Problem: The annual runoff from a 1000-10112 watershed in California was 200 mm of equivalent water depth on the basin. The watershed received a total of 760 mm of precipitation in the year. The total surface water storage was the same at the beginning and the end of the year. ET was estimated to be about 550 mm for the year for this watershed. Groundwater in?ows and out?ows are equal. What happened to the groundwater storage during the year?