Topic 3 Fresh Water Systems Topic 3 Fresh

Topic #3 Fresh Water Systems

Topic #3 – Fresh Water Systems n n n Less than 1% of the world’s water supply is available for drinking, cooking and other purposes This small % is found in fresh water systems Fresh water systems exist above ground (surface water) and below ground (groundwater)

Lakes, Ponds and Wetlands n n A lake and a pond are basically large holes in the ground, filled with standing water. They differ not in size, but in depth In a pond, sunlight reaches all they way to the bottom – in a lake, sunlight does not reach to the bottom. The depth to which sunlight penetrates depends on the water’s clarity

Lake Minnewanka Schriber Pond

n n Clarity is determined by the amount of matter suspended in the water. Wherever there is a low area in the land, wetlands can occur. There are different types of wetlands, but they all have one characteristic in common – they are all saturated with water all or most of the time. A marsh or slough are good examples of a wetlands.

Streams and Rivers n n n Streams (small) and rivers (large) are both fast-flowing waterways. However, the individual characteristics vary a great deal – water speed, temperature, clarity, types of banks and bottoms, and plants and animals that live in them. Fast-flowing waterways are usually rich in oxygen, which fish and animals need to survive.

Bow River

The Watershed Concept n n No matter where a raindrop falls, it will eventually end up somewhere else All water on Earth – either surface water or groundwater – is part of a watershed. A watershed, or drainage basin, is the area of land that drains a body of water, such as a river, pond, wetland, lake or ocean. Water hits the ground and either filters into the groundwater or flows downhill

n n n Water that doesn’t soak into the ground or evaporate, but flows across the Earth’s surface is called run-off In North America, a continuous ridge of mountain ranges divides the continent into two main drainage areas This ridge of mountains is known as the Continental Divide.

Alberta has 4 main watersheds. 1) The northernmost area drains into the Mac. Kenzie River and into the Arctic ocean. 2) Most of the southern area drains into the Sask-Nelson River & into Hudson’s Bay. 3) The little southern piece drains into the Missouri and into the Mississippi. 4) The little eastern piece

Watersheds (cont. ) n n n Landforms determine the size of a watershed. High ground such as mountains, hills, etc direct water one way or another The upstream areas of a watershed are called the headwaters. The end point of the water flowing through a watershed is called the outflow. What is the outflow for southern Alberta?

Affecting Watersheds n What are some ways to change the run-off patterns in watersheds?

Affecting Watersheds n What are some ways to change the run-off patterns in watersheds? - paving

Affecting Watersheds n What are some ways to change the run-off patterns in watersheds? - paving - logging

Affecting Watersheds n What are some ways to change the run-off patterns in watersheds? - paving - logging - damming rivers and streams

Run-off and Erosion n There are many factors that determine whether rain soaks into the ground of runs off – amount of rain, time it takes to fall, slope of the land, amount of vegetation. All of these things affect how much loss of soil or sediments occurs, called erosion. As water flows downhill, sediments are eroded and carried downstream where they will be deposited – called deposition.

n n Streamflow is used to measure the amount of water discharged by a watershed. It involves measuring the amount of water (volume) that flows past a certain point over a period of time (velocity). Watershed managers also measure the amount of sediment that streams and rivers carry. Why is sediment monitoring important?

Importance of Sediment Monitoring n n Sediment particles released in fish habitats can carry toxic chemicals from run-off Some farming practices increase soil erosion & add sediment-borne toxic chemicals to the environment. Deposition of sediment in rivers or lakes can decrease water depth and make navigation difficult. Sediment can affect the delivery of water – wear out pumps and turbines, etc.

Groundwater n n More than 25% of Albertans depend on groundwater for their water supply. If soil and rock have pore spaces that are connected and water can flow, they are said to be permeable. Some material, such as clay, has no pores and will not let water pass – impermeable. Some types of rock (sandstone) have so many pores that water fills it and flows from pore to pore creating an underground river of sorts – called an aquifer.

n The layer of porous rock in which all pores are full of water forms a water table.

Groundwater Contamination n Groundwater carries with it many dissolved particles of various origins Any addition of undesirable substances to groundwater caused by human activities is considered contamination. Contaminants can be hazardous wastes, chemicals, heavy metals, oil and even sediments.

Groundwater Contamination (cont) n n Groundwater contaminants come from 2 categories of sources. Point sources are those where the source of a pollutant is from a small, defined area. Non-point sources are those where a pollutant comes from a wide area. Hydrogeologists are scientists who study groundwater (ask me about the Wreck Beach story)

Too Much Water As we’ve seen in the recent past, too much water in a river stream can cause big problems. n A river may overflow its banks and spill out over a wide area of the valley floor called a flood plain. n

Woah!!!