Welcome, It only makes since to get this thing fixed for the kids that where running down the path to the pond---That is the best picture I have seen in a long time.
Now is the time to get the whole thing fixed,
Drain the lake.
install a drain pipe at the bottom of the dam with a valve so you can drain the pond when ever you need or want to.
The spillway pipe should be either schedule 40 plastic or concrete.
As Wild Bill Cody said when it is drained add some depth, and re shape it as much as is needed.
You have another option and that is enlarging the whole pond, with as much water as you are draining down stream you can consider that option.
Most of the people on the planet would love to have that much water. GOOD LUCK keep us posted
