow 40 Flow (cms) 1.0

20 20 0.5

0.0 0 0 13 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Spius Creek near Canford

Stump Lake Station ID: 08LG008 Spences Bridge

e Period of record: 1911-2003 N r C 80 ic

o n l a o R

i ch Complete records: 33 years v i e r u 2 G Lytton Nic Douglas Lake Drainage area: 780 km ola Nic ola R. 3 -1 Low er Nicola Coy le Merr itt Mean Annual Discharge: 10.2 m sec Merritt Collettville Runoff: 430.9 L m-2 year-1 60 k e e r k C ree ena C s uilch u Q i p

Canyon Alpine

r North Bend e Boston Bar iv Trépanier R Pe

r 40 e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 20 Number of Days Apr to Oct

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr 5 2.5

with Less Than September Median Flow 0 4 2.0

3 1970 1975 1980 1985 1990 1995 2000 1.5

2 1.0 1970 1980 1990 2000 1970 1980 1990 2000 0.5 1 Jan Feb Mar Apr 0.0 0 3 May Jun Jul Aug May Jun Jul Aug 5 2 2.5 4 2.0 1

3 1.5 0

2 1.0 -1

0.5 1 -2 May Jun Jul Aug 0.0 0 Mean Flow (cms) 3 Sep Oct Nov Dec Sep Oct Nov Dec 5 Minimum Flow (cms) Minimum Flow 2.5 2 4 2.0 1 3 1.5 0 2 1.0 -1 0.5 1 -2 0.0 0 Sep Oct Nov Dec 3 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Residual monthly flow

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 0 Jan Feb Mar Apr Jan Feb Mar Apr 5 -1 3.0

2.5 4 -2

1970 1980 1990 2000 1970 1980 1990 2000 2.0 3

1.5 2 1.0 1 0.5

0.0 0 May Jun Jul Aug May Jun Jul Aug 5 3.0

2.5 4

2.0 3

1.5 2 1.0 1 0.5

0.0 0 Sep Oct Nov Dec Sep Oct Nov Dec 5 3.0

2.5 4 10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms)

2.0 3

1.5 2 1.0 1 14 0.5

0.0 0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Knutsford percentiles Bestwick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month

Brigade Lake Westw old Station Name: Guichon Creek near Lower Nicola Logan Lake Jan 0.28 0.26 0.02 0.72 0.07 0.13 0.18 0.23 0.26 0.30 0.34 0.43 0.49 Jan Station ID: 08LG004 Stump Lake Spences Bridge Feb 0.32 0.26 0.04 0.93 0.12 0.20 0.22 0.24 0.26 0.30 0.35 0.49 0.59 Feb

Period of record: 1911-1984 e

e N r C Mar 0.40 0.33 0.01 1.42 0.12 0.18 0.23 0.27 0.33 0.37 0.47 0.65 0.78 Mar ic

o n Complete records: 20 years l a o R

i ch v i e 2 r u Apr 0.83 0.56 0.01 6.19 0.12 0.24 0.33 0.40 0.56 0.76 0.93 1.30 1.83 Apr Drainage area: 1230 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 1.04 m sec Low er Nicola Coy le May 5.35 3.40 0.02 26.80 0.14 0.62 1.32 1.88 3.40 4.70 7.87 9.58 13.10 May Merr itt -2 -1 Merritt Runoff: 27.76 L m year Collettville Jun 2.72 1.66 0.01 17.00 0.05 0.13 0.36 1.11 1.66 2.80 3.57 4.84 6.58 Jun k e e r k C ree ena C s uilch Jul 1.00 0.66 0.00 8.18 0.03 0.08 0.16 0.51 0.66 0.88 1.08 1.56 2.55 Jul u Q i p S Aug 0.39 0.16 0.00 4.59 0.01 0.06 0.07 0.12 0.16 0.29 0.44 0.60 0.86 Aug Canyon Alpine

r North Bend e Boston Bar iv Trépanier R Pe Sep 0.30 0.14 0.00 2.97 0.03 0.06 0.09 0.11 0.14 0.17 0.28 0.45 0.60 Sep r e t a w ld Osprey Lake Bankeir o Oct 0.26 0.18 0.00 1.20 0.03 0.07 0.11 0.15 0.18 0.23 0.28 0.51 0.58 Oct C Nov 0.28 0.20 0.00 1.33 0.06 0.10 0.13 0.17 0.20 0.25 0.28 0.53 0.71 Nov Streamflow Gauge Dec 0.28 0.24 0.02 1.07 0.05 0.13 0.16 0.20 0.24 0.27 0.30 0.43 0.62 Dec PoR 1.04 0.29 0.00 26.80 0.05 0.11 0.17 0.23 0.29 0.42 0.58 0.87 2.40 PoR

6 all flow s mean Jan median Feb 10th Mar 2.0 min 8 Ap r 5 May Jun Jul Au g Se p Oct 4 Nov 1.5 6 Dec MAD

3 4 1.0 Flow (cms)

2 Flow (cms) Flow (cms)

2 0.5 1 MAD

Median 0 0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 Quantiles of observed flow s

2.0 mean min 15

1.5

1.0 Flow (cms) Flow Flow (cms)

5 0.5

0.0 0 15 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Station Name: Guichon Creek near Lower Nicola Logan Lake Station ID: 08LG004 Stump Lake Spences Bridge

Period of record: 1911-1984 e

e N r C ic

o n Complete records: 20 years l a o R

i ch v i e 2 r u Drainage area: 1230 km G 150 Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 1.04 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 27.76 L m year Collettville

k e e r k C ree ena C s uilch u Q i p S 100 Canyon Alpine

r North Bend e Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 50 Number of Days Apr to Oct

