SKAHA LAKE

A view on the lake

Photo.
Photo: R.Nordin




A. LOCATION

  • British Columbia, Canada.

  • 49:25N, 119:35W; 338 m above sea level.


B. DESCRIPTION

    Skaha Lake is the fourth of the chain of five major lakes which occupy portion of the Okanagan Valley in the interior of British Columbia. The Okanagan Valley is a structural trench overlying a system of sub-parallel linked faults that separate the late Paleozoic or early Mesozoic Monoshee group of metamorphic rocks of differing lithology but of similar age. The trench is partially filled with several hundred meters of unconsolidated material (400 m in the Skaha Lake area). It is likely that the unconsolidated material was deposited in association with early glaciations of the Pleistocene Epoch. It seems probable that during the Pleistocene the valley was the site of deposition resulting from glacial outwash, direct glaciation and lacustrine fluvial sedimentation. During deglaciation a number of terraces were formed as lowering of post glacial lake levels was repeatedly arrested.
    Prominent silt and clay cliffs border Skaha Lake as a result of this period of glacial down-washing and degradation. Deglaciation was well advanced by 9750 B. P. and the lakes of Okanagan valley were formed about 8900 B. P.
    Skaha Lake is comprised of two distinct basins separated by a bedrock sill at a depth of 24 m. The surrounding watershed has "benches" (terrace) along the east and west shores which rise to mountainous slopes with the flat valley bottom at the north and south ends. Skaha Lake is separated from Okanagan Lake to the north by a narrow stretch of valley bottom on which the city of Penticton has developed.
    The watershed of Skaha Lake was first settled by Europeans in the last half of the 19th century. The climate (dry warm summers) and soil and availability of irrigation water led to the development of a substantial tree fruit industry around the lake and throughout the valley. Logging occurs in the upper elevation forests of the valley. The lower elevation vegetation of the Skaha Lake watershed is described as a Ponderosa pine (Pinus ponderosa)/bunchgrass community and the higher elevation is dominated by Douglas fir (Pseudotsuga menziesii) forest.
    Little limnological information was collected prior to 1969 when the Okanagan Basin Study was undertaken. Initiative for this comprehensive program came about primarily due to complaints to deteriorating water quality in Skaha Lake as a result of sewage discharge from the city of Penticton to the Okanagan River draining into Skaha Lake. Tertiary treatment was undertaken in 1971. Water quality subsequently improved.
    The lake is highly utilized as summer recreation location and tourism is presently a major component of the local economy (Q, 2).


C. PHYSICAL DIMENSIONS (Q, 2, 3)

    Surface area [km2] 20
    Volume [km3] 0.558
    Maximum depth [m] 55
    Mean depth [m] 26
    Water level Regulated
    Normal range of annual water level fluctuation [m] 0.6
    Length of shoreline [km] 29.5
    Residence time [yr] 1.2
    Catchment area [km2] 6,090


D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL

  • Sketch map: Fig. NAM-53-0l.

  • Bathymetric map: Fig. NAM-53-02.

  • Number of outflowing rivers and channels (name): 1 (Okanagan R.).

D2 CLIMATIC

  • Climatic data at Penticton Airport, 1940-1970 (4)

    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    Mean temp. [deg C] -2.9 0.3 4.7 8.7 13.4 17.1 20.1 19.2 14.7 8.7 3.1 -0.4 8.8
    Precipitation [mm] 9 10 12 23 28 36 25 22 18 20 19 10 232

    Fig. NAM-53-01
    Sketch map of Okanagan lakes (Q).


    Fig. NAM-53-02
    Bathymetric map [50 ft=15.24 m](Q).


  • Number of hours of bright sunshine: 2,032 hr yr-1.

