Pond Maker

Hello Gregorio,

The different curves represent different tailwater levels when you are analyzing the rating curve for the riser. These tailwater conditions depend upon you minimum and maximum head-water conditions specified for the Composite Outlet Structure. See the below article on using the PondMaker tool for more details;

Using PondMaker

Another article which you might find useful;

What do all the lines in PondMaker step 4 represent?

Hope this helps.

Thank you