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.
can be stacked up a little higher and still have accurate measurements.
nnot overtop or wear through the fill. If fill has to be trucked in, that means extra cost and work to install it.
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.
flooding (backing up water) in the ditch, and other factors. 