Flow Alteration

 

There are three types of Flow Alterations in the NHD:

 

Unknown: A point on the surface water network where water is either removed or added to the network,  

                 typically through a conveyance such as a CanalDitch or pipeline.

                    The Hetch-Hetchy Aqueduct in California - Photo by Kristiana Elite, USGS.

 

Removal: A point on the surface water network where water is removed from the network,  

                        typically through a conveyance such as a CanalDitch or pipeline.

             

                 The Colorado River Aqueduct and Central Arizona Project Aqueduct are withdrawing water

                  from Lake Havasu. NAIP Imagery.

 

Addition: A point on the surface water network where water is added to the network, typically

                          through a conveyance such as a CanalDitch or pipeline.

             

                 The Colorado River Aqueduct terminates at Lake Matthews where water is contributed back into

                 the drainage network. NAIP Imagery.

 

 Fcodes: .

57201

Flow Alteration = Addition

57202

Flow Alteration = Removal

57203

Flow Alteration Unknown