1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 Jan Feb Mar Apr Jan Feb Mar Apr 3.0

with Less Than September Median Flow 0

2.5 1.5 2.0 1965 1970 1975 1980

1.0 1.5 1965 1970 1975 1980 1965 1970 1975 1980 1.0 0.5 Jan Feb Mar Apr 0.5 0.2 0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.1 3.0 0.0 2.5 1.5 2.0 -0.1

1.0 1.5 -0.2

1.0 -0.3 0.5 May Jun Jul Aug 0.5

0.0 0.0 0.2 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 3.0 0.1

2.5 1.5 0.0 2.0 -0.1 1.0 1.5 -0.2 1.0 0.5 -0.3 0.5 Sep Oct Nov Dec

0.0 0.0 Residual monthly flow 0.2 1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 0.1

0.0

1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 -0.1 Jan Feb Mar Apr Jan Feb Mar Apr -0.2 2.5 2.0 -0.3 2.0 1.5 1965 1970 1975 1980 1965 1970 1975 1980 1.5 1.0 1.0

0.5 0.5

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 2.5 2.0

2.0 1.5 1.5 1.0 1.0

0.5 0.5

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 2.5 2.0

10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 2.0 1.5 1.5 1.0 1.0

0.5 0.5 16 0.0 0.0

1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 1965 1970 1975 1980 Knutsford percentiles Bestw ick Monte Lake month mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Station Name: Guichon Creek at Mouth Logan Lake Jan 0.22 0.22 0.01 0.73 0.03 0.05 0.12 0.19 0.22 0.23 0.26 0.31 0.46 Jan Station ID: 08LG067 Stump Lake Spences Bridge Feb 0.30 0.23 0.01 6.39 0.03 0.05 0.16 0.21 0.23 0.27 0.32 0.38 0.54 Feb

Period of record: 1984-2003 e

e N r C ic Mar 0.31 0.26 0.01 1.49 0.03 0.08 0.18 0.23 0.26 0.30 0.36 0.48 0.73 Mar

o n Complete records: 19 years l a o R

i ch v i e 2 r u Apr 0.66 0.37 0.01 12.00 0.03 0.09 0.20 0.28 0.37 0.47 0.65 0.84 1.60 Apr Drainage area: 1230 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 0.74 m sec Low er Nicola Coy le May 2.59 1.09 0.00 35.60 0.07 0.32 0.52 0.75 1.09 1.62 2.27 3.24 4.81 May Merritt -2 -1 Merritt Runoff: 19.74 L m year Collettville Jun 1.98 0.93 0.02 11.60 0.07 0.26 0.67 0.77 0.93 1.24 2.11 3.19 5.55 Jun

k e e r k C ree ena C Jul 1.07 0.59 0.01 7.64 0.06 0.22 0.36 0.49 0.59 0.74 0.90 1.70 2.63 Jul s uilch u Q i p S Aug 0.52 0.25 0.01 4.25 0.07 0.13 0.17 0.20 0.25 0.50 0.68 0.78 0.94 Aug Canyon Alpine

r North Bend e Trépanier Boston Bar iv Sep 0.37 0.26 0.02 1.87 0.07 0.13 0.20 0.23 0.26 0.31 0.54 0.66 0.75 Sep R Pe

r e t a w Oct 0.32 0.24 0.01 1.55 0.04 0.08 0.15 0.19 0.24 0.28 0.40 0.53 0.73 Oct ld Osprey Lake Bankeir o C Nov 0.26 0.21 0.01 1.07 0.03 0.05 0.10 0.18 0.21 0.25 0.29 0.42 0.55 Nov Streamflow Gauge Dec 0.24 0.20 0.01 1.12 0.03 0.05 0.10 0.14 0.20 0.24 0.28 0.34 0.57 Dec PoR 0.74 0.28 0.00 35.60 0.04 0.09 0.18 0.23 0.28 0.38 0.57 0.77 1.52 PoR

all flow s mean Jan median Feb 3.0 10th Mar min Apr 2.5 May 4 Jun Jul Aug 2.5 Sep Oct 2.0 Nov Dec 3 MAD 2.0

1.5 1.5 2 Flow (cms) Flow (cms)

1.0 Flow (cms) 1.0 MAD 1 0.5 0.5 Median

0.0 0 0.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 Quantiles of observed flow s

mean 1.0 September min 20

0.8

0.6

10 0.4 Flow (cms) Flow Flow (cms)

5 0.2

0.0 0 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 17 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestw ick Monte Lake

Brigade Lake Westw old Station Name: Guichon Creek at Mouth Logan Lake Station ID: 08LG067 200 Stump Lake Spences Bridge

Period of record: 1984-2003 e

e N r C ic

o n Complete records: 19 years l a o R

i ch v i e 2 r u

Drainage area: 1230 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. 150 Mean Annual Discharge: 0.74 m sec Low er Nicola Coy le Merritt -2 -1 Merritt Runoff: 19.74 L m year Collettville

k e e r k C ree ena C s uilch u Q i p

Canyon Alpine 100 r North Bend e Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 50 Number of Days Apr to Oct

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr Jan Feb Mar Apr 1.5

with Less Than September Median Flow 0 0.8

0.6 1.0 1985 1990 1995 2000

0.4 0.5 1985 1990 1995 2000 1985 1990 1995 2000 0.2 Jan Feb Mar Apr

0.0 0.0 0.3 May Jun Jul Aug May Jun Jul Aug 1.5 0.2 0.8 0.1

1.0 0.6 0.0

0.4 -0.1 0.5 0.2 -0.2 May Jun Jul Aug 0.0 0.0 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec 0.3

