A Nevada Supreme Court ruling has triggered a tidal wave of legal uncertainty over decades of water rights sought by thirsty Las Vegas, dealing a big setback to the Southern Nevada Water Authority's plan for a massive pipeline project and raising questions about thousands of water rights around the state.

At issue is whether water rights applications dating to 1947 that were not acted upon by the state engineer within a year -- a time frame that until 2003 was mandated by Nevada law with few exceptions -- are valid.

A unanimous Supreme Court, in a Jan. 28 ruling, said, well, maybe, at least as they pertain to SNWA's water rights applications in Spring Valley near the Nevada-Utah line that were filed in 1989 but not acted upon for nearly 20 years.