Data Portal
water quality DATA
LAKE WINDERMERE
Water Temperature
Temperature is one of the most important water quality parameters. It plays a critical role in determining the growth, survival, and reproduction of aquatic life.
Temperature also impacts water chemistry, influencing the amount of dissolved oxygen, electrical conductivity, water density, and the rates of chemical and biological reactions occurring in the water.
Why does it matter?
Lake Windermere’s temperature is warmer than many other freshwater lakes in B.C. because of its shallow depth. Unlike deep lakes, Lake Windermere does not separate into different layers of temperature and density within the water column.
Although this means we have nice, warm water for swimming, it also means there are no cool waters where fish can go to seek relief on a hot day.
Brain Teaser:
Many of the native fish species observed in this lake have optimum temperature ranges below 18°C for rearing, spawning, and incubation. Historical temperatures in Lake Windermere have been recorded up to 25°C. How do you think this impacts our native fish?
Dissolved Oxygen
Dissolved oxygen, or “DO”, is another name for free oxygen gas that has dissolved in water. Oxygen is transferred to the water from the atmosphere, and is also produced by submerged aquatic plants during photosynthesis. It is removed from the water by respiration in aquatic plants and animals, by chemical reactions, and through organic decomposition.
The capacity for water to hold DO is inversely related to water temperature. In simpler terms, warmer water holds less oxygen, while cooler water holds more oxygen.
Why does it matter?
Some amount of DO is required for nearly all species of aquatic life to survive, but too much or too little DO can harm aquatic life and negatively impact water quality. Lake Windermere’s susceptibility to very warm water means that aquatic life can be easily stressed by low oxygen levels.
Brain Teaser:
Climate change is predicted to increase the number of hot, dry summers we experience here in the Columbia Valley. How do you think this might impact the amount of dissolved oxygen that is found in the lake water?
Dissolved Oxygen
Dissolved oxygen, or “DO”, is another name for free oxygen gas that has dissolved in water. Oxygen is transferred to the water from the atmosphere, and is also produced by submerged aquatic plants during photosynthesis. It is removed from the water by respiration in aquatic plants and animals, by chemical reactions, and through organic decomposition.
The capacity for water to hold DO is inversely related to water temperature. In simpler terms, warmer water holds less oxygen, while cooler water holds more oxygen.
Why does it matter?
Some amount of DO is required for nearly all species of aquatic life to survive, but too much or too little DO can harm aquatic life and negatively impact water quality. Lake Windermere’s susceptibility to very warm water means that aquatic life can be easily stressed by low oxygen levels.
Brain Teaser:
Climate change is predicted to increase the number of hot, dry summers we experience here in the Columbia Valley. How do you think this might impact the amount of dissolved oxygen that is found in the lake water?
Conductivity
Conductivity is a measure of water's ability to pass an electrical current. This ability is directly related to the concentration of ions in the water, as well as the temperature of the water. Conductive ions come from dissolved salts and inorganic materials, such as alkalis, chlorides, sulfides and carbonate compounds.
Conductivity will be higher in "hard" water and will be very high in the water that is polluted with sewage, salts or minerals. Conductivity will be low in the water that might be polluted with oil because oil reduces the ability of water to pass electricity.
Why does it matter?
Many species of aquatic life only have a specific range of conductivity that they can tolerate. Monitoring long-term for conductivity in the water can tell us how this parameter may be changing over time, and, in conjunction with other parameters, whether there might be a pollution risk.
Brain Teaser:
The conductivity of water increases as temperature increases. What do you think is happening to the ions in the water when they warm up? Why does this improve the water's ability to pass an electric current?
Lake depth
Lake Windermere is a wide portion of the main Columbia River channel, meaning it is very different from typical lakes you might find in southern BC. The main difference is that it is very shallow - on average, between 3-4 m depth in mid-summer.
In deep lakes, water at depth tends to be cooler and more dense. Water closer to the surface tends to be warmer, because it is receiving radiation from the sun.
Why does it matter?
Depth can be an important consideration for aquatic life, as well as for recreational boaters and drinking water users. Shallow water poses more risks because boaters can easily get caught on sediment bars or clog their motors with aquatic vegetation.
Shallower water also warms up more quickly, which can pose issues for drinking water quality and for the survival of aquatic life. There is no objective set for lake depth in Lake Windermere, but levels below 2 m generally cause concern for boaters.
Brain Teaser:
Do you think a deep lake flows more quickly, or more slowly, than a shallow lake? If you were a fish, would you rather live in a deep lake, or a shallow lake?
Lake depth
Lake Windermere is a wide portion of the main Columbia River channel, meaning it is very different from typical lakes you might find in southern BC. The main difference is that it is very shallow - on average, between 3-4 m depth in mid-summer.
In deep lakes, water at depth tends to be cooler and more dense. Water closer to the surface tends to be warmer, because it is receiving radiation from the sun.
Why does it matter?
Depth can be an important consideration for aquatic life, as well as for recreational boaters and drinking water users. Shallow water poses more risks because boaters can easily get caught on sediment bars or clog their motors with aquatic vegetation.
Shallower water also warms up more quickly, which can pose issues for drinking water quality and for the survival of aquatic life. There is no objective set for lake depth in Lake Windermere, but levels below 2 m generally cause concern for boaters.
Brain Teaser:
Do you think a deep lake flows more quickly, or more slowly, than a shallow lake? If you were a fish, would you rather live in a deep lake, or a shallow lake?
Turbidity
Turbidity is a measure of the light that is scattered by particles suspended in water. It indicates the clarity of the water.
When waters are highly turbid － for instance, when they are filled with lots of suspended sediment (as tends to happen during spring runoff in April/May) － light does not penetrate as easily to reach aquatic plants, which reduces photosynthesis.
Why does it matter?
Aquatic life in Lake Windermere has adapted to seasonal flushes of sediment into the lake. The acceptable amount of turbidity depends on the time of year. If there is heavy construction or soil disturbance near the shoreline or upstream, it can contribute unnatural turbidity to the lake. Fish can become stressed by high turbidity due to a reduced ability to navigate, clogging of gills, and other physiological stressors. Plants may slow down their photosynthesis due to high turbidity, which makes the concentration of oxygen in the water decrease.
Brain Teaser:
Take a look at the graph for turbidity above. Which month had the highest turbidity, and at which site in the lake? Can you hypothesize as to why this site had the highest turbidity, compared to the other sites? How does it change with time?
pH
pH is a measure of how acidic or basic a substance is. pH is a measure of the free hydrogen ion concentration (H+) of a solution and is reported on a scale from 0 to 14. Solutions with a pH between 0-7 represent an acidic environment, while solutions with a pH between 7-14 represent a basic or alkaline environment. The pH of natural lakes is rarely neutral, because of the presence of dissolved salts and carbonates, aquatic plants, and the mineral composition of the surrounding soils.
pH can fluctuate daily as well as seasonally: for example, during photosynthesis and respiration by submerged plants or phytoplankton in the water, or due to other chemical and hydrological processes that add or remove acids from the water.
Why does it matter?
Many aquatic species are sensitive to sudden changes in pH. However, most species have adapted to deal with the natural pH fluctuations of a lake that are spread over time. If the pH changes dramatically within a short time frame, it could be an indicator of a pollution event or some other form of disturbance.
Brain Teaser:
Take a look at the graph for pH above. Why do you think the pH increases as the summer wears on?