Simulation 101: Creating Catchments in Civil 3D to Simulate Hydrology in InfoDrainage

KEN DRISCOL: First of all, welcome to Catchments in Civil 3D. This first disclaimer that I want to make is the safe harbor statement.

As you know, this is Simulation 101-- Creating Catchments in Civil 3D to Simulate Hydrology in InfoDrainage. Hi, my name is Ken Driscol. I'm a civil application implementation consultant with Graitec Applied Software. A little bit of history about me, because I come from a long history of way, way back when Autodesk kind of started out in the early '90s. But over 20 years experience in civil engineering. Worked from civil to survey and about 14 years of design with residential and commercial developments. And this is just a little bit of history about me.

So as we move on, the agenda for the day is really learning about catchments in Civil 3D, how to set up catchments, learn about catchments, the workflow with Civil 3D and InfoDrainage. How do we model a pipe network after bringing it from Civil 3D into InfoDrainage? Utilize some of the runoff tools and generate some rainfall data. And in the end, show some interoperability between how to simulate hydrology accurately from Civil 3D and InfoDrainage from those catchments that we brought in.

So as we move forward, the first thing we want to talk about is catchments in Civil 3D. And some people say catchment, some people say watersheds. Ultimately, you can create catchments based upon a terrain surface. And when you create a catchment based upon a terrain surface, that catchment creates a flow path that's created at the same time that you create that catchment. It's drawn between the specific discharge point-- that's going to be the most hydraulic, most distant point that's calculated.

And one of the things that a lot of individuals run into is this idea of using water drops and the catchments that are typically on the Civil 3D contextual ribbon. And sometimes it creates a catchment, sometimes it doesn't. But one of the main reasons it doesn't is because the calculation algorithm used may not result in a valid catchment because of the grate and slopes.

In order for that to produce a catchment, the surface triangles must form a channel toward the discharge point. So when you're running that water drop at the path that runs closest to your location, then you might want to create a catchment or a grate. Either selecting a point along the discharge point will typically yield a catchment. But if the grate and slopes break off or go to a high point, then it's not going to create a catchment. So it's just something to keep in mind.

So as we talk about catchments in Civil 3D, what you will get is this idea of catchment is comprised of a boundary and a flow path. That boundary is going to represent the watershed area that produces runoff. The flow path represents the time of concentration from the most distant part of that watershed all the way down to its discharge point.

One of the things that's really nice with that catchment area when you build them with Civil 3D is you can use the time of concentration data that defines the NRCS or SCS TR-55 method. Or you can use user-defined. More importantly, when that catchment is associated to a structure from Civil 3D, then that data can be exported from Civil 3D into Autodesk InfoDrainage for further analysis and drainage of that model, which is what we aim to do today.

So catchments in Civil 3D, once we create that catchment, if we wanted to catchment properties on the Prospector tab, we can associate a different style. And then from those properties, the Catchment Contextual ribbon gives us hydraulic properties, sheet flow, shallow concentrated flow, and also channel flow, and then, of course, time of concentration, either user-defined or TR-55.

So the idea of catchments in Civil 3D, as we start looking at the actual program, we can draw a surface with Water Drops. You can have a 2D line that delineates the area that represents your drainage area for runoff. And typically, I use 3D polylines, because you want to be able to perform visualization when you look at the actual surface in 3D. You also can create a feature line from that water drop with Civil 3D.

Then, calculating surface catchment areas from a surface, you can create it from a surface. You can create it from an object. That catchment will create a flow path. Label the catchment area and also label the flow segments.

And as we move forward, in terms of the flow path and segments, there's something that becomes critical. Because the flow paths are used for calculating catchment time or concentration, and a flow path may use the TR-55 method if you've used that for time of concentration. So you've got a flow path from a surface using terrain to determine that flow path of water. It may be defined from a polyline. You also can define it from a catchment, or it may be created or edited from a catchment's flow path.

When a flow path is initially created, you've got a number of flow segments defined under Catchment Settings. You can also edit that flow path. Flow paths don't have grips-- so from one point to the other in terms of that channel flow. And then flow segment lengths and slopes cannot be edited. So something to consider as you're looking forward to that.

