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  AMERICAN SOCIETY OE AGRICULTURAL ENGINEERS 
1985

Submitted by @PraliteMonks