EPANet Design 1

[cmm1080]

I am working on my first water system upgrade. I would like to use EPANet because its free and its what I used in school. What is the best way to go about building a model for a very large rural system? The system covers approximatley 36 sq.miles. I've attached a large portion of the network for review.

This is a very old system with mains and laterals all over the place. It contains two stand pipe tanks and two 30+ year old ground tanks.

I was intitally directed to place a node everywhere I had an elevation change of 10-12 feet... this resulted in almost 300 nodes and a sytem model that is a mess.

Any advice is appreciated...

 

[hydrae]

Start with the sources, reservoirs and large pipes with loops.
combine the demands at the major intersections
get the system working
once you have a model working, then refine as needed

As an example, don't bother with Berry rd, Davis rd Craig dr, newhouse rd. ect. just put all the demands on Colsen(sp). If later you need to model that area in detail, that is when you split up the demands and add more pipes.

I would say you should be able to get a rough model of this system with 30± pipes and 30± nodes.

Hydrae

 

[RWF7437]

Why not start with some basics ?

Get a good map of the system drawn to scale.
Show on that map a North arrow and a graphic scale so that when you shrink or enlarge it it remains to scale.
Note elevations on the map such as the highest service, lowest service, pressure zones ( if any) and overflow elevations of the tanks and standpipes.
Use color if you wish but also use line symbols or line weights to distinguish pipe sizes:
For example you could use ,
2 -inch ------ ..-------
3 -inch ------ ... -----
4-inch ------- .... -----
6-inch ------- ___ -------
8-inch ------- ___ .. ------

etc. This will help when you reproduce your map in black and white ( as you did with your attachment ).

Also clearly distinguish between what is existing and what is proposed.

You may eventually want to model the entire system of several hundred pipes but you can start with only the 6-inch and 4-inch pipes. Concentrate on the os pipes that form loops and connect to your source or sources.

This "spaghetti" system will not be capable of delivering significant fire flows.

So, you will probably want to estimate Average Day Demand, Maximum Day Demand, and Peak hour Demand from your metering records ( I sure hope you have such records ).

Then, if possible do some flow test to calibrate your EPANet model as best you can.

Once you have a calibrated model you can add pipes and run "what if" scenarios to test the existing and proposed systems.

good luck

 

[RWF7437]

http://map.deq.louisiana.gov/index2.htm