General Questions about Drainage

Bill

These error messages are basically telling you that parts of your drainage netowrk are going up hill.  The first two messages are sating that the link in question enters a node at a lower elevation than the outflow pipe of the node.  The third message says you have configured a link whos upstream elevation is higher than the downstream.  In this situation the link will be automatically reconfigured to use the minimum slope defined in your preferences.  Drainage will not allow an up hill pipe.

Note:  the differences, especially at nodes can be in 2nd or 3rd decimal place in which case a simple tweak can resolve the errors without affecting the validity of your modeled network.  If the exisitng pipes are truly going uphill then it will be a challenge to make the calcs work.

Bill

These error messages are basically telling you that parts of your drainage netowrk are going up hill.  The first two messages are sating that the link in question enters a node at a lower elevation than the outflow pipe of the node.  The third message says you have configured a link whos upstream elevation is higher than the downstream.  In this situation the link will be automatically reconfigured to use the minimum slope defined in your preferences.  Drainage will not allow an up hill pipe.

Note:  the differences, especially at nodes can be in 2nd or 3rd decimal place in which case a simple tweak can resolve the errors without affecting the validity of your modeled network.  If the exisitng pipes are truly going uphill then it will be a challenge to make the calcs work.