ECHO SUMMIT, California — A nearly average spring snowpack in the Sierra Nevada will likely prolong tough water conservation measures in drought-stricken California — although the restrictions could be loosened in some areas after an El Nino storm system drenched the northern half of the state this winter, officials said Wednesday.

“The message is still very strong: Conservation measures are still going to be important,” Frank Gehrke, chief of the California Cooperative Snow Survey Program, said.