Another thread on SF about dumb things you've done reminded me of an incident about 4 years ago.
Geese and more pond troubles...
The standpipe (vertical drain pipe) for our dam is a 24" galvanized corrugated pipe. On top sits a removable grated cover to keep trash from entering the pipe and clogging it up. The cover is about 30" across, and is propped up on spokes about 4 inches from the pipe, so in normal conditions the water drains by coming up around underneath the sides of the cover and over the pipe.
A new one looks like this (not ours):
In the spring about 4 years ago two geese built a nest right on top of our grate cover. Being lazy, I manage to pretend not to notice this for a long time. Seeds blew onto the old nest and grass started to grow on there. Not really a problem as long as there are no heavy rains. (You can probably see where this is going.) One day after some heavy rains I happened to go to the pond and the water was up about 2 feet, even with the boat dock, and starting to trickle over the emergency spillway. It was a bit startling. Sticks and trash had completely shut off the drain.
So I got my mother and we hopped in the boat and rowed out to remove the trash from the cover, which was now below water. The grate was sitting lopsided so I thought I could just lift it and straighten it while I was at it, but turns out the spokes were broken. It was much heavier than I expected, almost dropped it in the pond, but it had to be put back or else the pipe would clog. The water formed one of those funnel things (I think it's called a vortex) like in the bathtub drain, only huge. We were safe in the boat but leaning out over the pipe without a trash cover was very stupid. Then it started making this very loud sucking sound you could hear even from the other side of the pond.:eewwk: This noise went on for several hours, at least, until I had to leave. I was afraid the neighbors would hear it and call the sheriff.
Shortly after that I hired some guys to replace the old trash cover (front of boat) with one they built. I don't know the guy in the middle but the one rowing is a contractor I've hired several times to do excavation and fencing work. He is a bit of a free spirit, and folks out there either love him or hate him. I like him.

This is the new cover they made (during a drought about a year later). You can see how the standpipe is deteriorating.

Btw, those two geese would come back every year for several years, and I don't think they ever got a young one to survive. Usually they would nest near the bank and I doubt they survived the raccoons, foxes and turtles. Only once did I see them with young ones---3 swimming in tow. I don't think they could have survived the turtles. That is evolution in progress, I guess. Whatever "stupid" genes these two had were likely never passed on. Geese with better instincts at choosing a safer pond and place for a nest would prevail.
ps. There *is* something you cannot find on the internet---an audio of that giant sucking sound. Otherwise I'd have stuck that in here, too.
Geese and more pond troubles...
The standpipe (vertical drain pipe) for our dam is a 24" galvanized corrugated pipe. On top sits a removable grated cover to keep trash from entering the pipe and clogging it up. The cover is about 30" across, and is propped up on spokes about 4 inches from the pipe, so in normal conditions the water drains by coming up around underneath the sides of the cover and over the pipe.
A new one looks like this (not ours):

In the spring about 4 years ago two geese built a nest right on top of our grate cover. Being lazy, I manage to pretend not to notice this for a long time. Seeds blew onto the old nest and grass started to grow on there. Not really a problem as long as there are no heavy rains. (You can probably see where this is going.) One day after some heavy rains I happened to go to the pond and the water was up about 2 feet, even with the boat dock, and starting to trickle over the emergency spillway. It was a bit startling. Sticks and trash had completely shut off the drain.
So I got my mother and we hopped in the boat and rowed out to remove the trash from the cover, which was now below water. The grate was sitting lopsided so I thought I could just lift it and straighten it while I was at it, but turns out the spokes were broken. It was much heavier than I expected, almost dropped it in the pond, but it had to be put back or else the pipe would clog. The water formed one of those funnel things (I think it's called a vortex) like in the bathtub drain, only huge. We were safe in the boat but leaning out over the pipe without a trash cover was very stupid. Then it started making this very loud sucking sound you could hear even from the other side of the pond.:eewwk: This noise went on for several hours, at least, until I had to leave. I was afraid the neighbors would hear it and call the sheriff.
Shortly after that I hired some guys to replace the old trash cover (front of boat) with one they built. I don't know the guy in the middle but the one rowing is a contractor I've hired several times to do excavation and fencing work. He is a bit of a free spirit, and folks out there either love him or hate him. I like him.

This is the new cover they made (during a drought about a year later). You can see how the standpipe is deteriorating.

Btw, those two geese would come back every year for several years, and I don't think they ever got a young one to survive. Usually they would nest near the bank and I doubt they survived the raccoons, foxes and turtles. Only once did I see them with young ones---3 swimming in tow. I don't think they could have survived the turtles. That is evolution in progress, I guess. Whatever "stupid" genes these two had were likely never passed on. Geese with better instincts at choosing a safer pond and place for a nest would prevail.
ps. There *is* something you cannot find on the internet---an audio of that giant sucking sound. Otherwise I'd have stuck that in here, too.