So what about this idea of working with Civil 3D and InfoDrainage? Well, on catchments and InfoDrainage, basically, it gives you the ability to export from a Civil 3D drawing. You get this wizard that creates this IDDX file. When you open it up in InfoDrainage and export it out, you get a file network selection, a parts mapping. You can export the surface from Civil 3D and, with that catchment, also with runoff.

Again, this idea of workflows, as I move further down. Let's go back here. So workflows and InfoDrainage.

And then, once we bring that catchment into InfoDrainage, then we can see Catchment Properties. So we have a catchment name, and we can give it a description if we wanted to. There are some things within the properties that we want for, like, area automatically from Civil 3D. Preliminary sizing, you get volumetrics, you get percentage impervious areas. You also have time of concentration. And then you get dynamic sizing that does the same thing. You also have with that Catchment, Pollution, Advanced, and Rainwater taps.

And then from that, we can export it out of Civil 3D, import it into InfoDrainage to open it up, and then do some design, and then export it to InfoDrainage. So to export allows a singular pipe network from Civil 3D. If it's the original created from InfoDrainage, it will attempt to maintain stormwater controls and channel connections. That wizard guide will walk you straight through it.

Then, you want to import from InfoDrainage. This allows me multiple phases from InfoDrainage to be imported back into Civil 3D. So it's going to create a pipe network and, for each phase as imported, closed sections and manholes. The import wizard, it's a pretty seamless process-- File Selection, Phase, Surface, Results, and then Parts Matching. And we'll take a look at that.

And then, of course, the workflows in Civil 3D, export the model. From Civil 3D, import InfoDrainage pipe network and manholes. Create the catchments in Civil 3D. Export the model.

From Civil 3D to InfoDrainage, import the model into InfoDrainage for stormwater design. Complete the hydraulic design in InfoDrainage. Import the completed hydraulic model from InfoDrainage back into Civil 3D. And there you have your results.

OK, as we move further, now, I don't like doing a lot of PowerPoint here and there. So ultimately, we want to see the product. And from seeing the product, one of the first things that we make reference to is I just want to look at Civil 3D in itself. So a couple of things that I mentioned that we want to take a look at-- so I just have a surface in this drawing. And from the surface, if I pick on it, a couple of things that I made reference to in that PowerPoint, a couple of things that I made reference to was the idea that, one, we want to learn about catchments in Civil 3D.

So, catchments in Civil 3D, we have this idea of this water drop. And if I show it, if I pick a point here, I've got a Cogo Point already here. And if I hit select Water Drop, remember 2D and 3D. I like to use 3D. So if I pick on it and select OK, it allows me to drain to specific points for my water drop.

Ultimately, also from the Contextual ribbon, which I don't use-- and there is a reason I don't use it. It doesn't allow me to create hydraulic data. So if I went in here and picked on this, it creates a catchment area. Yeah, I can create catchment areas. Yes, but this is the data that can't be converted to InfoDrainage.

So, how do we set up catchments that will work actually for Info Drainage? So this part of Civil 3D has been around for some time. What's kind of new in the last couple of years is the idea of-- And I'm just going to pick on this, because I'll right click and select Similar. And then we'll just erase that out.

In the Prospector tab, we have catchments. We want to right click and create a catchment. From this catchment, we can specify a group, put in a description. I'll select OK. From creating that catchment group, I can right click and select the two options-- Create a Catchment from an Object, Create a Catchment from a Surface.

We've got a surface right here. If we had polylines, we could do that also. Let's keep that in mind-- polylines, polygons.

So I'll create a catchment for a surface. And all we really want to see is the data that's created. So we get this great catchment from a surface. We have one catchment group, the existing ground surface, and we can also push that catchment data into a structure. And then with that catchment, we can also use a different calculation method, so TR-55 and user-defined.

And I just want to show you what that catchment looks like as it's created. So it creates a catchment for me. And if I pick on this point here, creates a catchment for me. Creates a catchment, shallow concentrated flow of length and a slope.

