Applicable to: CivilStorm, StormCAD, PondPack, OpenRoads Drainage

The use of surface polygon/land use area make calculating weighted runoff coefficients and curve numbers much easier. Currently we can review the tabulated list of land use polygons and their area that overlap with a drainage area. However, there is no easy way to report this. It would be nice if there was a flex table that could tabulate the total areas for each type of C or CN. This would make the review/quality control process easier. And this would make the report/computations more complete as the report could list the drainage area, total area of C=0.3, total area of C=0.5, total area of C=0.95, the total drainage area, and the weighted C value all in one easy to read table.

Additionally, there are issues in the computation of weighted C and CN values when a land use area polygon overlaps with a drainage area more than once. Once one crossing of the land use area is counted, resulting in incorrect C and CN values for the area. It is tedious to break up land use areas into multiple shapes to prevent this error from happening. Fixing this would make the use of this tool actually useful for the design, where currently it can only be limited to preliminary design due to the constant need to for checking.