What hydrologic parameters do you have? (Stage, aerial rainfall estmates, inflow, outflow, etc.)

Also what resolution is your DEM? If its too course your modeled parameters could have a high/low degree of error. (i.e. 1/9 arc second, 1/3 arc second, etc.)

What questions are you trying to answer? (i.e. nutrient loading under different hydrological scenarios, Changes in upstream nutrient management, etc.).

Hi Wisdom, actually ArcGis has a toolbox where you can calculate a volume from a DEM. First you need to delineate the border of the wetland. Furthermore, you need information of the depth of the water body. What kind of wetland do you study? Is there any open water body? Otherwise you need to address the questions Paul raised.

Thanks all. I'm using a 30m resolution DEM. I got it resolved. I was able to compute the SA and volume using the spatial analyst tool function in ArcGIS.

Hi Wisdom, thumbs up:-)

You can use Alos Polser DEM 10m resolution for better information