CalWATRS – improvement or just change?

How is the Water Board’s CalWATRS database working out, and is it an improvement on eWRIMS? In summary, it’s changed, and so far the changes take more of our time to enter and review information. The Initial Statement to enter new water rights is working poorly.

The part of CalWATRS that works well is that there are a few really good folks that work with it, like Jeffrey Parks (Jeff.Parks@waterboards.ca.gov) and Carmen (Carmen.Artrip@waterboards.ca.gov). They and a few others are the most positive aspect of CalWATRS, I think. Jeff and Carmen always get back to me quickly, sometimes the same day. Of course, they want you to initiate all new contacts with CalWATRS-Help@waterboards.ca.gov and not bug people directly.

There was no pilot program with real water right holders before October 1, 2025. It would work much better if it had been tried out with 10 water right holders, including several who are not expert with the use of computers and have just one water right. That is a basic rule for any technology implementation – make it work for a few people first. The Water Board did not do that. Well, there is a possibility that some folks got to preview it, but none of what was learned was applied.

Login page for the California Water Accounting, Tracking, and Reporting System (CalWATRS), detailing system updates and user registration information.

Instead, we ALL got to suffer through it, try things, complain when it failed, and sometimes just wait some days or weeks until it was fixed. So many things were working poorly that I waited until December to start filing annual reports. Our rallying cry is “CalWATRS will work in 2027!” We can only hope.

My experience filing several hundred annual reports for Water Year 2025 is that it takes about 1-1/2 to 2 times as long to file as it did in eWRIMS. The wait between pages is longer for some of the pages, and there are more pages.

When the form is ready to submit, there is a page to review your entered information. However, the page is mostly blank. Don’t worry – I have gone back and reviewed page by page the information, and all the information was usually there.

Once your information is submitted, a PDF can be immediately downloaded, the same as with the old eWRIMS system. The PDFs seem to have all of the entered information. They are harder to read than the eWRIMS forms, and it takes longer to review the information. Next year…hopefully….

A webpage titled 'Initial Statement of Use' from the California Water Boards, featuring a prominent river flowing through a vibrant autumn landscape with colorful trees.

The Initial Statement submittal process is mostly not working:

  • There are no text boxes. There is not even a Supplementary Text Box at the end, somewhere before the signature, in which a user can enter text such as “Please refer to attached map “Real Map Of All Features Of This Water Right.pdf” to see the true map of this water right, including all Places Of Use, Points Of Diversion, Ditches, Measurement Devices, Etc.”.
  • No existing maps can be uploaded and be visible in the Initial Statement.  Maps can only be in attached files.  When submitting paper Initial Statements before CalWATRS’s debut, maps were part of the submittal and were always visible when downloading the Initial Statement.  Existing maps can include many types of relevant information that didn’t fit into the paper forms…and a lot less information is allowed to be entered into CalWATRS compared to the paper forms.
  • No KMLs of polygons can be entered for the Place Of Use.  Digitizing simple Places Of Use works okay, but complex polygons can take significant time.
  • Only one Point Of Diversion can be entered.  Many water rights have more than one POD, so the Initial Statement is inaccurate as soon as it is entered.
  • Only one water source can be entered.  For complex parcels or ranches with multiple water sources, this makes it impossible to list all the actual water sources.
  • Points Of Diversion cannot be edited.
  • Places Of Use cannot be edited.
  • Most of the basemap layers are not working.  For example, the public ownership parcels layer is not working.  I wanted to enter a large Place Of Use polygon using ownership parcels, but there was no information to do that.  Instead of fighting CalWATRS and alternating between Google Earth and CalWATRS for an hour or more, I finally digitized the boundaries of PLSS Sections that contain the Place Of Use.
  • Uploaded maps have to be downloaded to be viewed.  CalWATRS should allow uploading at least one, preferably many existing maps that are viewable within the CalWATRS Initial Statement itself.  The modern Internet can easily handle image files including JPEG, TIF, PNG, BMP, GIF, and so on, as well as Adobe Acrobat PDFs.
  • No Measurement Device can be entered.
  • The CalWATRS Initial Statement entry system as it now exists does not allow water right holders, agents, consulting engineers, or others enter all the required information.  Therefore, many people inputting an Initial Statement will have to lie to sign the document.  One of my Initial Statements allowed only one of 22 Points Of Diversion to be entered at all, and the Place Of Use is only the boundaries of PLSS Sections that encompass the Place Of Use.  I had to sign the document to enter it into the system.  Without even one text box to enter comments, I could not make the document a true representation of the water right. No PDF of the entered information can be downloaded as a draft of what was entered into the Initial Statement.  All that can be given to water right holders to prove an Initial Statement was entered is a cryptic email that does not have the Water Right ID.  This forces a water right holder or agent to log in and go through all the pages just to see what was entered.

Flow calculation Excel sheet for flume hourly data

How do you calculate hourly flows from flumes, weirs, and orifices, when what you actually measure is water depths? That’s how these devices work: the device creates an engineered curve, so that the depth at a certain distance from the entrance or exit gives an accurate flow.

Getting the flow equation is simple enough – for the flume below, flow = 11.6948 * (depth + 0.0068932) ^ 1.64505. What if you divert for seven months of the irrigation season? 7 months * 30 days * 24 hours. That comes to 5,040 measurements – too much to calculate by hand.

A concrete and metal water control structure with a gate and surrounding vegetation, situated in a streamside environment.

You’ll need to use Excel or similar software to handle all the data. Here is an example of a spreadsheet for this flume. Data is copied into the sheet from the water level logger output, then the spreadsheet automatically calculates the corrected depth, flow, and hourly volume.

Why are there columns “Year” and “Month” in this spreadsheet? Those are for pivot tables, which can quickly sum many thousands of rows of data, by year and month. A pivot table is used to get summed monthly flows and the maximum flow for each month, which are necessary to fill out your annual report to the Water Board.

A downloadable Excel file of this example spreadsheet is included at the bottom of this post.

Spreadsheet showing data for the Watchman Briggs 3-Foot Wide, 2-Inch-Ramp Flume, including water depth, flow rates, and calculations from the Hobo MX-2001 Transducer as of April 2, 2026.

Flume Flow Calcs 20260402 aDownload

Recent stuff – expert witness and added rectified maps

The last 12 months have been interesting. For the first time, I testified as an expert witness in a Superior Court trial. Thankfully I had time to prepare, so questions weren’t a surprise and I had ready testimony and answers. I’ll save details for when the trial is concluded.

Also, I added scanned images and rectified maps to court decrees under the “Some Decrees & Maps” heading on the left sidebar of this blog. The scanned images are higher resolution than the PDF maps and so more detail might be discernable. The rectified maps are in either the Universal Transverse Mercator Zone 10 or California State Plane Zone 1 coordinate systems. GIS software can translate incoming coordinates in one coordinate system, to the one you are working in, so the actual coordinates aren’t much of an issue.

If you are trying to split up decreed water rights in decrees, keep in mind the “(How To) Water Rights Determination and Reapportionment December 14, 2009” document. It is the only written, comprehensive explanation that I have seen which describes how to start with a decree and maps and subdivide water rights for an existing ownership parcel today.

That’s it for now, more later as I work to add posts with useful information.

The Water Bible – Water Measurement Manual

Watermasters, technicians, diverters, and anyone who needs to regulate diversions in the field uses the U.S. Bureau of Reclamation Water Measurement Manual. I used this as a watermaster, and I still take it with me on some visits to clients. The manual answers a lot of questions:

What kind of measurement device should I install?

How do I get the flow from my measurement device?

How accurate is my device, and how can I figure that out?

You can buy a hardback version like I have by starting at the webpage https://www.usbr.gov/tsc/techreferences/mands/wmm.html . You can download a PDF version from https://www.usbr.gov/tsc/techreferences/mands/wmm/WMM_3rd_2001.pdf . I put a link to the PDF on the left sidebar here, too.

I should have posted this years ago. Better late than never….