  • Solar radiation (Summerland)[MJ m-2 day-1](5)

    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    3.4 6.5 11.5 16.7 20.8 22.6 23.7 19.6 14.5 8.5 3.8 2.5 12.8
  • Water temperature [deg C](6)

    Station 0500615, 1985
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0.5 - - 0.5 3.3 13.5 13.0 19.3 21.0 16.0 11.5 6.0 2.7
    5 - - 0.5 3.0 8.5 13.3 19.2 20.5 15.9 11.5 6.0 2.6
    10 - - 0.5 3.0 7.8 8.5 15.5 19.8 15.9 11.5 6.0 2.8
    15 - - 0.5 2.8 6.3 5.6 9.5 11.2 13.9 11.5 6.0 3.1
    20 - - 0.5 2.8 5.2 4.8 7.5 9.6 10.0 11.0 6.0 3.3
    30 - - 1.2 2.6 4.0 3.2 6.0 8.7 8.2 9.2 6.0 3.6
    45 - - - - - - - 7.5 7.5 8.0 6.0 3.5
    55 - - - - - - - - 7.2 - 6.0 -
  • Freezing period: January-February (not freeze every year).

  • Mixing type: Monomictic.

  • Notes on water mixing and thermocline formation
    Mixing dominated by the large inflow volume of the Okanagan River. Strong thermocline between 10-20 m from July to October. Free mixed November to April at 1-4deg C (if ice free).


E. LAKE WATER QUALITY

E1 TRANSPARENCY [m]

    Station 0500615, 1985
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    - - 4.7 4.0 3.8 4.0 5.1 5.8 4.8 4.8 5.0 5.0

E2 pH (6)

    Station 0500615, 1986
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 - - 8.2 8.2 8.4 5.2 8.5 8.5 8.5 8.5 - -
    6 - - 8.1 8.2 - - - - - - - -
    20 - - - - - - - 8.0 7.8 7.8 - -
    32 - - 8.1 7.6 8.2 8.0 8.2 7.9 7.8 7.8 - -

E4 DO [mg l-1](6)

    Station 0500615, 1985
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0.5 - - 13.8 15.0 12.2 10.0 10.2 9.8 10.0 10.0 12.0 13.2
    5.0 - - 14.8 15.0 15.0 9.7 9.7 9.7 9.8 10.0 12.0 13.1
    10 - - 15.0 15.0 14.0 10.4 9.8 8.7 9.7 10.2 12.0 13.0
    15 - - 14.7 14.5 13.5 11.2 9.6 8.6 8.1 10.1 12.0 12.7
    20 - - 14.3 13.5 13.3 11.9 10.0 9.0 7.3 9.8 12.0 12.6
    30 - - 12.5 13.8 13.2 11.7 10.2 9.7 8.5 6.6 12.0 12.4
    45 - - - - 12.8 10.8 10.2 8.2 7.0 5.8 12.0 11.7
    50 - - - - - - - 6.8 5.3 5.1 12.0 -

E6 CHLOROPHYLL CONCENTRATION [micro l-1](6)

    Station 0500615, 1986
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0-10* - - 9.3 5.9 3.7 1.7 1.4 1.7 1.8 - - -
    * Mean.

E7 NITROGEN CONCENTRATION (6)

  • Total Kjeldahl N + NO3-N [mg l-1]

    Station 0500615, 1986
    Depth [m] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    *1 - - .320 .230 .230 .230 .210 .230 .220 - - -
    *2 - - .300 .240 - - - - - - - -
    20 - - - - .230 .200 .240 .230 .320 - - -
    32 - - - - .270 .260 .250 .260 - - - -
    45 - - - - .240 .300 .370 .310 - - - -
    *1 0-10 composite. *2 0-45 composite.

E8 PHOSPHORUS CONCENTRATION (6)

  • Total-P [micro l-1]

    Station 0500615, 1986
    Depth [m] Jan Feb*1 Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    *2 - - 16 16 15 20 8 11 8 - - -
    *3 - - 15 16 - - - - - - - -
    20 - - - - 17 12 6 10 16 - - -
    32 - - - - 16 14 11 14 - - - -
    45 - - - - 20 20 44 27 - - - -
    *1 Overturn (February 1987: 24 micro l-1). Spring overturn variable.
    *2 0-10 composite. *3 20-45 composite.


F. BIOLOGICAL FEATURES

F1 FLORA

  • Emerged macrophytes
    Scirpus sp., S. lacustris, S. americanus, Equisetum fluviatile, Polygonum amphibium.
  • Floating macrophytes: Lemna minor.