Minimum Flow (cms) Minimum Flow 1.5 0.2 0.8

0.1 0.6 1.0 0.0 0.4 0.5 -0.1 0.2 -0.2

0.0 0.0 Sep Oct Nov Dec Residual monthly flow 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 0.3

0.2

0.1

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 0.0

Jan Feb Mar Apr Jan Feb Mar Apr -0.1 1.0

1.5 -0.2 0.8 1985 1990 1995 2000 1985 1990 1995 2000 0.6 1.0

0.4 0.5 0.2

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 1.0

1.5 0.8

0.6 1.0

0.4 0.5 0.2

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 1.0

1.5

10th Percentile Flow (cms) 10th Percentile 0.8 90th Percentile Flow (cms)

0.6 1.0

0.4 0.5 0.2 18 0.0 0.0

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Knutsford percentiles Bestw ick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month Brigade Lake Westw old Station Name: Guichon Creek at Mouth Logan Lake Jan 0.25 0.23 0.01 0.73 0.04 0.10 0.16 0.21 0.23 0.26 0.30 0.38 0.48 Jan combined with Guichon Creek near Stump Lake Spences Bridge Feb 0.31 0.25 0.01 6.39 0.05 0.15 0.20 0.23 0.25 0.28 0.33 0.44 0.57 Feb

Lower Nicola e

e N r C ic o n Mar 0.36 0.30 0.01 1.49 0.07 0.14 0.21 0.24 0.30 0.34 0.41 0.58 0.77 Mar Station ID: 08LG067 + 08LG004 l a o R

i ch v i e r u Period of record: 1911-2003 G Apr 0.75 0.43 0.01 12.00 0.05 0.17 0.26 0.34 0.43 0.61 0.81 1.18 1.70 Apr Lytton Nic Douglas Lake ola Nic ola R. Complete records: 39 years Low er Nicola Coy le Merritt May 4.00 1.79 0.00 35.60 0.10 0.43 0.73 1.21 1.79 2.64 3.94 7.69 11.80 May 2 Merritt Drainage area: 1230 km Collettville

3 -1 k e Jun 2.36 1.17 0.01 17.00 0.06 0.18 0.63 0.83 1.17 2.03 2.95 4.21 6.24 Jun Mean Annual Discharge: 0.89 m sec e r k C ree ena C -2 -1 s uilch u Q Runoff: 23.85 L m year i p Jul 1.03 0.61 0.00 8.18 0.03 0.11 0.29 0.50 0.61 0.80 1.04 1.63 2.58 Jul S

Canyon Alpine r Aug 0.45 0.22 0.00 4.59 0.03 0.07 0.12 0.17 0.22 0.35 0.54 0.73 0.91 Aug North Bend e Boston Bar iv Trépanier R Pe

r e t a Sep 0.33 0.22 0.00 2.97 0.04 0.08 0.11 0.15 0.22 0.27 0.35 0.56 0.72 Sep w ld Osprey Lake Bankeir o C Oct 0.29 0.20 0.00 1.55 0.03 0.08 0.13 0.17 0.20 0.26 0.33 0.51 0.65 Oct Streamflow Gauge Nov 0.27 0.21 0.00 1.33 0.04 0.07 0.12 0.17 0.21 0.25 0.29 0.45 0.65 Nov Dec 0.26 0.22 0.01 1.12 0.04 0.07 0.13 0.17 0.22 0.25 0.29 0.39 0.58 Dec PoR 0.89 0.28 0.00 35.60 0.04 0.10 0.17 0.23 0.28 0.40 0.58 0.81 1.91 PoR

all flows mean Jan median Feb 3.0 10th 4 Mar min Apr May 6 Jun Jul Aug 2.5 Sep Oct 3 Nov Dec MAD 2.0 4

2 1.5 Flow (cms) Flow (cms) Flow (cms) 1.0 2 1 MAD 0.5 Median 0 0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 Quantiles of observed flow s

median before 1983 2.0 mean median after 1983 September min 20

1.5 15

10 1.0 10 Flow (cms) Flow (cms) Flow Flow (cms)

5 0.5 5

0.0 0 0 19 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestw ick Monte Lake

Brigade Lake Westw old Station Name: Guichon Creek at Mouth Logan Lake combined with Guichon Creek near Stump Lake Spences Bridge 200

Lower Nicola e

e N r C ic

o n Station ID: 08LG067 + 08LG004 l a o R

i ch v i e r u

Period of record: 1911-2003 G Lytton Nic Douglas Lake ola Nic ola R. Complete records: 39 years Low er Nicola Coy le Merritt 2 Merritt 150 Drainage area: 1230 km Collettville

3 -1 k e Mean Annual Discharge: 0.89 m sec e r k C ree ena C -2 -1 s uilch u Q Runoff: 23.85 L m year i p

Canyon Alpine

r North Bend e 100 Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C

Streamflow Gauge 50 Number of Days Apr to Oct

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr

2.0 with Less Than September Median Flow 0

1.5 1.5 1970 1980 1990 2000

1.0 1.0 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr 0.5 0.5 0.3

0.2 0.0 0.0 May Jun Jul Aug May Jun Jul Aug 2.0 0.1

0.0 1.5 1.5 -0.1

1.0 1.0 -0.2

-0.3 0.5 0.5 May Jun Jul Aug 0.3

0.0 0.0 Mean Flow (cms) 0.2 Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 2.0 0.1

1.5 1.5 0.0

-0.1 1.0 1.0 -0.2

0.5 0.5 -0.3 Sep Oct Nov Dec

Residual monthly flow 0.3 0.0 0.0 0.2 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 0.1

0.0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 -0.1

Jan Feb Mar Apr Jan Feb Mar Apr -0.2 2.5 2.0 -0.3 2.0 1970 1980 1990 2000 1970 1980 1990 2000 1.5 1.5 1.0 1.0

