I used the dock of the Bait Shop as my foundation. Electric fences running horizontally with dart traps shooting down on their heads. If they can make it through the first 8 rows, the blade traps quickly take them down. I've found this base to be very effective and efficient. The space needed is minimal, and you barely need to use any ammo. I only shoot the radiated cops so they don't damage anything with their explosion.
Day 49 Blood Moon:
Day 49 Blood Moon: