Can You Save Some Bucks? Flow Device Economics by CDWR

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:

Economics of Flow Measurement Devices

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.

EconomicsOfFlowMeasStructures

Some considerations for the proper use of weirs are:

  1.  Always seal leaky flashboards with sediment, horse manure if available, and if necessary, sheet plastic.  Use newer flashboards, replaced every year or two, and trim boards on site to ensure a level top board, and reduce gaps prior to use.
  2.  1.5 inch (2″ nominal lumber e.g. 2″ x 8″) flashboards are not measurably less accurate than a thin steel plate metal with sharp edges, provided that the head on the weir is great enough to cause separation of the water from the upstream edge of the flashboard.  The air bubble on top of the board is easy to see when the weir is working right.  The minimum required head is around 0.25 feet.  As an example, CDWR watermasters compared the use of flashboards to
    sharp-crested weirs on November 20, 2008, as they have done several times in the past.  Differences were recorded and weirs with flashboards had flows that were both slightly less and slightly more than the flows calculated for sharp-crested weirs.  Any difference is well below the margin of error when taking into account all possible errors.  In summary, 1.5-inch flashboards provide results indistinguishable from sharp-crested weirs for the use of measuring diverted flows.
  3.  CDWR designed the Briggs-manufactured Twin-Track Wsuppressed_weir_jackson_smalleirs© 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.
  4.  CDWR measures weir heads wSticking_Weir_zoom_sharpenedith weir sticks, as specified in the USBR Water
    Measurement Manual, 3
    rd Edition, 2001, on Page 13-4.  CDWR has checked the use of weir sticks numerous times and found the difference between the head measured with a weir stick and that at a staff gage nearly always to be 0.00 feet (the same to the hundredth of a foot).
  5.  Even when diverters are careful, the amount delivered may occasionally be somewhat more than the water right as streamflows vary due to diurnal fluctuation, changes in upstream diversions, and from increased flows due to storm events.  However, more than half the time when flows are not at the legal amount, they are less than the water right amount for the following reasons:
  • Floating debris sometimes accumulates on the upstream side of a diversion headgate, reducing flow.
  • Water right holders who grow hay shut off their diversions to cut, dry, bale and haul hay for several days, reducing their total volume of diversion.
  • Irrigation season damage to ditches requires diversions to be reduced or stopped during repairs.
  • Weed growth or sediment in the ditch reduces the hydraulic capacity of ditches.
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Smart Ranchers & Farmers Save Money for Them AND You

A 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 wantPMC_page - Edited 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.

Time_Cost_Scope_triangleYou 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!

How Do I Comply With Water Board Regulations? Part 3

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.  Shawn_pointing_with_ruleWhat 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:

  1. What if your water right is smaller than 3.7 cfs, diverting 100 AF to 1,000 AF per year?
  2. A BIG question right now: What is “alternative compliance”, and how might it be done to meet the Water Board’s regulations?

Shawn_pointing_at_orificeTo 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 contracted_weircfs.  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:

  • weirs as little as 0.5′ (0.5 feet, or 6″) wide, or wider with boards cut to make contracted weirs
  • free-flowing orifices with holes down to 0.16 x 0.16′ (2″ x 2″) square and a piece of steel plate to adjust it smaller
  • submerged orifices down to 0.25′ x 0.25′ (3″ x 3″) with an adjustment plate.
  • small flumes and meters

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 tWaterBoard_Meas_AlterComp_Para - Editedhat; 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.”

 

SOU_alternative_methods - EditedThis 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  …………”

New_Weir

eWRIMS Board Water Rights Search – Part 3

This is the third part of the discussion of the Water Board‘s Electronic Water Rights Information Management System – eWRIMS.  In eWRIMS Board Water Rights Search – Part 2,  we looked at how to search by Water Right type, Status, ID, County, etc., and most relevant for finding your own, by Primary Owner.  Let’s search by Primary Owner “Metropolitan”:eWRIMS_search_dialog_Met - Edited 2

The results we get are all the names with the word “Metropolitan” in them, and first on the list are the Metropolitan Water District of Southern California:eWRIMS_search_results_Owner_Met - Edited

We’ll scroll down the page until we get to Application Number A006406.  By the way, if you have a Permit or License, or you are looking for one, that Application Number is important.  It is the unique identifier for these documents, sort of like the Assessors Parcel Number is the true unique identifier for your property for tax purposes.  A006406 is for an Appropriative Permit for with a face value of 1,085,950 acre-feet.  If we click on the number A006406 in the left column, we get this summary:Permit_Summary - Edited 2

The summary doesn’t have that much more useful information – what we really want to do is go look at the original document.  Click on the “View Permit” text in the upper left-hand corner.  Now you get to see a scan of the permit.  You can see that document by clicking here:  a006406  The first page of the permit is shown here.  And this is the information you want to see for your application, permit, or license, the actual face value, purpose, place of use, and so on.

