try like this..
dtValidData = dsbmVillagedata.Tables[0].Clone();
foreach (DataRow dr in dsbmVillagedata.Tables[0].Rows)
{
dtValidData = dsbmVillagedata.Tables[0].Clone();
DataRow drNew=dtValidData.NewRow();
drNew.ItemArray =dr.ItemArray;
dtValidData.Rows.Add(drNew);
int a = dtValidData.Rows.Count;
}