0.5 0.5

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 2.5 2.0

2.0 1.5 1.5 1.0 1.0

0.5 0.5

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 2.5 2.0

10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 2.0 1.5 1.5 1.0 1.0

0.5 0.5 20 0.0 0.0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Knutsford percentiles Bestwick Monte Lake 10th 20th 30th 40th 50th 60th 70th 80th 90th Brigade Lake month mean median min max month Westw old Logan Lake Station Name: Guichon Creek Jan 0.2 0.2 0.0 0.5 0.0 0.0 0.1 0.1 0.2 0.2 0.3 0.3 0.4 Jan

Stump Lake at outlet of Mamit Lake Spences Bridge

k Feb 0.2 0.2 0.0 0.4 0.0 0.1 0.1 0.1 0.2 0.2 0.3 0.3 0.4 Feb

e Station ID: 08LG041 N r C ic

o n l Mar 0.2 0.2 0.0 0.9 0.0 0.1 0.1 0.1 0.2 0.3 0.3 0.4 0.4 Mar a o R

i ch Period of record: 1936-2003 v i e r u G Apr 0.5 0.3 0.0 8.1 0.0 0.1 0.2 0.3 0.3 0.4 0.6 0.7 1.4 Apr Lytton Nic Douglas Lake Complete records: 18 years ola Nic ola R. 2 Low er Nicola Coy le Merr itt May 2.6 1.5 0.0 23.1 0.4 0.7 0.8 1.2 1.5 1.8 2.4 3.1 6.6 May Drainage area: 842 km Merritt Collettville Mean Annual Discharge: 0.8 m3 sec-1 k Jun 2.2 1.4 0.2 9.8 0.5 0.7 1.0 1.1 1.4 1.8 2.3 3.5 5.4 Jun e e -2 -1 r k C ree Runoff: 30.34 L m year ena C s uilch u Q i Jul 1.4 1.0 0.2 7.6 0.5 0.6 0.8 0.8 1.0 1.2 1.6 2.0 3.0 Jul p

Canyon Alpine Aug 0.8 0.7 0.1 3.1 0.4 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 Aug r North Bend e Boston Bar iv Trépanier R Pe

r Sep 0.4 0.4 0.0 1.7 0.1 0.2 0.3 0.3 0.4 0.5 0.6 0.7 0.8 Sep e t a w ld Osprey Lake Bankeir o C Oct 0.3 0.3 0.0 0.9 0.0 0.1 0.1 0.2 0.3 0.4 0.4 0.5 0.6 Oct Nov 0.2 0.2 0.0 0.8 0.0 0.0 0.1 0.1 0.2 0.2 0.3 0.4 0.5 Nov Streamflow Gauge Dec 0.2 0.2 0.0 0.6 0.0 0.0 0.1 0.1 0.2 0.2 0.2 0.3 0.5 Dec PoR 0.8 0.4 0.0 23.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.9 1.7 PoR

5 all flow s mean Jan median Feb 10th Mar min 2.5 Apr May 2.0 Jun 4 Jul Aug Sep Oct 2.0 Nov Dec 1.5 3 MAD

1.5

2 1.0 Flow (cms) Flow (cms) Flow (cms) 1.0

MAD 1 0.5 0.5 Median

0.0 0 0.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Quantiles of observed flow s

14 mean 1.0 September min

0.8 10

0.6 8

6 0.4 Flow (cms) Flow Flow (cms)

4 0.2

0.0 0 21 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Guichon Creek 120 Stump Lake at outlet of Mamit Lake Spences Bridge

e Station ID: 08LG041 N r C ic

o n l a o R

i ch Period of record: 1936-2003 v i e 100 r u

G Lytton Nic Douglas Lake Complete records: 18 years ola Nic ola R. 2 Low er Nicola Coy le Merr itt Drainage area: 842 km Merritt Collettville Mean Annual Discharge: 0.8 m3 sec-1 80 k e e -2 -1 r k C ree Runoff: 30.34 L m year ena C s uilch u Q i p

Canyon Alpine 60 r North Bend e Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C 40

Streamflow Gauge

20 Number of Days Apr to Oct

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr Jan Feb Mar Apr 1.0

with Less Than September Median Flow 0 1.0

0.8 0.8 1985 1990 1995 2000 0.6 0.6 1985 1990 1995 2000 1985 1990 1995 2000 0.4 0.4 Jan Feb Mar Apr 0.3 0.2 0.2

0.2 0.0 0.0 May Jun Jul Aug May Jun Jul Aug 1.0 0.1 1.0

0.8 0.8 0.0

0.6 0.6 -0.1

0.4 0.4 -0.2 May Jun Jul Aug 0.3 0.2 0.2

0.0 0.0 0.2 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum Flow 1.0 1.0 0.1

0.8 0.8 0.0

0.6 0.6 -0.1

0.4 0.4 -0.2 Sep Oct Nov Dec 0.2 0.2 0.3 Residual monthly flow

0.0 0.0 0.2 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 0.1

0.0

-0.1

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 -0.2 Jan Feb Mar Apr Jan Feb Mar Apr 1985 1990 1995 2000 1985 1990 1995 2000 1.5 1.0

0.8 1.0 0.6

0.4 0.5

0.2

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 1.5 1.0

0.8 1.0 0.6

0.4 0.5

0.2

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 1.5 1.0

10th Percentile Flow (cms) 10th Percentile 0.8 90th Percentile Flow (cms) 1.0 0.6

0.4 0.5 0.2 22 0.0 0.0

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Knutsford percentiles Bestwick Monte Lake month mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Logan Lake Station Name: Guichon Creek above Jan 0.03 0.03 0.01 0.11 0.01 0.02 0.02 0.02 0.03 0.03 0.03 0.04 0.05 Jan

