## Where to get Proportional Sutro Weir Design Spreadsheets

For *proportional sutro weir design* spreadsheets in either U.S. or S.I. units, click here to visit our spreadsheet store. **Obtain convenient, easy to use spreadsheets for proportional sutro weir design calculations at reasonable prices.** Read on for information about the use of Excel spreadsheets for *proportional sutro weir design*. ** **

## Principles of Proportional Sutro Weir Design

For the commonly used rectangular weir or V-notch weir, the flow rate over the weir increases as the head over the weir increases, but the flow rate increases at a faster rate than the head over the weir. For some applications, it is desirable for the flow rate over a weir to be proportional to the head over the weir. The sutro weir, also known as a proportional weir accomplishes this by having the width of the opening above the weir crest decrease with increasing head over the weir crest as shown in the diagram of a sutro weir at the right. Equations that can be used for *proportional sutro weir design* are discussed in the next section.

## Equations for Proportional Sutro Weir Design

Equations for the base width and base height of a sutro weir are as follows:

- W
_{b}= base width in ft (m for S.I. units) - H
_{b}= base height in ft (m for S.I. units) - H
_{c}= max height or curved portion of weir in ft (m for S.I. units) - Q
_{max}= design maximum flow over the weir in cfs (m^{3}/s for S.I. units) - Q
_{min}= design minimum flow over the weir in cfs (m^{3}/s for S.I. units) - g = acceleration of gravity = 32.17 ft/s/s (9.81 m/s/s for S.I. units)

The equation for the curved portion of a proportional sutro weir is:

X and Z are position parameters as shown in the diagram above. They will have the same units as W_{b} .

## A Screenshot for a Proportional Sutro Weir Design Spreadsheet

For a *proportional sutro weir design* spreadsheet with calculations in S.I. or U.S. units, or for other spreadsheets for open channel flow measurement calculations, see: www.engineeringexceltemplates.com

The Excel spreadsheet screenshot below shows part of a spreadsheet for *proportional sutro weir design* calculations, available at our spreadsheet store in either U.S. or S.I. units at a very reasonable price.

**Reference**

Bengtson, Harlan H.**, **“Proportional Weir Design Equations,” an online blog article