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original signed by

Barry Chilibeck, M.A.Sc., P. Eng. northwest hydraulic consultants Middle and Upper Vernon Creek Hydrological Analysis

Prepared For:

Ministry of Water, Land, and Air Protection 201 - 3547 Skaha Lake Road Penticton, BC V2A 7K2

Prepared By:

northwest hydraulic consultants 30 Gostick Place North Vancouver, BC V7M 3G2

May 2003

3-3787 Table of Contents . . Study Scope and Objectives ...... 1 Previous Studies ...... 2 Watershed Characteristics ...... 4 Watershed Setting ...... 4 Climatology ...... -5 Hydrology ...... 6 Fisheries Resources ...... 8 lnstrearn Flows for Fish and Fish Habitat ...... 9 Historical Instream Flows...... 10 Proposed Instream Flows ...... 10 Water Use ...... 12 Water Licenses ...... 12 Actual Water Use ...... 12 Calculation of Water Use Demand ...... 13 Return Flows from Water Use ...... 13 Water Balance Model ...... 15 Sensitivity to Water Use ...... 16 Accuracy to Gauged Stations ...... 16 Model Output and Results ...... 16 Discussion ...... 18 Potential Solutions for Instream Flow Deficits ...... 20 Recommendations ...... 23 Glossary ...... 25 Definitions ...... 25 Notation ...... 25 Acronyms ...... 25 References ...... 26 Tables ...... 29 Figures...... 53 Appendices...... -78 Model Parameters. Options and Output ...... 79

Middle and Upper Vernon Creek Hydrological Analysis 1 List of Tables Table 1 Water Survey Gauges used in the Analysis of Middle and Upper Vernon Creek Watershed ...... 30 Table 2 Sub-basin Watershed Summary ...... 31 Table 3 Summary of Gauged Stations in Regional Analysis of Mean Monthly Flows ...... 32 Table 4 Mean Annual Monthly Runoff Distribution ...... 34 Table 5 Mean Annual Runoff Relationships (Coulson and Hunter 1974) ...... 34 Table 6 Comparison of Gross Unit Runoff in Inches for Minimum. Mean and Maximum Years ...... 34 Table 7 Mean Annual Runoff Estimates by Sub-basin ...... 35 Table 8 Mean Monthly Flow Estimates by Sub-basin ...... 35 Table 9 Referenced Instream Flows for Lower Vernon Creek ...... 37 Table 10 Flow Standards and Required Duration-of-Flow...... 37 Table 1 I Recommended Middle Vernon Creek lnstream Flows ...... 38 Table 12 Recommended Upper Vernon Creek Instream Flows ...... 39 Table 1 3 Water Management Branch Water Use Classifications Applicable to Middle and Upper Vernon Licensees ...... 41 Table 14 Summary of all Water Licenses Issued within Middle and Upper Vernon Creek Watershed by Source ...... 42 Table 15 Comparison between District of Lake Country Diversions and Licensed Amount (1 972 . 2002) ...... 45 Table 16 Distribution of Water Demand for Water Balance Model ...... 46 Table 17 Distribution of DLC Water Demand by Month (1994) ...... 46 Table 18 Modelled Annual Demand for 1 969- 1 995 ...... 47 Table 19 Sensitivity of Middle Vernon Creek Predicted Net Runoff to Changes in Water Use Demand ...... -48 Table 20 Comparison of Predicted Net Runoff with Measured Net Runoff ...... 49 Table 2 1 Estimated Flow Reliability of Upper and Middle Vernon Creek ...... 50 Table 22 Modelled Instream Flows in Upper and Middle Vernon Creek ...... 51

Middle and Upper Vernon Creek Hydrological Analysis i i List of Figures Figure 1 Vernon Creek and Sub-Basins ...... 54 Figure 2 Hydrologic Region 12 . Mean Annual Runoff ...... 55 Figure 3 Curves fit to Coulson and Hunter Elevation-Runoff Data (1 974) ...... 56 Figure 4 Vernon Creek Fish Periodicity Chart ...... 57 Figure 5 Middle Vernon Creek Sub-basin 1 . 4 Mean Monthly Naturalized Flows ...... 58 Figure 6 Upper Vernon Creek Sub-basin 1 Mean Monthly Naturalized Flows ...... 59 Figure 7 Clark Creek Sub-basin 2 Mean Monthly Naturalized Flows ...... 60 Figure 8 Ellison Lake Sub-basin 3 Mean Monthly Naturalized Flows ...... 61 Figure 9 Historical Daily Middle Vernon Creek Flows and Instream Standards ...... 62 Figure 10 Upper and Middle Vernon Creek Schematic ...... 63 Figure 1 1 Predicted and Actual values for Net Runoff in Upper Vernon Creek (Sub-basin 1) ...... 64 Figure 12 Predicted and Actual values for Net Runoff in Middle Vernon Creek (Sub-basin 4) ...... 65 Figure 13 Full-Record Hydrograph for Upper Vernon Creek (Sub-basin 1) ...... 66 Figure 14 Full-Record Hydrograph for Clark Creek (Sub-basin 2) ...... 67 Figure 15 Full-Record Hydrograph for Ellison Lake (Sub-basin 3) ...... 68 Figure 16 Full-Record Hydrograph for Middle Vernon Creek (Sub-basin 4) ...... 69 Figure 17 Mean Annual Hydrograph for Upper Vernon Creek (Sub-basin 1) ...... 70 Figure 18 Mean Annual Hydrograph for Clark Creek (Sub-basin 2) ...... 71 Figure 19 Mean Annual Hydrograph for Ellison Lake (Sub-basin 3) ...... 72 Figure 20 Mean Annual Hydrograph for Middle Vernon Creek (Sub-Basin 4) ...... 73 Figure 21 Flow Balance Summary for Upper Vernon Creek (Sub-basin 1) ...... 74

... Middle and Upper Vernon Creek Hydrological Analysis 111 Study Scope and Objectives Northwest Hydraulic Consultants (nhc) was retained by the Ministry of Water, Land and Air Protection (MWLAP) to refine the instream flow requirements for fish in the middle and upper portions of the Vernon Creek watershed. The following tasks were completed during the course of this study:

A review of pertinent literature on Vernon Creek, including the 1974 Water Investigations Branch Report: WRMS, the 2001 nhc report: Hydrology, Water Use and Conservation Flows for Kokanee Salnfon and Rainboll) Trout in the Okanagan Basin, BC, and the 2002 Geostream report: Middle Vernon Creek - Water Management Plan, Establishment of gross runoff hydrographs for Middle and Upper Vernon Creek for the period 1969 to 1995 using an update of the hydrologic analysis completed during the WRMS, Refinement of the rearing, spawning and flushing ilow requirements for Kokanee and Rainbow Trout in Middle and Upper Vernon Creek for dry, normal and wet runoff years using the gross runoff estimates minus evaporation losses, Verification of the flow budget of the Middle and Upper Vernon Creek systems based on available information, a An assessment of the systems ability to meet the refined instream flow requirements, using a model similar to that used by Letvak (1992), and A presentation and discussion of the model results, including options for the provision adequate fish ilows in Middle and Upper Vernon Creek.

Middle and Upper Vernon Creek Hydrological Analysis 1 Previous Studies The British Columbia Okanagan Basin Agreement Report (OBA) is a comprehensive land and water resource management study completed in the 1970s on the Okanagan Valley, including the Vernon Creek watershed, and Middle and Upper Vernon Creek. Chapter 10 of the report describes the operation of the reservoirs at Crooked Lake and Swalwell Lake, and provides a detailed schematic of the water supply and distribution system. An estimate of the water budget for the system, corrected for consumptive water use, is provided for drought, normal and high runoff years. Importantly, 32 years ago the OBA water budget model predicted deficiencies in meeting monthly fish flow requirements under all three runoff conditions, assuming that water use licenses were fully utilized.

The former Ministry of Lands, Forests and Water Resources (MLFWR) produced the Kalamalka - Wood Lake Basin Water Resource Management Study (WRMS) in 1974. Among other topics, the report examines surface water hydrology, groundwater hydrology and water use in Middle and Upper Vernon Creek. The pre-existing network of precipitation, temperature, evaporation, streamflow, lake level and snow course gauges formed the basis for a quantitative analysis of water movement in the basin for the period 1969 to 1973. Additional streamflow and lake level gauges were added to facilitate a more detailed analysis from December 197 1 to July 1973, which included investigations of lake evaporation and groundwater movement. Data collected during the study led to predictions of monthly basin runoff for several sub-basins within Middle and Upper Vernon Creek, which allowed the authors to test the adequacy of the water supply for representative drought, normal and high runoff years.

Water demand and consumptive use for the model were determined by comparing licensed amounts with measured withdrawals and return flows in the year 1972. The results of the analyses showed that Middle and Upper Vernon Creek water supply maintained in Crooked and Swalwel l Lakes would be inadequate to meet the demands of downstream users by the end of a three year drought.

Letvak (1992) produced a follow-up to the 1974 OBA report in which he attempted to update his assessment of the water supply capability of the Kalamalka-Wood Lake system. In this report, Letvak estimated the risk of system failure, given all water supply needs, for several drought scenarios. He concluded that the system could easily supply the 1992 annual licensed demand with little probability of failure.

In 2001, nhc produced a document for Ministry of Water, Land and Air Protection entitled Hydrology, Water Use and Conservation Flows for Kokanee Salmon and Rainbow Trout in the Okanagan Lake Basin, BC. This report includes estimates of 'naturalized' flows (net flows corrected for water use) and conservation flows for lower

Middle and Upper Vernon Creek Hydrological Analysis 2 Vernon Creek. The report also concluded that the Vernon Creek watershed had large water demands in excess of current storage and unusually low peak flows relative mean annual flows likely due to storage re-fill.

In March 2002, Geostream Environmental produced a Water Management Plan for middle Vernon Creek for the Oceola Fish and Game Club; this report includes a comprehensive plan and recommendations for the watershed. In addition to the Watershed Management Plan, Geostream Environmental with Columbia Environmental Consulting recently completed a biological and hydrological assessment of the Middle Vernon Creek Watershed (2003). As a part of this study, fish distribution sampling and habitat surveys were conducted in Vernon Creek.

Middle and Upper Vernon Creek Hydrological Analysis 3 Watershed Characteristics

Watershed Setting Vernon Creek has a drainage area of 748 km2, making it the third largest watershed in the Okanagan Basin after Mission Creek (845 km2) and Trout Creek (758 km2). Middle and Upper Vernon Creek drain an area of about 153.9 km2, from the headwaters downstream to Kalamalka - Wood Lake (Figure I). The headwaters are located atop the Okanagan Plateau, an area comprised of basalts from the Chilcotin Volcanics overlain by recent and late glacial features, specifically the Grizzly Upland, a meltwater rill complex of the recent glacial history with moraines, till deposits, and colluviums on steeper slopes (Fulton 1975). Over 50% of the watershed area is above el. 1300 m and extends up to an elevation of approximately 1490 m.

