Any assets you have the rights to use (by creating them yourself or licensing them) are fine.
I was unable to find any specific legal/licensing on using the #TeamWater logo (from the larger campaign) but they literally distributed the materials in a press kit so they're actively encouraging use of it.
TeamWater Press Kit: https://drive.google.com/drive/folders/1w4yhwbUFKXeJMQscP_a4R4gs3kNM-KZw