There are standard measurement devices on the lower end of cost: weirs, orifices, and flumes. They can be easily purchased pre-fabricated, saving you time and money. Accuracy and speed of measurement make these great for reporting and for defending your diversion against challenges. High tech options like acoustic Dopplers, magnetic meters, and propeller meters cost more but save time for larger diversions. All are good to +/- 5% or better when installed, easily meeting any standard for field measurements.
See the new “How Do I … ?” link on the left. There are so many posts on this blog, it is getting harder to find stuff. Click on the link, or right-click then “Open link in new tab”, and the big questions are linked to the appropriate blog posts.
Another way to search is, as always, Google. For example, googling “allwaterrights measure weir” brings up the following results:
The Board had lots of new information. The morning sessions revealed:
disagreements” about whether diversions comply with new regulations, according to Kathy Mrowka and attorney Nathan…did not catch his last name. That means a diverter can reason with Board staff.
In the afternoon, Delta Watermaster Michael Patrick George gave a great presentation on the progress of Delta regulations. Some of the main points are:
to comply the Water Board will work with the diverter. The first response from the Board will NOT be a Cease and Desist Order if a diverter is communicating. 3) Plans will be posted online, and so anyone may comment or point out their real or alleged deficiencies. The effect is that if a diverter says it is too expensive to comply normally and has an ineffective plan, the diverter’s neighbors and state and federal resource agencies will likely complain to the Board that the plan is deficient.
Kathy Mrowka and Nathan came back and did a great job of explaining how stockponds and other ponds can comply, including the use of staff gages and stage-storage curves. There will be more information online shortly.
Kathy also discussed the Report Management System (RMS). She said:
Here is the draft form to request additional time (up to 24 months) to comply: SWRCB_DRAFT_Request_Addl_Time_bw.pdf
By the way, there is a parking lot right across
the street from the EPA building, at 10th and I streets. It was full so I parked out at the City of Sacramento Parking structure at 14th and H; I needed the 4-block-walk for exercise anyway.
That’s enough for now! I will be out of town for a couple of days, and I will write more then. A good night to all!
Why would a diverter even think about installing a weir, when cost-effective flumes are available? It sure would be nice to have just ONE flow measurement device to consider!
After all, a weir should ideally convey only 1 cubic foot per second (cfs) for every foot of interior width, per the USBR Water Measurement Manual. For example, the 3′ weir on the left should only convey 3 cfs.
A flume like the Nuway Ramp Flume to the left can convey up to 8 cfs per foot of width. A weir has to have boards correctly installed, and a flume has no boards.
Flumes can have some drawbacks, though, which is why in ditches with adequate slope, the California Department of Water Resources Watermasters have preferred weirs for 15 years. A formed-up flume that is poured in place is expensive compared to a prefabricated weir. The new, prefabricated, galvanized metal flumes will reduce the cost compared to concrete, so cost is not as much an issue today. Even so, these flumes probably won’t last 20 to 40 years like the older, well-built concrete flumes do.
Flumes have a history of the ditch downstream filling in. This isn’t the flume’s fault; it was cheaper for a landowner not to do ditch maintenance and over years of neglect, the bottom of the ditch gradually got higher, flooding out the flume a greatly reducing its capacity and accuracy. Weirs can handle the lack of maintenance better – boards 
can be stacked up a little higher and still have accurate measurements.
When a flume settles in the ground, or if a galvanized metal flume tips sideways or up- or downstream, its accuracy is seriously affected. It will only work right if a new calibration curve is developed by measuring flows in the ditch at different elevations within the flume.
However, when a weir settles or tips, boards can be cut so that the top board is still level. In fact, some settled or worn-out flumes have had weir racks and boards installed inside, to regain accurate flow measurement. It is not 
an ideal fix, but it is better than a +/- 30%-accurate flume.
