High Sierra Topix

Ever wonder how California estimates the amount of water that’s in the snowpack? Snow surveys are done periodically through the winter, but the most important one is the April 1st snow survey, as snow usually reaches its maximum depth by then. A snow surveyor uses a snow tube at sample points. The tube is pushed into the snow to reach ground level beneath the snowpack. The inches scale along the outside of the tube measures the snow depth, and the tube is weighed to determine its water content or “snow water equivalent”.

This year, it took a combination of park staff, USGS scientists, and others with extensive winter experience in remote areas to complete these surveys. Many snow surveyors across the state experienced difficult conditions with extreme snow depth and density, multiple ice layers, and challenging access to sites due to storms coinciding with survey dates or post-storm issues with roads and trails. Snow surveyors were able to survey all of the snow courses in the Kern/Kaweah/Kings watersheds but one - avalanche danger was too high at Farewell Gap in Mineral King.

A few impressive highlights included:
• At about 7,760 feet elevation, Park Ridge (aka Ridge Trail) in the Grant Grove area was at 500% of normal. Given the lower elevation and aspect, surveyors typically walk to this site on April 1 surveys and usually only have a couple of feet of snow to measure there!
• At 8,640 elevation, Panther Gap depth was measured at 20 feet! The conditions were so difficult it took 5 hours to collect 2 cores.
• At over 10,000 feet, Crabtree Meadow was at 300% of normal, which was similar to all other snow courses in the park’s Kern drainage this year.
• The Kaweah River Basin was at 271% of normal snowpack!
• Overall, stations showed we were near 300% of normal snowpack in the southern part of the state in early April.

Kudos to all our snow survey team members for gathering these critical data during a challenging year! This information will help water managers estimate how much water may end up in their reservoirs and how to balance keeping reservoirs filled and preventing floods by releasing water at key times.