The largest lake that we have put a siphon pipe in has been the 6.4 acre lake in the pictures. We have put several in lakes of this size.
If you are just using the siphon for draining purposes I would say use PVC. The only big downfall to the PVC siphon is if pipe ever pulls apart due to swelling and contracting of the ground you will have to dig it up and repair.

A 24 acre lake that we are bidding on to replace existing drop pipe with a 24"siphon pipe . The main thing is to have accurate drainage numbers in order to get right size pipe. TCEQ got involved due to dam blowing out about 10 years ago and didnt want to do the siphon pipe but it would work.


Engineered plans that we recieved today through TCEQ say otherwise. Have to use reinforced concrete pipe, concrete headwall with debree guard and use stabilized sand around concrete pipe.