Pond Boss Forums Thread Like Summary - Spillway vrs Drainpipe

For a 1.5 acre pond 20 ft deep with a live spring would a concrete spillway discharging onto riprap be better than a drainpipe?

For my 1.8 Acre BOW, I have a 20' wide spillway, with 3-4" tall bermuda grass. 6" in 2-3 hours off of 35-40 Acres of watershed ( all grassland ) , 3 days of overflow and the bermuda acting like over lapped shingles , NO damage, no ruts, it never clogs . Very happy with my spillway . But, the dynamics of each pond , of each watershed is different . It all depends , probably applies . I've hired a professional dam builder for both of my ponds, who's primary income for last 50 years has been Federal water shed control dams .
Hire a professional . If going with spillway, maintain it .

Typically, the main pond exit is a pipe while the emergency spillway is an open area higher than the primary overflow but below to of the top of the dam that is located beyond the dam on a gentle slope to avoid erosion. The emergency spillway is intended to carry much larger volumes of water than the primary spillway but gets used infrequently.