If the ditch is significantly wider than a flume, then a couple of things have to be done to make it work. First, it has to have wide wingwalls, maybe much wider than the flume itself. These wingwalls have to be added upstream and downstream. Then, much more fill has to be used so water ca
nnot overtop or wear through the fill. If fill has to be trucked in, that means extra cost and work to install it.
A weir is already wider than a flume, so shorter wingwalls can be used, if they are necessary. Less fill is needed. Installation can be substantially less hassle, and less expensive, depending on the ditch and proximity of the property to main roads.
However, in some wide ditches, 2 weirs have been installed side-by-side to measure a larger flow than just one could handle. And, as Watermasters understood orifices better and worked with them more, they discovered that sometimes, more flow can be conveyed through an orifice than over a weir and still have accurate flow measurement, +/- 5%.
Finally, weir boards can be cut for a wide range of flows and elevations. A weir can become an orifice, which may be more appropriate for low flows or variable submerged conditions downstream.
We need both flumes and weirs! Which one is better, more durable, or more cost-effective, depends on the total diverted flow; width, depth, and slope of the ditch; proximity of the property to road access; downstream
flooding (backing up water) in the ditch, and other factors. That is what I do for a living: help you get rid of headaches, upset, and trouble, to comply with State law, make sure you are getting your water right, and cut off complaints from other diverters. The phone call is free to discuss your diversion, (530) 526-0134, and email is also free at RightsToWaterEng1@gmail.com.
Photo on the right: Intermountain Environmental Inc. Nuway Ramp Flume with stilling well, 20 cubic feet per second (cfs) capacity. Shipped disassembled including fasteners; stilling well not included (but inexpensive to add).
20 cfs irrigates 400 to 2,000 acres of crops, trees, pasture, or hay, depending on where you are. As a Professional Engineer with wide experience installing and operating flow measurement devices, I can solve your headaches, heartburn, and trouble meeting the Water Board’s Regulations, diverting 20 cfs, for as little as $6,000 with one of these flumes. These flumes can go in an almost flat ditch, needing a water drop of less than 4″, and still maintaining accuracy of plus or minus 5%, twice what is needed by the Water Board. Smaller flumes cost less; even larger diversions could use 2 of these side by side.
Frank Crowe, farmer/rancher and the neighbor of some readers of this blog, has been doing research for 7 months on all possible flow measurement and datalogging devices. He has found some lower-cost options, including the Nuway flumes, that in past years, I did not think would work well. After checking into them, I know many of these can save 
you headaches, anguish, trouble, and some money. Technology has improved and computing costs have come down to make smaller, less expensive data loggers very useful for diversions. For example, the eTape sensor and Track-It datalogger shown here, and similar equipment from other manufacturers, will work well for many diversions:
Frank checked into the smallest Nuway flume, for 3.5 cfs, and found that the cost is fairly low at $580. With a size of about 12″ wide, 15″ high, and 48″ long, it will be easy for one person to assemble and would be possible to install by hand, without a backhoe.
Larry Forero, County Director o
f the Cooperative Extension in Shasta County, has been doing a great job of searching and asking the how diverters can comply with the law economically, particularly through alternative methods. The “Alternative Compliance” form will be available any day now on the Water Board’s website. Larry has also been checking on devices, costs, and applicability for particular locations and uses.
Most diversions will have to comply using standard, accepted methods of measurement and recording data. Following up on Frank’s resea
rch, I contacted Intermountain Environmental, Inc. in Utah and asked Josh Hanks about their 10 cfs and 20 cfs galvanized flumes. They cost $1,017 and $1,995 respectively. Shipping would be less than $300. Josh provided detailed information, including how these flumes have performed in the field. They are designed and built to be plus or minus 5% accurate, well within the Water Board’s regulation of +/- 10% accuracy as certified in the field. Many installations have worked with soil backfill only, instead of poured concrete. Installations will probably require a mass-concrete anchor, and may need steel plate inlet wingwall extensions, or outlet wingwalls added.