From the headwaters, Upper Vernon Creek runs through a series of small lakes, which are joined together as a result of backwatering from a dam on Crooked Lake. These lakes are formed from glacial depressions in the basalt that have infilled with silts, sands and gravels, and are separated by moraines or deposited alluvial materials. Passing through the Swalwell Lake reservoir, the creek drops steeply off the plateau at grades of approximately 9% through a confined channel before exiting the bedrock valley into a large, broad alluvial fan. This fan is a recent glacial feature which infilled the post- glacial remnant of Penticton Lake to form Ellison and Wood Lake (Nasmith 1981). The tributary Clark Creek joins the system 4 km upstream of Ellison Lake, and is sourced by spring flows. Ellison Lake is the terminus of Upper Vernon Creek and is one of only a few Lakes in the watershed that has not been developed for water supply.

The large alluvial fan spanning the breadth of the valley provides the setting for the complex hydrogeological conditions that affect streamflows in Upper and Middle Vernon Creek. The glaciofluvial materials provide both a source and sink of water from Vernon Creek, with losses from Upper Vernon Creek and likely recovery of flows in the lower reaches of Middle Vernon Creek and Wood Lake. It is suspected that losses occur in the upper portion - perhaps third - of the channel on the fan with northerly groundwater gradients towards Wood Lake. The groundwater may partially resurface at Winfield Creek, which appears to be entirely groundwater sourced.

Ellison Lake is not underlain by bedrock, tills, silts or clays, and loses water to evaporation and seepage. Middle Vernon Creek downstream of Ellison Lake, for approximately 5 km runs at a low gradient through the towns of Winfield and Woodsdale before joining Wood Lake at an elevation of 390 m.

Middle and Upper Vernon Creek Hydrological Analysis 4 Climatology The Okanagan Watershed has a semi-arid continental climate, characterized by hot, dry summers and cold winters. In addition, the Thompson Plateau, home of the Vernon Creek watershed, lies in the rain shadow of the Coast and Cascade Mountains. Average temperatures at Vernon are around 7.9 "C. January is the coldest month with a normal mean temperature of -4.2 "C. Temperatures drop to a minimum of about -25 "C to -30 OC when arctic air intrudes into the valley (Wittneben 1986, Valentine et a1 1978). The Vernon Climate Station (CDA 1128551), at an elevation of 555 m, records normal average maximum July and August temperatures of 26.2 "C and 26.1 "C. Extreme maximums reach nearly 40 "C.

The Okanagan Lake Watershed lies in the lower half of the Southern Interior hydrologic region (Region 12). Coulson and Obedkoff (1998) show that mean annual flow increases with elevation to the east and west from Okanagan Lake, and is expected to vary from less than 100 mm to more than 200 mm, depending on the elevation and position in the watershed (Figure 2).

Total precipitation and the portion falling as snow both increase with elevation (nhc 2001). Normal precipitation at the Vernon climate station, on the valley bottom, is 390 mm; 122 mm (31%) falls as snow. Precipitation is distributed fairly evenly throughout the year, with a springtime minimum and winter maximum. Significantly more precipitation falls in the upper watershed, with a total annual precipitation of 727 mm at Nicklen Lake (el. 13 17 m). A large percentage of this precipitation, 38 percent (278 mm), falls as snow on average, however the annual snow pack can be quite variable. The provincial snow survey station: 2F 19 Oyama Lake (1 969 - present) provides estimates of snow-water equivalent on February 1 ", March 1 ", April 1 ", May I ", May 1 5th,June I st and June 1 5thof each year.

May to September precipitation (summer rainfall) ranges from about 26 to 42 mm at Vernon. These totals are less than evapotranspiration and soil moisture deficits of 200 to 400 mm expected each year (Valentine et al. 1978). Reksten (1 973) noted that westerly circulation is dominant in summer and that greater rainfall is expected on west-facing slopes than on east-facing ones. Recorded daily maximum precipitation is typically 20 to 30 mm, with totals of over 40 mm at Vernon and these storms typically occur in summer and fall. In Middle and Upper Vernon Creek, as much as 75 to 85 percent of the annual runoff occurs from April through July, in response to melting of the winter snow pack. The month with the greatest runoff is usually May, which contributes 32 to 49 percent of the annual total. Mean monthly flows decrease after May, generally reaching a minimum in August or September (OBA 1974, MLFWR 1974).

Middle and Upper Vernon Creek Hydrological Analysis 5 Hydrology

Streamflow Gauging Numerous Water Survey of Canada gauges have been operated within the Middle and Upper Vernon Creek watershed from as early as 1919, but the majority are no longer active. Many were operated seasonally as a means of managing the supply of water used for irrigation. Some of the streamflow and lake level gauges installed or re-instated in the early 1970s as part of the WRMS remained active for several years afterwards, and have made it possible to update the results of the study. The gauge records used in the preparation of this analysis are summarized in Table 1. Monthly Distribution of Runoff Other active and historic WSC gauging records are available for tributaries to Okanagan Lake, as well as in the same or similar hydrologic zone - 12B (Figure 2). All of these creeks are located on the east side of the Okanagan Basin and have elevations in the range of el. 400 m (1,300 ft) and el. 1,650 m (5,400 ft). These stations included Bellevue Creek (WSC 08NM035), BX Creek (WSC 08NM020), Clark Creek (WSC 08NM146), Coldstream Creek (WSC 08NM 14), Daves Creek (WSC 08NM 137) and Pearson Creek (WSC 08NM 172).

The creeks are not greatly affected by regulation, as storage is a relatively small proportion of mean annual runoff. The records were reviewed, adjusted and used to provide a template for the distribution of mean annual runoff for systems naturalized for regulation or significant water use for dry, normal and wet years. The average monthly distribution of runoff in Table 4 is used for Sub-basins 1, 3, and 4. The monthly runoff distribution for Sub-basin 2, Clark Creek, is based on the record of daily discharge at Clark Creek near Winfield (WSC 08NM 146). Mean Annual and Mean Monthly Runoff For the purpose of hydrologic analysis, the Middle and Upper Vernon Creek watershed has been divided into four sub-basins:

Sub-basin I - Upper Vernon Creek

Sub-basin 2 - Clark Creek

Sub-basin 3 - Ellison Lake

Sub-basin 4 - Middle Vernon Creek.

A summary of their characteristics is provided in Table 2, and historic runoff from the sub-basins is provided in Table 3. Note that the downstream limits of the sub-basins correspond with the location of Water Survey of Canada (WSC) streamflow gauges. Sub-basin 1 combines sub-basins 1A - Swalwell Lake and sub-basin 1B - Upper Vernon Creek from earlier studies into a single basin. The gauges and sub-basins are paired as follows:

Middle and Upper Vernon Creek Hydrological Analysis 6 . Sub-basin 1 - WSC 08NM175 (1973-79) Vernon Creek below ARDA Dam . Sub-basin 2 - WSC 08NM 146 (1969-82) Clark Creek . Sub-basin 3 - WSC 08NM182 (197 1-74) Vernon Creek at Outlet of Ellison Lake . Sub-basin 4 - WSC 08NM009 (1969-86) Vernon Creek at Inlet to Wood Lake.

An estimate of mean annual runoff for the sub-basins is made by updating the hydrologic analysis completed by Coulson and Hunter (DLFWR 1974). The period of record for this analysis is 1969-1 995 and is defined as such for modeling purposes. Coulson and Hunter used hydrometric data from several regional gauges, where runoff is unaffected by diversion or consumptive use, to establish relationships between watershed elevation and runoff per unit area. They developed regional elevation - runoff curves for the years 1970, 1972 and the average of years 1969 to 197 1, which were considered to be representative of minimum, maximum and mean runoff years. The elevation-runoff data and associated curves are presented in Table 5 and Figure 3.

In updating Coulson and Hunter's analysis, the record of annual runoff at Coldstream Creek above Municipal Intake (WSC 08NM142) was used as a basis for estimating the unit runoff in years other than 1970 and 1972. For example, if the measured runoff in a given year at Coldstream Creek lies between the values for years 1970 and 1972, then the elevation-runoff curve for that year is interpolated between Coulson and Hunter's 1970 and 1 972 curves. Conversely, if the measured runoff either exceeds the 1972 value, or is less than the 1970 value, then the elevation-runoff curve is extrapolated above, or below, the appropriate Coulson and Hunter curve.

Estimated unit runoff values for this study and the 1974 study are compared in Table 6. The current estimates of mean and maxima are more extreme than those of the 1974 study. The discrepancies are attributed to the fact that the current study uses a much larger sample of measured flows to produce the estimates and also that a single gauge (WSC 08NM142) is used to scale the unit runoff as opposed to using a set of regional gauges, therefore subject to a higher degree of variation and deviation.

Using percentile of flows for the period of record, we have estimated the 25thand 75th percentile flows as well as the means. Flows equal to or less than the 25thpercentile are considered dry runoff conditions, flows greater than 75thpercentile runoff are wet conditions and flows between are considered normal. The calculated unit runoff in each condition is multiplied by the sub-basin area to obtain a mean annual runoff estimate or naturalized mean annual stream flow.

We estimated the mean annual discharge (MAD) for Upper and Middle Vernon Creek to be approximately 0.78 m3/s with dry and wet mean annual discharges of 0.52 m3/s and 0.98 m3/s respectively. This would equate to an overall basin mean annual runoff (MAR)

Middle and Upper Vernon Creek Hydrological Analysis 7 of 159 mm which corresponds well to estimates from Coulsen and Obedkoff (1 998). These various sub-basin flows for dry, normal and wet runoff conditions are summarized in Table 7. Using the appropriate distributions of runoff by month according to annual runoff, estimates of the mean monthly flows were provided by sub-basin and for the entire study watershed. Mean monthly flows varied from zero in Middle Vernon Creek during a dry runoff year to 3.3 m3/s in Upper Vernon Creek in a wet year. These estimates of naturalized runoff or discharge are provided in Table 8 and illustrated in Figure 5, Figure 6, Figure 7 and Figure 8 for each sub-basin.

Fisheries Resources Aside from the study and inventory of habitats, Middle and Upper Vernon Creek has not been well studied with regards to fish populations, distribution and use relative to streamflows in the system. Fish Wizard (BC Fisheries and Fisheries and Oceans Canada) lists rainbow trout, redsided shiner, sculpin and sucker as resident in Vernon Creek. The 1974 Okanagan Basin Agreement reported that Middle Vernon Creek had kokanee and "probable" rainbow trout spawning, but no migration of juveniles (OBA 1974).

More recently, electrofishing surveys of Middle Vernon Creek were undertaken (Geostream Environmental Consulting and Columbia Environmental Consulting Ltd. 2003), during which a variety of resident fish were caught. The survey did not record utilization by salmonids (rainbow trout), which was attributed to low streamflows and high water temperatures above the range suitable for their utilization.

Kokanee escapements are recorded by MWLAP over the last 12 years have recorded an escapement of approximately 7300 fish to Middle Vernon Creek. Habitat surveys completed within the creek have summarized that sub reach 4 is likely the highest quality spawning habitat within the system. Escapement recording and habitat data should be consolidated in order to determine spawning habitat quality, quantity and relative utilization, which would be valuable in restoration and water use planning.

