Case Study

Portable stream gauging

Customer

Warner College of Natural Resources - Colorado State University

Background

Warner College of Natural Resources (WCNR) at Colorado State University (CSU) is the largest named and most comprehensive natural resources program in the United States.  WCNR serves as a leading institution in the education of both undergraduate and graduate students in the areas of:  

• Fish, Wildlife, and Conservation Biology

• Forestry

• Geology

• Rangeland Ecology

• and Watershed Science

Watershed Science is offered both as a major and minor concentration at WCNR.

Problem

Warner College of Natural Resources (WCNR) had a need for a a primary device for stream gauging and instructional use.  The device had to meet three criteria:

• It had to provide measurement flexibility as it would be used to monitor a series of stream and creeks that would have different flow rates

• The device had to be rugged, as it would be moved from site-to-site on a regular basis.

• The device had to be one commonly used in stream gauging and watershed monitoring, as it would be used to instruct undergraduate students on proper field techniques

Finally, the time to get a solution in place was limited as the fiscal year for WCNR was about to close.     

Solution

Openchannelflow's experience with stream gauging and watershed monitoring lead to an initial recommendation of a thin-plate weir.   While flumes are common in stream gauging and watershed monitoring applications, thin-plate weirs are the predominant devices.  Installation of a weir plate is also less involved that that for a flume.

Application flexibility was achieved though the use of interchangeable weir plates.  Four weir plates were provided for mounting to a common weir carrier. The plates could be removed in the field, allowing each installation to be tailored to the site's specific flow conditions.  

The weir plates provided were:

• 22-1/2° V-notch (3.991 - 67.53 gpm [0.242 - 4.318 l/s])

• 45°V-notch (8.309 - 143.4 gpm [0.5039 - 9.051 l/s])

• 90° V-notch (20.07 - 346.5 gpm [1.217 - 21.86 l/s])

• 12-inch [30.48 cm] Cipolletti (135.1 - 534.2 gpm [8.196 - 32.40 l/s])

Stainless steel is both rugged and holds a edge well, so the problemes of weir crest rounding and damage would be minimized.  Stainless steel is heavy, however, so Openchannelflow modified the design of its standard portable weir plate / carrier set to include lift handles cut directly into the top of the carrier.

Shipment was made to WCNR well in advance of their fiscal EOY, ensuring the WCNR could maximize their budget.