How to unclog a long culvert?

We recently had multiple storms and the parking lot was flooded. The culvert was flowing slowly and causing water to back up on the higher end of the ditch and overflow. I think it is clogged with leaves and mud and need to be cleaned. It is 12" in diameter and 50 ft long. Is there a DIY option or I have to call professional service? Thanks.

This is the method me and some buddies have used. A lawn mower sized old tire could be utilized for a 12" culvert. The trick is to have a long enough pole to 'fish' a role through so you can drag a chain through via the rope. We utilized some old conduit and picked straws who was getting a little muddy.

If you choose this method, please be careful. Good chains and easy throttles.

Great idea to clean up shorter and smooth culvert with tire! I am not sure I can get a pole through it at all. When the water recedes, I will try a long handled rake to fish out debris on both ends first. Is the metal one in the video custom made? As for pressure washing, maybe I can use a 212 hp water pump with the hose shoved down as deep as possible...

This doesn't help with the immediate problem, but when it's cleared leaving a wire rope (cable) inside from end to end will help the next time it clogs. It will make it easy to fish through more heavy duty items like chains.

First thing is to check no small logs, twigs and leaves have piled across the inlet.
I see these often on my forest road.
BE CAREFUL ABOUT STANDING NEAR THE PIPE, IN THE WATER, YOUR LEG MAY BE DRAGGED IN
I stand on top of the pipe between the vortex in the water and the road edge.
Then use my arm to reach in and fiddle with whats there.

I've cleared a clogged pipe culvert by using a garden hose with a skinny spray nozzle set to the narrowest and hardest possible stream. I just jam it in there and hope for the best. It helps if you can try from both ends, since sometimes it's easier to loosen it from the "downhill" or outflow side because things aren't packed as tightly.

I've also had success with a long piece of stiff wire with a U-shaped hook in the end.

Timothy Norton wrote:This is the method me and some buddies have used. A lawn mower sized old tire could be utilized for a 12" culvert. The trick is to have a long enough pole to 'fish' a role through so you can drag a chain through via the rope. We utilized some old conduit and picked straws who was getting a little muddy.

Wow.....just brilliant!   I've been facing this problem with multiple culverts on the property slowly filling with clay silt.  So excited to try this and have not only long steel well-pipe, but chains, long towstraps,  and multiple old lawnmower tires laying about.  I will probably afix a piece of livestock panel to the rear roll-bar of my tractor before trying this....would not want a lawnmower tire under tension to come flying out of that culvert "at pace" like a cannonball when I give the tractor some gas!

Thanks for this tip and video!

The ground is drying up slowly and I was able to take a closer look. There were rocks near the entrance and I raked those out. I shined a bright light down the pipe and found debris down there.  I connected two 8' long PVC pipe but still couldn't reach it. The clog is about 20 ft from the upstream end and I don't know how long it could be. I can't see far enough from the other end. The culvert is 18" wide and about 65 ft long. The clog is closer to the upstream end and I am going to work from that side.  At least it's not a solid block as water still drains slowly. I bought a small rake and will try to secure it to a super long and sturdy handle to see if I can loose the debris. Do you think it's feasible? Or is there a powerful vacuum with wide hose that I can rent to suck it out?

Rental houses carry very long "snakes" for cleaning clogs in sewer lines. They are designed to rotate and get into or through the blockage. I wonder if that might be enough to snake a cable or stout rope through from end to end. Once you have that, you have plenty of options.

BTW the old timers would have used half a stick of dynamite. But that is frowned upon these days.

Not sure it would help in this case, but I've got a 36" culvert that's about 30 feet long that a family of beavers LOVE to clog as the start of their damming festivities.  First time I had to clear it I tried everything (other than renting a sewer snake) but they'd pushed in stones, wood, and mud to seal it solid for about eight feet.  I managed to get a bit of a trickle through it with shovels and a long breaker bar but that's about it.

Then I found a birch that was downed by the beavers and floated it down to the culvert.  Narrow and tall, it made for the perfect 'pipe cleaner'.  I tied a rope to the top in case it got lost in the culvert and got to pushing and pounding like a battering ram at the castle gates. :D  Once it broke through, the water cleared much of the mud and floating the birch through a few times scraped out the wood and stones.  Since that day, I've left my 'pipe cleaner' on the bank next to the culvert hooked into tree stumps and each time the little buggers clog it I lift it back into the creek.

Great tip about the pole that floats, thanks. Today we tried a 10' + 10' pvc pipe and confirmed the blockage started at 18 ft. But due to the weight and the corrugated nature, the tip of pvc stayed low and got stuck to the mud at the bottom part of blockage. I plan on filling the pipe with water again and let some wooden 2×2s (joint by sturdy brackets) to loosen to debris near the top. Then maybe the water will carry some of them away.
Also I was really bad at estimating distance,  we measured the culvert length on the ground with the pvc pipes and it came up to 100 ft.

Those hose snakes Douglas mentions are great.
They have a head which sprays a series of jets backwards which causes the hose and the jet to move down the pipe.
I would have a hose long enough to go through the culvert so the whole culvert can be cleaned if needed.
Sometimes the hose can pull itself through the blockage opening a passage for water to flow and thus start  washing the blockage away, down the culvert.
Monitoring the culvert exit and pulling the hose back and forward will eventually cause the block to break up and wash away.