Middle and Upper Vernon Creek Hydrological Analysis 8 lnstream Flows for Fish and Fish Habitat Based on earlier assessments of limits to fish production in Okanagan streams (Tredger 1989), we considered several key lifestages with respect to the assessment of flow to be: rainbow trout spawning, rainbow trout parr rearing, and kokanee migration and spawning. A periodicity chart was used to super-impose the estimated annual hydrograph, fish habitat and ecological needs of the stream channel with fundamental fish life history requirements. Periodicity is defined as the pattern or timing during a biological year when a given organism or life stage is active or present in the system. The use of life stage requirements and periodicity also allows for critical review and analysis through the water years of fish flow needs and water demands from storage or consumption. A fish periodicity chart has been prepared for Upper and Middle Vernon Creek based on known utilization by kokanee and rainbow trout, and is presented in Figure 4.

Typically the highest flow need for a particular period is used when there are several different flow needs due to overlapping fish or ecological events (Estes 1996). Inability to meet certain conservation flows one time of year may have the effect of minimizing the fish production for that lifestage which is ultimately reflected in fish populations. The phenomena of limiting habitats and bottlenecks are important but often poorly understood (Weins 1977). The basic premise of the bottleneck is that populations of aquatic organisms are related to availability of habitat through time. Flow-related habitat bottlenecks typically occur in earlier lifestages, when their effects are detectable in the adult population (Nehring and Anderson 1993, Bovee et al. 1994). In addition, Bovee et a1 (1994) found that:

There may be several consecutive and independent habitat events that can affect adult populations (such as spawner passage flows, spawning habitat, fry rearing habitat, parr rearing habitat, temperature regime, and adult feeding habitat), Limiting events frequently occur over variable time scales, Habitat may be limited by low or high flow events and by the rate of change of flow events with respect to habitat thresholds, The smallest amount of habitat available during the year may not necessarily be the limiting event (such as over-wintering when fish are inactive), and Habitat types not directly utilized by the target fish species (such as riffle- dwelling insects as it affects food supply for fish) may be more important than habitat directly used by the species.

Middle and Upper Vernon Creek Hydrological Analysis 9 Historical Instream FIows Minimum instream flows for fish have been recommended in the past by various parties. However, most work has been conducted on Lower Vernon Creek, and not on Middle or Upper Vernon Creek. In 1973, Kochinsky and Willcocks recommended a minimum discharge for spawning of 0.28 m3/s, and a minimum discharge of 0.23 m3/s for incubation for Lower Vernon Creek.

Pinsent (1 974) in the Okanagan Basin Agreement (OBA) suggested minimal optimum fisheries discharge requirements of 0.43 m3/s for the winter months, and of 0.86 m3/s during the summer, with an absolute minimum discharge of 0.29 m3/s. Most recently, Shepard and Ptolemy (1 999) have suggested optimum fish flows for Vernon Creek of 0.841 m3/s over the winter and 8.41 1 m3/s in the spring, which are markedly higher values than those recommended in the past, and were intended to provide optimum rainbow trout migration and spawning flows. A summary of previously recommended flows for fish in Lower Vernon Creek is found in Table 9.

Proposed lnstream Nows Specific fisheries conservation flows for the Okanagan basin were developed in nhc (2001), and these provide a contemporary context of instream flow needs for Vernon Creek. Conservation flows address the streamflows required for long-term sustainability and health of aquatic ecosystems, within the constraints of the naturalized flows available and on a stream-specific basis. The Ptolemy method, as described in Hatfield et al. (2003), that uses flow criteria based on a percent of mean annual discharge and duration appropriate for specific criteria that encompass biological, physical and ecological needs of stream and river systems. Table 10 provides an overview of the Ptolemy criteria used in this study. Instream flows for Vernon Creek were developed from two sources and applied using the hydrological data developed from estimates of mean annual runoff and mean monthly flows. Both Ptolemy and the conservation flow model (nhc 2001) provide similar results with both mean annual flows and monthly flows.

The strength of the biological work undertaken earlier on other Okanagan tributaries tends to support the use of the flows identified with the conservation flow standards (nhc 2001). It is recommended that these standards be adopted for Upper and Middle Vernon Creek until more detailed fish habitat and fish use/distribution work is completed. Any instream flows should be adjusted to reflect notional flows at the point-of-diversion. Upper Vernon Creek was determined to include all sub-basin areas above the confluence of upper Vernon Creek with Ellison Lake. Middle Vernon Creek include all sub-basins above the Ellison Lake outlet into Middle Vernon Creek. The 25thand 75thpercentiles of streamflows for the period of record are used to define dry and wet years, all other years are considered normal. By month instream flows using the conservation standard were

Middle and Upper Vernon Creek Hydrological Analysis 10 developed from estimates for wet, normal and dry years and provided in Table 1 I and Table 12 with a comparison to Ptolemy's flows for reference.

Direct application of conservation standard (nhc 2001) for kokanee spawning of 20% MAD results in a flow of 0.1 5 m3/s in September and October downstream of Ellison Lake in Middle Vernon Creek. This data is supported by results of physical habitat simulation (phabsim) weighted usable area (WUA) versus % MAD as presented by Tredger (1 989) for Lamby, Powers, Shorts and Mission Creeks. WUA for kokanee spawning was at or near maximum available over a range of 2 - 30% MAD. While this clearly identifies requirements for spawning, the data does not provide an assessment of flows for migration. Low streamflows in Okanagan streams cam limit the migration and distribution of kokanee spawners, and may limit access to spawning habitats due to low flow barriers, difficult hydraulic conditions, and lack of pool habitat and cover (nhc 2003). In a similar manner, the conservation standard for rainbow parr rearing (overwintering and juvenile rearing) from nhc (2001) provides a flow of 20% MAD or 0.14 m3/s in Upper Vernon Creek. WUA versus % MAD for Mission, Lambly, Powers, Shorts and Trepanier Creeks also show maximum or near maximum available habitat for rainbow parr at 20% MAD over a range of approximately 5 - 30% MAD

An important issue of instream flow standards is ensuring that those standards that have required durations less than a month - often a matter of days or weeks - are satisfied in a regulated state where monthly standards are implemented. Migration and spawning flows, outmigration, geomorphic and off-channel connectivity flows are standards that require flows of relatively short periods (Table 10). There are hydrological conditions that may or may not provide the conditions required for these short duration flow standards in years of low inflow. This is especially true on shoulder months when the impacts of storage refill may be greater than in high annual inflow years. Another critical time period is April (Julian day 90 - 120) where early freshet flows are required for rainbow trout migration and spawning.

As seen in existing flow records for Middle Vernon Creek (WSC 08NM182 1972-1 974) in Figure 9, streamflows likely provided more than adequate flows for geomorphic other processes that require relatively large freshet flows in relation to MAD for 2 of the 3 years of data. These years also have flows optimum for rainbow trout migration and spawning however there are several periods where streamflows are less than optimum for life history requirements. The water use data indicates that the relatively significant amount of storage relative to the mean annual flow, combined with lower than normal inflows, can result in less than adequate flows relative to normal or dry year flow standards. This is critical in the watershed where storage is relative high in comparison to mean annual runoff (i.e., lake storage 13,672 ac-ft and Upper Vernon Creek mean annual runoff estimated at 14,235 ac-ft). In most cases, a freshet flow does occur albeit at greatly reduced ratios to mean of high inflow years.

Middle and Upper Vernon Creek Hydrological Analysis 11 Water Use

Water Licenses The major influences to natural streamflows in the system include consumptive water demands, storage and inputs of water from outside the basin. The District of Lake Country (DLC) water diversion is located between the outlet of Swalwell Lake and Ellison Lake. DLC also imports a small volume of water from Okanagan Lake to Upper Vernon Creek on an 'as-needed' basis for irrigation and waterworks use. This import is permitted by the former Hiram-Walker Distiller license (C10828 l), which the DLC now owns. Other major licensees that store and extract water from Middle and Upper Vernon Creek include the Okanagan Indian Band and the Eldorado Ranch.

The Ministry of Sustainable Resource Management (MSRM) maintains a computerized database of water licences in British Columbia, which includes current licences plus outstanding applications. Water licenses are classified into consumptive and non- consumptive uses and further classified by type of user. Computer-generated summaries, obtained from the database utilize the main classification, as well as providing detail on the type of user, producing a total of 73 sub-categories (including non-consumptive uses). Consumptive license classifications include waterworks, irrigation, domestic, stock watering (livestock), watering, incidental domestic, processing, enterprise, and land improvement. Non-consumptive water use classifications include storage (non-power) and conservation (stored water and constructed works). Table 13 reproduces part of the water licence classification system used by the MSRM.

A full water license summary for Middle and Upper Vernon Creek, categorized by source, is provided in Table 14. Irrigation is approximately 36% of all licenses and 88% of all consumptive demand in the system. Total consumptive licenses are 9,825 ac-ft with total storage licenses of 14,179 ac-ft (1 3,672 ac-ft in lake storage in Crooked and Swalwell Lakes). Instantaneous consumptive demand totals 0.38 m3/s and storage demand is 0.55 m3/s. Based on MWLAP Water Management policies, Upper and Middle Vernon Creek are considered "fully recorded" such that the 1 :5 year 7-day low flow is licensed. For storage licenses, MWALP uses the 1:5 year low freshet volume. Records indicate that Vernon Creek was fully recorded in 193 1, however extensive licensing has occurred since that period with some demand supported by storage in the watershed.

Actual Water Use Letvak (OBA 1974) estimated diversion requirements for the Winfield-Okanagan Centre Irrigation District (WOCID) in 1970 and compared them with licensed amounts held by WOCID at that time. Letvak estimated domestic requirement based on population, and the irrigation requirement based on irrigated area and a water duty of 2.05 ft. He

Middle and Upper Vernon Creek Hydrological Analysis 12 estimated a requirement of 100 percent of the licensed amount for domestic use, compared to 68 percent of the licensed amount for irrigation. For reference, 1970 was a drought year with runoff in about the 1 othpercentile of historical records at Vernon Creek at outlet of Swalwell Lake (WSC 08NM022).

Anthony (1974) made direct measurements of diverted volumes for all Kalamalka-Wood Lake Basin in 1972, which was a high runoff year. He found that domestic diversions were 73 percent of the licensed amount, while irrigation diversions were only 42 percent of the licensed amount. Total runoff in 1972 was in the range of the 7othpercentile of recorded flows and considered a normal year. Table 15 provides a comparison between DLC (WOCID) diversions and licensed amounts for the period 1972 to 2002. The record of diversions is taken from Letvak (1 992) and DLC data (2003). Licensed amounts are the sum total of domestic and irrigation licenses held by DLC on Middle and Upper Vernon Creek, excluding Swalwell Lake. Total utilization ranged from a low of 34 percent of license in 2001 to a high of 97.3 percent in 1974.

An analysis of the water use data provided no positive correlation between annual water use and annual runoff. Water use in each year is likely correlated with precipitation occurring in the late spring and summer, which directly affects irrigation and household watering practices but has little influence on mean annual runoff.

