2 Methods of Keeping Parshall Flumes Free of Algae

algal growth in a Parshall Flume For a Flume to operate accurately, the flow surfaces must be kept free of debris and biological growth. In surface water applications, the growth of algae can present a considerable problem in trying to keep the flume clean.

If a sufficient amount of algal growth is allowed to accumulate, the width of the flume may be affected - restricting the flow and increasing the apparent flow rate.

Two simple methods of have been successfully used in irrigation applications to slow / reduce algal growth:

Erecting a shade over the flume
Applying copper-based paints to the flow surfaces

Both approaches have their drawbacks (shades are impractical for large flumes / wide channels), but the when appropriate, they can serve to reduce the amount of maintenance need to keep a flume operating accurately.

Image: University of New Mexico, Water Resources Program