And if we go right here, just as an example, I select OK. It's going to show me from the farthest point all the way draining down to my discharge point-- shallow, concentrated flow of the length and the slope. So, as an example, just creating that catchment, I'm going to right click and go to Properties. From that Properties, TR-55, Runoff Coefficient, Catchment Properties. Pretty straightforward. Also, I have the ability to reference the structure.

That's one of the fundamental things in terms of the hydraulic modeling to get this discharge point in the distance. And really, if you think about it, for you old preliminary guys out there, this is really nice.

And if I pick on my surface, I'll go to Edit Surface Style. And I just want to see how water really flows. And if we could see, we can see water flows down to a discharge point. Catchments in Civil 3D-- so, slope arrows to have an idea of where water actually travels.

And then these catchments, I'll go in and delete those. Pretty straightforward. Gone.

OK, so, how do we get this idea of knowing hydraulic design, where we've got a storm network? And then we've got catchment areas. And we want to create that data and push that data after creating the data with catchments with Civil 3D and pipe networks, connect that data all together, and then push it to InfoDrainage. Huh?

The first thing we want to do is, typically, because we're doing some really conceptual things, I'm going to go down my pipe network, location of me creating pipe networks. So I'll just come right up here, not a big deal-- Create Pipe Networks from an Object. I'll pick on it. It shows me the direction of my pipe networks. I'll select Inner. I'm going to call this Storm 01.

From the parts list, I'm going to go ahead and select the InfoDrainage Specific. Not a big deal. And then for my structure and my pipes, just something real basic. But, ultimately, I need to let Civil 3D's pipe networks know the surface for rules and files that we're going to create.

So there's my pipe network. So pretty straightforward. And typically, I don't like to see things that big. But, if I highlight my pipe network, I like to look at things in my Object Viewer. So there's my pipe network. Not a big deal, just letting you know it works.

Ultimately, if I want to see it in a profile, I'll use my Project Explorer. Project Explorer is a one-time use interface that allows me to go in here at any point and pick on my pipe network. And there's that pipe network.

So there it is in profile. I don't need to create anything more. I just want to be able to see it. And it's connected. That's my first step.

Now, the second step, how about some drainage areas? We'll select drainage areas from this. We're going to follow the drainage areas.

So in Civil 3D, I want to create catchments. So here's this catchment group. Just showing different options in terms of showing my catchment group. I'll select OK.

Now, the beauty of working with this, now I can create a catchment from an object. I'll pick on the polygon or polyline. Hit Enter. The nice thing is, now, catchment area labels, I still have my TR-55 that I want to be able to use on runoff coefficient. But ultimately, I want to save everything that makes reference to draining in this catchment is going into this structure.

Just a second. It's going into this structure. So, I'll just pick this pick the structure that I want my catchment area to go in, and it creates that structure.

I'm just going to continue on because it's just that simple. Right click, hit Enter. Tell it what structure it's draining into.

Sometimes when you're doing pipe network design and we know these inlets, sometimes a smaller municipality will say, you can only have this much of cfs going into an inlet. And I'm laying out my inlets, I'm laying out my catchments, because this is the data that I need that I want to push to InfoDrainage.

So we'll just create this really quick. I'll pick on that, hit enter, and I'll select this structure. And I'll pick on this, hit enter, select the structure. And two more-- pick out my structure and the last one. We pick on my structure. And I'll select OK.

So now my catchments are connected to my structure. So if I pick on this catchment, and I go into Catchment Properties-- and I can right click or go Catchment Properties-- it's telling me that Structure 1 is giving me a runoff coefficient. It's giving me TR-55 for my time of concentration method. So we've got the sheet flow, shallow, concentrated flow, and we've got this channel flow. And you may not need any of those.

But, a couple of things from this Create Catchment from a Surface, that exclusionary-- remember, I made a reference-- specifies that a catchment will be excluded from other catchments. And then we've got this catchment group. And then we have this surface that specifies the surface from the catchment and the flow path. And we select the surface. And then we've got this reference pipe network and then from the reference pipe structure that we also want to address.

And then sometimes people get a little confused about the shallow concentrated flow and sheet flow and channel flow. So these types are available in this TR-55. And they just represent the time of concentration method that we want to be able to set for TR-55.

