Flow Accumulation issues

Discussion created by Lady_Jane on Nov 12, 2010
Latest reply on Nov 16, 2010 by Lady_Jane
Hi everyone,
I am trying to create flow accumulation grids from flow direction grids that I downloaded.  The flow direction grids can cover quite a large area.  For some of them, the flow accumulation grid created has a pixel type of signed integer, and for others it is floating point.  Whenever I try to run stream definition on a floating point grid I get an "overflow" error.  From what I've read, floating point occurs when values are too great to fit into an integer, so I tried cutting my flow direction grid into smaller pieces and re-computing the flow accumulation.  I'm also making sure that all areas of the grid aren't draining into one single point.  But I am still getting a floating point grid as a result.  I'm going to try doing this on an even smaller area, but I thought I would post about it on here and see if there might be another solution I am missing.
So has anyone else had this issue?
Since every time I compute a new flow accumulation grid it takes at least 3 days, this 'trouble-shooting' is becoming very time consuming.