Our house has one downspout that drains into a 5" flexible hose which continues vertically underground. During very hard rainstorms, water gushes out of the downspout-hose connection. I disconnected them and ran an electrical snake in the hose, and it seemed to hit a hard stop at about 8'. I asked the previous owner where the drain went, and he thought it went into a drain around the house. The blueprints do show a perimeter drain pipe near the foundation, which would put it about 5' underground.

That raises some questions.
1) If that perimeter drain pipe exists, why would all other downspouts (7 of them) have simple horizontal extensions to direct the water about 6' away from the house, rather than also draining into the perimeter drain pipe? This downspout cannot do that because it would flow across a walkway.

2) Where would the perimeter drain pipe go? It cannot go into the public sewer system, I am confident. At that depth, I am pretty sure it has no place on my property to drain onto the surface. Can it drain into a street storm drain system (even though I do not see one nearby)?

3) There are 2 clean out caps in our yard. One is near the house, and above ground level. One is near the street and is barely at ground level. I had assumed that both were sewer clean outs. Could one access a storm drain? (Is there no requirement that storm drain clean outs be above grade?)

4) If it does not drain into a perimeter pipe, how do I approach improving flow through this hose? If it travels across the property, it could drain above ground. If so, I want to know where it goes and assure it stays open. I tried running water from a hose in it and looking for water coming out somewhere unsuccessfully. The hose did NOT overflow, so there is some runoff. What do I do to track it?

5) If it empties into a perimeter drain pipe, I do not want to risk plugging the connection with an object on the end of a snake to allow better pushing of the snake. How would I determine where the perimeter pipe empties? To check the connection of the hose with where ever it goes, digging is not a good option because there is little space between the house and walk, and I would risk cracking the walk by undercutting it. What would I do here? I have good runoff except with huge downpours, so I guess a spillover collection and horizontal drain can direct the excess away from the house. I have never seen such a thing, so would envision having to fabricate my own. Suggestions?

 

Update
I ran an electrical snake, and it got wet 2' in, despite no rain in days. The snake hit a soft stop at 12' now. I ran water in it, and it very quickly filled and had a very slow run off. I am now suspecting this ribbed flexible line has collapsed and is now blocked. I am guessing this does NOT connect to a perimeter drain system, and I will be trying to find out where it goes, and will be exploring ways to find it with a magnet on the end of the snake and a compass or something like that.

 

Hi Ed - I think it would be unusual for a gutter to drain onto a foundation drain. Typically buried gutter drains are laid shallow. I have 3 and they are only a foot or so beneath the surface. Two of mine terminate in dry wells and the other empties at the surface.

I would probably start digging where you think the blockage is located.

 

Thanks, Wayne.

I thought it was not so likely that the downspouts emptied into a foundation drain, since that would take surface water closer to the foundation rather than keep it away. The previous owner said that, and he was involved with the house's design, so I did not fully dismiss that idea. Anyway, I think the foundation drain is likely lower than any point on the property, so where does it likely go? Where do these usually go when the foundation is so deep?

I can rent a metal detector for $10/half day. I have tried to find how deep detectors can detect objects, and depths I see are about 6" to 9" for small objects like coins and jewelry. I can send a large steel item like a piece of pipe or even a magnet, but I do not know how well I can extrapolate a detectable depth for larger objects. My guess is it is about 2' deep where it might be blocked, and it is very likely beyond a concrete walkway, do digging along it all the way to the blockage is not possible. Twelve feet to the blockage means a large arc for random digging, so I am hoping I can do some localizing.

Is there any experience with metal detectors for this purpose out there?

 

My area has 2 sewers per home - one for waste and one for storm water/runoff. The gutters and foundation drains do go down into one set of pipes which are routed underground to the storm sewers at the street. The waste drains take the other stuff to the sanitary sewer.

What you are describing sounds lke a collapsed or clogged drain line. Interesting that, if I read your post correctly, all other downspouts drain onto your property. I would guess that the drain failed at some point and the downspouts were redirected at that time execept for this one which has now failed as well.

Digging is the cheaper and labor intensive way to proceed. Digging and following the pipe into the ground will stop you from wondering about a 12' arc of where the clog would be. I would also suggest a more sturdy pipe replacement that plastic corrugated pipe if you are burying it several feet underground. I have seen entire perimiters dug up for this because it causes leaks around the foundation when the water begins to pool. There are very specific techniques for rebuilding perimeter drains around the house and this would benefit from that as well.

There are also cameras used to see into pipes that cold more easily identify the problem as a clog or collapse.

Godd luck.

 

I can report that a rental metal detector cannot find metal more than 10" away. I lost detection of the 6" piece of pipe I taped to an electrician snake 2' into the drain before I even knew which way it was going. It is not feasible to start digging, because the drain enters the ground about 18" from a sidewalk that extends out and makes a large sweeping "T", and the drain could emerge from under the sidewalk anywhere along the walk about 12' away in any direction. Which way it goes once it goes under the walk is not deducible from following it 18" to the walk. I can say that I can detect metal-containing rocks with a metal detector, and had to dig up some to see if without the rocks there was a signal from the intended target. Nope. No diamond rings, either.

Anyway, I can now say that these metal detectors may detect coins at 9", but they can detect larger items (steel pipe or copper pipe) no further, since the electronics seem designed to limit the range to about 9". My drain apparently goes deeper than that near its entry point, and is not any less deep as the ground starts to slope down away from the sidewalk.

Now I need to go to plan B. I think that will need to be a plumbers transmitter/receiver drain detector. Seeing with video what is in the pipe I think will be of little help. Seeing it filled with leaf debris will not let it be cleaned with an auger because I think the thin flexible hose will be destroyed with a router-router. I think I will need to dig it up at the stoppage, but need to know where that is.