  • Submerged macrophytes (7)

    • Myriophyllum spicatum (dominant), M. exalbescens, Elodea canadensis, Utricularia vulgaris, Ceratophyllum demersum, Najas flexilis, Chara sp., Potamogeton pectinatus, P. nodosus, P. praelongus, P. pusillus, P. natans, P. gramineus, P. zosteriformis, P. crispus, P. perfoliatus, P. foliosus, P. illinoensis, Hippuris vulgaris, Heteranthera dubia.
  • Phytoplankton (2, 31, 32, 33, 45, 46)
    Fragilaria crotonensis, Asterionella formosa, Anabaena circinalis.

F2 FAUNA

  • Zooplankton (2, 31, 32, 33, 45, 46)
    Cyclops bicuspidatus thomaso, Diaptomus ashlandi, Mysis relicta.
  • Benthos (2, 29, 50)
    Chironomus spp., Limnodrilus hoffmeisteri, Procladius sp.
  • Fish (19, 38, 40)
    Peamouth chub, squawfish*, kokanee*. * Important for sport-fishing.
  • Supplementary notes on the biota
    Hatchery in operation to supplement kokanee population.

F6 PAST TRENDS (6)

  • Trend of annual mean epilimnetic (0-10 m) chlorophyll a concentration [micro l-
    1]

    1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985
    4.4 4.5 3.0 6.7 6.7 6.6 3.3 5.3 7.4 - 3.8

F7 NOTES ON THE REMARKABLE CHANGES OF BIOTA IN THE LAKE IN RECENT YEARS (6)

    Myriophyllum spicatum was introduced into Skaha Lake in the early 1970's. By the mid-1980's it had become the dominant plant in the lake's littoral zone.


G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA (8)

    [km2] [%]
    Natural landscape
    - Woody vegetation*1 ca. 3,650 60
    Agricultural land
    - Crop field*2 ca. 1,220 20
    Residential area*3 ca. 1,220 20
    Total 6,090 100
    *1 Forested.
    *2 Horticulture/orchard.
    *3 Urbanized.
  • Types of important forest vegetation
    Ponderosa pine (Pinus ponderosa)/bunchgrass community (low elevations), Douglas fir (Pseudotsuga menziesii) forest (higher elevations).
  • Main kinds of crops and/or cropping systems: Orchards (tree fruits).

  • Levels of fertilizer application on crop fields: Moderate.

  • Supplementary notes
    Logging occurs in the upper elevation forests. Substantial tree fruit industry has developed over a larger part of the lower watershed with irrigation from Skaha Lake.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE (9) (1981)

    Main products or major industries
    Primary industry Crop production Apples

G3 POPULATION IN THE CATCHMENT AREA (1981)

    Total population of much larger Similkameen Regional District: 57,185. Largest urban settlement, Penticton: 23,181.


H. LAKE UTILIZATION

H1 LAKE UTILIZATION (10)

    Source of water, sightseeing and tourism (no. of visitors in 1980: total Okanagan 6.28 million; South Okanagan area 30% of the total), recreation (swimming, sport-fishing) and fisheries.

H2 THE LAKE AS WATER RESOURCES (10) (1985)

    Use rate [m3 day-1] [m3 yr-1]
    Domestic
    - Waterwork 3,241
    - Private intake 875
    Irrigation 5,300,000
    Industrial 9


I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS

I1 ENHANCED SILTATION

  • Extent of damage: Not serious.

I2 TOXIC CONTAMINATION

  • Present status: No information.

