How to Implement a Futile Call

A futile call, as implemented in StateMod, allows a tributary stream to operate independently of the mainstem. Therefore, the impact of upstream diversions and return flows are not passed downstream of the futile call locations. This operating rule was originally developed for use in the Rio Grande, where dry stretches of the river can occur and create an opportunity for a futile call to extend upstream in these reaches.

1. In the river network (*.rin) file, add a river node downstream of where a futile call occurs and keep the downstream location (cstadn) blank.

   

   Example River Network (*.rin) File with Futile Call (see also the full-size image)