How do I determine how much water is in my well?

To determine how much water is in your well, the most common method involves measuring the depth to the water level from the top of the well casing.

Here's a detailed explanation:

Measuring the Water Level:

1. Prepare a Measuring Tool: The most reliable way to measure your well's water level is by using a weighted steel tape measure. Ideally, use a steel tape measure that's long enough to reach the bottom of the well. Coat the bottom few feet of the tape measure with chalk.

2. Lower the Tape: Slowly and carefully lower the tape measure down the well casing. Be careful not to drop the entire tape into the well!

3. Listen and Feel: As the weighted end of the tape reaches the water surface, you may hear a slight splash or feel a change in tension.

4. Retrieve and Read: Pull the tape measure back up. The point where the chalked portion of the tape is wet indicates the water level.

5. Record the Measurement: Note the distance from the top of the well casing to the water level. This measurement is called the "depth to water."

Calculating the Amount of Water:

To determine the amount of water in your well (the volume), you'll need a few more pieces of information and potentially some more advanced methods:

1. Determine the Total Well Depth: You'll need to know the total depth of the well. If you don't know this, you may need to consult well drilling records or contact the company that drilled the well.

2. Determine the Diameter of the Well Casing: This is the inner diameter of the well pipe. Common sizes are 6 inches or greater.

3. Calculate the Water Column Height: Subtract the "depth to water" from the total well depth. This gives you the height of the water column inside the well.

4. Calculate the Water Volume: You can use the following formula to calculate the approximate volume of water in the well:

   • Volume = π (radius)² height

   Where:

   • π (pi) is approximately 3.14159
   • radius is half of the well casing diameter (convert inches to feet by dividing by 12)
   • height is the water column height (total well depth minus depth to water)

Example:

Let's say:

• Total Well Depth = 200 feet
• Depth to Water = 50 feet
• Well Casing Diameter = 6 inches (0.5 feet)
• Well Casing Radius = 0.25 feet

1. Water Column Height: 200 feet - 50 feet = 150 feet

2. Volume: 3.14159 (0.25 feet)² 150 feet = approximately 29.45 cubic feet

3. Convert to Gallons: One cubic foot is approximately 7.48 gallons. Therefore, 29.45 cubic feet * 7.48 gallons/cubic foot = approximately 220.3 gallons.

Therefore, in this example, there are approximately 220.3 gallons of water in the well.

Important Considerations:

• Accuracy: These measurements and calculations provide an estimate of the water volume. Actual volume may vary depending on well construction and geological factors.
• Well Recovery Rate: Knowing the static water level and the well's recovery rate (how quickly it refills after water is drawn) is crucial for understanding its overall capacity.
• Professional Assessment: For a precise assessment, consult a qualified well technician or hydrologist. They have specialized tools and knowledge to accurately measure well capacity and performance.