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With the drought, some homeowners with their own wells suddenly run out of water.  How to know if you’re at risk?  The best way is to know the level of water in your well, relative to the location of the pump.  When the well’s water level reaches the pump, you’re out of water.  Run the pump without water too long, and you may burn it out – with a repair bill a thousand dollars or more, and it may take weeks to get someone out to fix it. ​


The most common method of measuring the water level is by dropping something down the well - typically a probe is lowered until it detects the water level by electrical conductivity. This is usually done when the pump is off, and measures the "static" water level, which is the highest.  This provides useful information, but does not tell the whole story.  Two other measurements are helpful, particularly if the static level is getting close to the pump (for example, within 20 feet):

  1. How far does the water level drop when the pump runs?  When running, the pump usually takes water out of the well faster than in can be replenished from the surrounding aquifer, so the water level will temporarily drop and then return to the static level some time after the pump stops.  If this temporary water level drop gets to the level of the pump, your water delivery will be interrupted, and the pump could be damaged.

  2. Is the static water level dropping over time?  Typically, it drops during the dry season, and then comes back up during the rainy season.  Knowing how fast it’s dropping (and how much water you have above the pump) can help you predict if and when the water might run out.


I use a sonic level sensor – which repeatedly sends a sound pulse down the well every few seconds, which echoes back from the water surface.  The sensor times how long it takes for the echo to return, and calculates the water level depth.  This way, I measure how far the water drops when the pump runs.  A measurement of one pump cycle may be enough to know if you have plenty of water.  I can also record the level for a day, if the water level is getting close to the pump, to get the full picture on how your particular water use impacts the well.

If we find the well is likely to run out, there are steps you can take:

  1. If you’re using too much water at one time, as might happen with irrigation, spread the usage out to let the well recover.

  2. If the pump draws the water level too far down when each time it runs, its control could be adjusted to run for shorter periods.

  3. You may be able lower the pump (a job best done by a well company) to make more of the groundwater available to you.

  4. Have the well drilled deeper - if more water bearing formation is available.

  5. Add a storage tank and booster pump to meet high demand periods, or enable you to have water hauled in.

ECMC is able to offer this level measurement service throughout Sonoma County, California. There are three options available:

Option 1: The measurement of a single pump run will often be enough to know if there’s an imminent danger of running out of water.  It takes about one hour.


Option 2: We measure and record the level continuously for a day during normal use; if the pump runs too frequently during heavy use, the water level may drop even lower than measured with Option 1.  Then you’ll see how close the level got to the pump in the worst case, when demand was highest. 

Option 3: Follow up static level check.  At least a few weeks after completing options 1 or 2, a static measurement will allow a prediction of if and when the well might run out of water.

Use the contact form below, or email, or call 707-861-6649 to learn more, request a quote, or schedule your measurement.

Use the links below to learn more about these services:

Well Level Testing