Permit_7641_firstpage - Edited

In the same way, we can view and download Statements Of Use (SOU).  Clicking through the Summary is a little different – we scroll down the page and then pick the statement for the year we want.  Here is the summary for SOUs for one of the City of Santa Barbara’s Permits:SB_SOU_Sum - Edited

Clicking on the year 2015 brings up the following report, showing that under this Permit, Santa Barbara diverted a total of 287.8 acre-feet last year:

Santa_Barbara_SOU - Edited

That’s how we use eWRIMS to search for information on water rights and Statements Of Use.  Remember, many thousands of adjudicated and riparian rights, and some pre-1914 rights, are not in the database.  What do we do if we think there is a water right, and we’re not sure where the information is?

  1. Start with eWRIMS, and call the Water Board if the database answer is inconclusive.  You may have to call several times, these folks are way too busy.
  2. Call the Watermaster if it is an adjudicated water right under watermaster service.  Even if the right is under a decree with no Watermaster, whoever you call probably has a good idea of who to call next to find out.  Google the county and name of the stream to see if one of the first five or so results brings up a Watermaster’s name or phone number.
  3. Call the Clerk of the Superior Court in the county where the water right is.  Ask if they have a searchable index of some kind that would give you a Case Number for an adjudication.  Some counties even have old water rights books where you can search for a pre-1914 recording of a right.

That’s plenty for now.  Have a great weekend!

How Do I Comply With Water Board Regulations? Part 2

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?Board_2017_Table

  1.  Who has to have a certified, accurate device by January 1, 2017?  How often is it monitored?

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 dropAbout_1.4_cfs_over_weir_edited_small 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 abovJohn_Headgate_edite 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 automawl16ted flow GE_PT878measurement 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 FTS_GOES - Editedthat 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 thesnotebook-405755_1280e 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 Sticking_Weirand 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 WMM_Cover_smalland 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!

How Do I Comply With Water Board Regulations? Part 1

Yesterday I met with some nice folks up in Hat Creek and Old Station.  A big Board_AF_Dates_Freqquestion 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 areAbout_1.4_cfs_over_weir_edited_small 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.

Shawn_sticking_Orifice

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.

John_Headgate_edit

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.

Photo_5566

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 SOUthe 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!

Water Board Legal Actions, Part 1

The Water Board takes legal actions against individuals, associations, companies, etc. (parties), regarding diversions, surface and groundwater pollution, mis-reporting or not reporting diversions, noncompliance with permits and licenses, underground storage tanks, and more.  Prior to assessing fines, Water Board managers, attorneys, or staff make phone calls to to the suspected parties, and they may make field visits to confirm allegations or gather more information.  Sometimes that’s enough – a phone call or visit may move a person to change practices, or take corrective action, and comply with the law.swrcb_complaints_program

The Water Board will follow up their calls or visits with a letter summarizing the facts, allegations, and actions taken by parties.  That may close out a complaint (if that is how the actions came to the Board’s attention) or may complete an investigation, with the provision that the promised corrective action will be done.CDO page

Their letters may seek information about alleged infractions, or may be cease and desist orders, or may convey the results of investigations and hearings including what fines or other penalties are assessed.

 

CWC page

The Water Board relies on the California Water Code, case law from lawsuits in the State Superior Courts or other courts, and those resolutions, orders, and decisions made by the Board itself, which it designates as “precedential”.  That means the Board looks back at these documents to help make decisions in the future.SWRCB ROD prec

In many cases the Board does not act alone, since it is just one of many California state and federal agencies.  It may combine its efforts with the California Department of Fish and Wildlife (CDFW, was Fish and Game), the U.S. Fish and Wildlife Service (USFWS), the State Attorney General (AG), the U.S. Army Corps of Engineers (USACE)…the list could include many more.  How does this cooperation with other agencies work?

The Water Board has authority over many water rights and uses of water, but other agencies have the primary authority over other uses of water.  For example, CDFW has authority over the California Fish and Game Code, which gives guidance on how much water must be left in streams by diverters.  Solid scientific studies must be made to prove how much water is needed.  In place (or pending the outcome) of these expensive, long-term studies, CDFW determines and/or negotiates flow amounts, and the Water Board uses their power to convince diverters to comply.  This works because CDFW could not prove the exact need in the near future, and CDFW is very reluctant to go to court to sue diverters.  However, the Water Board can act on the “best available information” or “reasonable estimates” to determine how much water must be left…and the Water Board can assess fines by itself without having to go to the Superior Court.  This makes for some very interesting stories…and those will be taken up in a later post.wbwa