# Reservoir Volume from Contour

Volume of water in basin with reference to incremental height of DAM?

I know there's already a link that answers this question. I am not quite sure about the results from Surface Volume Tool. It seems that the results are way above what I expect.

Supposed the results show:

275, 256, 949

but the Tool provides me I am using ArcGIS 10 and I my raster surface is ASTER DEM.

I would like to do, basically, the same tasks as indicated in the link: To calculate volume from ASTER-DEM with increasing height.

• Could you please provide us the information needed to understand what your results mean and precisely why they are above what you expect? Dec 12 '12 at 17:32
• Is there a way to compute volume from surface area? Dec 13 '12 at 3:51
• In general, no. But of course you can compute volumes from DEMs. And there is a link between volumes and sequences of surface areas: if you imagine gradually filling the region with water and take a snapshot every time the water rises a small fixed amount, you can estimate the added amount of water by multiplying the new surface area by the amount of rise. Adding these estimates gives the total volume. Dec 13 '12 at 3:54
• Here's what I did: 1. generated reservoir using Raster Calculator and calculated area using Calculate Geometry; Now, I'm stuck with what to do next on calculating volume. Dec 13 '12 at 3:56
• Please tell us how your question differs from the one you reference: if you cannot clarify the differences, we need to close it. Dec 13 '12 at 15:07

## 1 Answer

I already found the solution to my problem:

1. Clip raster dataset to the maximum reservoir elevation. This would provide input raster dataset to surface volume tool.
2. Calculate volume using Surface Volume Tool assuming that the lowest elevation is the break or the damsite. For example, if the reservoir elevation is 300 masl and the damsite is at 200 masl then you can use Surface Volume Tool to calculate reservoir volume at elevation BELOW 300 masl down to 200 masl.

Hope this helps.