Streamflow trends over the past year at John Day River At Mcdonald Ferry in an interactive calendar format. View seasonal patterns on the river and see how an evolving climate has affecting streamflow levels over the past year. Click on any day to see what the streamflow was for that day, or sign up for a free account to view data for the past 115,327 days. The streamflow average over the past 10 days was 21.58 ^cfs, with a day to day variation of about 3.8^cfs.