[Lioneljeff33]

Hello, I am going to start a project soon in my backyard using the NDS Flo-Well Catch Basin. Its a 50 gallon basin which I am going to use to catch my downspout water from the back roof of my house. I have one downspout that will go into the catch basin 15 feet from back of house. The hole I am going to dig will be 4'x4'x4'. Lined with 2B limestone and will use landscaping fabric around the hole and catch basin itself. I will be using all 4" PVC piping. Has anyone here ever done this? If so, could you give me some tips or advice on how to do this correctly? I have all the things I need, except (2) 10ft PVC pipes. How much 2B limestone will I need? The hole itself is 64 cubic feet, but minus the basin which is roughly 16 cubic feet. So, 48 cubic feet is what I need about. That should be about 2 tons, sound about right? I have not started digging yet, but what if the dirt is all clay? Then, what should I do? Dig another spot? Thanks and hope you can help.

 

[Old Thomas]

If your soil is clay, it will not take water well but if there is no other option it will be a lot better than nothing. I would dig a test pit first. And why would you not dig a round hole?

 

[huesmann]

Gravel is about 100 pcf, bulk density, give or take 5 pcf. You'll need about 48 CF of gravel, which at 100 pcf is 2.4 tons.

What will you be connecting with the 4" PVC?

Why are you doing this in the first place?

 

[Lioneljeff33]

It is easier to dig a square hole and makes things less complicated.

 

[Lioneljeff33]

I am connecting my rear downspout to the 4" PVC piping and running that to the Flo-Well. I am doing this because I have water coming to the back foundation wall when the old pit floods up. I need to dig a new pit and see if this works. If I get over an inch of rain the old pit floods up and water goes to the back of my house foundation wall and seeps into my basement. The old pit is about 12 feet from the house, but is just a 3 inch PVC pipe emptying basically into the yard, Don't even think there is gravel. Poor design.

 

[Bondo]

If I get over an inch of rain the old pit floods up and water goes to the back of my house foundation wall and seeps into my basement. The old pit is about 12 feet from the house,

Ayuh,..... The new pit will do the same thing, unless you build in a drain, that takes the excess water elsewhere,.....

 

[Lioneljeff33]

I will have a top drain coming out the center top of the Flo-Well. Any excess water will comes out the top. There is no where else to drain the water except into yard. I do not have a road in my back yard to drain the water. My yard slopes down to the park in my back yard.

 

[huesmann]

OK, so you're gonna have 16 CF of volume in the bucket, and about 19 CF in the gravel. If you get an inch of rain, I hope your roof footprint is less than 420 sq ft.

If you have clay soil it won't infiltrate, and will remain full. You'd need to pump it out somewhere periodically.

 

[Lioneljeff33]

How did you get 19 CF in gravel? My hole is 64 CF and the Flo-Well is 16 CF. My ranch house is 36' x 26' at the base. The roof is not very steep. And the downspout that will empty into Flo Well is only for half the roof, back portion only.

 

[Lioneljeff33]

Pump it out to where? I cannot pump water to road in the front of the house.

 

[Bondo]

There is no where else to drain the water except into yard. I do not have a road in my back yard to drain the water. My yard slopes down to the park in my back yard.

Ayuh,..... Then skip the bucket, 'n put a string line straight fallin' pitch swale across yer yard to a lower point,.....

Then throw some grass seed on it, 'n call it a day,.....

 

[Lioneljeff33]

I will stick to the Flo-well solution, thanks though.

 

[huesmann]

How did you get 19 CF in gravel? My hole is 64 CF and the Flo-Well is 16 CF. My ranch house is 36' x 26' at the base. The roof is not very steep. And the downspout that will empty into Flo Well is only for half the roof, back portion only.

Um, gravel has a porosity of about 0.4, i.e. your gravel is 60% stone, 40% air space. So 100 CF of gravel only has about 40 CF of volume available for water to fill.

36x26 is 936 SF. Assuming half goes to your infiltration pit (what it really is), you can handle about 0.9" of rainfall, maybe a little more, since some water stays on the roof.

 

[Lioneljeff33]

Bottom line is, will it work? I know it will be better than what I have now. Might I need two Flo-Wells? Thanks.

 

[3onthetree]

My yard slopes down to the park in my back yard.

I'm not sure why the insistence of dumping to a street in the front. You say you have slope, so dump a pipe to the back. You can probably run it to within 3' to 10' of the property line, your AHJ will dictate that.

Drywells work great in sandy soil. So picture sandy Florida, you get a blast of rain then dry. The surrounding sand drains quickly, so the extra capacity in the drywell can then percolate out before the next blast of rain. There is no freezing where 3-4 months of the year there is very little to no percolation depending on depth.

 

[Calson]

Installation instructions are available online from NDS for the Flo-well. The fabric goes around the tank and is tapped where the pipes go through the fabric. The hole does not get the fabric. Easiest to get a few yards of 3/4" rock dumped at your place and wheel barrow it to the hole you dug.

Dry well like this one is the best solution for dealing with water off your roof and not sending it off to your neighbor's place and creating a problem for them.

 

[3onthetree]

Dry well like this one is the best solution for dealing with water off your roof and not sending it off to your neighbor's place and creating a problem for them.

I would flatly disagree. They are not the best solution, they are only successful with certain soil types, climates, and amount of rain. You are allowed to, and must be able to, drain your slice of land to other slices of land just as it was before it was sliced up and sold to you to build a house.

 

[Calson]

I would flatly disagree. They are not the best solution, they are only successful with certain soil types, climates, and amount of rain. You are allowed to, and must be able to, drain your slice of land to other slices of land just as it was before it was sliced up and sold to you to build a house.

My neighbor did what you recommend and diverted the water off his property using a French drain that concentrated the water going onto my property. If cost me over $20,000 to repair the damage and his insurance company had to pay for this. If I had gone for the damage in property value it would have been over $50,000.

By law, when you change the natural drainage you are responsible, period. Adding a building and pavement and downspouts alters the drainage and permeability that originally existed. Pretty basic and not that difficult for most people to understand.

So very American to pass problems onto others rather than taking care of them properly. I find this attitude and behavior too disgusting for words.

 

[3onthetree]

By law, when you change the natural drainage you are responsible, period. Adding a building and pavement and downspouts alters the drainage and permeability that originally existed. Pretty basic and not that difficult for most people to understand.

Actually you do not know the law then. You are allowed to drain your property, even your roof downspouts, patios, whatever the property improvements that are allowed by code, onto other's parcels just as natural drainage would occur. You cannot, however, create an excessive point load, or dump it right at the property line. This has been covered and litigated, much to what seems counterintuitive to what should be allowed, at least from the perspective of those downstream of the water.

I do not know your situation, but I suggest you replace your disgust with research. Google "drainage law."

 

[huesmann]

Actually you do not know the law then. You are allowed to drain your property, even your roof downspouts, patios, whatever the property improvements that are allowed by code, onto other's parcels just as natural drainage would occur. You cannot, however, create an excessive point load, or dump it right at the property line. This has been covered and litigated, much to what seems counterintuitive to what should be allowed, at least from the perspective of those downstream of the water.

You can drain as per natural drainage, but in general, you may not increase the quantity of runoff at each outfall point from your site, which means you either need to drain to a spot where it infiltrates, or to a storm drain.

Used to be nobody cared, but now stormwater regs are very specific.