My Ditch Is Too Flat / Too Shallow To Measure With a Weir

The simplest measurement device to install is a weir. Vertical side walls with board slots, or channel iron bolted onto the concrete, hold 2″ x 4″ boards. The boards need to be stacked 12″ to 18″ high, and the channel depth needs to be 24″ or deeper. Here is a 3′ wide weir with a 12″ board height:

But, what if the ditch is less than 24″ deep? The ditch shown below is about 18″ deep, and it must convey flow that comes near to the top of its banks. The ditch here is about 10′ wide and is passing 20 cfs:

The solution was to install a Watchman Replogle flume that is nearly as wide as the ditch – 8′ wide. It is installed on a concrete base so it stays level and does not tip. The flume floor is 3″ above the bottom of the ditch, and the maximum depth upstream of the ramp is 15″. In other words, the top of the flume as the same elevation as the top of the bank:

The flume is conveying about 12 cfs in these photos. It does so with a total accuracy better than +/- 10%.

The maximum ditch flow is 30 cfs. Will the flume convey that maximum flow, without overtopping? The photo below shows the flume conveying a flow of 30 cfs. Yes, it still measures flow accurately, without overtopping.

Here is the same size of flume in a different location, at a lower flow. Even with the low flow, the depth of water is the same all the way across the flume:

Here is another version of the same flume. The ditch here has plenty of depth, so overtopping was never an issue. So, why is a low-head flume installed here? This ditch is very flat and there is a possibility of restricting the flow into the ditch as it enters from a low pipe. Measuring the flow this way ensures accurate measurement without flooding the incoming pipe:

Write It Down (Or Possibly Lose A Water Right)

I got a call from a distraught diverter.  “My grandfather has irrigated this land since at least 1910, from _______ Creek.  Everyone knew about it at the time, we get 1.2 cubic feet per second for 105 acres of pasture up here.  Nobody was worried about filing on water rights back then, so we didn’t file at the Water Board until a few years ago.  But a new guy moved in next door and he says we don’t have a water right, it’s all his water.  We do have a well but we don’t use it until late in the season when the creek flow drops way down.  The neighbor claims we only use the well and never use the water from the creek.  Then he went and filed a complaint with the Water Board saying we never used water, which is a lie.  We got some letters from the state, we figured they were just the regular reminders and we were really busy.  It turns out one of the letters said the Water Board wanted to come to the ranch and see if we really divert water.  Now we have a letter that says we have to ‘cease and desist’ within 30 days or pay $500 per day fines!  What can we do about this?”

I asked, “Did your grandfather, parents, or you write down notes when you were irrigating?  Do you have photos at the diversion showing you were taking water?  Did you measure the flow somehow?”

“No, we don’t have anything like that.  But everyone around here used to know who used the water!  It wasn’t a problem until there were new owners.”

Have you heard the saying, “Write it down, or it never happened.”?  That is true in everything – conversations, phone calls, purchases, 

From one legal website, here is a list:

What Types of Contracts are Required to be in Writing?   Contracts that are for the transfer or sale of land, are for the sale of goods over $500, cannot be fully completed within one year of signing (according to the contracts terms), are related to marriage, involve a promise to pay another person’s debt (“surety contracts”), or will continue beyond the lifetime of a party performing the contract.

Water rights definitely belong on the list!

When I was a bureaucrat, I learned early on to document the work I was doing, document processes so I and others could do some technical process faster next time, and document all important conversations.  When email came around, I learned to email things to myself to have a record.  Then, 5 or 10 years later when questions came up, I had a dated electronic document to answer with.

So what happened with that diverter who called?  The diverter called the Water Board staffer who wrote the letter and arranged a visit to the property.  I went out and took photos, measured the diversion, put in a temporary measurement device, and wrote a report detailing all that the diverter told me.  Two Water Board engineers visited and wrote up a report.  Then nothing happened for three years.  The diverter is still using water from the creek, and now is measuring the amount of water and reporting it every year.  Hopefully the state won’t take any further action, but we don’t know.

The lesson is, keep records!  Even if something happened 100 years ago, write down now what you know about your water right, the diversion rate, the acreage irrigated, number of livestock.  When a complaint comes, it’s a lot easier to refute when you can just hand over a written account.