So if you're talking about sheet flow, you're talking about some very shallow flow. First component of time of concentration starts with, again, the most hydraulically, most distant watershed point. If we're looking at SCS shallow flow, now we're making reference to what normally happens after the first 300 feet of that furthest hydraulically distance, so that kind of combination of two separating the first 300 feet out. And then the SCS channel flow, this begins where surveyed channel cross-section information and typically that cross-section information is obtained where channels are visible, maybe from an aerial photography.

And I'll select OK. That's it. So now what we want to be able to do is we want to be able to push this data into InfoDrainage. So I'm just going to come here, and I'll move this around a little bit, move the labels. So labels are dynamic. We'll label out of here a little bit just for clarity purposes.

OK, so, we need to push this data that we have from Civil 3D that we created, export it out to InfoDrainage. So that's where, on my InfoDrainage tab, so Innovyze, we can export to InfoDrainage. Import, export. We also have this Parts Mapping, pretty straightforward, and we'll venture to that a little later.

File, select Export to InfoDrainage, and it brings up this Select InfoDrainage File. So I'll select this InfoDrainage file and I'm going to call this Test. And I'll just save it as Test, and I'm going to replace that. Not a big deal. In fact, you know what, because they gave me a little signal there, how about AU2024? So AU2024, select Next.

Now, remember, I said, you can select a pipe network, and you can export the surface. Well, I know already have a surface that's going to come in with this model, but I can use this existing topo surface to push this data out, also. So I'm going to select Next.

And then it says we'll select the pipe network and surface. And it says, OK, well, you have a structure, you've got structures from Civil 3D part family, and you've got a Civil 3D part size, but I need to tell it specifically what that diameter is. And I can just go in here and say, 100. And then for my junction, it says, well, you're using a concentric junction and a concentric structure, that's 1.2. The diameter is going to be 1.2. Just to make sure they match.

Then I'll select Finish. And then it exports it out to a folder that I designated. Now we want to be able to not come from here, but come to InfoDrainage.

So now that we're in InfoDrainage, one of the first things that you will see in InfoDrainage is similar to what you will see in Civil 3D. We've got this big ribbon across the screen. And we've got this kind of toolbox and tool space on the left-hand side. And then we've got some other tools on the right-hand side. So similarities in terms of the transition of working with Civil 3D and InfoDrainage, it makes it a lot simpler for the transition.

So the first thing, going to go File, Open. We can go File as an example. We can import background data, CAD data, aerial photography, MicroStation, MicroDrainage file, Files from CAD, LandXML files, GIS data, and text files. I'm going to select Open.

I'm going to go right here. And you can see I've got this AU2024. And it opens it right up. And what do I get? Well, let's see what we get.

OK, so, one, here's my surface. Two, here's my catchment. Three, here's my pipe network.

So for clarity purposes, let's do a few things. Now, let's cut off that surface, because I know it's there in the background. So it's still reading information from the surface in the background. Ultimately, I can't see. Well, I want you to be able to see things, of course. So I'm going to say on my Display Settings, on my Plan sheet, I am going to make this 4, and I'll make this 10 for clarity, so we can see.

So what has come over? So here you can see all my catchment areas have come over. If I double-pick on my catchment area, I can come in and I can see the area, volumetric runoff, my impervious area, and time of concentration. Let's say five minutes. Time of concentration, and let's say 0.75 and five.

So I've just put in some information from my time of concentration for my volumetric runoff coefficient. I do have a Pollution tab, Advanced tab, and Rainwater tab. And now I've set that catchment area.

But here's the thing that I run into a lot. Let's say we're working on this really large subdivision, and we've got 50 catchment areas. Well, InfoDrainage allows you to address that really quick. If I right click, and I select all, and then go into, I can change my template in reference to green roof, hydrograph, base flow, in terms of what I want to use.

So let's say I'm working in one country, and I need to change it from TR-55 to user-defined, or green amp, or use it as a hydrograph. I can change those automatically all at once. It'll come back.

And, for whatever reason, it changed that to these pipes. The nice thing in InfoDrainage is I can say, undo. There's a beauty in working with these applications.