Calculation of Water Use Demand The water licences are expressed in various units, ranging from acre-feet for irrigation licences, to gallons per day or gallons per year for waterworks and domestic licences, to cubic feet per second for conservation licences. To avoid confusion, all licensed amounts reported have been converted to acre-ft. In any time period, the total water use demand is calculated by adding the diverted amounts from waterworks, domestic, industrial and irrigation licences.

Letvak (1 974) provides the following detailed breakdown of monthly use requirements for the WOCID in Table 16. We have adopted these same distributions for the current study, assuming that they are still applicable to the WOCID as well as all other water users in the study area. Table 17 provides a record of demand for DLC for 1994 water use but does not provide a breakdown of irrigation versus domestic use. Based on the records and experience with other water systems in the Okanagan, domestic use is a relatively insignificant percentage of the total demand as illustrated by percent use during late fall through to summer.

Return Flows from Water Use Domestic water use is a consumptive demand that has a portion of return flow to the watershed. In summer, a large portion of the domestic use is for watering of lawns and gardens, and some of this water may re-enter the stream, through groundwater, as return

Middle and Upper Vernon Creek Hydrological Analysis 13 flow. In unorganized areas, septic flows and domestic grey water is often discharged to ground and it too may be return to the stream eventually. In organized areas, water may be diverted out of the basin and return flows may not end up in the same stream resulting in a true loss to streamflow. In DLC, treated wastewater returned to ground within the watershed would further balance domestic return flows on a basin-wide perspective.

There are a few land improvement licenses, totalling 1.6 acre-ft per year, found within the Upper and Middle Vernon Creek system. They are used to provide water for ponds, which may then be used for landscaping or to raise fish. On older licences, removal rates were set from an evaporation rate of one-eighth inch per day (doubled to one-quarter inch for a factor of safety), multiplied by the pond surface area, and converted to gallons per day. On newer licenses, the licensee is permitted to divert whatever quantity is required to maintain water levels in the pond(s) up to the licensed amount. The land improvement licenses are mostly consumptive since most water is lost to evaporation; although some may enter groundwater and re-appear as return flow. Most withdrawals will be during hot, dry weather when evaporation is greatest and streamflow is least. Much smaller withdrawals are expected during winter or rainy, cold weather.

A certain percentage of the water diverted for irrigation re-enters the stream as return flow. When flood irrigation (by ditches and flumes) was prevalent it was assumed that roughly 25% of the diverted volume returned to the stream. Foweraker (DLFWR 1974) back-calculated the volume of irrigation return flow on Ribbleworth Creek and found that it was equal to roughly 28 percent of the total irrigation water applied. Sprinkler and dripltrickle irrigation are expected to produce considerably lower return flows as these are inherently more efficient means of irrigation.

Anthony (DLFWR 1974) uses a return flow of 50 percent to the Kalamalka - Wood Lake system from domestic and municipal water use, and 25 percent for irrigation use. Letvak (OBA 1974) uses a return flow of 65 percent for domestic and waterworks and 50 percent for irrigation. In both cases, the authors suggest that the majority of return flow will seep directly to either Okanagan Lake (Letvak) or Wood Lake (Anthony), instead of recharging Middle Vernon Creek. However, Anthony points out that a minor amount of return flow may also occur by way of springs in the Middle Vernon Creek area. For the purpose of this study, it was assumed that five percent of the total irrigation water used upstream will return to Middle Vernon Creek and the remaining return flow, regardless of its magnitude, is assumed to seep either to Kalamalka - Wood Lake or Okanagan Lake.

Middle and Upper Vernon Creek Hydrological Analysis 14 Water Balance Model A water balance model of Middle and Upper Vernon Creek was created to produce a multi-year hydrological analysis where instream fish flows, water use and other gains or losses of water were subtracted from mean annual runoff in order to model potential stream flows in the system. The model simulates runoff, storage and consumption over the period 1969 to 1995. The simulation period matches the period of record at Vernon Creek at Outlet oj'Swalwell Lake (WSC 08NM022), a major input to the model, and allows for comparison of results. Both instream flows and water use were adjusted based on wet, dry and normal conditions reflecting normal adjustments that would be undertaken on a year-by-year analysis (Table 18).

The water budget for Middle and Upper Vernon Creek is presented as a schematic in Figure 10. Gross runoff in each sub-basin is represented by light arrows. For each year of simulation, the cumulative demand from water use, lake evaporation and influent groundwater are subtracted from gross runoff. Similarly, effluent groundwater and imports of water are added to the gross runoff. The resulting net runoff is represented in the schematic by dark arrows.

Beginning in Upper Vernon Creek (Sub-basin I), a monthly flow balance is computed by subtracting total demand (ID 1 and NID 1 ) from monthly gross runoff, which includes local runoff to Upper Vernon Creek and observed monthly outflow from Swalwell Lake (WSC 08NM022). The net outflow from Upper Vernon Creek flows downstream and combined with the net outflow from Clark Creek (Sub-basin 2) and the gross local runoff to Ellison Lake (Sub-basin 3). The total demand from Ellison Lake (ID 2 - NID 3 - GWL 1 - GWL 2 + GWG 1+ IMPI) is then subtracted from this amount to determine flows into Ellison Lake and into Middle Vernon Creek. Flows from Ellison Lake are re-routed to Middle Vernon Creek with no accounting of lake storage. A small routing model examined the potential storage effects and found that the lake provides a maximum of 3 days storage effect and would not have any influence on the current model, which operates on a monthly time step. A similar process is repeated for flows through Middle Vernon Creek (Sub-basin 4).

A positive flow balance in Upper of Middle Vernon Creek indicates that there is a net outflow to the creek in that reach, while a negative balance indicates that reach runs dry (i.e., outflow is zero). The model compares the net outflow to the creek with the recommended monthly instream flow and reports any surplus or deficit volumes. Surplus would indicate that there is additional water over and above the amounts required to provide instream flows for fish and fish habitat. A deficit represents the amount of water that would be required to provide those instream flows.

Middle and Upper Vernon Creek Hydrological Analysis 15 Sensitivity to Water Use The sensitivity of the model to changes in water use demand is summarized in Table 19. A comparison is made between predicted net runoff in Middle Vernon Creek for the base case and for two trial cases in which basin-wide water use demand is raised and lowered by 20 percent. The 20 percent adjustment in basin wide water use equates to a volumetric change of 2,340 acre-ft, yet the difference in predicted net runoff for the two trial cases relative to the base case is only 1,061 acre-ft. The estimate of water demand accounts for approximately 45 percent of the variability in predicted net runoff. Sensitivity with respect to lake evaporation and groundwater losses has not been assessed as both parameters are represented by constant annual averages in the model. We assumed that the Hiram Walker cooling water return flow was operating for historical analysis and comparison to gauged data but all calculations assume no return flow as the existing facility is shut down.

Accuracy to Gauged Stations Model accuracy is assessed by comparing predicted net runoff in selected sub-basins with observed net runoff at corresponding WSC gauges. Table 20 provides the results of such comparisons for Upper Vernon Creek (Sub-basin 1) and Middle Vernon Creek (Sub- basin 4) and illustrated in Figure 1 I and Figure 12. Note that for this exercise, the modelled water use was set to historic levels. The average (absolute) deviation of the predictions is 2,214 acre-ft in Upper Vernon Creek, and 2,677 acre-ft in Middle Vernon Creek. The relatively good agreement between predicted and observed runoff (R' = 0.97) in Upper Vernon Creek results from the fact that in most years the water use data are taken directly from metering records (Letvak 1992). The discrepancy is attributed mainly to systematic errors in the gross runoff estimating procedure.

Discrepancies in predicted net runoff (i.e., a lower R' value) are substantially larger in Middle Vernon Creek, which is not surprising since there is compounded uncertainty in the estimates of annual water use demand, evaporation and groundwater losses. Noted evaporation losses fluctuate by up to 15 percent from year to year (WRMS 1974), and significant changes to relative losses to groundwater likely persist. Additional studies and resulting data collected on use, evaporative and groundwater losses would likely improve the accuracy of estimated flows.

Model Output and Results The water balance model analyzed the Upper and Middle Vernon Creek system considering present levels of water use and the instream flows related to wet, dry and normal conditions as identified through mean annual runoff conditions. The fundamental assumption is that instream flows are adjusted to match existing runoff conditions in the watershed. There is less water is available at lower runoff conditions and corresponding more water is releases during wet runoff conditions.

Middle and Upper Vernon Creek Hydrological Analysis 16 Long-term output is presented in Figure 13 through Figure 16, which are the full-record hydrographs for Sub-basins 1 through 4. The various components of the water budget are displayed as distinct hydrographs to illustrate their influence on the overall water budget in each sub-basin. The hydrographs presented in Figure 17 through Figure 20 provide an average 'snapshot' of the water budget in each sub-basin. Naturalized mean annual hydrographs reflects the removal of the Hiram Walker diversion from the mean annual water budget, and expected domestic and irrigation water use and consumption.

The flow balance for each sub-basin is presented in Figure 21 through Figure 24. The flow balance is defined as the difference between mean annual runoff and the sum of gains and losses affecting the stream at a particular point, which include water use, evaporation, losses to groundwater and imported water. A positive flow balance indicates that there is net runoff remaining in the stream and a negative flow balance indicates a zero-flow condition. The flow deficit - flow required to make up to the suggested instream flow in any given month - are negative values in the flow balance.

Middle and Upper Vernon Creek Hydrological Analysis 17 Discussion The results of the water balance model confirm that Upper and Middle Vernon Creeks do not have sufficient runoff or streamflow to concurrently provide flow for water use demands and suggested instream flows to support fish and fish habitats. With respect to the ability of the watershed to sustain healthy aquatic ecosystems there are two critical situations:

substantial instream flow deficits in 3 of 4 sub-basins, and periods of zero streamflow with current licensed water use demands.

Table 21 provides a record of the calculated reliability with respect to zero flow and flow deficits by year for each of the basins. Based on the analysis period of record under normal runoff conditions, zero flow occurs approximately 14% of the time in the system and flow deficits occur approximately 70% of the time. Under wet runoff conditions, zero flow is infrequent (1 0%) and flow deficits are less (45%). Under dry conditions, the situation is dire with zero flow conditions 25% of the time and flow deficits greater than 90%. lnstream Flow Deficits The full-record hydrographs indicate that conservation flow deficits occur in most years and in every sub-basin except Clark Creek, where the conservation flow is assumed equal to the available net runoff as there is licensed demands on that system are minor (approximately 6 ac-ft). The mean annual hydrographs indicate that the largest deficits occur in April, May and June as a direct result of water storage in the upland reservoirs of Swalwell and Crooked Lake. Smaller deficits persist through the summer months, when irrigation demands are greatest, and eventually taper off in the fall. The information shown can be summarized as follows:

The period from April through June has substantially larger deficits in all sub- basins due to the combined effect of increasing demand for water and storage filling in upstream reservoirs, In dry years, the Ellison Lake and Middle Vernon Creek Sub-basins have less than one third of the recommended conservation flow in April, May and June, and A second large deficit occurs either in August or September depending on the sub-basin from the combined effect of naturally low runoff and high irrigation demand.

