model a gutter as a v ditch.

Question

I would like to model a gutter as a v ditch. Attached are the parameters I have set. Can you model a v gutter between catch basins as shown? I would like to get the spread of this scenario. Thanks

Yashodhan Joshi · Answer

Hi Brian, 
 If you wish to model a V-shaped gutter running through the middle of two lanes you can try modeling it as an "irregular" shaped gutter. 
 The default V-shaped gutter type in the storm-sewer products is defined with the road cross slope on only one side. This is assuming that the gutter is laid on one side of the road and not through the center as it is in your case. 
 In the above dialog box try using an irregular shaped gutter by defining the ordinates and station values to recreate your V shaped gutter and analyze. 
 I would also like to mention that as of CONNECT Edition 2 we have added the capability to view gutter cross sections and see the varying HGL through time. More information on that is available in the below article; 
 What's New with SewerGEMS and CivilStorm CONNECT Edition Update 2 
 Hope this helps.

Jesse Dringoli · Answer

Thanks for the information. In the model you provided, you have the catchbasin nodes (where the inlet is located) set to use a grate inlet with a v-shaped gutter, and the gutter links between them are also set to use a v-shape. 
 The setup of the v-shaped gutter appears to match your sketch showing 10% gutter slopes and 2% road slopes, on each side. However, HEC-22 seems to define the v-shape gutter as having a curb and gutter slope (which would both be your 10% sides), and one road slope on one side - see the help topic "V-shaped gutter cross section" - 
 
 where: Sx1 = Curb side slope Sx2 = Gutter cross slope Sx3 = Road cross slope 
 So, if your ditch has a road on each side (2%) and you anticipate the depth in the gutter rising high enough to extend into the road, you may need to compensate by adjusting the road cross slope value, given the above diagram. (so that the spread / top width of flow is correct) 
 Also, since your grates have a flat bottom, consider changing the catchbasin (inlet) gutter definition to the Ditch type, and the inlet type to the "ditch" as well (you currently have it set as a grate). This assumes a flat-bottomed cross section (because of the flat bottom of the grate) with slopes extending on each side. This may be more appropriate, because the spread and depth reported at the catchbasin element represent the depth and spread just on the upstream side of the inlet location itself, where the spread tends to be at its highest (before some flow is captured), and where the cross sectional view has a flat bottom due to grate inlet. 
 See: Modeling a Drainage Ditch 
 However, the ditch inlet type only assumes a single right side slope and single left side slope. So, you might want to approximate the single side slope, or assume the v-notch shape that you were previously assuming (which might be OK if the ditch has a v-shape just upstream of the grate location), but with the above note about the three slope assumptions in mind.

Scott Kampa · Answer

Hello Brian, 
 I didn't see the user notification that you mentioned. However, it does appear that none of the catchments are attached to an outfall. Some adjustment to the connection of the system may be needed to assure that the results are accurate. For instance, you may want to connect all of the catch basins with a link (such as a conduit or gutter) and have an outfall at the end of the system. 
 Also, are there supposed to be conduits to convey subsurface flow? 
 Otherwise, it might be useful to get a screenshot of the user notification you are seeing. 
 Regards, 
 Scott