Open bottom culvert?

[RobA]

I was reading some culvert literature on the internet when I saw a reference to an "open bottom culvert". It was being touted as a way to disturb the creekbed as little as poossible, be "fish friendly" and lessen the chance of the culvert washing out. Has anyone every used an "open bottom" culvert". It basically looked like a round culvert cut in half lengthwise.

Would a culvert like this still support weight as well as a round culvert if properly surrounded by dirt?

 

[schmism]

id be worried about the bottom continueing to erode and the culvert sinking into an ever deaper hole.

else what you have is called a bridge.

 

[firemanpat2910]

I agrre sounds like a bridge. Every open bottom culvert I have seen started its life as a regular culvert and rusted out, then washed out and needed to be replaced.

 

[Willl]

And I'd bet they want more $$$$ for 'em too.

If it's a short run, couldn't you take a uncut culvert and fill the bottom half with gravel and get the same thing ?

 

[CTyler]

Never heard of them....Sounds like a great way to double profits.

 

[schmism]

btw how big of a culvert are you talking about... i usually dont have fish in my front ditch....

anything over about 3' usually goes to concreet box culvert (like real streams under roads) and those usually only go to about 12'. any larger than that (more water flow) and you now have a "river" and now you need a bridge....

so....

 

[dirtworksequip]

Open bottom culvert= bad idea.

 

[randy41]

a quick search over on google way reveals it to be quite common.

 

[Tom_Veatch]

id be worried about the bottom continueing to erode and the culvert sinking into an ever deaper hole.

I almost wish it would. I have more problems with the culvert in front of my place silting up, water going over the top, and the driveway washing out. Couldn't be because the (expletive deleted) road maintainer keeps pushing the top of the dirt/gravel road off into the ditch.

 

[KennethBrown]

btw how big of a culvert are you talking about... i usually dont have fish in my front ditch....

anything over about 3' usually goes to concreet box culvert (like real streams under roads) and those usually only go to about 12'. any larger than that (more water flow) and you now have a "river" and now you need a bridge....

so....

I don't know about that. I put in a 20 foot long 48" culvert last year in my creek.

 

[RobA]

I don't know about that. I put in a 20 foot long 48" culvert last year in my creek.

That's what I'm looking at doing - 42" or 48" x 20'. An open bottom culvert sounded interesting since I thought the width was more important than the height. Cutting a 10' culvert in 1/2 would give me a 20' culvert 48" wide. The fish are not the concern but having the culvert wash out is. Perhaps putting the culvert 6-10" down in the creek bed would help the water pass through and lessen chances for erosion at the bottom.

 

[KennethBrown]

Now I'm taking it out of the thread but back into it at the same time........... On mine I very slightly scraped the bottom to creat a reccession for the culvert, maybe 2" at the most. Layed the pipe in and started backfilling a little at a time. Before the fill I put a t-post on each side and end to hold it steady, didn't exactly do that but it showed me how bad it would have moved if I hadn't. I used limestone road base (72 tons!) since I needed to make **** sure it wasn't going anywhere. Put the fill in slowly and work it with a shovel/rake/chipper bar/whatever. You want to pack it into ALL of the crevices. A water source here helps tons. After you get most of the fill in ya gotta build funnels/retaining walls on the end. This is not an option if the creek evr has water flow through it, its mandatory, and yes on both sides. I figured it didn't matter on the outflow side, WRONG! I have had one washout and it was on the outflow. The water will churn in a circle when it leaves the culvert and eat away at you riprap till it gets to your fill and then start on it. I used some cheap recycled plate steel for mine along with used pipe driven into the ground to hold it. After you get these in you will need riprap. I used bricks as I had about 12 yds of old ones in a pile out back. Layed them in by hand to my satisfaction. Then I poured a couple of bags of dry concrete into the crevices. Next I mixed concrete in a bucket with the creek water and slathered it onto/in/around everwhere. It was a lot of work to do by myself ( a little help from my dad setting the pipe) but the results were well worth it. This creek basicly blocked me from my land. I have 36 acres and could only use about 5-6 of it unless I went by horse or foot. Now we can travel all the time.

PS- My creek is about 6-7 foot deep. This was put in in an old crossing. Some times during BIG rains the water level is about 1 1/2-2 foot above the road/culvert. Two years now and I've lost maybe 2 yds of rock.

 

[KennethBrown]

One thing I forgot to add. The cost will be lots cheaper to get the 48" in 20' long than the 10' in 10' long. Mine ran about $700.

 

[RobA]

..... On mine I very slightly scraped the bottom to creat a reccession for the culvert, maybe 2" at the most. Layed the pipe in and started backfilling a little at a time..............

Great description. That sounds like what I was envisioning. This is all new to me and I have heard of many horror stories about culverts washing out. My creek does not have as much water as yours but there's enough to do damage. I want to do it right and have been a little intimidated and have delayed doing it. Like you the creek cuts off a lot of my acreage.

If you took pictures along the way I'd love to see them. Even the finished project would be great to see. Thanks for posting.

 

[Soundguy]

Sounds like standard box culvert to me. The GC I work for has used this as a bridge for vehicular trasffic, orver wetlands ( per county and state engineer and plans on specs ). Headwalls are typically poured 'in place' . It's a common structure...

Soundguy