I3 EUTROPHICATION

  • Nuisance caused by eutrophication (Q)
    Unusual algal bloom (Lyngbya and Anabaena) and aesthetic damage to recreational use.
  • Nitrogen and phosphorus loadings to the lake [t yr-1](11) (1980)

    Sources Industrial+Domestic* Agricultural Natural Total
    T-P 2.4+1.8 0.4 7.5 12.7
    * Sewage plant+septic tanks.
  • Supplementary notes
    Increasing volume of discharge from Penticton sewage treatment plant in late 1960's was responsible for public concerns and complaints about deterioration of water quality (cyanobacteria blooms) in Skaha Lake. The sewage treatment plant was upgraded to incorporate tertiary treatment in 1971. The lake responded to the reduction in loading and then lake concentrations rose in the late 1970's and early 1980's. The significant effect of inter-annual variation in hydrology and increase in non-point loading appear to be major influences. Environmental standard for Total-P: 15 micro l-1 (spring overturn). (cf. 2, 10, 12, 13, 28, 31, 33-36, 38, 39, 43, 47, 49).

I4 ACIDIFICATION

  • Extent of damage: None.


J. WASTEWATER TREATMENTS

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

    (d) Measurable pollution with limited wastewater treatment.

J3 SANITARY FACILITIES AND SEWERAGE

  • Municipal wastewater treatment systems
    No. of tertiary treatment systems: 1.


M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS

M1 NATIONAL AND LOCAL LAWS CONCERNED

  • Names of the laws (the year of legislation)

    1. British Columbia Waste Management Act (1979)
    2. British Columbia Waste Management Act (1982)
    3. British Columbia Environment Management Act
    4. Federal Fisheries Act
  • Responsible authorities

    1. Government of British Columbia, Ministry of Environment
    2. Government of British Columbia, Ministry of Environment
    3. Government of British Columbia, Ministry of Environment
    4. Government of British Columbia in cooperation with the Government of Canada
  • Main items of control

    1. Discharge of water to land, air and water
    2. Licensing of consumptive and non-consumptive water use
    3. Prevention of detrimental environmental impacts
    4. Management and protection of fisheries

M2 INSTITUTIONAL MEASURES

  1. Okanagan Basin Study (Canada-British Columbia Okanagan Basin Agreement) 1969-1974 (2, 13, 14-27)
  2. Okanagan Basin U. C. Implementation Study - Joint Agreement between Canada and British Columbia, 1976-1982 (11, 30-32, 44)
  3. Okanagan Basin Water Quality Control Program, British Columbia Ministry of Environment, Penticton, B. C., 1986-1989 (49)

M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES

  1. National Water Research Institute (NWRI), Pacific & Yukon, West Vancouver
  2. British Columbia Ministry of Environment, Okanagan Sub-regional Office, Penticton, B. C.
  3. British Columbia Ministry of Environment, Fisheries Research
  4. University of British Columbia, Vancouver


