Hi Eric,

Thank you for taking the time to share your article with us.  Once again, I am impressed with the depth of your research.  However, I think it is important to point out that many irrigators measure irrigation flow across the United States. One method for determing the flow rate is by using a water application rate calculator. Other irrigators use a device called a propeller flow meter. The propellor meter measures the velocity inside a pipe and displays the flow rate on a dial.  In recent years, irrigators began using portable ultrasonic flow meters. They cost somewhere between $3,000 to $5,000 each, but they are portable and can be installed in many locations.

With transit-time flow meters, paths of sonic beams travel back and forth across the pipe - with one beam moving downstream while the other moves upstream. When installed properly, the accuracy ranges from +/-1 to +/-5 of full scale. Producing crops is a science. And farmers understand the importance of monitoring and delivering the correct amount of water to the crop during irrigation. Even small farmers have tools to measure the water they are using through mathematical equations.  My great grandfather had methods for measuring irrigation flow back in the 1800’s.  I’m sure that over the years, many irrigators have shared crop irrigation data with the USDA, Universities, Irrigation Districts and Conservation Districts.  And, in turn, that data is used to calculate averages for the amount of water used to grow a particular crop.  It’s only natural that the amount of water used during a particular irrigation year will fluctuate, depending on temperature, rainfall and other factors. Thanks again for a thought provoking article.

It would be helpful to have the bar chart labelled along the x-axis, too. Sure, we can find that info  by lookng at Eric’s report, but we shouldn’t have to. Also, from what Elisabeth says, it seems it should be possible — though perhaps difficult — to assemble actual measured water usage data for a given year. If so, that would also be helpful to have in assessing how good these estimation methods are.

 Thanks to Elisabeth Britt for pointing out various methods that have been developed and deployed to estimate agricultural irrigation water use. The point of my article is that the public and public agencies have no real-world data on the actual amounts of water used for irrigation in Whatcom County. Data may exist for, say, Yakima County, but the weather, soil and crops grown there are different from those in Whatcom County. If we are to seriously address local water resources issues, farmers (like the rest of us) must meter and report their water use to the public.

The graph actuay does have the x-axis labeled.  Click the graph and it will fully display in a lightbox - showing the labeling and caption.  This partial view of photos and graphics is intentional for design reasons.  But it is confusing for graphics such as this one.  So, we will be changing it very soon to not clip off any of a photo or graphic.  It was a nice idea, but does not work as intended.

Hello again,

I need to admit that I’m a bit confused. So, let’s see if we can come to some sort of an understanding regarding the Department of Ecology’s WACs governing irrigation withdrawals from both surface and groundwater.

First, state law requires all irrigators to install a water meter. As you well know, water rights in the state of Washington are subject to relinquishment. So, its in the best interest of the water rights holder to use a meter to record actual water usage in order to protect his/her water right. In fact, we can verify that metering is required and that reports are being filed by examining a copy of a DOE Report Evaluation from Skagit County . As you scroll down through the document, you will note that metering and reporting are required.  This information is also required in a DOE Change Report. And, believe it or not, it is also required from an irrigator who is asserting a Water Right Claim. 

A water right document typically includes the following information:  a priority date (that’s the effective date of the water right); a fixed point of withdrawal or surface water diversion (see the Skagit Evaluation);  quantities (both instantaneous and annual); a defined period and place of use; and, provisions that govern the use (such as installation of a meter or a fish screen and the frequency of filing meter reports with DOE.  I hope my comment helps clarify why I’m feeling confused about your references to “but they are only estimates of the water being used” comment.  The Department of Ecology has verified irrigation metering data on file from across the state. 

That said, the agricultural community is very supportive of water management reform and has stated repeatedly that metering actually increases water usage - because under existing water law, a farmer is forced to use the maximum amount of water allowed in his/her water right,  in order to avoid relinquishment.  I’m looking forward to reading your response.

As usual, Elisabeth makes interesting points. However, they deal with topics not discussed in my recent paper on different ways to estimate agricultural irrigation water use.

Elisabeth focuses on state law, which, as she correctly notes, requires metering and reporting. However, as far as I can tell the state dept. of Ecology does nothing with these data; see my Feb. 2016 paper Ecology’s Role in Metering Whatcom Water Use. I note that “Unfortunately, Ecology, in spite of state law, a court order, and its own rules, is not managing, analyzing, and reporting metered water use [which] is especially serious for the agricultural sector … .”

Although Elisabeth argues that these data exist and are available, she has not presented any evidence to support that claim. Discussions of other estimation methods, state law on water meters, and relinquishment are all interesting but not germane to my paper. My key conclusion remains unchallenged: The methods used to estimate agricultural irrigation water use differ substantially from each other. The only way to actually know how much water is used in Whatcom County to grow particular crops, month by month, is to meter the water used by these farms and report, in summary form, that data to the public.

As always, thank you for your comment.  I have an idea. What if I contact the Department of Ecology personally to request specific information about the process the  DOE uses to conduct analysis, manage and process reports of metered water use in the agricultural sector?

If, by accident, I should actually  find “evidence” that this data exists and is available for public dissemination, I promise to  share it with you.  After all, the mere act of not being able to find data, doesn’ t mean that it doesn’t actually exist; nor ,does it naturally lead  a person to  conclude that the data isn’t being used for regulatory purposes.

Just for grins, would you mind describing to me, the method for measuring the different forms of irrigation techniques that are acceptable to you? Since it appears from your comment, that you have little confidence in the methods  (meters) that are being used to date.

Thank you.

Let me jump in here with what I think are relevant comments that could help resolve this issue.

Even if only some water-metering data were to be available for Whatcom County, but perhaps not aggregated to tell us what the actual annual usage is county-wide, it would still be useful to getting a better idea of the total usage and addressing Eric’s question about agricultural water usage. If one could obtain a representative sample of agricultural properties for the various kinds of crops being watered, then one could also form ratios of measured/estimated usage for the different categories. By applying these correction factors to the estimated totals in each category and adding the results, one would obtain a much more accurate value for the overall county water usage for agriculture.

This could also be done month-by-month or year-by-year, assuming such detailed data exists. Let’s see what Elisabeth comes up with.

To a skeptical experimental physicist like me, measurements are always much better than estimates. Theorists can speculate, but experimenters can prove or disprove their theories.

Thank you,  Michael.

I visted the local Department of Ecology office earlier this afternoon and will schedule a meeting with a DOE  Water Resources Specialist (irrigation) early next week. 

Unfortunately, the individual that I  need to speak with is out of the office today.

Elisabeth, thanks for a great offer! I like the idea of you contacting Ecology to see if your experience with their water use data is different from mine (see pages 6-8 of my paper on Ecology’s Role in Metering Whatcom Water Use). It would be great if you can obtain water-meter data on a sample of Whatcom County farms that are suitable for analysis. Better yet, perhaps you can get Ecology publications that document their analyses and interpretations of these data.

The answer to your question on what “method for measuring the different forms of irrigation techniques” would be acceptable to me is simple: Real-world, water-meter data for Whatcom County irrigation.

Because agricultural irrigation so dominates summer water use, I would prefer water-meter data on all farms. But I think Michael’s suggestion to obtain data for a representative sample of farms is excellent.