Water Series: Pt 6 ~ Understanding Groundwater Management ~ Tips from UCCE Advisor, Allan Fulton


Groundwater pumping in the Mojave Desert

Today we are featuring an important discussion about groundwater management. Allan Fulton, UCCE Irrigation and Water Resources Advisor in Tehama County, gives us important tips for drought-proofing the farm. His tips are framed with your farm and larger local community perspective in mind — public districts and agencies included. Everyone has a stake in the effort.

Yet, Allan suggests that farmers especially need to pay attention. To be implemented at a community level, many of his suggestions for groundwater management require individual farmers to understand the issues and decide whether they can support them in concept, and then engage in efforts to make them a reality.

Read on as Allan shares his tips and insight on the importance of better groundwater management during and beyond times of drought.

Written by Allan Fulton.

The drought forces much more – if not total – reliance on groundwater when surface water supplies are very scarce. Storage reservoirs are nearly empty this Spring because the snowpack in the higher elevations of our watersheds did not materialize. Municipal and environmental uses are given priority over irrigation when surface water is scarce. As a result, irrigated agriculture must rely heavily – if not solely – on groundwater, along with continuing to implement a wide variety of other conservation practices to endure the drought.

Now, when we find ourselves in the midst of a severe drought, our options to manage and endure it are relatively limited, and we are pretty much faced with the reality of “making the best of a bad situation”. Yet, at the same time, it also provides us with a yard stick to measure our level of prior preparation to endure the effects in the present. When the drought ends, it will be vital that we reflect on how we can better prepare for more droughts in the future.

Managing our water resource isn’t only about today’s drought. The issue is whether we can improve management of excess water in years with normal or high runoff and snowpack, and be better prepared for future times of lack.

Why is groundwater management important? 


Groundwater flow and effects of pumping

Most of the surface storage in California was constructed prior to 1970. We still need to maintain surface water storage in an environmentally acceptable manner, but we also need to look more closely at groundwater management, particularly in normal and wet years.

Is it possible to more effectively capture excess surface water and infiltrate it back into the ground? Measures that help recharge, stabilize, and preserve groundwater in storage enables us to be better prepared when surface water is scarce.

Additionally, whether well water is for domestic, municipal, industrial, or agricultural purposes, we need to understand the aquifers from which we extract groundwater, how wells are constructed in relation to the aquifer, and how our pumps are set and designed to work. If we have this knowledge, we can better anticipate whether our pumps and wells will perform adequately when surface water supplies are dwindling.

Understand the groundwater conditions on your farm

  • Learn about the various methods to measure groundwater levels, and learn how to measure levels in your farm wells.
  • Monitor static (non-pumping) and pumping groundwater levels to better anticipate when groundwater quantity and reliability might become a problem.
  • Understand these potential issues and be prepared financially to deal with them.
  • Learn more about monitoring ground water conditions in The Landowner Monitoring Guide & Groundwater Level Monitoring.
  • Know how deep the well is and how this relates to the groundwater levels.
  • Check with the California Department of Water Resources (DWR) Regional Offices.
    By law well logs are supposed to be filed by well drillers at the time of well construction, and therefore, a well log may be on file for your well. Well logs are confidential, so only landowners can acquire them.
  • Know the depth of the well perforations or screens in the well, and how this relates to the groundwater levels. This will affect well yield.
  • If the well is older and has not had much previous maintenance, consider video logging the well casing for plugged screens or collapsed casings. The goal is to operate an efficiently constructed and maintained well that will effectively intercept groundwater and reduce pumping drawdown.
  • Video logging is a good alternative to acquiring well logs from DWR offices. Approximate costs are $1,000-2,000 for the video logging. This doesn’t include cost to remove the pump from the well.
  • Learn a basic background on water well construction and gain insight as to why knowledge about your well is important in Water Well Design, Construction, and Development.
Measuring the depth to water table through an entry point in a domestic well with a metal tape.

Measuring the depth to water table through an entry point in a domestic well with a metal tape.

Be familiar with your pumping plant

A pumping plant consists of an electric motor coupled to pump bowls (impellers) that are submersed below the groundwater table inside the well casing. Sometimes a diesel engine or natural gas engine is used to provide power to run the pump bowls instead of an electric motor. The electric motor or engine provides power to a shaft, to which the bowls are attached, and causes the bowls to spin at high speeds. The centrifugal forces created by the spinning bowls lift the groundwater to the ground surface.

Familiarity with specific pump design in your well can help ensure that you extract groundwater as efficiently as possible.

  • Know how deep the pump bowls are set in relation to the static and pumping water levels to better anticipate if the groundwater levels could decline below the pump bowls.
  • Know how deep the pump bowls are set in relation to the total well depth to know the extent that the pump bowls can be lowered as groundwater levels decline.
  • Lower pump bowls to anticipate declining groundwater levels during drought.
  • Know the size and design characteristics of the pump bowls in the well to understand how the pump will respond to declining groundwater levels. Some pump bowls perform better in declining groundwater conditions than others.
  • Possibly repair or replace pump bowls so they pump more water and operate more efficiently when groundwater conditions are declining.
  • Learn more about basic knowledge at pumping plants in Pumping Plants and Pumping Plant Efficiency.

Benefits of monitoring groundwater levels

Monitoring groundwater levels and the information gained from it can provide benefit beyond a single farm. It can also provide information that helps you understand the cumulative effect of many individuals extracting groundwater. Some of the types of insights that can be gained include:

  • Determining annual and long-term changes of groundwater in storage.
  • Estimating recharge rates.
  • Determining direction and gradient of groundwater flow.
  • Understanding how aquifer formations work and interact with surface water.
  • Insights for well construction and where to set pump bowls for efficient extraction and perhaps reduce competition among different wells.

Think about water supply reliability beyond the scope of a single farm and for the long run! Some questions to consider:

  • Is it possible that water supply decisions made from the perspective of a single farm might have certain desirable outcomes, but that the cumulative effect might have different outcomes when they are repeated for tens or hundreds of farms?
  • Is it better to think about water supply reliability from a single point of view with a focus on either groundwater or surface water, or is it better to think about water supply reliability recognizing that surface water and groundwater are naturally connected?
  • Is there more capacity to cope with drought as far in advance as possible, or is it better to cope with it in the moment of crisis?
  • Are you familiar with local water resource management efforts and if not would you be interested in researching it further?

Thank you Allan for this insightful article. For more information on groundwater management, get in touch with Allan: aefulton@ucanr.edu.

For more practical water-related resources, see our Water & Irrigation Toolkit.  

If you happened to miss them, check out the other articles in our Water & Drought Management Series:

If you have questions, words of wisdom or other great tips for the many farmers dealing with the drought, visit FarmsReach Conversations and post a question or comment!

If you have other great water management resources to share, get in touch with me: evaa@farmsreach.com. We’d love to hear from you!

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