Middle and Upper Vernon Creek Hydrological Analysis 18 Zero-Flow Periods The frequency of occurrence of zero- flow periods is illustrated in the flow balance summaries. Negative flow balances are relatively infrequent in the Upper Vernon Creek Sub-basin. There are four major zero-flow events in the Ellison Lake Sub-basin (1 971, 198 I, I 989 and 1993) and five smaller events. The model predicts that the major zero- flow events can last for up to five months due to low inflows and high demand. These events may or may not be as significant a duration with adjustment of model parameters like groundwater, return flows, etc., but they likely would occur.

All zero-flow events in Ellison Lake result in zero flow conditions in Middle Vernon Creek. However, it is likely the magnitude and duration of the low-flow periods in Middle Vernon Creek are tempered by groundwater return flows from Ellison Lake and Upper Vernon Creek. The analysis does highlight the precarious hydrological conditions of Middle Vernon Creek and the extreme sensitivity to variations in runoff and water use. Any period of zero flow would result in dewatering of fish habitats or rendering them isolated and subject to the effects of thermal heating, low dissolved oxygen and predation. lnstream Flow Deficits Modeling of the 'base case' scenario with present day water use demand and reservoir operations indicates that it is unlikely that the suggested instream flows would be achieved with much consistency or reliability. Our analysis indicates that none of the sub-basins modelled can meet conservation flow requirements with 100 percent reliability except under very 'wet' runoff conditions. The actual instream flows and percentage of suggested instream flows are in included in Table 22.

This inability of the basin to meet existing demands results from following conditions. First, the irrigation, domestic and other water use demands are large relative to the total yield of the basin. In a normal runoff year, the average annual water use is 7,060 acre-ft compared to 21,500 acre-ft of average annual gross runoff. In dry years (e.g. 1970, 1988 and 1992), the average annual water use is 6,550 acre-ft compared to just 9,300 acre-ft of annual gross runoff. Second, the spring filling period of the upland reservoirs coincides with the months when conservation flows are highest, which causes large flow deficits. This deficit occurs typically as reservoir management generally suggests low minimum flows be released through the filling period and excess flows are spilled typically after filling and later in the freshet. Third, losses of runoff to groundwater and evaporation are likely high and unmitigable. Losses to groundwater in Upper Vernon Creek - the reach from the canyon to immediately upstream of the Hiram Walker flume - are likely considerable relative to the amount of runoff that is typically available. Similar losses occur also in Ellison Lake and where estimated for modelling purposes. It is not known how much of these potential losses to local groundwater are recovered to streamflow in the lower portion of Middle Vernon Creek. The water budget model currently accounts

Middle and Upper Vernon Creek Hydrological Analysis 19 for only a minor amount of return flow from irrigation in Middle Vernon Creek. Losses due to evaporation from the surface of lakes are also significant, and reduce the amount of water stored in lakes that would otherwise be available for conservation flows during the summer period.

These factors are particularly acute for sub-basins with relatively low summer inflows and high water use demands, such as Ellison Lake and Middle Vernon Creek. The fisheries impacts of the hydrological state of the system - generally stated as reduced streamflows - are numerous and include:

Loss of primary and secondary productivity (algal and benthic production), Loss of available spawning, incubation and rearing habitat for fish - notably kokanee and rainbow trout, Loss of longitudinal connectivity of stream habitats (migration), and Increased risk of stranding, dewatering and desiccation.

Losses of primary and secondary productivity are related to loss of wetted habitat - typically stream riffles - for periphyton (algae) and benthic invertebrates. Increased stream temperatures due to low flows and thermal heating may also influence growth rates and suitability or productive capacity of these habitats.

Reduced riffle habitat, decreased pool volumes and increased water temperatures negatively influence the habitat values for spawning and rearing fish. Less available habitats, increasing frequency of limiting conditions coinciding with reduced food sources could lead to less overall fish production.

Critically low flows eventually lead to loss of surface flows through sections of riffle habitat or coarse substrates that prevents the movement of fish and create a loss of connectivity. This may limit the migration of adult or juvenile fish from poor habitats to better areas in connection with food or rearing conditions. Stranding with reduced water quality conditions and flows may lead to fish kills. If total loss of streamflow occurs, desiccation and dewatering may lead to total loss of ecosystem within stream reaches.

Potential Solutions for lnstream Flow Deficits There are several potential ways that flows in Upper and Middle Vernon Creek could be increased to address limiting habitat conditions caused by low streamflows. These generally involve increasing the available streamflows in order to provide a Iarger base of suitable habitat for limiting lifestages. A structure risk assessment would involve the quantification of benefits (habitat) with risk (hydrology and climate) and costs (water use).

Middle and Upper Vernon Creek Hydrological Analysis 20 For the purposes of this study, it is proposed that the streamflow recovery criteria be structured as follows:

I. Ecosystem protection flows 2. Minimum summer flows for rearing 3. Spawning and migration flows for kokanee 4. Spawning and migration flows for rainbow trout.

Using these criteria, the highest priority would be to reduce the frequency of occurrence or eliminate streamflows less than 10% MAD in order to protect the fundamental aspects of the aquatic ecosystem. The second priority would be to recover streamflows such that 20% MAD would be provided for instream rearing conditions, and kokanee migration and spawning. The requirement of flows for kokanee have a secondary priority as the duration of flow required is much reduced as compared to rearing flows - which are required for months. Lastly, spawning and migration flows for rainbow trout should be provided. Additional analysis of flows and fish observations may conclude that these flows provide suitable conditions given the habitats, stream geomorphology and anthropogenic impacts on the system. The exact flow and hydraulic conditions required for all these criteria should be further investigated by both biological and physical surveys and analysis. Water Use Management It may be possible to provide recovery of streamflows by reducing water use demand, perhaps only during critical periods when streamflows drop below a predetermined level. However, our analysis has shown that conservation deficits exist even with the potential under-utilization of irrigation licenses (modelled irrigation demand never exceeds 80 percent of the licensed amount, and averages about 60 percent). Ideally, water use monitoring, metering, and education and awareness programs may help spur voluntary reductions in water use. DLC and MWLAP should develop a co-operative information supplement for mail-outs with tax statements, or provide water use and stream conditions information via local cable television. Water Storage There are still significant freshet flows that occur in the system, and - ideally - additional storage could be developed specifically to eliminate conservation flow deficits in normal and wet runoff years and provide critical flows in dry years. For instance, according to the WRMS (1 974) the live storage capacity of Swalwell and Crooked lakes was 12,045 acre-ft in 1974 compared to a licensed storage volume of 13,672 acre-ft. However, the record at Vernon Creek at Outlet of Swalwell Lake (WSC OSNM022) indicates that runoff in a normal year is approximately 12,400 acre-ft. It appears that available storage has been maximized in the upper watershed and there is no other suitable, reliable storage in the upper system.

Middle and Upper Vernon Creek Hydrological Analysis 2 1 It may be possible to adjust the rule curves of Swalwell and Crooked Lakes so that more water is released in April and May earlier in the freshet. However, we recommend better determination of flows during this period prior and recognize that the priority for the licensee is to ensure that the reservoirs can be filled before considering early releases.

Limited storage could also be developed on Ellison Lake by constructing a small low head weir on the lake outlet, which would provide additional flow to Vernon Creek. However, a cursory examination of the topography in and around Ellison Lake suggests that approximately 2,000 ac-ft may be available if the Lake were to be raised, however there may be significant flooding issues. In addition, any water stored within this lake is subject to additional losses to groundwater and evaporation. The nature of the lake outlet and discharge.structure would also result in the discharge of warmer surface waters, likely unsuitable for fish. Extra-basin Water Transfers Water could be imported from adjacent watersheds to provide streamflow in Middle and Upper Vernon Creek. In this case, nearby watersheds include Duteau Creek, Kelowna Creek and Okanagan Lake. However, both Duteau and Kelowna Creeks are already well used to supply the cities of Vernon and Kelowna. Water has historically been pumped from Okanagan Lake by the Hiram-Walker Distillery. When the distillery shut down in 1992, DLC took over the associated water license and now uses it to supplement Winfield-Okanagan Centre demands on an 'as needed' basis. The Hiram Walker License allows for diversions of up to 7,130 acre-ft per year and while it would be an expensive undertaking to fully utilize the license, a moderate increase in utilization would be beneficial to fish when periodicity is high (from mid-April to mid-June for rainbow and in September for kokanee). For example, supplementation of 50 L/s (800 Igpm) - approximately 10% of the dry year MAD - would cost $2,500 per month using the Hiram Walker system. Groundwater Extraction Foweraker et al. (WRMS 1974) estimated that the underflow in the main aquifer beneath Ellison Lake is approximately 3,700 acre-ft per annum (5 cfs). The authors surmised that the aquifer is charged by surface water losses from Upper Vernon Creek and Ellison Lake and that approximately half of the underflow, or 1,750 acre-ft, flows to Winfield Creek. This suggests that there may be up to 1,750 acre-ft of groundwater could be extracted and used to provide streamflows in Middle Vernon Creek. Due to source conditions, the water quality and temperature would be ideal for fish and less costly to operate than the Hiram Walker system. A similar 50 Lls (800 Igpm) pumping system would costs $20,000 to install and approximately $20 per day to operate. Additional Sources Other sources of available water in the basin include the use of recycled treated effluent. French drains or an infiltration gallery could be used to recover water currently put to ground. The recovered water could be pumped to local stormwater system or dedicated

Middle and Upper Vernon Creek Hydrological Analysis 22 pipe system for discharge downstream of Ellison Lake. Although we were not able to confirm it, flows of 0.0035 m3/s were to be discharged from the District of Lake Country wastewater treatment plant in 2000, with flows increasing to 0.093 m3/s by 2020 (Geostream 2000). It may be more cost effective to allow these flows to go to ground - ultimately supplementing flows in the system - or utilize them for irrigation to reduce water use. Costs could be used to support utilization of the Hiram Walker system or a dedicated well system for fisheries use.

Clearly, there are limited options to supply additional water to the Middle and Upper Vernon Creek systems, and none of them can stand alone to fully address flow shortages or full deficits in every hydrological conditions. These potential solutions should be considered preliminary and subject to further discussion and analysis. Long-term instream fish flows are only likely to be achievable if demands on the system are also reduced. Further studies into possible demand-side management options would be required in order to assess the best method to reduce water demand. However, with continued population growth in the DLC and Okanagan generally, the ability to manage or contain growth in water use appears limited as well.

Recommendations Improved streamflow gauging and monitoring would assist in rationalizing flows in Upper and Middle Vernon Creeks, and determining if and when projected conservation flows are achieved. Overall, there is the need to better determine the dynamic water balance between storage in the upper watershed, Upper Vernon Creek flows, Ellison Lake and Middle Vernon Creek flows. We recommend that a dedicated flow metering and gauging program be conducted on this system to identify potential losses to ground, lake evaporation, and flows throughout the Vernon Creek throughout the season.

Analysis of well log data and long-term monitoring of groundwater levels in the Middle Vernon Creek fan complex is also important. Hydraulic gradients and groundwater levels may assist in determining overall flux through the fan, as well as potential for groundwater pumping for streamflow supplementation. A monitoring program, candidate wells or potential sites should be identified with the assistance of an engineer or geoscientist with a background in hydrogeology.

