Gutter Problem

[DEKE]

This isn't really mechanical, but it seemed the closest topic area. 

We have a new barn.  The gutter downspouts are 4" x 6".  I have found online an adapter to go on the bottom end of the gutter that will connect the rectangular gutter to 6" corrugated drain pipe.  I have found the 6" pipe to send the water a safe distance from the barn. 

Now I need advice on what to do at the end of the drain pipe.  I plan to bury the drain pipe to make it more presentable because this is a high traffic area for visitors.  Also horses and occasionally cattle will be grazing in the adjacent pasture where the drains are so they need to be strong.  Around my house, the gutters go under ground and 30 feet away in the yard they surface at a plastic box that lets the water out at the ground level.  Works great, no french drain needed, but would not stand up to a 1200 lb beast standing on it. 

I have 18 of these gutters and the volume of water is B I G.  Each gutter downspout has to be able to handle 10,500 gallons in a 24 hour period based on a 25 year rain of 11 inches (a county requirement to ensure I do not flood my neighbors of which I have none but the national forest which is a swamp).  Because our soil is so sandy, we have had 5in rains in a 3 hour period and within an hour there was no standing water anywhere.  So I'm not worried about the water dissipating in the sand, I simply need to have some way to end the drain pipe at something where the water can safely flood into the pasture. 

It has to be strong from a livestock perspective and strong from a water pressure/erosion perspective. 

Ideas?  And remember I have to do this 18 times, so it needs to be like I like my women, cheap and easy. 

[Jolly]

Drain covers made from angle iron and expanded metal?

[DEKE]

Jun 6, 2019 17:44:13 GMT Jolly said:

Drain covers made from angle iron and expanded metal?

that was my first thought.  Build a concrete box in the ground, cover it with a welded metal grate.  But I have to do this 18 times.  I was hoping for some brilliant shortcut from you folks.  Like maybe I could bury one of Joebills car wrecks and pipe to it. 

[Deleted]

Do you have 18 buildings, or an 18 sided barn?

When I think of all that water, I wonder how it could be stored as part of a catchment system. But you're in an area that gets adequate rainfall.... hmmm....

I don't know how far apart these 18 contributing pipes are, but it would be lovely to build your own pond or lake.

[DEKE]

There are 9 downspouts each on two sides, spaced 25 ft apart. The county did make me dig a retention pond, so now I have a 6 ft deep, 125ft long, 75 ft wide hole in the ground. I was required to have a hole large enough to contain a half acre foot of water, which is about 180,000 gallons, which gives me about 10,000 gallons per downspout.

We made the pond part of DW's horse obstacle course so that she can teach skittish horses to go over logs and bridges and as of two nights ago, wade thru alligator infested waters. But that's a different problem.

On the pond side of the barn, I'm going to have the drain pipe exit into a swale/trench that leads to the retention pond. But I still have to have the pipes exit into the swale with some sort of strong exit point. Horses will be running thru that area or a regular basis.

On the front side of the barn, where people will park cars and horse trailers, there will not be a swale. Or at least I don't think so now. I think the water can simply dissipate into the field. The county will not be happy but I have met the legal requirements by digging the retention pond. The county would prefer I install underground pipes that all exit into the pond. Nope. Way too expensive.

edit:  I don't know if this is common knowledge or not, it was new to me.  Big water, like a lake, is measured in acre feet.  It is just what it says, one acre covered with one foot of water.  The county computed my problem as .5 acre feet, or 6 inches of water covering one acre. 

[ceresone]

Sounds too simple, but couldn't you just dig a trench, fill with gravel, and cover back with dirt?like I said probably don't fit the problem

[DEKE]

Jun 6, 2019 22:28:37 GMT ceresone said:

Sounds too simple, but couldn't you just dig a trench, fill with gravel, and cover back with dirt?like I said probably don't fit the problem

That is basically a French Drain and they work great for slow and small volumes of water, especially in Florida sand.  I have to plan for big water coming down fast because that is the norm here every summer.  Three of four inches of rain in a few hours is sure to happen at least once a year.  And that is going to produce enough water that 4 downspouts could fill a normal backyard swimming pool. 

[Ozarks Tom]

Without surveying the elevations, and knowing the distances involved, the best suggestion I can come up with is another small collecting pond with a trash pump piping back, possibly underground, to the big pond.

[DEKE]

Jun 7, 2019 0:38:53 GMT Ozarks Tom said:

Without surveying the elevations, and knowing the distances involved, the best suggestion I can come up with is another small collecting pond with a trash pump piping back, possibly underground, to the big pond.

It's Florida.  There are no elevations.  OK, not much of them anyway.  It is very flat, but the water does drain towards the barn, mostly because my idiot erector screwed up.  That why I need to get at least 20 ft from the barn to allow the water to flow out into the field rather than back to the barn. 

[Ozarks Tom]

Okay, I'm beginning to understand the problem. We have a similar one here, in that our sheep barn is on a down slope, and if allowed the rain water would run through it. Our answer was to set concrete blocks in concrete bedding, then fill in the joints. In other words, we built a dam along that wall. The small lateral slope takes the water past the barn where it spreads into the grass.

I'm sure your situation involves more water and longer distances, but have you considered pouring a concrete curb against the barn, along with a concrete gutter that would take the water away from the barn and dissipate it into the surrounding grassy areas? It was our only answer to the elevation problem that couldn't be avoided without totally reshaping our area. We put gutters on the barn, and extended the downspouts beyond the curbing.

Your situation is obviously different, but the solution may be similar.

[themotherhen]

What if you planted some beauty berries where the water empties? That way you all would at least get some food, thus not wasting the water, and it would probably get the county to leave you alone. That or another native plant, people from the county extension seem to love native plants.

[gob]

What I will do to dump rain water into a field off the barn here in KY----The pipe would have 3" to 6" of dirt on top of it. At the end of the pipe in the field it would run into one or two concrete blocks. This will keep the end of it from getting crushed shut over the years. At the end the blocks would be below ground level and the pipe would dump into a field of #3 rock or a little bigger. This will slow the water down and allow it to disperse without washing the ground away at the end of the pipe. Just make sure the rocks are deep enough and the field is big enough to handle the traffic over it and the water coming out of it. The rocks are not there to let the water seep into the ground, but to get the water on top of the ground to run off.

Hope I was some help.

[DEKE]

Well done, Tom. That does give me an idea. We still have a concrete pour coming to do the walk ways in front of the stalls. Maybe a raised portion,a 2x4 frame high would be enough to stop the draining into the barn.

But I still need to get the water away from the barn, so you've got some more work to do to figure out how that is going to work. Chop, chop. I'm a busy man, I can't wait on you all day.

[DEKE]

TMH and GOB, you guys do have me thinking. I'll discuss with DW later today. Maybe instead of trying to use concrete and steel to reinforce an outlet so that horses and trucks won't crush it, I just build a planter box of some sort. Use the rock to slow the water down in the planter box. We already have plans to put in some oak trees for shade and acorn production. A 6 ft square, 2 rail fenced planter would protect the trees from the horses and cattle and also hide the gutter outlet.

That might solve several problems all at once. I'm liking that idea.

[Ozarks Tom]

It doesn't take much of a grade to run water off. I'd use a string level to determine any existing slope at the barn wall to see if with just a bit of work with a scraper the curb and gutter would work. If you could get just a couple inches of slope it would probably be sufficient. With the long length of the building, you might consider running slopes both directions.