Stump Lake Tunkwa Lake Diversion Spences Bridge

k Feb 0.03 0.03 0.01 0.12 0.01 0.02 0.02 0.02 0.03 0.04 0.04 0.05 0.05 Feb

e Station ID: 08LG056 N r C ic

o n l Mar 0.04 0.04 0.01 0.12 0.02 0.02 0.03 0.03 0.04 0.05 0.05 0.06 0.07 Mar a o R

Period of record: 1967-2003 i ch v i e r u G Apr 0.13 0.10 0.01 0.88 0.04 0.06 0.07 0.09 0.10 0.12 0.14 0.17 0.23 Apr Complete records: 33 years Lytton Nic Douglas Lake ola Nic ola R. 2 Low er Nicola Coy le Drainage area: 78.2 km Merr itt May 0.52 0.34 0.05 2.92 0.14 0.20 0.25 0.29 0.34 0.44 0.59 0.83 1.13 May Merritt Mean Annual Discharge: 0.13 m3 sec-1 Collettville k Jun 0.38 0.25 0.02 2.33 0.10 0.14 0.18 0.21 0.25 0.31 0.43 0.58 0.86 Jun e e -2 -1 r k Runoff: 53.6 L m year C ree ena C s uilch u Q i Jul 0.16 0.10 0.01 2.30 0.03 0.04 0.06 0.08 0.10 0.13 0.17 0.22 0.33 Jul p

S Canyon Alpine Aug 0.07 0.04 0.00 0.77 0.02 0.02 0.03 0.03 0.04 0.05 0.06 0.09 0.14 Aug r North Bend e Boston Bar iv Trépanier R Pe

r e Sep 0.05 0.04 0.01 0.47 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.07 0.09 Sep t a w ld Osprey Lake Bankeir o C Oct 0.05 0.04 0.01 0.16 0.03 0.03 0.04 0.04 0.04 0.05 0.05 0.06 0.08 Oct

Streamflow Gauge Nov 0.04 0.04 0.01 0.13 0.02 0.02 0.030.030.040.040.050.060.07Nov Dec 0.03 0.03 0.01 0.11 0.01 0.02 0.020.020.030.030.040.040.05Dec PoR 0.13 0.05 0.00 2.92 0.02 0.02 0.03 0.04 0.05 0.06 0.09 0.15 0.30 PoR

all flow s mean Jan 0.30 median Feb 10th Mar min 0.8 Ap r 0.5 May Jun 0.25 Jul Au g Se p Oct 0.4 Nov 0.6 Dec 0.20 MAD

0.3 0.15 0.4 Flow (cms) Flow (cms) 0.2 Flow (cms) 0.10

MAD 0.2 0.1 0.05

Median

0.0 0.0 0.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 Quantiles of observed flow s

median before 1985 mean median after 1985 September 1.4 min 0.20 1.5 1.2

1.0 0.15

1.0 0.8 0.10 0.6 Flow (cms) Flow (cms) Flow Flow (cms)

0.5 0.4 0.05

0.2

0.0 0.0 0.0 23 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Logan Lake Station Name: Guichon Creek above 120 Stump Lake Tunkwa Lake Diversion Spences Bridge

e Station ID: 08LG056 N r C ic

o n l a o R

Period of record: 1967-2003 i ch v i e r u 100

G Complete records: 33 years Lytton Nic Douglas Lake ola Nic ola R. 2 Low er Nicola Coy le Drainage area: 78.2 km Merr itt Merritt 3 -1 Collettville Mean Annual Discharge: 0.13 m sec 80 k e e -2 -1 r k Runoff: 53.6 L m year C ree ena C s uilch u Q i p

Canyon Alpine r 60 North Bend e Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C 40

Streamflow Gauge

20 Number of Days Apr to Oct

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr 0.14

0.20 with Less Than September Median Flow 0 0.12

0.10 0.15 1970 1980 1990 2000 0.08

0.06 0.10 1985 1990 1995 2000 1985 1990 1995 2000 0.04 0.05 Jan Feb Mar Apr 0.02 0.3

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.2 0.14 0.20 0.12 0.1

0.10 0.15 0.0 0.08

0.06 0.10 -0.1

0.04 0.05 -0.2 0.02 May Jun Jul Aug 0.3 0.0 0.0 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec 0.14

Minimum Flow (cms) Minimum Flow 0.2 0.20 0.12 0.1 0.10 0.15 0.08 0.0

0.06 0.10 -0.1 0.04 0.05 0.02 -0.2 Sep Oct Nov Dec 0.0 0.0 0.3 Residual monthly flow 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 0.2

0.1

0.0 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000

Jan Feb Mar Apr Jan Feb Mar Apr -0.1 0.14

0.12 0.3 -0.2

0.10 1985 1990 1995 2000 1985 1990 1995 2000 0.08 0.2

0.06

0.04 0.1

0.02

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.14

0.12 0.3

0.10

0.08 0.2

0.06

0.04 0.1

0.02

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 0.14

0.12 0.3 10th Percentile Flow (cms) 10th Percentile 90th Percentile Flow (cms) 0.10

0.08 0.2

0.06

0.04 0.1

0.02 0.0 0.0 24 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 percentiles Knutsford Bestwick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month

Brigade Lake Westw old Station Name: Pennask Creek near Quilchena Logan Lake Jan0.130.120.030.330.070.080.090.110.120.140.160.180.20Jan

Station ID: 08LG016 Stump Lake Feb0.120.120.030.310.070.090.100.110.120.130.140.160.18Feb Spences Bridge