A dedicated instream flow assessment should undertaken on Middle and Upper Vernon Creeks habitats that contain important freshwater fish species - kokanee and rainbow trout. Through the establishment of reaches and transects, flows required for the various lifestages should be determined by hydraulic analysis and suitability of use. The criteria for instream flows could follow that suggested earlier for solution of flow deficits. However, an emphasis should be placed on the spawning and migration flows for kokanee as these are a high priority stock of freshwater fish in the Okanagan basin.

Middle and Upper Vernon Creek Hydrological Analysis 23 With current water demand and the potential for expanding use in the District of Lake Country, the instream flows identified for Middle and Upper Vernon Creek will not be met in the future without improved water management and innovative use of other water supply sources. MWLAP fisheries staff, DLC and water users must continue to work to find solutions to provide water for fish in this watershed with relatively low runoff, high water use and unique hydrological conditions.

Middle and Upper Vernon Creek Hydrological Analysis 24 Glossary

Definitions Gross Runoff The total quantity of runoff available before natural demand (i.e. evaporation, groundwater losses) or water use demands have been accounted for. Net Runoff Gross runoff minus total demand. Naturalized Runoff Gross or net runoff before any diversions or imports outside of the watershed have been considered. Drought Year Defined by a gross annual runoff that is below the 25th percentile of historical values. Wet Year Defined by a gross annual runoff that is above the 75th percentile of historical values. Normal Year Defined by a gross annual runoff that is between the 25th and 75th percentile of historical values.

No tation Acre-ft Unit of water volume; used in this text to describe a total volume per month or per annum. 1 Acre-ft per annum = 3.9 1 x 1 o-~m3/s 1.23 dam3 per annum 271,326 gal per annum

Acronyms BC British Columbia DLC District of Lake Country; consortium of improvement and irrigation districts including the Winfield-Okanagan Centre Irrigation District DLFWR Department of Land, Forest and Water Resources (since superseded by MWALP) MSRM Ministry of Sustainable Resource Management MWLAP Ministry of Water, Land and Air Protection OBA Okanagan Basin Agreement completed in 1974 W OCID Winfield-Okanagan Centre Irrigation District WRMS Kalamalka-W ood Lake Basin Water Resource Management Study completed in 1974

Middle and Upper Vernon Creek Hydrological Analysis 2 5 References Anthony, B.D. 1974. Water Use Studies. Chapter 5. Kalamalka-Wood Lake Basin Water Resource Management Study. Water Investigations Branch, Department of Lands, Forests, and Water Resources, Victoria, BC. Atmospheric Environment Service. 1989. Climatological Station Catalogue: British Columbia. Environment Canada. A publication of the Canadian Climate Program. 268 pp. Bovee, K.D., T.J. Newcomb, and T.G. Coon. 1994. Relations Between Habitat Variability and Population Dynamics of Bass in the Huron River, Michigan. National Biological Survey, Washington, D.C., Biological Report 2 1, 63 pp. British Columbia Fisheries and Fisheries and Oceans Canada. Fish Wizard -FISS Database. Internet. Error! Hyperlink reference not valid.. Accessed Feb 20, 2003. British Columbia. 2002. Ministry of Agriculture Food and Fisheries. Statistical Services Unit. Policy and Economics Branch. Census ofAgriculture 2001 and Historical Comparisons, BC Summary. May 2002. British Columbia. Department of Lands, Forests, and Water Resources. 1974. Kalamalka- Wood Lake Basin Water Resource Management Study. December 1974. City of Kamloops. 2001. Universal Water Metering - The Vernon Experience. Water Use Efficiency Committee, Final Report - Appendix E. The Corporation of the City of Vernon. 2001. Plan Vernon: The Official Community Plan for the City of Vernon, Schedule A, Bylaw 4676, 2001. December 17, 2001. Coulson, C.H. and W. Obedkoff. 1998. British Columbia Streamjlow Inventory. Water Inventory Section. Resources Branch. Ministry of Environment, Lands and Parks. March 1998. District of Lake Country. 2001. District of Lake Country Official Community Plan. Estes, C.C. 1996. Annual summary of instream.flow reservations andprotection in Alaska. Alaska Dept. of Fish and Game, Div. of Sport Fish. Fishery Data Series No .96-45, Anchorage. Fulton, R.J. 1975. Quaternary Geology and Geomorphology, Nicola-Vernon Area, British Columbia. Geological Survey of Canada, Department of Energy, Mines and Resources, Ottawa.

Geostream Environmental Consulting. 2002. Middle Vernon Creek - Water Management Plan. Prepared for Oceola Fish and Game Club, Winfield, BC. March 2002. 2000. Middle Vernon Creek and Winfield Creek: Stewardship Action Plan. Prepared for Oceola Fish and Game Club, Winfield, BC. March 2000.

Middle and Upper Vernon Creek Hydrological Analysis 26 Geostream Environmental Consulting and Columbia Environmental Consulting Ltd. 2003. Biological and Hydrological Assessment of the Middle Vernon Creek

Watershed - Draft Report. Prepared for Oceola Fish and Game Club, Winfield, BC. March 2000. Hatfield, Todd, Adam Lewis and Dan Ohlson. 2002. British Columbia Instream Flow

Standards for Fish, Phase 1 - Initial Review and Consultation. Prepared for British Columbia Ministry of Water, Land, and Air Protection, Victoria BC. April 24,2002. Hunter, H.1, and C.H, Coulson 1974. Hydrology Studies. Chapter 3. Kalamalka-Wood Lake Basin Water Resource Management Study. Water Investigations Branch, Department of Lands, Forests, and Water Resources, Victoria, BC. Letvak, D.B. 1992. Kalamalka- Wood Lake Water Supply Hydrology. Prepared for Hydrology Branch, Water Management Division. Ministry of Environment, Lands and Parks. October 1992. Letvak, D.B. 1980b. Annual RunoffEstimates for East Side Okanagan Valley. Memo to File 0256957. Ministry of Environment, Lands and Parks. July 21. Nasmith, H. 1 98 1. Late Glacial History and Surficial Deposits of the Okanagan Valley, British Colurnbia. Ministry of Energy, Mines and Petroleum Resources. Province of British Columbia Nehring, R. B. and R. M. Anderson (1993). Determination of population limiting critical salmonid habitats in Colorado streams using the physical habitat simulation system. Rivers 4 (1): 1-1 9. nhc. 2001. Hydrology, Water Use and Conservation Flows for Kokanee Salmon and Rainbow Trout in the Okanagan Lake Basin, BC. Prepared for BC Fisheries, Fisheries Management Branch, August 2001. Obedkoff, W. 1978. S.E.K.I.D. Watershed Hydrology. Memorandum to Mr. C. Coulson, Head, Surface Water Section, Hydrology Division. Water Investigations Branch. March 1 1978. Okanagan Basin Agreement 1974. Summary Report of the Consultative Board including the Comprehensive Framework Plan. Canada-British Columbia Okanagan Basin Agreement. Pinsent, M.E. 1974. Fisheries and Sport Fish Potentials of the Okanagan Basin. Technical Supplement IX(A) to the Final Report, Canada - BC Okanagan Basin Agreement. Prepared for BC Fish and Wildlife Branch, Department of Recreation and Conservation, Victoria BC. 249 pp. Ptolemy, R.A. 1999. DeveIopment and Application of Flow Standards for British Columbia: 30 years of experience with fisheries instream flow methods. Presentation to the June 15, 1999 WUP Instream Flow Workshop at Edmonds, Vancouver, BC.

Middle and Upper Vernon Creek Hydrological Analysis 27 Reksten, D. 1972. Final Report: Regionalization of Okanagan Sub-Basin Runofffrom Basin Characteristics. Canada-British Columbia Okanagan Basin Agreement Water Quantity Studies. Task 53 - Regionalization of Sub-Basin Hydrology. Regional District of Central Okanagan. nd. Economic ProJile: Population Growth. Internet. Error! Hyperlink reference not valid.. Accessed March 2003. Regional District of North Okanagan 2003. Rural Vernon Official Community Plan, For Portions of Electoral Areas 'B' and 'C'. January 9,2003. Rood, K. 1989. An Examination of Natural and Regulated Flows in Duteau Creek, British Columbia. Prepared for Fisheries and Oceans Canada, 39 pp. and appendices and figures. Shepard, B.G. and R. Ptolemy 1999. Flows for Fish: Requirements for Okunagan Lake Tributaries. Prepared for BC Ministry of Environment, Lands and Parks. Tennant, D.L. 1976. Instreamjow regimes-forfish, wildlife, recreation, and related environmental resources. Pages: 359-373 in J.F. Orsborn and C.H. Allman, editors. Instream Flow Needs, Volume 11, American Fisheries Society, Bethesda, Maryland. Trivett, Neil B.A. 1984. Lake Okanagan Evaporation Study. Canadian Climate Centre Report No. 84-2. Downsview, Ontario. Valentine, K., P. Sprout, T. Baker and J. Lavkulich (eds). 1978. The Soil Landscapes of British Columbia. Agriculture Canada and the BC Ministry of Environment. Victoria, BC Weins, J.A. 1977. On competition and variable environments. American Scientist 65:590-597. Wittneben, U. 1986. Soils of the Okanagan and Similkameen Valleys. MOE Technical Report 18 (Report No. 52 British Columbia Soil Survey). BC Ministry of Environment. Victoria, BC. 229 pp.

Middle and Upper Vernon Creek Hydrological Analysis 2 8 Tables

Middle and Upper Vernon Creek Hydrological Analysis 29 Table 1 Water Survey Gauges used in the Analysis of Middle and Upper Vernon Creek Watershed Drainage Stat'on Station Name Period of Record Other Info No- Area (km2) 08NM009 Vernon Creek at Inlet to Wood Lake 151 191 9-21,1969-71,1969-98

Reg, Rec, Continuous -...... , ...... ! Reg, Man, Vernon Creek near the mouth 08NM160 ; Seasonal

Reg, Rec, 08NM236 Vernon Creek Diversion to WOClD 1973-78 Continuous Table 2 Sub-basin Watershed Summary

Note: Sub-basin 1 includes sub-basins 1A and 1B from earlier studies. Table 3 Summary of Gauged Stations in Regional Analysis of Mean Monthly Flows All Years Normal Years

Drv Years Table 4 Mean Annual Monthly Runoff Distribution

Table 5 Mean Annual Runoff Relationships (Coulson and Hunter 1974)

Table 6 Comparison of Gross Unit Runoff in Inches for Minimum, Mean and Maximum Years

1. Minimum, mean and maximum values based on the period of record 1969-1995 2. Minimum, mean and maximum values based on the period of record 1969-1972 3. Coulson and Hunter, 1974. 4. The values listed for Swalwell Lake represent net unit runoff and are based on the record Vernon Creek at outlet of Swalwell Lake (08NM022)

Middle and Upper Vernon Creek Hydrological Analysis 34 Table 7 Mean Annual Runoff Estimates by Sub-basin

Note: Dry conditions approximate 25thpercentile flows and wet conditions approximate 75th percentile flows. Mean flows are normal flow conditions over the period of record.

