Add turkey, wild rice blend, carrots, celery, onion, poultry seasoning, salt, chicken broth, and water to slow cooker.
Cook on high for 4 hours or low for 8 hours.
Once cooked, remove turkey from slow cooker and shred. Return to slow cooker.
In a separate large pot, add butter over medium heat.
Once melted, add flour and stir until combined.
Slowly add milk, whisking constantly.
Let cook for 1-2 minutes, until all flour is whisked in and milk is slightly thickened.
Stir milk mixture into slow cooker, until well combined.
Taste and season with additional salt and pepper, to your preference.
Serve and enjoy!