Period of record: 1920-2003 e

e r Mar0.140.140.050.510.080.090.100.120.140.150.160.180.20Mar N C ic

o n Complete records: 33 years l a o R

i ch v i Apr0.530.260.066.990.110.140.170.200.260.330.460.711.43Apr e 2 r u

Drainage area: 87 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. May 3.18 2.51 0.09 12.80 0.85 1.28 1.65 2.10 2.51 3.06 3.82 4.81 6.44 May Mean Annual Discharge: 0.74 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 286.6 L m year Collettville Jun 2.90 2.11 0.25 17.70 0.70 1.01 1.33 1.70 2.11 2.69 3.45 4.44 6.01 Jun

k e e Jul0.760.550.076.150.160.250.340.430.550.710.871.091.57Jul r k C ree ena C s uilch u Q i p Aug0.270.180.013.100.060.090.120.160.180.230.290.380.58Aug S

Canyon Alpine r Sep0.200.160.021.150.060.080.100.130.160.190.230.300.43Sep North Bend e Boston Bar iv Trépanier R Pe

r e t Oct0.190.170.030.930.080.090.120.140.170.200.230.280.34Oct a w ld Osprey Lake Bankeir o C Nov0.240.170.043.090.090.120.130.150.170.210.240.290.41Nov

Streamflow Gauge Dec0.190.140.042.940.080.100.110.120.140.160.190.230.28Dec PoR 0.74 0.19 0.01 17.70 0.08 0.11 0.13 0.16 0.19 0.24 0.37 0.80 2.12 PoR

all flows mean Jan 1.2 median Feb 10th 5 Mar min Apr 3 May Jun Jul 1.0 Aug 4 Sep Oct Nov Dec 0.8 MAD 2 3 0.6

2 Flow (cms) Flow (cms) Flow (cms) 0.4 1 MAD 1 0.2

Median 0 0 0.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Quantiles of observed flow s

median before 1987 mean median after 1987 September min 10 8 0.5

8 0.4 6

6 0.3

Flow (cms) Flow (cms) Flow 0.2 4 Flow (cms)

2 0.1 2

0.0 0 0 25 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Station Name: Pennask Creek near Quilchena Logan Lake Station ID: 08LG016 Stump Lake Spences Bridge 120

Period of record: 1920-2003 e

e N r C ic

o n Complete records: 33 years l a o R

i ch v i e 2 r u 100

Drainage area: 87 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 0.74 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 286.6 L m year Collettville 80

k e e r k C ree ena C s uilch u Q i p S 60 Canyon Alpine

r North Bend e Boston Bar iv Trépanier R Pe

r e t a w 40 ld Osprey Lake Bankeir o C

Streamflow Gauge Number of Days Apr to Oct 20

with Less Than September Median Flow 0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr

0.4 0.5 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr 0.4 0.3 0.15

0.3 0.10 0.2 0.2 0.05 0.1 0.1 0.0 0.0 0.0 May Jun Jul Aug May Jun Jul Aug -0.05

0.4 0.5 -0.10 May Jun Jul Aug 0.4 0.3 0.15

0.3 0.10 0.2 0.2 0.05 0.1 0.1 0.0 0.0 0.0 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec -0.05 Minimum Flow (cms) Minimum 0.4 0.5 -0.10 Sep Oct Nov Dec 0.4 0.3 0.15 Residual monthly flow

0.3 0.10 0.2 0.2 0.05 0.1 0.1 0.0 0.0 0.0 -0.05 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000

-0.10 1970 1980 1990 2000 1970 1980 1990 2000

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 Jan Feb Mar Apr Jan Feb Mar Apr 0.8 0.5

0.4 0.6

0.3 0.4 0.2 0.2 0.1

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.8 0.5

0.4 0.6

0.3 0.4 0.2 0.2 0.1

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 0.8 0.5

10th Percentile Flow (cms) Flow 10th Percentile 0.4 90th Percentile Flow (cms) 0.6

0.3 0.4

0.2 0.2 26 0.1

0.0 0.0

1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 1970 1980 1990 2000 percentiles Knutsford Bestwick th th th th th th th th th Monte Lake month mean median min max 10 20 30 40 50 60 70 80 90 month

Brigade Lake Westw old Station Name: Beak Creek at Mouth Logan Lake Jan 0.08 0.07 0.01 0.26 0.02 0.03 0.04 0.06 0.07 0.09 0.10 0.11 0.13 Jan

Station ID: 08LG064 Stump Lake Feb 0.08 0.08 0.01 0.22 0.02 0.04 0.05 0.07 0.08 0.09 0.10 0.11 0.13 Feb Spences Bridge

Period of record: 1982-2001 e

e r Mar 0.13 0.11 0.01 0.90 0.02 0.05 0.06 0.09 0.11 0.13 0.15 0.18 0.22 Mar N C ic

o n Complete records: 18 years l a o R

i ch v i Apr 0.81 0.52 0.03 4.30 0.18 0.23 0.32 0.42 0.52 0.68 0.90 1.18 1.98 Apr e 2 r u

Drainage area: 85 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. May 2.22 1.87 0.28 12.50 0.69 0.93 1.19 1.43 1.87 2.27 2.63 3.22 4.32 May Mean Annual Discharge: 0.47 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 183.3 L m year Collettville Jun 1.22 0.86 0.05 8.80 0.21 0.32 0.47 0.63 0.86 1.09 1.32 1.76 2.71 Jun

k e e Jul 0.52 0.32 0.01 4.82 0.05 0.12 0.17 0.24 0.32 0.43 0.57 0.79 1.14 Jul r k C ree ena C s uilch u Q i p Aug 0.17 0.10 0.00 2.02 0.02 0.03 0.05 0.07 0.10 0.13 0.16 0.23 0.40 Aug S