Using Circular Headgates as Submerged Orifices

If you have a circular headgate, how can you use that as an orifice to measure flow? It’s easy if the gate is fully open – orifice equations from the USBR Water Measurement Manual can be used. The area of a circle is PI*r^2.

Here are the orifice equations for a rectangular headgate – the same equations are used for a circular headgate, or really a headgate of any shape:


A = the area of the orifice
g = gravity, 32.2 ft/sec^2
h1 = the upstream depth in feet
h2 = the downstream depth in feet

The first equation with the coefficient of 0.61 is for a gate on a wall. The second with the
coefficient of 0.70 is for a circular gate at the end of a pipe.

The difference between h1 and h2 can also be measured down from the top of a
wall with a level top.

Now, how do you get the area of a partly open circular headgate? There is a long equation with a good description at: https://mathworld.wolfram.com/Circle-CircleIntersection.html However, it sure is easier to get it from a table:

There you go. Based on the change of stem height, you can calculate how much the headgate is open. Convert that to a percentage. For example. A 2.0′ diameter headgate open 0.5′ is 25% open. Then use the table’s 50% row to where it intersects the 2.00 foot diameter column to get an area of 1.913 square feet.

Some Hope For Amendments: SB 389, AB 460, AB 1337

At Don Wright’s WaterWrights news, his July 20 article explains that there is some hope for amendments to bills SB 389, AB 460, AB 1337.

“Legislative committee consultant Alex Dominguez said he has been attending many, many meetings and has seen the opposition to the three big water rights bills: SB 389, AB 460 and AB 1337. He said AB 460’s author Assemblywoman Rebecca Bauer-Kahan or RBK, has dug her heels in and isn’t willing to work with the water community. That’s what I’ve been hearing also. It sounded to me like there is some hope for SB 389 being amended in a way that could actually be helpful. Let’s see what happens with that. Attorney Lauren Layne added there is some indication AB 1337’s author Assemblywoman Buffy Wicks may be willing to amend the bill to make it more palatable.“

https://waterwrights.net/kings-river-water-association-june-20-2023/

State Aims To Take or Control Your Water Rights: SB 389, AB 460, AB 1337

Three water rights bills are headed to the floor for votes, as of May 18, 2023. These bills propose to make water right holders prove their claims whenever the Water Board demands, inspect your diversion without your permission if the Water Board says it’s for public health and safety, and make senior (riparian and pre-1914) water right holders curtail their water rights. Your Farm Bureau, Cattlemen’s Association, and other groups are working to reduce these bills, and to encourage legislators to vote against them.

I summarize bill information below, and you should read the bill text yourself. Each bill name below is linked to the bill text at https://leginfo.legislature.ca.gov/. There are a few good newspaper articles; one is at the Modesto Bee.

SB 389 would make you have to prove your water right, regardless of whatever information you or previous holders of the right have submitted to the Water Board. Then the Water Board would decide whether you have a right at all, and what kind of water right you have. The Water Board would demand information including your use of the water including your measurement device, calibration, accuracy, photos, maps, quantities, all diversion data, etc.; the basis of the water right claimed; patent date claimed for the place of use; notice date of the appropriation and the date of actual delivery of water to beneficial use; prior diversions and use, including direct diversions and diversions to storage; and diversions and use of transferred water.

AB 460 would let the Water Board inspect your property with no warrant if they decide that public health and safety are at risk, and if you don’t voluntarily let them inspect. The Water Board could now issue you an interim order to stop diverting or take some other action, whether or not there is a complaint. The bill language is not clear on this, but it looks like the daily fines for violating “a term or condition of a permit, license, certificate, or registration issued by, or an order or regulation” would increase from $500/day to $1,500/day, up to $10,000/day. You could request a hearing within 20 days after being served with the complaint, but the Water Board could make an interim order before the hearing if they think that “immediate compliance is necessary to prevent imminent or irreparable injury to other legal users of water, or to instream beneficial uses.”

