Spillway is a toxic waste dump with four bloon paths, each coming from the four corners. Bloons enter around the toxic pool and then exit on the opposite path that they entered from.
In the middle of the toxic waste pool, there is a metal barrel that small footprint towers can be placed on.
On the outside, there is concrete floor with a bunch of contaminated gas masks, bottles of toxic fluid, and a contaminated lab coat.
There are four inflatable walls on each side of the toxic waste pool that can be removed for $2000 each. When removed, a visual Engineer Monkey will deflate the valve of the inflatable wall, and the inflatable wall falls into the toxic waste.
- Main article: Spillway/Strategies
- This is the first map to have obstacles that cost more than $1500 per obstacle.