The bottom line, what does it cost for me to solve your problem, and to purchase, install, attach a datalogger, and certify the device to the satisfaction of the Water Board? For the largest flume, which can measure up to 20 cfs, in a typical location with vehicle access, I can have these working right, logging data, and certified for you, for $6,000 to $9,000. Telemetry and/or solar power, if needed or required by the Water Board, could add another $1,000 to $4,000.
Done! No more headaches, turmoil, or trouble for you, and I will have the pleasure of helping you keeping your business working well.
Good morning, California diverters. It was great to meet you folks last night in Hat Creek! Thank you to Henry and Pam Giacomini and Mark and Debbie Bidwell for inviting me up to the combined meeting of the Northeastern California Water Association, Farm Bureau, and Cattlemen’s and Cattlewomen’s Associations.
This blog is to help solve diverters’ headaches by providing peace of mind and helping stay out of trouble. Here are some posts aiming to do just that:
Demo Measuring Weir and Orifice; & Who To Call At The Board?
The links above will get you halfway to knowing what to do to comply. The other half is in other blog posts, on water flow measurement devices, how to measure flow, and other topics. Have a great day and rest of the week!
What is the cheapest flow measurement device to install, that is durable, accurate, and easy to maintain? The California Department of Water Resources (CDWR) Red Bluff office wrote a memo in October of 2010, detailing findings on flow measurement devices over decades of watermaster service. Part of the memo is summarized here – not direct quotes:
CDWR watermasters helped water right holders to install and operate a variety of structures over eight decades. Physical factors such as flow range, ditch width and slope, soil type, whether or not a site is protected from livestock, and access to the site, play a large role in picking the right device. Cost is also important, including design, installation, replacement, operation, maintenance and repair.
The following chart shows the relative costs that the watermaster service and water right holders have experienced for various devices. The chart shows that pre-built weirs are the least expensive to install and repair. Flumes are the least expensive to operate, but are the most expensive to design and construct or install.
Some considerations for the proper use of weirs are:
eirs© with two flashboard slots. The upstream flashboard slot holds the nominal 2-inch wide weir flashboards. The downstream slot provides the air gap for the nappe, as specified in the USBR Water Measurement Manual, 3rd Edition, 2001, in Figure 7-8 on Page 7-13.
ith weir sticks, as specified in the USBR WaterA local farmer, rancher, and apiarist, whose name you likely know, referred me to a pretty smart ranching friend of his who has been researching more cost effective flow measurement and data collection schemes. This retired aircraft engineer has found data collection devices with installed costs in the $500 – $600 range, instead of $1,200 up to $20,000. I’ll publish their names if they agree later; they should have a chance to read this before they put their names on it.
They aim to save themselves and all of you some of your hard-earned money. I really want
to see what data collection setups are available, hopefully this week there will be an all-in-one system that meets State requirements and is not such a budget-buster. There are also be some pre-fabricated flow measurement devices that can be easily dropped in a flat ditch where a weir (the least expensive device) won’t work, saving money compared to a formed-up flume.
From my years at DWR, my coworkers and I dealt with the trade-off between high accuracy and durability, at a high cost, and reasonable accuracy and lower durability for less money. This was always the tension, whether acquiring surveying equipment, portable flow measurement devices, or flow gaging components like data collectors, bubbler pressure sensors, or GOES satellite radios.
You have probably seen this triangle before – it is useful for planning prrojects. For the purposes of evaluating data collectors at diversions, Time is the owner’s, contractor’s, or engineer’s level of effort to make a diversion comply with the law. Scope is meeting the Water Board requirements – the length of that side cannot change. Everyone, including me, wants to reduce the Cost side of the triangle. Reducing Time means getting the labor, equipment rental, engineer’s report, and certification done cheaper – it’s the other way to reduce cost.
What is the effect of reducing cost? The size of the triangle equals quality, and that goes down. How much loss of quality is acceptable? In the case of data collectors, quality equates with the durability – maybe the device will only last 2 years instead of 4, or maybe it is twice as likely to quit working in the middle of an irrigation season. If quality goes down too much, then the data collection scheme will not meet Water Board requirements.
