How about creating perpendicular intersecting lines at specific points along the line, as defined by actual points that run along the line at arbitrary distances from each other? So I have a line, and along that line there are six points. I want intersecting lines drawn at each of those points.
That tool that I created will create a perpendicular line but the "perpendicular line" is perpendicular to an imaginary line that runs from the start node to the end node so some care is required to get what you want. If you want to create perps at specific places why not create a new line file where each line is tangent to your stream course at the intersect of the point locations, buffer the points some reasonable distance, clip the tangent lines so your tangents are centered on the points, then run the perpendicular lines tool creating new perps at the midpoint of your tangent line.
This tool will create a perpendicular line at a user defined length from the center ( or end nodes) of the line. It is not exactly what you want but the code is a starting point to solving your problem..
ftp://lnnr.lummi-nsn.gov/GIS_Scripts/createperpendicularlines.zip
To All....
if you're interested in getting a tool that generates perpendicular lines and considers m-values and z-values you may want to support this posted idea --> https://community.esri.com/t5/arcgis-pro-ideas/generate-transects-along-lines-tool-define-spacing/id...