FRESNO, Calif. -

The snowpack atop mountain peaks in California and Colorado has a new set of eyes watching from high above to better gauge the amount of water that will rumble down rivers and streams each spring as runoff.
   
In a new mission, NASA fixed a lumbering twin-engine plane with high-tech equipment to make regular snow surveys, starting last weekend in drought-stricken California. At an altitude of up to 20,000 feet, the so-called Airborne Snow Observatory measures snowpack's depth and water content with precision.
   
Scientists say that from the lofty heights they can calculate snow depth to within 4 inches and water content within 5 percent.
   
NASA scientist Tom Painter, the mission's leader, said up to 80 percent of our water comes from the snowmelt, making it important to understand.