Enter the width and depth of the stream and the flow rate into the calculator to determine the stream velocity.

Stream Velocity Formula

The following equation is used to calculate the Stream Velocity.

SV = Q / (W*D)
  • Where SV is the stream velocity (ft/s)
  • Q is the volumetric flow rate (ft^3/s)
  • W is the width of the stream (ft)
  • D is the depth of the stream (ft)

To calculate the stream velocity, divide the volumetric flow rate by the product of the stream width and depth.

What is a Stream Velocity?

Definition:

A stream velocity is a measure of the linear rate of change of distance with respect to the time of a stream or river.

How to Calculate Stream Velocity?

Example Problem:

The following example outlines the steps and information needed to calculate Stream Velocity.

First, determine the volumetric flow rate. In this example, the volumetric flow rate is found to be 3,000 ft^3/s.

Next, determine the width of the stream. For this problem, the width of the stream is found to be 50 ft.

Next, determine the depth of the stream. In this case, the depth of the stream is measured to be 3ft.

Finally, calculate the Stream Velocity using the formula above:

SV = Q / (W*D)

SV = 3000 / (50*3)

SV = 20 ft/s

FAQ

What factors can affect stream velocity?

Stream velocity can be influenced by several factors including the slope or gradient of the streambed, the shape and roughness of the stream channel, the amount of water flowing through the stream (discharge), and environmental conditions such as temperature and wind.

How does stream velocity impact the ecosystem?

Stream velocity plays a crucial role in shaping the aquatic ecosystem. It affects sediment transport, erosion and deposition processes, the distribution of nutrients, and the habitats available for aquatic organisms. High velocities can lead to erosion, while slower velocities can result in sediment deposition, affecting the stream’s morphology and the types of habitats available.

Can stream velocity vary throughout the year?

Yes, stream velocity can significantly vary throughout the year due to seasonal changes in precipitation, snowmelt, and human activities such as irrigation and dam operation. During periods of heavy rainfall or snowmelt, stream velocity can increase as the volume of water in the stream rises. Conversely, during dry periods, the velocity may decrease due to lower water levels.