Canyon Alpine r Sep 0.12 0.08 0.00 1.23 0.01 0.03 0.05 0.06 0.08 0.10 0.14 0.17 0.26 Sep North Bend e Boston Bar iv Trépanier R Pe

r e t Oct 0.11 0.09 0.00 0.96 0.03 0.05 0.06 0.08 0.09 0.11 0.13 0.15 0.20 Oct a w ld Osprey Lake Bankeir o C Nov 0.13 0.09 0.02 0.72 0.04 0.05 0.07 0.08 0.09 0.12 0.16 0.20 0.24 Nov

Streamflow Gauge Dec 0.10 0.08 0.02 0.66 0.03 0.04 0.06 0.07 0.08 0.09 0.11 0.14 0.17 Dec PoR 0.47 0.13 0.00 12.50 0.03 0.06 0.07 0.10 0.13 0.17 0.27 0.58 1.34 PoR

2.5 all flow s mean Jan median Feb 10th 3.0 Mar min Apr May 0.8 2.0 Jun Jul Aug 2.5 Sep Oct Nov Dec 0.6 1.5 2.0 MAD

1.5 1.0 0.4 Flow (cms) Flow (cms) Flow (cms) 1.0

0.5 MAD 0.2 0.5

Median 0.0 0.0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1983 1985 1987 1989 1991 1993 1995 1997 1999 Quantiles of observed flow s

median before 1992 0.25 mean median after 1992 September 6 min

6 5 0.20

4 0.15

4 3 0.10 Flow (cms) Flow (cms) Flow Flow (cms) 2 2 0.05

0.0 0 0 1983 1985 1987 1989 1991 1993 1995 1997 1999 27 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Bestwick Monte Lake

Brigade Lake Westw old Station Name: Beak Creek at Mouth Logan Lake Station ID: 08LG064 120 Stump Lake Spences Bridge

Period of record: 1982-2001 e

e N r C ic

o n Complete records: 18 years l a o R 100 i ch v i e 2 r u

Drainage area: 85 km G Lytton Nic Douglas Lake ola 3 -1 Nic ola R. Mean Annual Discharge: 0.47 m sec Low er Nicola Coy le Merr itt -2 -1 Merritt Runoff: 183.3 L m year Collettville 80

k e e r k C ree ena C s uilch u Q i p 60 S

Canyon Alpine

r North Bend e Boston Bar iv Trépanier R Pe

r e t a 40 w ld Osprey Lake Bankeir o C

Streamflow Gauge Number of Days Apr to Oct 20

with Less Than September Median Flow 0

1985 1990 1995 2000

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr Jan Feb Mar Apr 0.25 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr 0.20 0.20 0.10

0.15 0.15 0.05 0.10 0.10

0.0 0.05 0.05

0.0 0.0 -0.05 May Jun Jul Aug May Jun Jul Aug 0.25 May Jun Jul Aug 0.20 0.20 0.10

0.15 0.15 0.05 0.10 0.10

0.0 0.05 0.05

0.0 0.0 -0.05 Mean Flow (cms) Sep Oct Nov Dec Sep Oct Nov Dec

Minimum Flow (cms) Minimum 0.25 Sep Oct Nov Dec 0.20 0.20 Residual monthly flow 0.10

0.15 0.15 0.05 0.10 0.10

0.0 0.05 0.05

0.0 0.0 -0.05

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000

1985 1990 1995 2000 1985 1990 1995 2000

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr Jan Feb Mar Apr 0.25

0.6 0.20

0.15 0.4

0.10 0.2 0.05

0.0 0.0 May Jun Jul Aug May Jun Jul Aug 0.25

0.20 0.6

0.15 0.4

0.10 0.2 0.05

0.0 0.0 Sep Oct Nov Dec Sep Oct Nov Dec 0.25

0.20 0.6 10th Percentile Flow (cms) Flow 10th Percentile 90th Percentile Flow (cms)

0.15 0.4

0.10 0.2 0.05 28 0.0 0.0

1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 1985 1990 1995 2000 percentiles Knutsford

Station Name: Spahomin Creek near Douglas Lake Bestw ick Monte Lake mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Station ID: 08LG018 Brigade Lake Westw old Logan Lake JanNANANANANANANANANANANANANAJan Period of record: 1920-1967 FebNANANANANANANANANANANANANAFeb Complete records: 0 years Stump Lake Spences Bridge

2 k MarNANANANANANANANANANANANANAMar e

Drainage area: 233 km e N r C ic

o n l Apr 0.294 0.255 0.000 1.730 0.000 0.127 0.242 0.255 0.255 0.314 0.367 0.428 0.510 Apr Mean Annual Discharge: NA a o R

i ch ve i r u Runoff: NA G May 1.300 0.943 0.127 6.800 0.227 0.283 0.439 0.659 0.943 1.168 1.273 1.858 3.235 May Lytton Nic Douglas Lake ola Nic ola R. Low er Nicola Coy le Jun 2.344 1.995 0.558 9.490 0.838 1.026 1.190 1.634 1.995 2.440 2.762 3.124 4.820 Jun Merritt Merritt Collettville Jul 0.944 0.616 0.105 3.200 0.259 0.368 0.481 0.519 0.616 0.762 1.042 1.560 2.320 Jul

k e e r k Aug 0.168 0.127 0.014 0.906 0.025 0.071 0.093 0.109 0.127 0.152 0.222 0.280 0.329 Aug C ree ena C s uilch u Q i p S Sep 0.099 0.085 0.003 0.496 0.003 0.014 0.031 0.057 0.085 0.099 0.113 0.172 0.242 Sep