Table 8 Mean Monthly Flow Estimates by Sub-basin Dry Year

Upper Clark Ellison VernonMiddle Month Vernon Creek Lake Watershed Creek Creek

December 0.083 0.012 ' 0.006 0.000 0.110 Average 0.390 0.105 0.027 0.000 0.522

Middle and Upper Vernon Creek Hydrological Analysis 35 Normal Year n Middle Month VernonUpper Clark Ellison Vernon Creek Lake Creek Creek Watershed I

December; 0.089 0.013 0.009 0.001 1 0.123 Average 0.556 ' 0.153 0.056 ! 0.009 j 0.775

Wet Year

Middle and Upper Vernon Creek Hydrological Analysis 36 Table 9 Referenced lnstream Flows for Lower Vernon Creek

1. Sheppard and Ptolemy mean annual discharge - 4.21 m3/s 2. nhc 2001 mean annual discharge - 3.34 m3/s

Table 10 Flow Standards and Required Duration-of-Flow

Middle and Upper Vernon Creek Hydrological Analysis 37 Table 11 Recommended Middle Vernon Creek lnstream Flows Middle Vernon Creek - Dry Runoff Conditions b Naturalized MMF 1 Month

Average 0.52 1 0.35

Middle Vernon Creek - Normal Runoff Conditions I Month

Average 0.77 1 0.39 , 0.47

Middle and Upper Vernon Creek Hydrological Analysis 38 Middle Vernon Creek -Wet Runoff Conditions Naturalized MMF Ptolemy's Method 1 Month

Table 12 Recommended Upper Vernon Creek lnstream Flows Upper Vernon Creek - Dry Runoff Conditions I - Month

Average 0.50 j i 0.25 1 0.34

Middle and Upper Vernon Creek Hydrological Analysis 3 9 Upper Vernon Creek - Normal Runoff Conditions

. . . . I January . 0.10 14% . 20% 0.14 ' OW11 20% 0.15 1

. - - I Average / 0.71 / , 0.36 1

Upper Vernon Creek -Wet Runoff Conditions

Month

Middle and Upper Vernon Creek Hydrological Analysis 40 Table 13 Water Management Branch Water Use Classifications Applicable to Middle and Upper Vernon Licensees

CONSUMPTIVE 1 Waterworks -conveyed by local authority (municipality, gallonslday regional or improvement district) to more than gallonslyear 5 dwellings -conveyed by others (individual, utility, Indian band) 2 Domestic use -water use for up to four dwellings, gardens to gallonslday '14 acre, stock watering 3 Industrial -processing (sawmills, food, manufacturing, any etc.) -cooling -enterprise (hotels, motels, restaurants, etc.) -ponds -watering -bottling for sale -commercial bulk export -mineral water sold in containers and used in bathing pools -all other industrial uses 4 Irrigation -conveyed by Water District or other authority acre-feet or private individual -use on cultivated lands or hay meadows 5 Land improvement e.g. draining property, creating ponds any NON-CONSUMPTIVE 6 Storage - non -storage for purposes other than power acre-feet power generation 7 Conservation -storage (e.g. waterfowl habitat any enhancement) -use of water (e.g. hatchery) -construction of works in and around a stream (e.g. fish culture, fish ponds, personal)

Middle and Upper Vernon Creek Hydrological Analysis 4 1 Table 14 Summary of all Water Licenses Issued within Middle and Upper Vernon Creek Watershed Dy Source

L hfidddle ond Uppr Vernon Creek Hydrological Anulys,r 42 I Licensee

I MOHNS GARY L 8 WENDY L: 1W50 MEADOW RD WlNFlELD BV4VlV6 ---- 1 4 i 57929 ! 1 --- 10.50i 1 -4 18981008 / 31 --THOMPSON ELAINE E: BOX 168 BONANZA AB TOHOKO i : 0.50 i ! ! 1 18981008 1 31 ~GVANHOLDINGS LTD ET AL: C/O ASPEN GROVE GOLF CLUB BOX 41015 RPO S WINFIELD BC V4VlZ7 ' i 43.25 ' 1 4 j 68958 i_ ' j ! +-- i / 18981008 / 31 ~ARENTEAUHENRY 8 AURORE: 11218 RElSWlG RD WlNFlELD BC V4VlX3 ' 4 i 58683 + i 8.00 I / 19030421 1 41 -- -. ----& -.--. I- HOGABOAM RlCKY D: 11 12RElSWlG RD LAKE COUNTRY BC V4VlX3 I p~: 4 i 58683 l___ ; __i 1 10.00 ! . i 1 19030421 1 41 ~EYNO-~OW BOTTOM WOODS LK RD WINFIELD BC VOHZC~-- 4 58683 I 1 1 i -- 1 ! 1 &--; 24.40 j / 19030421 / 41 MXlGLAS M: 9719 MCCARTHY RD WINFIELD BC V4VlS5 4 58683 1 - i 25.40 1 ; 'i 19030421 41 PAY 1 -+- 1 / 1 FOMEAXLEONARD: 11262 ROYAT RD WINFIELD BC V4VlX4 4 / 58683 i 11.80 1- , , -+ ! 19030421 i 41 POLT KATHLEEN D: 10410 LODGE RD WINFIELD BC V4VlV6 4 1 58682 1 ;i 80.00 j ! 11 19030421 41 I _.&__Ii / ] I FAKENAKA HAROLD 8 MARGARE370LODGE RD WINFIELD BC V4VlV6 1 4 1 58681 1 i 36.25 / i s 1 19030421 1 41 7--- 7--- LDORADO RANCH LTD: 102 266 LAWRENCE AVE KELOWNA BC VlY6L3 ! 3 i 58692 1 1 : 383.00 i-C? ! 1 19170815 59 -- \ 7-/ 1 --LITCHMAN NORMAN E: 9819 BOTTOM WOOD LAKE RD WINFIELD BC ~4~1~7- 1 3 1 58690 i 1 4.60 i ! i 19490731 1 70 - PANMRWERFA=% ET AL: BOX 41015 RPO S WlNFlELD BC V4VlZ7 i 197004_30 79 -- -. 14i59152j 1 j2.00i - I / 1 ~EHREDWlN 8 SHANNON: 3010 REIMCHE RD WlNFlELD BC V4VlV4 ! 4 i 51518 : 1 0.67 ;-. I ! , . i i Y---- i19740711 / 83- WHITE THOMAS J 8 CHERYL K: 3090 REIMCHE RD WlNFlELD BC V4VlV4 - i 0.67 j I: I / 19740808 1 85 ~ALDRONBRUCE D: 3050 REIMCHE RD WINFIELD BC V4VlV4 ! 19750604 1 86 /REIMCHE HERBERT B:11225 DELOOR RD WlNFlELD BC V4VlV8 1 / 19780411 / 87 PEIMCHE HERBERT B:11225 DELOOR RD WINFIELD BC V4VlV9 1 19780411 87 /MEBECALVIN H: 3081 WOODSDALE RD SITE 48 COMP 54 RR 2 WINFIELD BC VOH2CO I 1 19880421 / 93 ~OW~~ANGLEN D: 3118 REIMCHE RD LAKE COUNTRY BC V4VlV4 ------! / 19950109 j 94 lark Creek FLDORADO RANCH LTD: 102 266 LAWRENCE AVE KELOWNA BC VlY6L3 :52.69 1 j i -77- i 18991207 / 38 . ELDORADORANCH LTD: 102 266 LAWRENCE AVE KELOWNA BC VlY6L3 ; 2 ! 58629 i ! ! 19050906 1 48 ~LDORADORANCH LTD: 102 266 LAWRENCE AVE KELOWNA BC VlY6L3 - I 19070815 49 ELDORAW RANCH LTD: 102 266 LAWRENCE AVE KELOWNA BC VlY6L3 i 193006067 wakell Lake SAKE COUNTRY DISTRICT OF: 10150 BOTTOM WOOD LK RD LAKE COUNTRY BC V4V2M1 ) 19070823 / 50 $AKE COUNTRY DISTRICT OF: 10150 BOTTOM WOOD LK RD LAKE COUNTRY BC V4V2M1 ! 2.69 / ! j19081019 1 57 . . - KE COUNTRY DISTRICT OF: 10150 BOTTOM WOOD LK RD LAKE COUNTRY BC V4V2M1 71-58085 1 - / 550.00 i / ' j / 19081019 57 KKECOUNTRY DFCTOF: 10150 BOTTOM WOOD LK RD LAKE COUNTRY%C- llal580851 I I , moo:------1 1941030- :rooked Lake CAKE COUNTRY DISTRICT OF: 10150 BOTTOM WOOD LK RD LAKE COUNTRY BC V4V2M1 I 19330602 61 -- \la/58081/ : t-ii i .i -- i 4000.007- : / / 1 , i ,mold Brook.- ~~E~~R_J~~EF:~.~~Y~oKA~LcTR!oEvvR"~oB?!~wx~....----....-3.3.-3.-3...._- 1 -4W5E5L3L_. j--~ iii7.50 i 7- ' -.--- + ! 19430720 / 66 ~OMMERJOSEF: 10651 OKANAGAN CTR RD E WINFIELD BC V4VlK3 1 / 1 19660308 ] 73 - --- 74 1 58953 \ _i I j17.00! I 'laremont LizINTz I ! ~LL~AMF: 8051 SHANKS RD WINFIELD BC VOHZCO i / 19440722 1 68 pring I - I 1 19440722 1 68 c I--I..--I ~

--

J-- , i 19351202 1 63 lay Spring 19381126 1 64 I 19491031 i 71

ile and Upper Vernon Creek Hydrological Analysis 43

Table 15 Comparison between District of Lake Country Diversions and Licensed Amount (1972 - 2002)

Percentile of

1. Licensed amounts listed excluding Swalwell Lake 2. DLC Data (2003) 3. shaded data from Letvak (1992) 4. Based on estimated mean annual runoff of 8,201 ac-t3 per annum

Middle and Upper Vernon Creek Hydrological Analysis 4 5 Table 16 Distribution of Water Demand for Water Balance Model

Table 17 Distribution of DLC Water Demand by Month (1994)

Middle and Upper Vernon Creek Hydrological Analysis 46 Table 18 Modelled Annual Demand for 1969-1995 Table 19 Sensitivity of Middle Vernon Creek Predicted Net Runoff to Changes in Water Use Demand

Middle and Upper Vernon Creek Hydrological Analysis 48 Table 20 Comparison of Predicted Net Runoff with Measured Net Runoff Sub-basin 1 Upper Vernon Creek

Sub-basin 4 Middle Vernon Creek Net Runoff (acre-ft) Year I ~odelled observed' I

Middle and Upper Vernon Creek Hydrological Anahis 49 Table 21 Estimated Flow Reliability of Upper and Middle Vernon Creek

Middle and Upper Vernon Creek Hydrological Analysis 50 Table 22 Modelled lnstream Flows in Upper and Middle Vernon Creek Sub-Basin 1A Swalwell Lake Flows

