State and federal hydrologists say twice the normal precipitation in March has created near record levels of snowpack in some Idaho mountain ranges.  The Idaho Water Supply Committee said Monday an increase in March snowfall between 15 percent and 40 percent should mean plenty of water statewide for the summer growing season. One of the best ranges is the Bear River Basin in southeast Idaho, with a snowpack 132 percent better than the 30-year average. That figure ranks in the top five for the valley since records began in the 1960s. Committee officials also say April has already seen more than 50 percent of average precipitation in most portions of the state. Officials say the snowpack and additional rain in the forecast translate to an above average threat of spring flooding.