Hi all,
Related to my other recent posts here - I want to make sure I understand what the outputs from the Stormwater Preprocessing and Analyses workflow are. It is not entirely clear to me whether following the workflow outlined there will provide the outputs that I need, or if I need to develop the unique workaround I've been trying to get at in my other posts.
That workflow specifies starting with a DEM as well as individual feature layers for storm drain pipes, nodes, and channels all in a feature dataset. I have all of these inputs, however, the channels feature class is rife with inaccuracies; I am hoping to use Arc Hydro to develop more accurate surface channels that reflect storm drain infrastructure (culverts, etc.). Ultimately, I need to be able to develop products including an accurate stream channel layer (ideally with stream order) that incorporates both the surface channels and the areas where they flow through pipes or drains, and to map watersheds (ideally for different stream orders) for the whole stream channel/storm drain pipe system.
My questions are:
1) For step 3 of the Data preprocessing, "Create drainage line structures representing open channels", does that step generate new surface channels between pipe networks that correspond to flow direction/accumulation on the input DEM? In other words, would I essentially get the updated (more accurate) DEM-derived surface channels from this step, without having to burn culverts into the DEM?
2) Following the workflow through, I can see that the Stormwater Delineation tool allows delineation of watersheds in the stormwater system - does any part of the workflow assign stream order to the channels in the system without being disrupted by pipes? i.e., if a third order stream channel enters a storm drain pipe, will the channel exiting the pipe still be third order, or would the order of the stream be reset? Would it be possible to generate watershed based on different stream orders from the raw outputs of the workflow, or would additional modification be needed?
Thanks in advance for any insights!
