I'm assuming this is a 1D unsteady flow model, with cross-sections?
- First, determine the nearest cross-section upstream and downstream of your area of interest.
- Delete all the cross-sections and structures data outside of those areas (to clip the model)
- Then use known water surface...
The long skinny open channel ponds are an option for such a flat area.
However, for the storm sewer have you considered large elliptical pipes (double barrel) and also check that you're not overestimating the loss in the system.
Bioretention are more for providing water quality, not quantity control. There are usually a limit to the drainage area or volume they can handle, like you said something like 6-inches. For quantity control - you would have to consider diverting to a detention pond using a weir or Riser...
Is the FIS flow based on a detail hydrology study or estimated from Regression equation?
You can create 2D model with boundary condition that utilize the FIS flow data (Unsteady/steady flow hydrograph),and add breaklines around the house for more detail flow parameter.
HEC-RAS Rain on Grid can be a good alternative to HEC-HMS. However, it does require more detail 2D mesh, including if you have any structures like bridges and culvert you want to incorporate.
In general, HEC-HMS should be used for hydrology and leave the hydrualic analysis for HEC-RAS. However...
My recommendation is to use HY-8 to determine existing culvert capacity and Headwater depth.
Then using the same HY-8, convert the existing rectangular culvert total opening to an equivalent circular Area.
For example:
-Determine the total area of the existing box culvert, lets say is a 12ft x...
For HEC-RAS 2D, are you asking about Projections to use for your project location (Australia).....?
The link you included appears to point to EPSG, which are projection files to assign coordinate systems.
For Australia, you will need to know which zone your project is located. Australia has...
I assume you mean HEC-RAS?
If so, the HEC Team has put together excellent training resources that you can complete on your own time. This include webcast, tutorial with material, online vidoecast, and many yoututbe videos to go along with it.
You may want to check out it at this link from...
@ Rye1
For Dam breaches in HEC-RAS, you would normally show before breach and after breach inundation map. Then followed by map showing the increase in Depth as a result of the breach wave. Normally, terminate the model where the difference between base and breach wave is less than 1ft or...
Usually saving your edits in RASmapper and closing RAS would help.
Or close Rasmpper and open the Geometric Editor. Open your Geometry A2_NE and check for the boundary conditions line.
Yes, StormCAD should be able to handle modeling stormdrains and inlet sizing including detention ponds.
Just need to to setup your Scenarios and layout your pond and piping network.
Alternatively, you can use HEC-HMS (free) or HydroCAD (no cost trial version, limited nodes).
You need to link to that unit hydrograph table in the 'Meteorologic Models' options, select 'Precipitation' and you can select which time-series data you want to use.
Make sure you are running the unsteady flow simulation. What type of Boundary Condition (BC) are you assigning to the River? Post a screenshot of your Unsteady Flow Data to better understand your situation. For Unsteady flow BC, you should have either a Flow Hydrograph, Stage Hydrograph, Normal...
In HEC-HMS, in your "Reservoir" - detention pond, you can add a 'Pump' to your outlet option and set the intake elevation, and 'ON' 'OFF' elevations for your pump. These are the elevations that the pump will be triggered to start and then stop after pumping down. This options requires you have...
Have you tried using USGS Streamstats? You may be a able to get Streamstats to get you started, its similar to ArcHydro. Again, it all depends on your outfall location. For such a huge area, the watershed should include a tributary/stream/river....which is likely to be delineated in USGS...
