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Flow measurement using ramped broad crested weirs. Research technical completion report Item Info

A low cost flow measurement device that will provide real-time data is needed for use in irrigation water distribution. In addition it must be easily calibrated, require low operating head, and require little if any periodic current meter measurements to verify the rating curve. The project goal was to evaluate the use of computer calibrated ramped broad crested weirs in establishing a stable stage-discharge relation within the head constraints of most irrigation canals. Structures were built in six canals in southeastern Idaho. Design discharges ranged from 100 to 600 cubic feet per second, while tailwater depths range from 2.75 to 5.45 feet. The required head loss at the design discharges ranged from 0.29 to 0.50 feet. Weirs were calibrated using as-built dimensions in the computer model and the calibration was verified by current metering of the canals every two weeks during the summer of 1986. The current metered flows and weir predicted flows usually differed less than 3 percent. Two of the weirs experienced submergence problems due to construction anomalies rather than weir characteristics. Recalibration using as-built dimensions in the computer model allows construction tolerances to be relaxed. Due to this and the simple geometry, ramped broad crested weirs are less than one fifth the cost of an equivalent Parshall flume. Both Water District 1 and the involved canal companies were pleased with the performance of the weirs. Submitted to Water District 1, Idaho Falls, Idaho.

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Title:
Flow measurement using ramped broad crested weirs. Research technical completion report
Authors:
France, Kevin E.; Brockway, C. E.
Date Created (ISO Standard):
1987-11
Description:
A low cost flow measurement device that will provide real-time data is needed for use in irrigation water distribution. In addition it must be easily calibrated, require low operating head, and require little if any periodic current meter measurements to verify the rating curve. The project goal was to evaluate the use of computer calibrated ramped broad crested weirs in establishing a stable stage-discharge relation within the head constraints of most irrigation canals. Structures were built in six canals in southeastern Idaho. Design discharges ranged from 100 to 600 cubic feet per second, while tailwater depths range from 2.75 to 5.45 feet. The required head loss at the design discharges ranged from 0.29 to 0.50 feet. Weirs were calibrated using as-built dimensions in the computer model and the calibration was verified by current metering of the canals every two weeks during the summer of 1986. The current metered flows and weir predicted flows usually differed less than 3 percent. Two of the weirs experienced submergence problems due to construction anomalies rather than weir characteristics. Recalibration using as-built dimensions in the computer model allows construction tolerances to be relaxed. Due to this and the simple geometry, ramped broad crested weirs are less than one fifth the cost of an equivalent Parshall flume. Both Water District 1 and the involved canal companies were pleased with the performance of the weirs. Submitted to Water District 1, Idaho Falls, Idaho.
Subjects:
Flow measurement Flowmeter Irrigation water Performance evaluation Weirs Computer models Calibrations
Location:
Southeastern Idaho
Latitude:
43.02
Longitude:
-112.64
Collection:
Boise Basin
Series:
Water for Idaho
IWRRI number:
198705
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
Idaho Water Resources Research Institute; University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
KIT
Date Digitized:
2017-09-05

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Source
Preferred Citation:
"Flow measurement using ramped broad crested weirs. Research technical completion report", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-198705.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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