Canyon Alpine

North Bend r OctNANANANANANANANANANANANANAOct e Boston Bar iv Trépanier R Pe

r e t NovNANANANANANANANANANANANANANov a w ld Osprey Lake Bankeir o C DecNANANANANANANANANANANANANADec PoR 0.934 0.396 0.000 9.490 0.042 0.105 0.186 0.265 0.396 0.597 0.991 1.560 2.630 PoR Streamflow Gauge

all flows max 5 Jan 2.5 Feb 90th Mar mean Apr median May Jun 8 10th 4 Jul 2.0 Au g Se p Oct Nov Dec MAD 6 1.5 3

4 1.0 2 Flow (cms) Flow (cms) Flow (cms)

0.5 1 2

0.0 0 0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.00.20.40.60.81.0 1920 1924 1928 1932 1936 1940 1944 1948 1952 1956 1960 1964 Quantiles of observed flow s

mean min

1.5

3 1.0 Flow (cms) Flow 2 Flow (cms) 0.5

0.0 0 1920 1924 1928 1932 1936 1940 1944 1948 1952 1956 1960 1964 29 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford percentiles Station Name: Spahomin Creek near the mouth Bestw ick Monte Lake Station ID: 08LG060 mean median min max 10th 20th 30th 40th 50th 60th 70th 80th 90th month Brigade Lake Westw old Period of record: 1972-1996 Logan Lake Jan 0.216 0.200 0.003 0.630 0.057 0.092 0.144 0.178 0.200 0.219 0.250 0.325 0.419 Jan

Complete records: 23 years Stump Lake Feb 0.248 0.235 0.007 0.650 0.085 0.147 0.188 0.212 0.235 0.261 0.297 0.343 0.430 Feb Spences Bridge

2 k e

Drainage area: 241 km e r Mar 0.310 0.301 0.048 0.660 0.194 0.228 0.252 0.277 0.301 0.328 0.352 0.399 0.462 Mar N C ic 3 -1 o n l Mean Annual Discharge: 0.678 m sec a o R Apr 0.413 0.362 0.074 1.480 0.263 0.289 0.320 0.340 0.362 0.391 0.436 0.513 0.630 Apr i ch ve i -2 -1 r u Runoff: 87.4 L m year G Lytton Nic Douglas Lake ola May 1.497 1.120 0.238 5.350 0.452 0.665 0.767 0.891 1.120 1.330 1.671 2.460 3.090 May Nic ola R. Low er Nicola Coy le Merritt Merritt Jun 2.716 2.665 0.767 7.900 1.049 1.268 1.720 2.336 2.665 3.038 3.400 3.656 4.485 Jun Collettville

k Jul 1.429 1.250 0.146 4.030 0.551 0.795 0.929 1.070 1.250 1.498 1.750 2.070 2.607 Jul e e r k C ree ena C s uilch Aug 0.566 0.480 0.051 2.320 0.110 0.221 0.284 0.350 0.480 0.573 0.682 0.810 1.157 Aug u Q i p S Sep 0.281 0.215 0.016 1.810 0.054 0.078 0.134 0.180 0.215 0.260 0.314 0.391 0.547 Sep Canyon Alpine

r North Bend e Boston Bar iv Trépanier Pe Oct 0.149 0.100 0.000 1.140 0.040 0.062 0.074 0.088 0.100 0.118 0.147 0.210 0.296 Oct R

r e t a w Nov 0.133 0.100 0.001 0.589 0.040 0.057 0.065 0.082 0.100 0.120 0.170 0.207 0.249 Nov ld Osprey Lake Bankeir o C Dec 0.163 0.134 0.003 0.985 0.037 0.057 0.085 0.105 0.134 0.158 0.190 0.227 0.308 Dec Streamflow Gauge PoR 0.678 0.300 0.000 7.900 0.067 0.113 0.185 0.238 0.300 0.383 0.550 0.963 1.910 PoR

3.0 all flows Jan 8 max Feb Mar 90th Apr mean May median 2.5 3 Jun 10th Jul Aug Sep Oct 6 Nov 2.0 Dec MAD

2 1.5 4 Flow (cms) Flow 1.0 Flow (cms) Flow (cms) 1 MAD 2 0.5 Median

0.0 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0.0 0.2 0.4 0.6 0.8 1.0 1972 1975 1978 1981 1984 1987 1990 1993 1996 Quantiles of observed flows

4 median before 1984 mean median after 1984 September min 1.0 4

3 0.8

3 0.6 2

Flow (cms) Flow (cms) 0.4 Flow (cms)

1 1 0.2

0.0 30 0 0 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Knutsford

Station Name: Spahomin Creek near the mouth Bestw ick Monte Lake Station ID: 08LG060 Brigade Lake Westw old Period of record: 1972-1996 Logan Lake

Complete records: 23 years Stump Lake Spences Bridge 200

2 k e

Drainage area: 241 km e N r C ic

o n l Mean Annual Discharge: 0.678 a o R

i ch ve i r u Runoff: 87.4L m-2 year-1 G Lytton Nic Douglas Lake ola Nic ola R. Low er Nicola Coy le 150 Merritt Merritt Collettville

k e e r k C ree ena C s uilch u Q i p

Canyon Alpine 100

r North Bend e Boston Bar iv Trépanier R Pe

r e t a w ld Osprey Lake Bankeir o C 50 Streamflow Gauge Number of Days Apr to Oct

with Less Than September Median Flow 0

1975 1980 1985 1990 1995

1985 1990 1995 2000 1985 1990 1995 2000 Jan Feb Mar Apr

0.10

0.05

0.0

-0.05

May Jun Jul Aug

0.10

0.05

0.0

-0.05

Sep Oct Nov Dec

Residual monthly flow 0.10

0.05

0.0

-0.05

1985 1990 1995 2000 1985 1990 1995 2000