On the other hand, computer technology and sensors have improved over the years. Computing costs a tiny fraction of what it once did. Sensors have come down in cost a little, while their quality has improved somewhat. Maybe we can get just-fine data collection at half the cost – we’ll see!
In Part 2, How Do I Comply With Water Board Regulations? Part 2, we considered the question: Who has to have a certified, accurate device by January 1, 2017? How often is it monitored? The answer is, those who divert 1,000 acre-feet (AF) per year or more, and it has to be monitored hourly. 
What size diversion is this, really? An irrigation diversion of 1,000 AF over 6 months, with flows starting at 100% of the water right, declining to 50% of the right by the end of the season (month 6) would calculate out to a water right of 3.68 cubic feet per second (cfs), or about 3.7 to 4.0 cfs (cfs). Depending on where you are, that irrigates somewhere between 80 and 400 acres of hay or pasture.
In this post, I’ll answer 2 questions:
To answer the first question, the next category down is 100 AF to 1,000 AF per year. Using the example of a 6-month irrigation season, with a diversion that starts at 100% of the water right and gradually declines to 50%, the water right we’re talking about is about 0.37 to 3.7 
cfs. This category does not have to comply as quickly – the deadline is July 1, 2017, or nearly a year from now. The measurement frequency is daily, which is possible to be done by a diligent person, if not not recorded automatically. For a sense of how much water this is, depending on where you are, what the soils are like, and how efficient the diversion is, the acreage of hay or pasture irrigated ranges from about 8 to 370 acres.
What kind of measurement devices would meet the regulations? The same types that we discussed in Part 2, but ranging down to smaller sizes:
The photos above show smaller-sized devices than the 4′ weirs shown in earlier posts.
The second, and these days much BIGGER question, what about alternative compliance? The Water Board requires submission of alternative compliance plans on a form that is not yet available. If it were my diversion, I would not worry about t
hat; I would put together my plan and send it in. The old rule applies that if you are not sure who to send it to, send it to several managers and maybe a Deputy Director. Emailing documents is cheaper; most computers will let you print to PDFs that can be emailed. Your submittal probably will not be accepted this way but the point is, the Water Board cannot say that you have not attempted to comply. Not complying at all can be very expensive; “Do something wrong, instead of nothing at all.”
This screenshot is from an OLD, no longer valid Statement Of Use form, but it
gives some ideas of what options for alternative compliance the Water Board has in mind.
What has to be in your alternative compliance plan? From the Water Board’s ADOPTED TEXT OF EMERGENCY REGULATION, the text gives 12 parts that must be in the plan (below). The plan may be rejected – having a plan (instead of a standard, certified measurement device) is no guarantee that the Board will accept it. In summary, the plan must detail contacts for all people on a ditch, Assessor Parcel Numbers, the water right(s), priority(ies), use(s), diversion(s), ditch(es) and/or pipe(s), measurement frequency and methods, dates for milestones and completion, permits required, financing plan, and map(s) showing the plan area including all physical features and place of use…and all of this must be signed by all water right holders on the ditch (the emphasized text in the bullet points is mine):
“………… §935 Alternative Compliance for a Measuring Device or Measurement Method Requirement.
(a) Alternative Compliance – Generally. In circumstances where strict compliance with sections 933 or 934 of this title is not feasible, would be unreasonably expensive, would unreasonably affect public trust uses, or would result in the waste or unreasonable use of water, a diverter may submit an alternative compliance plan.
