Drainage Trench and Water Retention Chamber

[Dog Lover]

My BX24 came thru again. I wanted to share some pics of a project I did over Father's Day weekend finishing today. It took me 5 days. Worked alone. I dug a pit for my water Retention Chamber by Storm Tech. I decided to use a chamber after researching all available ideas and also to handle any driveay runoff if a low spot is in finished drive at a later date. Tight elevations don't allow me to go to many directions with runnoff on the one end of the house or the with the finished drive surface.

Pit dimensions were 9 ft long, 6 ft wide and 5.5ft deep. It was at the limit of my BX24 as far as getting a clean flat bottom...but it did it . I cleaned it up with hand work but very little. I took 10 tons of dirt out of hole with the hoe. I put 8 tons of rock in the hole. I wrapped the entire pit in non woven Geo Textile. Prior to any back fill, entire chamber and rock were lapped and completed sandwiched in the textile. I then dug an 81 ft trench to tie in the downspouts on end of house. I also put in a short section of pipe in the chamber, other end, ready to be used to put a drain in a new asphalt driveway I will have put in later. This is in the event I have a low spot that will result. I can then drain the water into the chamber. I thought better do it now as it would be to late later.

The chamber has 1 ft of rock beneath it and 6 inch all the way around sides and top. This allowed for 24 inch of dirt on top of stone, spec for weight requirements of a vehicle that could rut on ground above the chamber without pavement. Total capacity volume for water is 700 gals. Hope we never need that much but I made it large enough for who knows what....

I placed the chamber in the hole by making a sling of rope thru the chamber and hooked to my FEL bucket hooks leaving slack enough to lower it in the hole. Worked nicely.

Project went well and even with three days of 91 degree heat both me and the tractor held out. I am very pleased with my Kubota as without it the project would never have gotten done. Ground was like rock, dry clay beneath 6 inches but the hoe cut right thru it. All we need now is some Rain!

 

[Edstir]

Your big project is an inspiration to me. I have to dig a 75 foot long 4 foot deep trench to my river ramp to eliminate my sump pump running all the time when the water table is high in the spring. I'm working on eliminating moisture in my crawl space and hope I won't have to worry about the sump pump losing power. I have to watch out for a gas line other than that it should be clean dig. Nice pictures.

 

[Volfandt]

Nice pic's, great project and good job. That hole looked pretty good. It's also a great example of what a BX TLB can do.
Been thinking about doing somthing similar so I can use it to water the garden. Veg's & plants much prefer rain water over city water.
Question, why wrap the hole in non woven Geo Textile?

 

[Lockport]

Nice job! I, too, have a similar project on the horizon. I am going to do a new septic chamber field with about a 200' run from the house. The field will have to be raised according to my soil analysis. Black muck of over 80% clay composite and it's hard to dig down past 3' when its wet. And that's with an 8" trenching bucket. If it goes anywhere as smoothly as yours seems to have, I'll be in luck.

 

[Dog Lover]

Thanks for the comments everyone.

Volfandt, Woven Geo Textile will tear with the rocks hitting it. Non woven will not, tough stuff, but light.

The BX is tough little tractor. A 4ft trench should not be hard, just take your time. If you do it right you won't have to get off seat, just keep moving back 4-5 ft at a time.

 

[MOPAULY]

Nicely done. I can only imagine the spoil pile size from a hole that big. I know how messy it gets when I just dig small trenches.

 

[njbmwgs]

wonderful job - that's exactly the stuff I need to get done, but without the well, I can go to daylight. Thanks for sharing the photos, it's very helpful.

? - does the pipe from the gutters have holes in it, so it's also acting like a french drain as well as a gutter pipe? I need to do something similar and wasn't sure about the correct method.

thanks again.

 

[Builder]

Nice pic's, great project and good job. That hole looked pretty good. It's also a great example of what a BX TLB can do.
Been thinking about doing somthing similar so I can use it to water the garden. Veg's & plants much prefer rain water over city water.
Question, why wrap the hole in non woven Geo Textile?

I think, but I could be wrong, what Wolfandt means is why wrap the chamber in ANY kind of fabric.

I *think* the answer is: When you bury a chamber you can make it work even better by surrounding it with stone, thereby enlarging the area that can uptake water. The chamber fills first, then if the chamber overflows, it purges water into the stone sump, acting like an overflow retention pit. The fabric keeps the stone clear of fouling from dirt from the bottom, sides and top. Since the chamber is buried pretty deep, might as well backfill with stone, increasing the chambers capacity and lessening the chance of settling later, too.

When I build stormwater retention systems, we simply line the hole with fabric, fill with stone and cover the sides & top with fabric. They don't sell large enough chambers to drain a big house. The downspouts run into 4" PVC feeders that go into a 6" #40 buried around the perimeter of the house, catching all downspouts then runs into an 8" main at the front of the retention pit. There's a clean-out and then into the stone with perf.

 

[Volfandt]

I think, but I could be wrong, what Wolfandt means is why wrap the chamber in ANY kind of fabric.

Yeah, thats basically what I was asking. I've not researched this yet and it didn't dawn on me that the larger hole wrapped with material then filled with gravel would be used as a sort of overflow container also.
Can this overflow be recovered or does just seep away into the ground?

 

[Dog Lover]

The pipe is solid with no holes. It was not meant for french drain. You could use that pipe if you intend the dual purpose.

With regards to the chamber and hole size, yes, the rock and the amount you use add to the chamber volume capacity. Purpose of the chamber is to unrestricted area for water to flow rather than directly into stone bed. As Builder said, fabric keeps the rock area free of sediment which will over time clog the leaching process. The chamber it self holds 380 gals of water. Calculate the rock area in the rest of the pit and total becomes 700 gals with proper flow rate into stone filled areas.