Definitely true that screens clog and can cause a problem. However in my trout pond where I have two outlets and continuous flowing water, I make screens out of plastic cage mesh like the following. My trout are quite small right now, and they have even more of a penchant to find running water and swim with it than other species.
They're made as a tube slightly bigger than the outlet drainage pipe and put together with zip ties. They slide on and off of the drainage pipe.I usually make two of them and just pull one off and put a clean one on while I spray off the algae and debris from the dirty one with a garden hose. Then that one's ready for the next change over.
I can get them them to clog less frequently by placing a floating boom of sorts in front of the drain. Not pictured, but I make a u shape with three pieces of 1 1/2 inch PVC pipe and two elbows. The ends are sealed with caps and of course the closed end faces the inflow. Floating debris such as leaves and floating algae gets stopped before it gets to the drain pipe screening.
It's also a good idea to extend the screening as far away as possible from the end of the drain pipe. That is, lots more surface area to slow down complete blockage. I run a drywall screw through the screen into the drainage pipe to hold the screen in place. It can be removed by hand and isn't screwed in very far.
More pictures:
