Water is an essential and mystical part of the Christian story and message, giving them unique motivations and resources for addressing this issue.

From the opening chapters of our Scriptures, water is seen as a a major source of conflict and depth when untamed; but when handled by God, it becomes a source of life and redemption. 

• The Israel story begins with God creating the world out of the murky depths. 
• The Israelite people are set free from bondage to a prince of death and find their redemption by passing through a Red Sea, which previously would have held certain death and return to bondage. 
• Israel enters the promise land in a similar fashion. God promises to sprinkle clean his people with the waters of redemption.
• It is by more than one water well that Patriarchs find their wives and Christ finds a woman in need of redemption. 
• It is in the world to come that the Tree of Life is seen once more, and a River of Life flows from its roots offering life and salvation to all who drink. 
• And perhaps in the greatest place that God meets His people–in the waters of Baptism–they find their Identity, his Covenant, and their Inclusion into the Family of God.

Water is essential to the story of Christianity. According to the sacrament of Baptism, God, in a very real sense, communicates Himself to His people through, of all means,water. Of all the substances He could have chosen to make Himself present in and through which to visibly identify His people, He chose water.  Christians should care about water.

•  As the visible representations of the hands, feet, and mouth of God, the Church has a powerful opportunity and responsibility to communicate the presence of Christ by subduing the chaos brought about by untamed and unsubdued waters and thereby bring redemption, wholeness, and healing to entire communities, nations, and regional economies.
  

When Jesus came and died, he died as the culmination of the history of the Israelite people–but not just that. As a product in the line of Evolution, within the body of Jesus was the entire evolutionary history of the cosmos and humanity. This being the case, when he died and was raised, he did not just bring a resurrected humanity, but a resurrected creation as well. And because of that, Christians were given the task of spreading this resurrection and redemption even to the natural world around them. 

with thanks to Paul Burkhart
http://blog.prodigalpaul.com/2010/10/15/a-theology-of-water-justice-blog-action-day-2010/