1. Groundwater Protection in the Southern Willamette Valley
The Aquifer
Groundwater Protection in the Southern Willamette Valley

2. What we’ll cover: Where drinking water comes from.
What is groundwater?
What is an aquifer?
Types of aquifers.
How groundwater moves in the aquifer?
Create your own aquifer and experiment with it!

3. What is Groundwater?
Groundwater is water located beneath the ground surface in pore spaces and in the fractures of rock formations.
The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table.
A saturated area that can hold a usable amount of water is called the aquifer.

5. Global Freshwater Resources
(< 3% of All Water on Planet!)
< 1%
25.92%
74.07%

6. Why is Groundwater Important?
Groundwater is a major source of water for lakes, streams, rivers, and wetlands
Groundwater is a significant source of irrigation water in Oregon
50% of all Oregonians and 90% of all rural residents in the state rely solely on groundwater for their drinking water
In the Southern Willamette Valley Groundwater Management Area many of the public water systems rely upon groundwater. Surface water is also a source for drinking water in some locations. It is always important to remember that public water systems are regulated and monitored by the city, Department of Human Services, Environmental Protection Agency, and Department of Environmental Quality. Private water systems are not regulated by anyone but the owner.
Population estimate of Oregon in million make roughly 1.9 million relying on groundwater for drinking.
3,825, population estimate

7. Type of Aquifers
Confined - more protected from surface contamination. Typically occur at deeper depths. Are characterized by having a layer of heavy clay or bedrock that “confine” it from the surface.
Unconfined – this type has little to no protection from surface contamination. Normally found at shallower depths and have faster draining soils above them.
Soil types are part of the determination of confined and unconfined. An example of a slow draining soil would by heavy clay. Faster draining soil would be a sandy soil.

8. Unconfined aquifer
Heavy clay
Confined aquifer
Bedrock

9. From Surface to Groundwater
There is a strong relationship between surface water and groundwater. In the water cycle precipitation can infiltrate or run-off of the surface. The water that infiltrates the surface can be used while in the root zone by plants. Water that moves past the root zone of plants continues its travels through pores spaces until it reaches the water table/top of the saturated zone.
Groundwater in the aquifer tends to move toward lower locations, for example towards the Willamette River.

10. Groundwater Flow Flow can change with the seasons
Drier months - groundwater tends to flow toward rivers, lakes, and streams.
Wetter months - these same rivers, lakes, and streams can actually provide recharge to the aquifer.
In the wetter months the flow of groundwater can reverse to recharge the aquifer. For understanding, think of two barrels that are connected in the middle with a hose. If one of the barrels in full of water and you open the hose to allow water to flow into the other barrel – what happens? The water will flow from one barrel to the other until the levels and pressure of water is equalized, that same concept applies to groundwater flow – water flows towards the path of lease resistance.

12. Aquifer Activity