Heat a medium (7qt) Dutch oven over medium-high heat.
Add 1 tablespoon of the olive oil and let heat.
Add the sausage and cook, breaking up with a wooden spoon, until browned through, about 5 minutes. Transfer the sausage to a small bowl or plate and set aside.
Reduce the heat to medium-low and add the remaining 2 tablespoons of olive oil. Add the leeks and season with salt and pepper. Cook until beginning to soften, 5 minutes.
Add the garlic and cook until fragrant, about 1 minute.
Add the white wine (or water) and cook until mostly evaporated, scraping the brown bits off the bottom of the pot, about 1 minute.
Reduce the heat to lowest possible and cover partially with the lid. Cook until the leeks are very soft, 5 to 7 minutes.
Stir in the beans, sage, and garlic powder.
Add the chicken broth and water and bring it to a boil. Stir in the pasta and cook until tender, 10 to 12 minutes. Remove from heat.
Add the sausage back into the pot and stir in the heavy cream. Taste and add more salt and pepper if needed.