Cold Weather

Bitter cold here in Polk County this a.m. Cold spots in the county went down to 22- 24 degrees last night. The good news it's very early in the bud stage for blueberries so there is no need to run water for freeze protection. There have been some growers running water and I don't know why unless they are protecting snowchaser. Can anyone enlighten me as to the purpose of running water all night at this point in time? I have some fruit on emeralds but it is not something we are going to sell therefore not work protecting.