Surface Water, Rainwater Tanks, Rock Holes, and Springs

• Surface water is not safe for drinking.
• Surface water can contain bugs, dirt, rocks, minerals, and chemicals.
• Animals may drink from and bathe in surface water, potentially adding animal droppings.
• Surface water has not been cleaned and filtered.
• Rainwater tanks collect and conserve water.
• Water from rainwater tanks may contain bugs, dirt, and minerals.
• Roof debris and gutter contents can contaminate rainwater tanks.
• Rainwater tank water is suitable for watering gardens and washing cars/clothes.
• Clean gutters of leaves and animal droppings before drinking rainwater.
• Waterholes, rock holes, and springs combine groundwater and surface water.

Rock Holes

• Rock holes are surface water features holding water in rocky areas.
• They are a crucial water source for Aboriginal people in arid Australia.
• Rock holes supply water in dry landscapes with little permanent surface water.
• They assist in traveling and accessing a larger range of resources.

Springs

• Springs occur when water from an underground aquifer surfaces naturally.
• The amount of water from springs depends on aquifer water pressure, rainfall, and human usage.
• Spring water is typically clear but can be discolored by naturally occurring minerals.

Rivers

• A river is a large natural stream of water that flows over land.
• Rivers may hold a tiny fraction of Earth's total water, but are essential to human civilization.
• Rivers carry freshwater to people, plants, and animals across Earth.
• Rivers provide transportation and water power.
• Rivers shape the land by carving out valleys and canyons.
• Rivers contain an upper course, middle course and lower course.

Upper River Course

• Rain falls in highland areas and collects in channels (streams).
• Streams join other streams, increasing in size and speed.
• A confluence is where two rivers join.
• Creeks eventually grow into rivers.
• In the upper course, rivers flow rapidly.
• Rivers cut through land, picking up soil and gravel.
• Moving water erodes rock and soil.
• Over long periods, the river creates canyons and deep valleys.

Middle River Course

• In the middle course, fast-flowing water causes erosion.
• The river erodes left and right, forming horse-shoe-like loops called meanders.
• In its middle course the river flows down gentler slopes.
• The river becomes larger and slower.
• Soil, gravel, and sand begin to sink and form sandbars and islands.

Lower River Course

• Rivers in the lower course are in flatland and flow slowly.
• The water force is lower here than in the other stages.
• Rivers deposit all the bits of eroded land it has been carrying with it.
• Rivers drop solid material and some material is carried to the mouth.
• Rivers drop material and that becomes land that is called a delta.

Erosion and Deposition

• Rivers do not travel in straight lines.
• They avoid obstacles downhill.
• People have altered river courses.
• Erosion and deposition can change the shape of a river.
• Erosion is when materials are moved by wind or water and are called sediments.
• Deposition is when sediments are deposited in a different location.
• These processes change the surface of Earth.
• Rivers demonstrate deposition by dropping materials from erosion in new locations.
• Moving waters pick up and carry sand, dirt and sediments downstream.
• Rivers often turn brown or murky.
• Rivers deposit sediments into lakes or oceans.
• The color of the water changes due to soil, rocks, and materials being deposited.

Meanders

• As meanders grow, water sometimes erodes the riverbanks causing them to merge.
• Water will take the new, shorter route.
• Over time, deposition blocks off the old part of the river.
• An oxbow lake will form due to deposition blocking the old river route.

Explore the characteristics and potential contaminants of surface water, rainwater tanks, rock holes, and springs. Understand the importance of rock holes for Aboriginal communities in arid Australia. Learn about the benefits and risks associated with different water sources.