FEB 0.004 79% ' 0.007 96% 0.009 96%

AUG 0.009 88% 0.015 100% 0.019 100% SEP 0.011 100% 0.016 100% 0.020 100% OCT 0.007 70 % 0.013 94 % 0.016 96%

3 3 3 m /s Yo m /s ' Yo m /s Yo JAN 0.003 65% 0.007 94% 0.008 90% FEB . 0.003 : 63% 0.007 i 93% 0.010 99% MAR 0.001 6% 0.003 23% 0.005 ' 33% APR 0.003 6% 0.024 38% 0.058 77% MAY 1 0.001 1 2% 1 0.090 1 87% i 0.127 1 100%

DEC 0.004 66% 0.008 94% 0.011 , 100%

Middle and Upper Vernon Creek Hydrological Analysis 5 1 Sub-Basin 3 Ellison Lake

Sub-Basin 4 Middle Vernon Creek I Flows

I APR 0.001 1% 0.033 38% 0.092 83% I MAY 0.008 8% 0.131 89% 0.186 100% I JUN 0.006 8% 0.085 85% 0.127 100% I JUL 0.000 0% 0.014 37% 0.042 93% I AUG 0.000 0% 0.000 ' 0% 0.000 0%

NOV 0.007 58% 0.015 86% 0.021 99% - t I DEC 1 6.004 47% 0.011 81% 0.016 97%

Middle and Upper Vernon Creek Hydrological Analysis 52 Figures

Middle and Upper Vernon Creek Hydrological Analysis 5 3

Middle and Upper Vernon Creek Hydrological Analysis 55 Middle and Upper Vernon Creek Hydrological Analysis 56 Figure 4 Vernon Creek Fish Periodicity Chart Rainbow Start End Peak Wt Bin JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC m3/s "C Adult Migration spawn lncubate Fry Rearing Pam Rearing Composite

Kokanee JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC m3/s "C Adult Migration spawn Incubate Fry Rearing Pam Rearing Composite

COMPOSITE SUMMARIES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Adult Migration spawn Incubate - - Fry Realing -- - - - Combined Species 8 ~ifestageim

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0.3 1 0.3 1 0.4 1 2.1 ( 7.2 1 4.7 1 1.4 1 0.5 1 0.4 1 0.4 1 0.4 1 0.3 I I I I I I I I I I I

8.0 7.0 - 6.0 -2 5.0 - 4.0 3 3.0 2.0 1 .o 0.0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Figure 5 Middle Vernon Creek Sub-basin 1 - 4 Mean Monthly Naturalized Flows

jry - MAD = 520 Its iormal - MAD = 780 Ils wet - MAD = 980 11s Figure 6 Upper Vernon Creek Sub-basin 1 Mean Monthly Naturalized Flows

.dry - MAD = 390 11s normal - MAD = 556 Ils .wet - MAD = 688 11s Figure 7 Clark Creek Sub-basin 2 Mean Monthly Naturalized Flows

dry- MAD = 105 Ils normal - MAD = 153 Ils wet- MAD = 195 11s Middle and Upper Vernon Creek Hydrological Analysis 6 1 S9E 1 SE LEE EZE 60E S6Z 181 L9Z ESZ 662 SZZ llZ L6 1 E8 1 69 1 SS 1 1P 1 LZ 1 €11 66 S8 1 L LS EP 62 9 1 1

Middle and Upper Vernon Creek Hydrological Analysis 62 Figure 10 Upper and Middle Vernon Creek Schematic

--- A --- @--- @ --.-

-pr --Pb"R.Dprd Middle and Upper Vernon Creek Hydrological Analysis §Imek

~~-~-~~aa~ Basin Water Budget Schematic m-Latrv-aaL

NHC 37Wa1 northwest hydraulic consultants

Middle and Upper Vernon Creek Hydrological Analysis 63 Figure 11 Predicted and Actual values for Net Runoff in Upper Vernon Creek (Sub-basin 1)

8,000 10,000 Actual Middle and Upper Vernon Creek Hydrological Analysis 65

Monthly Flow Volume (ac-ft)

-L ; .L -I. A .N ." P ul 9' .- ar o 0 "-000 0000000000 d9,@ g 0 0 0 Q>O9 oooo888888888 %

"4'3 "a '.$

"a'.3

"a'3 "a'..s "a '<>@ '<>@ "a '*3 "a'.* % '*+,

J d 'wo d4 87 '4 '9 "a '.@! '.@! Jt d *', (Ps '4 'b@

J *', 6 "a 'w& "a 2% '6 'so '4 's7 "a q+ '4 'u*

J %. 0'

Figure 15 Full-Record Hydrograph for Ellison Lake (Sub-basin 3)

--- - -Irrigation Demand -Non -Irrigation Demand -Groundwater ------Stream Flow -Flow Deficit -Hiram -Walker Imported Flow -. . ------

Middle and Upper Vernon Creek Hydrological Analysis Monthly Flow Volume (ac-ft) r/3 d'6$&4* "a 's.0 r/'z> r/@'. 0 r/ >' Q4 "a >' %+ r/ &4> "a'.+ ? r/ +4> %3 %-., r/ &4> %'-+ r/ +4> "a',+ r/ &4> "a'.+ * r/ &4> "a> %.$, %.$, r/

% @ 'b& r/ &4> r/ Q 3 r/ wo &% r/ 0 @' @' r/ w' &% "a' ,'w? &4@ r/?Q r/ w3 &% % ,'% ,'% "4%

"'w,r/ +w "a 'w* r/ +w r/Q * uw>&/ % w> ,'% &4@ %@ ,'% &/w "a 'a0 r/'zo r/h 0 r/ Q7 &4&, %''.+ r/'z* "a ? %Q3 r/ &4& "a 'k!! r/""91 "a 'aa r/ e4 Qa Figure 17 Mean Annual Hydrograph for Upper Vernon Creek (Sub-basin 1)

FlowDeficit Non-Irrigation Demand Irrigation Demand StreamFlow MeanAnnual Runoff

...... -. , ....--. -. ... - .... -.. - ...... -...... -......

.. -...... , ...... -... -.. -.... -...... ~ - . . . -~

...... --. 1

-1,000 Jan Feb Mar APr May Jun Jul Aug S~P Oct Nov Dec 1 L s!st(jauv pq8olo~pA~yaa~3 uouna~ ~addn puv alpp!~

Flow (ac-ft) ZL slsA)vu y [email protected]~ yaa.i3 uou.ia/i daddo puv alpplyy

Flow (ac-ft) Flow (ac-ft) Flow (ac-ft)

Flow (ac-ft) Appendices

Middle and Upper Vernon Creek Hydrological Analysis 7 8 Model Parameters, Options and Output

Water Use Demand The combination of conservation, domestic, enterprise, stock watering and waterworks demands are collectively termed non-irrigation demand (NID) in the water budget model. Annual hlID in the model is set to vary between 50 and 75 percent of the licensed amount, which is based on the DLC and City of Vernon records for domestic and waterworks diversions presented earlier in the report. In any given year, modelled NID is directly proportional to the amount of water available in the basin, which is best represented by observed annual runoff at Vernon Creek at outlet of Swalwell Lake (WSC 08NM022). NID ranges from a low of 50 percent in 1983 (the driest year on record) to a high of 75 percent in 1988 (the wettest year).

Irrigation demand (ID) is indirectly calculated as the difference between total water use demand and non-irrigation demand. For the period 1972 to 1990, the total water use demand for all sub-basins is assumed equal to the DLC diversion percentages shown in Table 17. The underlying assumption here is that the water use practices of those supplied by DLC are representative of all other water users in the basin. For the periods 1969 to 1971 and 1991 to 1995, total demand is estimated from growing season (May - Sept) precipitation totals at Winfield-Wood Lake (I 128958) and Winfield (1 128959). The following equation relating growing season precipitation and total annual demand was derived by least squares regression:

y = -001 3~ - 0.8587 where: y = demand, as a percentage of the licensed amount, and x = May to September precipitation (mm).

The Pearson product moment correlation coefficient (R*) of this equation is approximately equal to 0.50. Irrigation and non-irrigation demands for each year of simulation, based on present day licensed amounts. The monthly distributions of non- irrigation and irrigation demand used in the model are the same as those presented earlier in the report. Lake Evaporation Evaporation losses (EL) in the water budget model are held constant from year to year, and are based on the average observed depth of evaporation (in inches) for the period 1969 to 1971 (WRMS 1974). The annual estimated evaporation loss from Sub-basin 3 Ellison Lake (ELI) is 1,226 acre-ft. Groundwater Losses Hunter et al. (WRMS 1974) determined that portions of Upper and Middle Vernon Creek are influent, that is, they lose or exfiltrate a portion of their streamflow to groundwater

Middle and Upper Vernon Creek Hydrological Analysis 79 (GWL 1). Ellison Lake too was found to lose approximately 2,000 acre-ft per year to local aquifers (GWL 2). Foweraker et al. (WRMS 1974) estimated that the combined loss to groundwater (GWL 1 + GWL 2) is approximately five cfs or 3,630 acre-ft per year. This loss is included in the water budget for Sub-basin 3 Ellison Lake. Groundwater Gains A small groundwater gain (GWG I), representing return flow from irrigation, is included in the water budget for Sub-basin 4 Middle Vernon Creek. In any given year, GWG 1 amounts to five percent of the upstream irrigation demand (i.e. the sum of ID 1 through ID 3). Imported Water DLC imports water to Sub-basin 3 from Okanagan Lake (IMP I), under what is commonly referred to as the Hiram Walker License. Letvak (1992) provides estimates of the annual import from this licence for the period 1971-1 990 and we have adopted these estimates for use in the water budget model. There was no import under this license prior to 1971. For the period 1991 to 1995, the annual import is taken as the average of the imports from 1 97 1 - 1 990. Input Options The user has the option to model either historical or present day water use demand. In the latter case, the 1995 level of demand is used in all years. The demand can also be increased above 1995 levels in order to model future conditions. All other demands (i.e. lake evaporation and groundwater) can be modified. The Hiram Walker input to Ellison Lake (Sub-basin 3) can also be adjusted. If the Hiram Walker input is toggled off, the model simulates both Ellison Lake and Middle Vernon Creek under so-called 'naturalized' conditions. Reservoirs can be added to the model in order to assess the impact of additional storage in any one of the sub-basins. The required inputs for adding a reservoir are the minimum and maximum storage levels, a monthly storage level rule and outlet details. Output Options The model produces both tabular and graphical output. The tabular output summarizes gross runoff, all gains and losses pertinent to the sub-basin, the flow balance, outflow to the creek and conservation flow deficits. Additional tabular outputs for reservoir simulations include reservoir storage, reservoir stage, low level outflow and spillway outflow (in cases where the rule curve is exceeded). The graphical output consists of composite average annual hydrographs, composite full-record hydrographs and full- record flow balance summaries for each sub-basin. The flow balance summaries are intended to highlight the occurrence of negative flow balances (zero-flow conditions) in each sub-basin. Naturalized mean annual and full-record hydrographs for Ellison Lake and Middle Vernon Creek (Sub-basins 3 and 4) are produced by toggling off the Hiram Walker input to Ellison Lake as described above.

Middle and Upper Vernon Creek Hydrological Analysis 80