N. SOURCES OF DATA

  1. Questionnaire filled by Dr. R. N. Nordon, Supervisor, Limnological Studies, B. C. Ministry of the Environment, Victoria, British Columbia.
  2. National Topographic Series Maps, 1/50,000 Map, Sheet 82E5.
  3. Pinsent, M. E. & Stockner, J. G. (ed.) (1974) Limnology of the Major Lakes of Okanagan Basin. Tech. Suppl. V, Canada-British Columbia Okanagan Basin Agreement.
  4. Historical Streamflow Summary. 606 pp. British Columbia Inland Waters Directorate, Water Survey of Canada, Ottawa, 1983. Station 08NM050.
  5. Climatic Normals 1941-1970, Climate of British Columbia. British Columbia Department of Agriculture.
  6. Canadian Climate Normals 1951-1980, British Columbia. Environment Canada.
  7. British Columbia Ministry of Environment. Computer Databases EQUIS (1970- 1985), SEAM (1985-present), Site 0500615.
  8. Warrington, P. D. (1988) Aquatic Plants, Morphometry and Water and Sediment Chemistry for the Lakes in British Columbia. Unpublished Databases. British Columbia Ministry of Environment, Victoria.
  9. Canada; Energy, Mines and Resources. N. T. S. Penticton Sheet 82E/5, 1/50,000. Ed. EM, National Topographic Series Maps, 1:50,000 Map, Sheet 82E/5, 1988.
  10. Census of Canada (1981) Population Series, British Columbia, 93-910, Table 4.
  11. Water Management Branch, Waste Management Branch (1985) Phosphorus in the Okanagan Valley Lakes: Sources, Water Quality Objectives and Control Possibilities.
  12. Alexander, D. G. (1982) Summary of Nitrogen and Phosphorus Loadings to the Okanagan Main Valley Lakes from Cultural and Natural Sources. Working Report, Okanagan Basin Implementation Agreement. 22 pp. Penticton, B. C.
  13. Nordin, R. N. (1983) Changes in water quality of Skaha Lake, B. C., following reduction in phosphorus loading. "Lake Restoration, Protection and Management (EPA 440/5-83-001)", pp. 166-170. U.S. Environmental Protection Agency, Washington, D. C.
  14. Stockner, J. G. & Nothcote T. G. (1974) Recent limnological studies of Okanagan Basin lakes and their contribution to comprehensive water resource planning. J. Fish. Res. Board Can., 31: 955-976. The following (14)-(27) are manuscript reports prepared as part of the Canada-British Columbia Okanagan Basin Agreement Study which were used extensively in the preparation of (2).
  15. Blanton, J. 0. (1972) Relationships between heat content and thermal structure in the mainstem lakes of the Okanagan Valley, British Columbia. 17 pp.
  16. Blanton, J. 0. & Ng. H. Y. F. (1971) Okanagan Basin studies; data report on the fall survey 1970. 125 pp.
  17. --- & --- (1972) The physical limnology of the mainstem lakes in the Okanagan Basin. 2 volumes, 34 pp.+ 24 figures + 2 appendices.
  18. --- & --- (1972) The circulation of the effluent from the Okanagan River as it enters Skaha Lake. 23 pp.
  19. Lerman, A. (1972) Chemical limnology of the major lakes in the Okanagan Basin: nutrient budgets at present and in the future. 41 pp.
  20. Northcote, T. G., Halsey, T. G. & MacDonald, S. J. (1972) Fish as indicators of water quality in the Okanagan Basin lakes, British Columbia. 80 pp.
  21. Patalas, K. & Salki, A. (1973) Crustacean plankton and the eutrophication of lakes in the Okanagan Valley, British Columbia. 34 pp.
  22. Saether, 0. A. & McLean, M. P. (1972) A survey of the bottom fauna in Wood, Kalamalka and Skaha Lakes in the Okanagan Valley, British Columbia. 20 pp.
  23. St. John, B. E. (1972) The limnology of the Okanagan mainstem lakes. 46 pp.
  24. Stockner, J. G. (1971) Preliminary evaluation; water quality. 4 pp. (1972) Diatom succession in the recent sediments of Skaha Lakes, British Columbia. 17 pp. (1972) Nutrient loadings and lakes management alternatives. 13 pp.
  25. ---, Pomeroy, M., Carney W. & Findlay, D. L. (1972) Studies of periphyton in lakes of the Okanagan Valley, British Columbia. 19 pp.
  26. ---, Carney, W. & McKenzie, G. (1972) Task 122: phytobenthos, littoral mapping supplement. 10 pp.+ 16 plates.
  27. Williams, D. J. (1972) General limnology of the mainstem lakes in the Okanagan Valley, British Columbia. 12 pp.
  28. Patalas, K. & Salki, A. (1973) Crustacean plankton and the eutrophication of lakes in the Okanagan Valley, British Columbia. J. Fish. Res. Board Can., 30: 519-542.