(b) Minimum Standards – an alternative compliance plan under subdivision (a) shall meet the following minimum standards:
(1) The plan shall include the following information:
(A) The name and contact information for all diverters covered by the plan;
(B) The name and contact information for the person designated to represent all diverters covered by the plan in matters before the board;
(C) Identification of each individual water right type and priority covered by the plan;
(D) A detailed description of the area served by the plan, including all points of diversion whether used or not used, all methods of diversion, any conveyance systems, all beneficial uses of water, and all acreage served;
(E) The assessor’s parcel numbers and ownership within the area covered by the plan;
(F) Identification of the proposed measurement frequency;
(G) Identification of the proposed measurement methodology;
(H) Topographic map(s) or aerial photograph(s) of the area covered by the plan that show the separate places of use authorized to be served by claimed water rights covered by the plan and showing the acreage served;
(I) An implementation schedule, including date-specific, objective milestones of plan implementation from date of filing through final implementation, including the estimated milestones for acquiring permits required for plan implementation and the estimated milestones for compliance with the California Environmental Quality Act, if required;
(J) Budget for implementation of the plan and the source(s) of financing for the plan;
(K) A list of any permits required for plan implementation, the agencies that will issue the permits, and expected dates for issuance;
(L) An affirmation, signed by all diverters covered by the plan, that the plan will be implemented in accordance with the schedule contained therein and that all claimed water rights covered by the plan will not be exercised outside the scope of the plan …………”
In Part 1, How Do I Comply With Water Board Regulations? , we looked at what water flow measurement devices will meet and exceed the Board’s requirements. The questions right back to me were: 1) Yeah, but which dates apply to me? and 2) Yeah, but what about monitoring and collecting data and reporting? How do I do that?
This is the “worst case” if I am not already compliant – less than 6 months from today! The first to have to report are those who divert 1,000 acre-feet or more per year, or store 1,000 acre-feet or more per year. The reporting has to be hourly, or 8,760 data points per year. The average rate of diversion for 365 days is 1.38 cubic feet per second (cfs) (which I had rounded to 1.40 cfs in previous posts). That’s equal to 620 gallons per minute (gpm), or 2.74 AF/day.
What if all the flow is diverted just for the irrigation season? Let’s use 6 months for simplicity – the average rate of flow is 2.76 cfs. Available flows drop
as the summer proceeds, so what size of water right are we really looking at? Let’s say flows decline evenly from 100% at the beginning, to 50% of available flows at the end of 6 months. The right that would divert 1,000 AF per year under these conditions is 3.68 cfs. The summary is, if my water right is, say, 4 cfs or more, then it is very likely I will be in this category. The weir shown abov
e is a 4′ weir, capable of measuring up to 4 cfs very accurately, at plus or minus 5% (sometimes better) accuracy with new lumber. A headgate like the one to the left is easily capable of passing 4 cfs and, if the gate is used as a measurement orifice, the accuracy can be 5%, certainly within plus or minus 10% if care is used with an older gate.
I can get that 4′ weir shown above installed and working for somewhere between $2,000 and $10,000 – depending on how difficult the access is to the site, whether native materials can be used, or 3/4″ base rock and 12″ protective rock have to be hauled in, and whether I already have a backhoe or excavator to install it. The headgate will cost more than that, maybe $3,000 to $12,000. A larger bulkhead or box is required, and good gates can cost quite a bit.
A larger diversion will have to use a larger weir or orifice, or more likely a flume or acoustic measurement device. That makes sense – the larger the flow, the more complicated it is to measure.
How do I report hourly flows? I sure can’t run out to the diversion every hour, so that means I have to use some kind of automa
ted flow 
measurement device. The G.E. Panametrics acoustic Doppler meter on the left is an option, and it or an in-line propeller meter, or an inline mag-meter, will be necessary for some configurations of diversions (pumped or very flat). The price starts at $5,000, though. If I have enough fall (drop in water elevation), I would sure rather put in a weir, orifice, or flume. A weir or flume can use a water level measurement device and data collector like the water level logger above on the right. That Global Water device is relatively durable, takes readings as often as desired, and can store data for months. It costs a little over $1,000. Oh, and if the orifice is submerged, so that the hole is underwater both upstream and downstream, then I will need two water level loggers, for $2,000.
