OT: French drain

It's rare to install one for a shed, most sheds don't even have foundations, they rest on skids.

I hope this thread proves productive... I have similar needs but simply need to drain to street. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

I don't think most folks are aware of the *volume* of water that routinely comes down in such short amounts of time!

(Nor the shittiness of the soil! :> )

I have never seen a drain run to a sump. The only sumps I have seen are under the floors of houses, typically with an opening where a pump can be installed if needed. Every drain I have seen runs away from the structure to a suitable *other* drain like the street (via a more sloped portion of the yard) or stream. I take it this yard is truly flat across it's full size? If you can just get the drain to a sloped portion of the yard the water can flow on the surface.

I'm not sure what you mean by the term "shade". I assume you mean to block particulates from entering the drain. I've never seen anyone use filter cloth. I would expect that to silt up quickly and block the flow. I have not seen anything covering the entry to the drain. The ones I have seen are really catch ditches to prevent the flow of water running off a slope from reaching a house. So they are simply filled with gravel and covered with a layer of sod. This mostly prevents continued moisture from reaching the house rather than stopping downpours. Are you thinking of leaving your drain uncovered so that it will be visible?

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Rick

We get all our annual rain in one hour ;-) First thing I did when we moved here a year-and-a-half ago was install rain gutters. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

At times, it sure seems that way! :-/ When I first moved here, I used to think people were "odd" when they would "drop everything" to watch it rain. "Cripes! It rains ALL THE TIME!" Well, perhaps in *other* places, that was true... but, not here. And, nowhere near as spectacular! E.g., Denver it rains at 4:30P for 30-45 minutes -- like clockwork. Florida it rains, hard -- and you can almost see the water going back

*up* (evaporation) as soon as the rainfall ends! Here, it just hammers you until it's done.

We have watched the neighbor behind us replace his gutters every year or two as a storm will, eventually, exceed their capacity and tear them off the facia boards ("frontier style" house -- so all the rainwater comes off the *back* of the house). He just keeps replacing them...

If the roof is *perfectly* flat (left to right), you could probably get gutters to work, here, with a multitude of downspouts. OTOH, if the roof has imperfections causing water to favor certain spots to fall to the ground, then gutters don't cut it. E.g., there are spots where the water flows off our roof in a *sheet* and "flies" more than a foot beyond the drip-line of the roof. (i.e., it would jump *over* a gutter without even touching it!)

Have you worked the numbers for your home to guesstimate flow rates, etc.? A 1/2" event is ~1000 gallons. Over the course of an hour, that's

16G/M flowing "to the street". If it comes down in 30 minutes, double that. I.e., you're talking flow rates comparable to 3-5X the rate at which you fill your *bathtub*!

Our lot is relatively flat in all directions (I brought in many tons of topsoil to "fix" this when we moved in). So, getting excess water *off* the property *to* the street, out front, means very little net pitch to a (gravity fed) drain pipe. And, over that long a span, it would still have to go *under* the sidewalk (otherwise, there's no net pitch!) and *through* the curb to street level.

One neighbor has done this (cut the concrete curb, installed a protective metal grate so vehicles can drive over it, and routed the drain pipe to this point -- under the sidewalk). But, most of his yard is swimming pool and pooldeck (with built in drains) so I suspect he has much less water to "shed" (the pool eats much of it).

I figure it is probably easier/safer to let it pool in a sump and "actively" move it -- *push* it instead of letting it take its sweet time getting from here to there. This should also make it easier to maintain: to strain all the yard debris that will inevitably make its way through the gravel, etc. to clog the drain.

[Of course, if I can move it at will, then it makes sense to move it to a storage container. OTOH, even a 2000G tank would overflow in less than a week during Monsoon! You'd need a swimming pool volume -- 10,000G -- to capture just the stuff that falls on your roof in Monsoon, then again with Winter rains! That, of course, is the problem in the desert: you get it ALL in one shot, so can't make effective use of it!]