But what does this look like in terms of my pipe network? Well, I can come right here under Flow Paths, right click, and select Add. I'll pick my first structure, and I'll pick my last structure. And I'll right click and say, Show Profile.

Everything that was created in Civil 3D has been brought right into InfoDrainage. [COUGHS] Excuse me. And if I wanted to, I can pick on a pipe network, and it shows me what the sizes are, and what the Manning's coefficient is, and what the slope is. The upstream invert, downstream invert, what the part family is, and I can lock those if I didn't want to change. So again, from Civil 3D, which is just CAD-based, I brought it straight into InfoDrainage.

So now, I got this conceptual idea. I want to say, I want to create some rainfall data. I want to do a two year. I want to do a 100 year. I want to do a storm event so I can design these pipes. Because they come straight from CAD, so I really don't have any design. It's just based upon Civil 3D's pipe network.

So the first thing that I want to do-- I'm going to come up here to Build Options, because we got all these catchments and I want to change a few things. And just to show you how flexible and InfoDrainage is, I'll bring up these tables. So remember, Rainwater Tank, Time of Concentration. I'll select all these inflows, and I'll deselect them. And then I want to see preliminary percentage volumetrics. I want to see that. Now I want to see percentage and time of concentration.

So if I move this over here so we've got Preliminary, we've got Percentage Impervious area, I want to change this. So I'm going to highlight all of them. Let's say it's 100 catchment areas. I want to change what that land use is. I'm going to say, at 60. And I just hit equal, and then it changes it all.

I'll come right here for my preliminary time of concentration. Pick all of these. And I can say that's not five. Let's make that four. And I'll select Equal.

And then for my volume runoff coefficient, I'm going to highlight those. And I'm going to say, 0.75. Now select Equal.

Now I've set all for my inflows and my time of concentration, pretty straightforward. And I could do it individually, but this finger just won't allow it. So I'll select OK.

So now I've got my catchment area set. I've got my pipe networks. And I got my runoff coefficients. I got my time and concentration. Now I just want to go into preliminary rainfall and pollutants.

I want to create rainfall. So I'll select Rainfall. And if come in here, just different rainfall, this I can choose by selecting one. I can choose from a library. Select them all. So on the Analysis Criteria, I can create and set that for my rainfall. No big deal. I'm going to select Cancel.

It says, Analysis Criteria data has changed. Do you want to save it? No.

On my Preliminary Sizing, I got Network Design Criteria. I got my Network Design Wizard. I got Quick Storage. And then under Build and Analysis, I could set criteria. So same thing, just different places in terms of the data that I want to choose. So known rainfall data.

If I just picked on FSR, I can go in for FSR. Of course, this is over in-- And it doesn't matter where it's at. I'm going to say, 20 inches. And then I'm going to say this runoff coefficient for the summer and the winter months.

And then if I wanted to, I could use a map. So even if you're in the States, well, I can use a map. And let me just bring up the map. So I could use a map and just pick an area, and it's going to give me my rainfall data, so which is nice and convenient. But, for my return period, I'm just going to select the two years form. And I can give it an increase of rainfall data if I wanted to.

And then for my storm duration, I'm just going to select the defaults. We can have 15 minutes all the way to 6,000. And we can do it in time in minutes or duration. And I select OK. So now that's that's.

So, here, I can go to Preliminary Sizing. And my Preliminary Sizing, I can say, Network Design Criteria. When I select that, it says, well, what storm and what criteria are you going to use? Well, I want to use this FSR that I just created.

And then for my Design Options, I can go in and say, for my pipe sizing. So I want to lock slopes, inverts. So I want to change manholes. And I'm just going to leave that as defaults, because there's a lot of data there that we could really talk about. But, yeah, for time purposes, we're going to take a look at something different. And I'll select OK.

And then now that's been generated. So then I'll go to my Network Design Wizard. And it says right there I can select or specify a path that I want to complete my design, my network design.

Well, what does that mean? Well, if I only wanted to design one pipe, I could do that. If I only wanted to design one pipe, I can do that. So it's giving me the length, the pipe, the slope, Manning's roughness coefficient, the diameter of my pipes. And from this, I'll just select all my pipes. Then I'll select Next.