Some folks at the Water Board are talking about telemetered data, meaning the data is sent to a remote location, or even available online. This would only be necessary if there were a great possibility 
that the diversion would be tampered with, or if it is a large diversion having a big impact on the amount of flow left in the stream. This has little benefit for anyone at most diversions. I would only install it if the need were very clear to me and everyone else. The added cost can be anywhere from $1,000 for short-range radio, to $20,000 or more for a full-on gaging station like you see on streams. The annual cost of operation and maintenance goes up, too.
How do I read the data on thes
e devices, so I can report it to the Water Board? Well, that takes some expertise. If I have 5 diversions from a creek, I’ll make sure my foreman knows how to do it, and handle it myself. If I have 1 or 2 diversions, then it’s more cost effective for me to have a professional do it, and to maintain it periodically. Reading that data takes a laptop to hook up to the USB port, and the software that comes with the device, and the expertise to look at the data 
and make sure it’s reasonable. The data that is recorded is “stage”, or water surface elevation. Using the correct weir, orifice, or flume equation, or table from the Water Measurement Manual, the stages have to be converted to flows. For hourly flows, that means 8,760 data points per year, which will require a spreadsheet like Excel to make the conversions. A BIG caution is that if the boards are changed, it has to be written down 
and then a different zero-flow datum used to convert stages to flows starting when the change was made.
2. Who has to have a certified, accurate device by July 1, 2017? How often is it reported?
The “next worst case” is for those diversions from 100 AF to 1,000 AF per year – irrigation water rights of about 0.35 to 3.5 cfs. These have to be recorded daily. The measurement devices are the same, but smaller. It is possible someone might grab a reading every day…but it is more likely that these will also have some kind of automated water level logger. More on these later. Have a great weekend!
Yesterday I met with some nice folks up in Hat Creek and Old Station. A big 
question right now is, how do I comply with Water Board regulations? Also, what exactly do I need to do for a measuring device? And, where can I find out that what I do will be acceptable, so I don’t get dinged after I did what I was supposed to?
First: devices. The most common, long-lasting, and cost effective devices for measurement of irrigation diversions are: weirs, orifices, flumes, mag-meters, propeller meters, and acoustic Dopplers.
Weirs are
the least expensive, long-lasting, accurate devices. This weir was prefabricated and shipped from Briggs Manufacturing. Installation takes a few hours, and with new 2″ lumber, accuracy is plus or minus 5 %. That is better than the Water Board’s requirement of 10 % accuracy.
An orifice is often exactly the same as a weir, with the boards set as an orifice. Instead of the water going over, it goes through an exactly-sized hole. The accuracy is plus or minus 5 % if it is set up carefully. The cost is the same as for installing and operating a weir.
Here is another kind of orifice – a headgate. If it is a square headgate, or a new, round (Waterman) headgate, then the area of the opening can be determined with plus or minus 5% accuracy. An older headgate or one with a less-than-perfect opening can still be 10% accurate, within the Boards’s standards.
This is a Parshall flume. It uses no boards, so no debris can pile up. It is nearly maintenance-free. Flumes cost more to install, and if they settle and get out of level they lose accuracy. However, you’ll see many of these in Northern California. There are some prefabricated flumes just coming into production that will be easier to install and will include data collectors.
How do you know which one will work for a particular diversion? Someone with expertise can check the ditch, grade, soil-type, flow range, and other information and tell you within a couple of days what will work best, with an engineering report and cost estimate. Rights To Water Engineering does this for $300 to $500, and can install the device if you like, with an operations manual.
Filing Statements of Use with the Water Board is now all by computer through 
the Internet. That’s one of the things Rights To Water Engineering, and some other folks do at a reasonable cost. If that’s your worry then contact us and we can point you in the right direction or help you out with reporting.
This is the quick summary on compliance! Contact me at (530) 526-0134 or RightsToWaterEng1@gmail.com, and read this blog for more detailed information. Have a great weekend!
