Pond Boss Forums POND CONSTRUCTION Building a dam Advantages of a drain?

I was just reading Bretski's poste about a drain under his dam and I'm at that stage of construction that I can add one or not.

My question is if there's a real advantage to having a drain? Why would you drain your pond or lake? Has anybody actually done this once it's built?

If there is some good reason to drain it, would a siphon work and I could avoid having a pipe run under my dam?

I just read an article that said it was good to do so in winter to mow down the weeds and let them air dry, but if my shoreline drops down really quickly to 4 feet, will I have a weed issue anyway?

Thank you,
Eddie