Water law in Texas is often a matter of competing interests. Historic property rights come into conflict with growing populations, and lawmakers and courts must decide who has the superior claim. Much of Texas water law is therefore focused on tracing who has the rights to various water sources and how to decide conflicting claims. For a brief overview of Texas water rights, see these two Texas A&M AgriLife blog posts on groundwater law and surface water law. For a comprehensive research guide to water resources in Texas, the Texas Legislative Reference Library's Water Resources Research Guide is a wonderful resource.