Your well remains one of the most important (and expensive) improvements on your property. With proper usage and maintenance, it can last a lifetime. However, variable climate patterns, increased groundwater pumping, and seasonality changes can vary well production dramatically throughout the year. Fortunately, the ability to monitor your well opens up techniques to maximize water production and improve yield longevity.
Well Pumping Basics
To start, it’s important to understand how the water level changes during a typical pump cycle:
1) Static Level
This is the natural resting water level in the well and assumes the well is fully recovered. The time needed to fully recover depends on many factors and varies from minutes to days of no pumping. In fact, low yield wells may never fully recover if the demand consistently exceeds the recovery rate.
2) Pump Start
The well pump is often operated by a pressure switch or floats in a cistern. No matter the method, when there is a call for water, the pump turns on and begins pumping out the water in the well.
3) Drawdown
As water is pumped out faster than the recovery rate, the well levels will drop. In some wells, the water level may stabilize at a pumping level. In others, the levels will continue to drop, potentially all the way to the well pump depth if demand is not satisfied.
4) Recovery
Once the demand is satisfied (e.g. pressure or float switch cut off), the pump will stop, and the well will begin to recover back to the static level.
5) Cycle Repeats
See below example from our dashboard which shows 3x pump cycles. This well has a recovery of less than 0.5 GPM so it doesn’t quite recover to the static level after each cycle. Note, our sensor reports water level when the pump runs so the recovery level will be visible at the start of the next pump cycle.
Recovery Rate
The recovery rate depends on many factors, a detailed discussion of which is beyond the scope of this article. However, key variables include:
- Aquifer Properties: highly permeable materials such as gravel or sand allow for faster recovery than clay or dense bedrock.
- Well Construction: deeper wells, hydrofracking techniques, and proper screening can (but not always) intercept more water bearing zones with higher inflow.
- Seasonality/Climate: spring brings snow melt and wet conditions that improve recovery while drought conditions, dry spells, and blowing snow can reduce recovery.
- Regional Demand: the number of nearby wells and pumping demand can stress the aquifer and reduce inflow.
All these factors are mostly out of your control and can make the recovery rate highly variable even across adjacent properties.
However, the one factor you have the most control over is the hydraulic gradient. That is the pressure difference between the aquifer and water level in the well. In simple terms, the recovery will often be highest at maximum drawdown and will decline as the water level approaches the static level. Once the well reaches the static level, the recovery rate drops to zero.
Don’t Over Pump Your Well!
While the recovery rate is often highest with maximum drawdown, chronic over pumping can have significant consequences on the longevity of your well production. These include:
- Sediment Clogging: higher drawdowns can pull in more fine sediment which clog the perforations or screening into the well
- Mineral Encrustation: deeper pumping can bring in more minerals which plug water bearing fractures -> an analogy would be to think of hard water deposits in home plumbing fixtures
- Biofouling: faster inflow brings in more oxygen which can enable biofilm growth, clogging arterials for water flow
- Permanent Static Level Reduction: over pumping can reduce the water table over time, limiting your water storage in the well but also dewatering productive fractures that may have contributed to the overall yield.
While occasional deep pumping usually isn’t harmful, most often folks are unaware how deep their wells are being pumped and whether it is a chronic condition or sporadic. By monitoring the levels, you can diagnose chronic over pumping from occasional deep pumping.
For example, the below figure shows a deep pumping event. After the water level drops to a maximum, demand is returned to normal, but it takes over a week to fully recover. Monitoring for repeated events such as this, especially if the well isn’t allowed to fully recover, can be a good reason to take action (see next section).
Striking the Balance
Maximizing your water production can be thought of as a balance between achieving sufficient drawdown while minimizing over pumping. The well doesn’t produce water at the static level but consistent deep pumping can reduce yield over time.
How does one achieve this balance? A simple method is to alter your demand real time with lifestyle changes. If heavy usage activities (laundry, showers, etc) are all packed in a short duration, they can drastically draw the well down even to the point of running out of water. However, when spread out over the entire day, your well produces the same amount of water but limits deep pumping and allows the well to fully recover.
Alternatively, adding additional storage is a great way to smooth demand from the well. This could come in the form of a larger pressure tank or cistern. It’s important to note that this is only beneficial if the fill settings are optimized to limit static time with a balanced drawdown (fault timer, float levels, etc). Check out this article here which goes over an in depth process to optimize the cistern settings. In the meantime, see below example that shows how an optimized cistern fill cycle can maximize water generation while reducing stress on the well.
Wrap Up:
The techniques described are only possible with a method to visualize your well levels. Historically, this has been complex and labor intensive especially with deep wells common throughout the world. The imbrr Well Monitoring System provides a convenient method to track levels real time over WiFi by installing directly at the pressure tank or cistern. Our patented approach wraps around the pipe and doesn’t require any additional invasive sensors in your well. Contact us today to learn more about this innovative solution.
Feedback on this article or want to chat on your specific plots? Please reach out to us at support@imbrr.com. We are happy to provide additional suggestions and discuss ideas to solve your unique problem statements.