I have found an effective way to feed my bees during this extreme drought using an open feeding station on my deck which is about 400 from my 10 hives.
I designed a floating board that fits as tight as possible into a standard Langstroth super or deep hive box. I cut a sheet of 1/4" plywood to fit wall to wall (-1/8) into the box. I used a 1" forstner bit to bore holes through two of the three plys of the sheet. The center point of the bit pierces the third ply to allow sugar syrup into the 1 circular wells. I used another sheet of plywood (19 7/8 x 16 Ό) to close the bottom of the box. I stapled (1/4 x 1 crown staples) the bottom sheet to the box and sealed it with silicone caulk on the bottom and corners. SEE PHOTO BELOW.
I make up 5 gallons of sugar syrup every evening and put it in the feeder the following morning. In a few minutes thousands of bees are foraging on the board and the feeder is empty in 4 hours. I have had no bees drown beneath the board so far. A few bees die on the top of the feeder board for whatever reason. I bring the feeder onto a porch at night so I can load it up in the morning without dumping syrup on the bees.
1) Use a hive box that is perfectly square and smooth on the inside.
2) Cut the feeder board so that there is only a ½ beespace gap around the perimeter of the board.
3) Bevel the underside edge of the feeder board so it will float down without catching on the sides of the box.
4) If bees happen to get around the feeder board, use fiberglass screen as a soft shim. Staple a 1 ½ strip of the screen to the top and bottom of the feeder board using a standard office stapler.
Click on image to enlarge.