Water ice, especially any located in the sub-surface, has long been a focal point of Mars exploration efforts. Reasons abound as to why—from the need to grow plants to the need to create more rocket fuel to blast off the planet for a round trip. Most of that effort has focused on the poles of the planet, where most of the water ice has been found.
Source:
https://phys.org/news/2021-02-explorers-harvest-ice-mars.html