Not sure why it's being downvoted. From the training program email:
"Si te has visto afectado por la dana directa o indirectamente y no has podido realizar tus entrenamientos, pero quieres seguir corriendo, Cárnicas Serrano, a través de su entrenador José Garay, responsable de los planes de entrenamiento del Maratón Valencia Trinidad Alfonso Zurich, te ayudarán a adaptar tus entrenamientos las próximas semanas. Para ello, debes escribir un correo electrónico a..."
Which translates as:
If you have been affected by the dana directly or indirectly and have not been able to carry out your training, but you want to continue running, Cárnicas Serrano, through its coach José Garay, responsible for the training plans of the Valencia Trinidad Alfonso Zurich Marathon, will help you adapt your training in the coming weeks. To do so, you must write an email to...
Source:
If they're offering the chance for those most affected to carry on their training with updated plans, to me that sounds like they're going ahead, 100%.