PHILLIPS STATION, Calif. (AP) – California water managers say the Sierra Nevada’s most robust springtime snowpack in years could trigger flooding as it melts. Frank Gehrke, the state’s chief snow surveyor, took the measurement Thursday at Phillips Station near Lake Tahoe. It’s the first springtime reading of the year at a time when the weather typically begins to warm. Gehrke’s manual reading found the snowpack’s water content at 183 percent of normal. Overall, electronic monitors show the Sierra measures at 164 percent. It’s the most dense springtime snowpack since 2011, a year followed by five years of harsh drought. Mountain snowmelt is critical to providing roughly one-third of California’s water. Gehrke says flooding is possible if another round of stormy weather returns, causing the snow to melt quickly. Gehrke says managers throughout California are keeping in close contact.