Six people died in boating-related accidents on northern and central California rivers between May 1 and June 30 of 2005, during the height of spring snow melt runoff.With a snow pack at approximately 125 percent of normal heading into April of last year, heavy water flows and cold temperatures lasted well into the summer months, making streams, rivers and lakes dangerous.According to the California Department of Boating and Waterways, near record rainfall in March and April has left the 2006 Sierra snow pack standing between 150 to 190 percent of normal.The department also reports that because below normal temperatures delayed …