I grew up in WV where, in the summer, it rains at 2PM for 15 minutes, the brick streets steam, and the humidity is 95% and the temperature

As for stopping and watching the rain... when it lets loose we break out a bottle of wine and go out on the patio and watch ;-)

Mine is ~50% on the back (*), 6" gutter with two downspouts... seems to be holding, front load is split into many sections, so no problems expected.

(*) Around 1200 sq.ft. gathering area, so 1" rain in one hour is 100 cu.ft. or ~750 gallons, or ~12.5 gal/min

[snip] ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

Yeah, I am amused by folks who leave in the summer "because it's so HOT!"... and, spend it in places like Chicago, etc. Cripes, the humidity (there) is STIFLING! There's only so many showers you can take in a day before you start getting tired of being *in* the shower!

I just go out and get wet. Another thing that is different: elsewhere, folks act as if the water is going to "hurt" them... avoid getting wet, pull out an umbrella at the first few drops, etc.

As long as I remember to take off eyeglasses (so I don't have to clean and dry them, later!), it's just *water*...

And, when you enter a building wet like that, folks will perk up as they ask, "Is it *raining*?" and then rush off to find someplace where they can watch the rain.

Here, it's double that as it all comes off one "side". So, you see those sorts of rates for 1/2" of rainfall -- double that for the shorter/harder storms.

[10, 20, 30G/min is a lot more water than most folks can visualize. E.g., a bath draw is typically 5G/min and that's under pressure. Imagine coaxing water to flow out of a "nearly level" pipe at that rate!]

A neighbor just put in a 3" PVC pipe from backyard to street, ~70', no more than a foot drop.

I queried, "Is that big enough"? "Sure", he said. I can't wait >:-} ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

We couldn't get by with that, here. Figure you need to go down a foot to get "below grade". Then, at least a 6" drop (pitch) to the low side of the drain. Then, *under* the two footers between the back and front yards (i.e., you're already *below* the level of the street), then some additional pitch to make the trek *to* the street.

I imagine your neighbor's will *drain*; the question is, will it stay ahead of the falling rain or require some time to catch up? Esp in heavy downpours. Once the pipe starts to back up, the "catchment" becomes a nice little "swimming puddle"!

[Has he taken any measures to keep things from crawling *into* the drain? He might be chagrined to discover a packrat has opted to use the cozy little cave for his "stash"! :> ]

Yep, that concerns me as well. Having had same occupy my DCS barbecue during the January rains :-( ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

I have some clay sections that dont drain well so I'm thinking along these lines also. Lots of online information on building them. Lots of variants. I've seen pipes for sale at Lowes (I think it was) with the rock and fabric already in place. Just dig the trench and place the pipe. Generally it is trench, enough fabric to wrap completely, gravel, pipe, gravel, fold over fabric, cover trench.

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Chisolm 
Republic of Texas

I know the "basics". What I'm concerned with are the things that are NOT said... the issues that come up down the road (because you forgot some little "triffling", etc.).

E.g., backfilling with soil is probably less desirable than pea gravel. In either case, when the drain is (briefly) overloaded, you've got an unstable surface (to walk on, etc.)

We have hardpan/caliche, here. So, just digging a trench and laying in stone/perforated pipe means water will accumulate *in* the trench, below the lower surface of the pipe (cuz the "soil" won't absorb it). I'm not keen on having water near the foundation (termites, coccidioidomycosis, etc.) so I figure I need to do more than just "dig a trench" (perhaps shade the underside with sand, etc.).

At the very least, I'm sure I should anticipate needing to "flush it out" at some point in the future -- without having to excavate to re-expose the pipes.

If it was something that was easy to screw up and *do-over*, I wouldn't mind... :>

I think most mammals figure out pretty quickly that a pipe doesn't drain well enough to serve as a home.

About the various drops in the line, I think that as long as the outlet is sufficiently below the inlet the pipe will drain ok. I've seen 1/2 inch hose with a few feet of head drain a hot tub pretty durn quickly once it is full of water.

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Rick