A self-priming siphon has an inverted U-shaped tube filled with a hydrophilic material where one end of the tube is connected to a smaller diameter tube such that when the other end of the tube is immersed in a liquid, capillary action causes the fluid to rise in the tube above the level of the water and thereafter fall through said one tube end causing a suction which primes the siphon.

A self priming siphon device having a pilot siphon tube which discharges into a priming chamber thereby creating a partial vacuum within the priming chamber sufficient to cause flow through additional auxiliary siphon tubes. The partial vacuum is produced by liquid flowing from the priming chamber through priming tubes to a discharge point.

You should use a full port block valve installed below the lake water level on the discharge side of the siphon. Install a a tee fitting on the siphon and connect the siphon to a self-priming pump, eductor, or vacuum pump. Once you have all of the air removed from the siphon, valve off the pump and slowly open the block valve.