  29. Saether, O. A. (1970) A survey of the bottom fauna in lakes of the Okanagan Valley, British Columbia. Fish Res. Board Can. Tech. Report, 196: 1-17.
  30. Zeman, L. J. & Slaymater, H. 0. (1981) Determination of Nutrient Loads into and out of Skaha Lake. Inland Waters Directorate, Pacific and Yukon Region, Vancouver.
  31. Truscot, S. J. & Kelso, B. W. (1979) Trophic Changes in Lakes Okanagan, Skaha and Osoyoos, B. C., Following Implementation of Tertiary Municipal Waste Treatment. Department of Environment, Environmental Protection Service, Pacific Region.
  32. Jensen, E. V. (1981) Results of the Continuing Water Quality Monitoring Program on Okanagan Lakes for Years 1979 to 1980. 73 pp. Waste Management Branch, British Columbia Ministry of Environment, Pentiction, B. C.
  33. Stein, J. R. & Coulthard, T. L. (1971) A Report on the Okanagan Water Investigation. University of British Columbia. Prepared for Water Investigation Branch, British Columbia Water Resources Service.
  34. Fleming, W. M. (1975) A model of the phosphorus cycle and phytoplankton growth in Skaha Lake, B. C. Verh. Int. Ver. Limnol., 19: 229-240.
  35. --- & Stockner, J. G. (1975) Predicting the impacts of phosphorus management policies on the eutrophication of Skaha Lake, British Columbia. Verh. Int. Ver. Limnol., 19; 241-248.
  36. Coulthard, T. L. & Stein, J. R. (1970) Water quality survey. Trans. ASAE, 13: 430-432.
  37. Ferguson, R. G. (1949) The Interrelations among the Fish Populations of Skaha Lake, B. C., and Their Significance in the Production of Kamloops Trout (Salmo gardneri kamloops Jordan). 84 pp. University of British Columbia, Vancouver.
  38. British Columbia Research (1971) Sampling of the Okanagan Lakes - Spring 1970. Prepared for the Department of Lands, Forests and Water Resources, Victoria, B. C. Project No.1268 PHZ. 9 pp.+ Tables and Figures.
  39. Nordin, R. N. (1978) An Inexpensive in situ Algal Bioassay Procedure with Some Preliminary Results Bearing on Nutrient Limitations in Skaha Lake. 25 pp. Water Investigations Branch, British Columbia Ministry of Environment.
  40. Parkinson, E. A. (1986) Skaha Hatchery Evaluation. Fisheries Management Report No. 87. 17 pp. Fisheries Branch, British Columbia Ministry of Environment.
  41. Northcote, T. G. & Larkin, P. A. (1956) Indices of productivity in British Columbia lakes. J. Fish. Res. Board Can., 13: 515-540.
  42. Larkin, P. A. & Northcote, T. G. (1958) Factors in lake typology in British Columbia. Verh. Int. Ver. Limnol., 13: 252-263.
  43. Zeman, L. J. & Slaymaker, H. 0. (1985) Estimation of phosphorus flux in a regulated channel. Wat. Res., 19: 757-762.
  44. Deimert, D. D. & Kelso, B. W. (1980) Algal Analysis of 0kanagan Area Lakes in 1979. Report prepared for the Canada-British Columbia Okanagan Basin Implementation Agreement. 14 pp. Environmental Protection Service, Environment Canada, Vancouver.
  45. Findley, D. L., Findley, D. I. & Stein, J. R. (1973) Surface nitrogen and plankton in Skaha Lake, B. C., Canada. Freshw. Biol., 3: 111-122.
  46. Coulthard, T. L. & Stein, J. R. (1969) A Report on the Okanagan Water Investigation, 1968-1969. Prepared for the Water Investigations Branch, British Columbia Water Resource Service.
  47. Gray, C. B. J. (1986) Evaluation of Skaha Lake Database for Use in Predictive Models. Letter, 21 Feb. 1986, to P. F. Epp, British Columbia Ministry of Environment, Penticton, B. C.
  48. Blanton, J. O. (1972) Relationships between the heat content and thermal structure in the mainstem lakes of the Okanagan Valley, British Columbia. "Symposium on Lakes of Western Canada", University of Alberta Water Resources Centre, Edmonton.
  49. Bryan, J. E. (1988) Summary of Water Quality Trends in Lakes of the Okanagan Region to Spring 1988. Memo. Report to R. A. Nickel, 3 Oct. 1988, File 50.60000. 9 pp. British Columbia Ministry of Environment, Waste Management Branch, Penticton, B. C.
  50. Saether, 0. A. & McLean, M. P. (1972) A Survey of the Bottom Fauna in Wood, Kalamalka and Skaha Lakes in the Okanagan Valley, British Columbia. Fish. Res. Board Can. Tech. Report, 342. 20 pp.