The Parshall Measuring Flume
THE PARSHALL MEASURING FLUME
A HISTORICAL LANDMARK
OF
AGRICULTURAL ENGINEERING
SINCE THE BEGINNING OF IRRIGATED AGRICULTURE
IT BEEN IMPORTANT TO MEASURE FLOWS OF IRRIGATION
WATER. ACCURACY OF EARLY WATER MEASUREMENT METHOD
OFTEN SUFFERED BECAUSE OF TRASH OR SEDIMENT IN THE
WATER OR UNUSUAL FLOW CONDITIONS.
RALPH L. PARSHALL SAW THIS PROBLEM WHEN HE BEGAN
WORKING FOR THE USDA IN 1915, AS AN IRRIGATION RESEARCH
ENGINEER. IN 1922 HE INVENTED THE FLUME NOW KNOWN BY
HIS NAME. WHEN THIS FLUME IS PLACED IN A CHANNEL, FLOW
IS UNIQUELY RELATED TO THE WATER DEPTH. BY 1953 PARSHALL
HAD DEVELOPED THE DEPTH-FLOW RELATIONSHIPS FOR FLUMES
WITH THROAT WIDTHS FROM 3 INCHES TO 50 FEET.
THE PARSHALL FLUME HAS HAD A MAJOR INFLUENCE
ON THE EQUITABLE DISTRIBUTION AND PROPER MANAGEMENT
OF IRRIGATION WATER. THOUSANDS OF FLUMES HAVE BEEN
USED TO MEASURE IRRIGATION WATER AS WELL AS INDUSTRIAL
AND MUNICIPAL LIQUID FLOWS, THROUGHOUT THE WORLD.
THIS PLAQUE MARKS THE SITE OF THE ORIGINAL COLORADO
AGRICULTURAL COLLEGE HYDRAULICS LABORATORY, WHERE
PARSHALL CARRIED OUT HIST HISTORIC EXPERIMENTS.
DEDICATED
BY THE
BY THE
AMERICAN SOCIETY OE AGRICULTURAL ENGINEERS
1985
1985