And then it says, well, what storm and peak flow are you going to use? This is fine. I'll select Next. And then it goes to my design options for my path, my pipes and my structures. Then I'll select Next.

Then it says, whoa, wait, wait a minute! Something has happened. And if I hold my cursor, it shows me the change when I designed based upon that storm data-- rainfall data, I'll put it.

Remember, slopes were different. And if I hold my cursor, it shows me the previous one that was used. If I hold my cursor over my pipe, it shows me the previous one that was used.

I've just designed that whole network. And I'll select Finish. There's my network design. Pretty straightforward. Yeah, with a little repetition back and forth, but yes, it works out.

Yes, I will address that in a moment. So we have our new pipe design. So if I go right here, if I go back and show this profile, all my pipes and structures have been designed.

From that, if I go up here to Analysis, I want to validate it. This validates that everything is connected, all my pipes, all my structures. I select OK. Then I select Go. And it runs that analysis.

So now that I have that analysis, my critical storm, it shows me, for this two year, its surcharge. Well, what does that surcharge mean? Well, it's not flooding, but it's surcharge. So you want to be aware of it.

And it shows me my maximum velocity, my flow capacity, my maximum flow, and the status of my critical storm. And if I had all storms, it would show me all storms. And the nice thing about that is, clearly, the capacity and what the maximum amount of flow is going. Because if the capacity is only 10 and you got a maximum amount of flow that's going through, that's 15, that's going to be a problem.

So just some really simple things. I'm going to close that. So I've designed that pipe network. I got all my catchments.

On the Results tab, you can even get to the point of selecting-- what do my connections represent-- my rainfall data and my peak flow for my two year event. And if I wanted to see it in a table, I could see it in a table. If I wanted to check inflows, I could check my inflows.

So from this, I've designed my network. I want to be able to push this back out now. And I'm sorry about that.

So here, I'm going to Save This As. And I'm going to save this as AU2024Design. And I'll just save it. So now that network is saved.

I'm going to minimize that. I'm going to come back here.

For my catchment groups, I'm just going to right click and select Delete. This is the old stuff for my pipe networks. I'm going to pick on my Storm Sewer Network and select Delete.

So I'm back to my InfoDrainage. So I can import the data from InfoDrainage into Civil 3D. So we want to select that network. And we'll select Next. And then, from this, we can lower the surface event, two year event storm network. I'll select Next.

And then, from our Civil 3D structures, and then our pipe Civil 3D is in our Civil 3D structures. And for our maximum width, we can add that in. So if I just select Finish, I mean, it was only one button I just selected, Finish. So from that, it brought in the surface elevations.

So don't really need to see that. But no display. Got things going on.

Well, what does this network look like? It brought in my catchments. Brought in my pipe network.

And I'll just come on the Home tab. It's like Project Explorer. Because I can select my first catchment, my first storm structure, and create an alignment, and select the last one, and create a profile. But I want to see this thing without creating all this data.

And there it is. So you remember 1%, 1%, 1%. My storm network has been redesigned.

So ultimately, ultimately, when we start looking at some of the things that we discussed, we talked about catchment areas. We learned how to set up catchment areas. We learned about the catchment areas and then what workflow and Civil 3D and InfoDrainage in terms of interoperability. And then, we learned how to model a pipe network with some runoff routing tools and InfoDrainage, and rainfall data and InfoDrainage. And then we said, OK, well let's push it all the way back into Civil 3D to show the interoperability of how we simulated hydrology, and then accurately sized the drainage network from the catchments, and then pushed it back into Civil 3D.

So ultimately, step-by-step, with InfoDrainage, in terms of hydraulically designing a network drainage system from scratch. And from there, we get to the point where questions and responses. But ultimately, this is what we wanted to be able to do based upon this ideal of Simulation 101-- Creating Catchments in Civil 3D to Simulate Hydrology in InfoDrainage.

So thank you for your time. And ultimately, analyzing or flooding for downstream in terms of InfoDrainage, or most engineers who are using InfoDrainage, which typically you're using the other hydraulic programs that come with Civil 3D, this is a step above. But thanks for your time. And have a great day.