Combine the sage, garlic, salt and pepper in a small bowl and mix well. Rub seasoning mix over the pork roast evenly.
Combine the brown sugar, sriracha and apple cider vinegar in a medium bowl and mix well.
Place the pork in a slow cooker and pour the sriracha mixture over the pork, covering all sides of the roast. Add the water along the edges of the pot and cook on low for 8-10 hours (or high for 4-6 hours).
About 1-2 hours before the pork is done cooking, carefully separate the pork meat and mix well with the remaining juices in the slow cooker. Replace the lid and cook for the remaining time.
Once the pork is done cooking, heat the flour or corn tortillas according to package instructions and enjoy with your favorite taco sides and stuffings!