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View Full Version : How to create a trap low?



travis.penner
2008-12-15, 05:29 PM
Hi,

I've been asked at my job to take a stormwater Management drawing and use the contours to create several trap lows at certain specific elevations and tell the designer the areas for each one.

I've imported the drawing and it's surfaces into Civil 3d. However, so far I can't find a way to use Civil3d to automatically calculate these trap lows and draw them for me. Has anyone done this?


For those who don't know a trap low is simply put, an area that is designated to trap water. We try to calculate a probably yearly rainfall, and then also a major rainfall even that might happen every 1 in 100 years. The 1:100 is the maximum height and depth elevation of the trap low, which also describes the total area of the trap low.

So far, I haven't successfully used the grading tools to do this, and I'm at a loss for how to pull this off.

Travis

gandocadguy
2008-12-15, 05:45 PM
Travis, welcome to the group.

I think I know what you are trying to do. On the autodesk subscription website there is a stage storage utility for civil 3d. I have downloaded it but not used it. It claims to do what you seek.

An alternative, if you are not on subscription, would be to create a flat surface bigger than your trap at the elevation whose volume you wish to measure. Do an earthwork comparing that to your trap surface. Your fill number would be your storage volume.

Hope this helps.