Water Well Measurements: How to Measure Well Depth, Static Water Level, and Casing Size

Learn how to accurately measure well depth, static water level, casing diameter, and other critical well specifications required for configuring your Simple Pump system. Includes measurement methods, examples, and common mistakes to avoid.

Simple Pump Team
9/20/2025
3 min read

Related Systems:

Deep Well Hand Pump
Shallow Well Suction Pump
Motorized Well Pump
Solar Powered Well Pump

Accurate well measurements are essential for configuring your Simple Pump system correctly. This guide explains what measurements you need and how to obtain them.

Three Critical Measurements

1. Total Well Depth

What it is: The distance from ground level to the bottom of your well.

Why it matters: Determines maximum drop pipe length and ensures pump cylinder doesn't hit bottom.

How to measure:

  • Lower weighted string until it hits bottom
  • Mark the string at ground level
  • Measure the string length
  • Alternative: Check well driller's report

2. Static Water Level

What it is: The distance from ground level to the top of the water when the pump is not running.

Why it matters: This is the most important measurement for sizing your pump. It determines which cylinder model you can use.

How to measure:

  • Lower weighted string slowly
  • Listen for splash when it hits water
  • Mark string at ground level
  • Measure to the splash point
  • Alternative: Well water level indicator tool

Note: Static water level may vary seasonally. Measure during dry season for most conservative sizing.

3. Well Casing Diameter

What it is: The inside diameter of your well casing pipe.

Why it matters: Determines which well cap fits and whether dual installation is possible.

How to measure:

  • Measure across the inside opening
  • Report the inside diameter (ID)
  • If measuring outside, note it's the OD
  • Common sizes: 4", 5", 6", 8"

Where to Find Well Information

Well Driller's Report

Your original well driller should have recorded:

  • Total depth drilled
  • Static water level at drilling
  • Casing size and material
  • Well yield (gallons per minute)
  • Date drilled

County Records

Many counties maintain well records:

  • Contact county health department
  • Or county water resources division
  • Provide property address or parcel number

Well Tags

Some wells have identification tags:

  • Check well cap or casing
  • May reference permit number
  • Use number to look up records

Professional Measurement

If you can't measure yourself:

  • Well service company
  • Pump installer
  • Water system professional

Additional Helpful Information

Well Yield (Recovery Rate)

  • How fast water enters the well
  • Measured in gallons per minute (GPM)
  • Important for motor operation planning

Casing Material

  • PVC plastic
  • Steel
  • Concrete (older wells)
  • Affects installation approach

Presence of Submersible

  • Is there an electric pump in the well?
  • What size is the submersible?
  • Is there a pitless adapter?

Pitless Adapter Depth

  • How far below ground is the pitless?
  • Typically 4-6 feet below frost line
  • Important for tie-in planning

Measurement Tips

Use the Right Equipment

  • Weighted line (chalk line works well)
  • Tape measure (100+ feet)
  • Flashlight for viewing down well
  • Notepad to record measurements

Safety First

  • Secure well cap before removing
  • Don't drop anything in the well
  • Use caution around open wells
  • Consider professional help for deep wells

Measure Twice

  • Confirm measurements before ordering
  • Seasonal variation in water level
  • Note the date of measurement

Ready to Get a Quote?

Gather your measurements and request a quote:

Required Information:

  1. Static water level
  2. Total well depth
  3. Well casing diameter (ID)

Helpful Information:

  • Well yield if known
  • Presence of submersible
  • Pitless adapter (yes/no)
  • Intended use (backup, primary, pressure tank)

Technical Support: 877-492-8711 ext. 6

Request a Quote

Tags

static-water-levelwell-basicswell-casingwell-measurement

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