AB 1337 would let the Water Board curtail any water right at any time for any reason. This would include pre-1914 and riparian water rights. Also, it would let the Water Board continue its current practice of permanent curtailment, in which the Water Board lets you know each week that it’s okay for you to divert. The Water Board would continue to make you go check your curtailment status online each week.

What Can You Do?

  • Get all of your paperwork together. Whatever you have related to your water right, get it all in one place. Do this now, don’t wait for a call from the Water Board.
  • If you have a pre-1914 water right, you will need to have a copy of the original claim and any other related records from the Recorder at the county. Most have water right books with one or more indices to look up the original claim. Prior to 1910, most of them will be written in cursive, so they can take awhile to read and understand.
  • Make sure you have records of your water use. Ideally, there will be a diary, log book, or other notes recording what was grown each year and an estimate of the quantities. If you know the previous owner, ask for a note on when and how water was used. It is important to have documented water use at least every 5 years; this used to apply only to post-1914 water rights and the Water Board is now looking for this with pre-1914 water rights.
  • Upload digital copies of your most important records with your last Supplemental Statement (for pre-1914 water or riparian right) or Report Of Licensee (for post-1914 water right). Make things easy for the Water Board to find.
  • The Water Board posts your Initial Statement Of Water Diversion And Use on their website, along with the following Supplemental Statements. You may have more important records in your hardcopy water rights folder at the the Water Board. You can either go to Sacramento to review your folder, or request that your folder be scanned by a third party that you make arrangements to pay.

H-S Flumes For Accurate Measurements Of Small Flows

What if you have a small diversion, but grass or debris would interfere with a standard weir?  A weir has to have unobstructed, free-flowing water over

        Weir with debris and grass on crest

the crest so measured depths accurately relate to a calculated flow.  A weir with debris problems has to be cleared whenever flow is measured, which increases the time requirement.

When weirs have low flows, they trap debris more frequently, and they are less accurate when the depth over the crest drops below  0.2 feet (2.4 inches).  Then the only way to measure flow is with a narrow suppressed weir, or with a contracted weir, typically half or less the maximum width.  A V-notch weir can be used for measurement of low flows.

Changing the weir boards for different flows requires someone with experience,

                      Contracted weir

who will recognize when the depth over the weir is 0.2 feet or less and then use a contracted weir board.  However, people are busy when irrigating, and even busier when flows drop.  Weirs are often neglected during the time they need more frequent maintenance visits.

A good flume for passing debris and measuring low flows is the HS flume.  These are accurate right down to zero flow.  For the maximum flow, they require more

1.0-foot HS flume, for flows of 0.00 to 0.80 cfs

material than a rectangular Winflume, Montana, or Parshall flume.  However, they are more accurate than other flumes at very low flows – testing by the University of Minnesota found an average accuracy to be +/- 3.2% for ideal approach conditions.  They will pass debris down to zero flow – the flume shown here has an opening of 0.05 feet, or 5/8 inch at the flat bottom, and the opening increases with height.

        HS flume for flows up to 0.8 cfs

                 HS flume at 0.025 cfs

Why aren’t HS flumes common in California?  I suspect that the early adoption of Parshall flumes here established the standard.  I have seen a few hundred flumes, but I had never seen an operating HL (wide, high flow), H, or HS flume, prior to my installations.

Why go to the trouble of using an HS flume, if Parshall flumes are readily

                   New Parshall Flume

available?  A Parshall flume may be +/- 10% accurate down to perhaps 5% of its maximum flow.  Below that, the accuracy decreases.  An HS flume is +/- 10% accurate down to 1% to 2% of its maximum flow.  If the flow regime is predominantly low with occasional high flows, it is important to measure those low flows with the best possible accuracy.  Some places where low flow measurement is critical include field runoff where pollution is proportional to flow, small water rights, and dam leakage.

HS flumes are easier to construct than a Parshall, too.  The HS flume bottom is flat, and it has 3 vertical planes.  The photos of the Parshall flume here show

            Bottom of Parshall flume

that it has 3 horizontal planes, and 5 vertical planes.  An HS flume takes less time to build, and can be put together fairly quickly in any farm or ranch shop.  Parshalls are complex enough that they are purchased, including design and shipping costs.