Forum
« smaller bathroom fixtures What do you actually need permit »
April 22, 2009
Gutters and more
This is a long one, so get comfy folks. We own a three story brownstone in BK. Like many of you, when we had tremendous amounts of rain, storm water used to back up through the main trap of the building and into our basement. I'm talking a LOT of water. Disgusting. We were told that the location of our building at the intersection of several storm drains was to blame. Our neighbors have similar problems. At the advice of several plumbers, we installed a check valve in the waste line. Thankfully, no more storm water in the basement. However, where am I supposed to send the roof water? Currently, the downspout is improperly rigged to direct all the water from the roof onto the back patio from where it drains, slowly, into the waste line that runs under the building. When we get a lot of rain, the patio floods and water leaks in through the basement door. There is also a small extension off the first floor and honestly. I'm not sure where that roof water goes. There is a small drain on this roof that I suspect hooks up to the waste line somewhere inside the building. The real dilemma is, if the check valve is engaged, temporarily blocking water from coming in or out of the building, what is the best way to deal with the volume of water coming off the roof? Is it possible to create a system where it drains into the waste line but can be diverted into the yard if that line is full? I know a few other people on the forum have confronted this problem. What was your ultimate solution?
We'd appreciate your advice.
Comments
A thought the purpose of a check valve was to allow the water to flow out to the main sewer line but not back-up in the opposite direction.
Posted by: newsouthsloper at April 22, 2009 1:30 PM
We had a very similar problem - run-off from 2 roofs and then back-up from the street. We have a manual valve to stop flooding from the street coming into our cellar laundry sink and bought 2 rain barrels to catch the roof water. Monday night's deluge filled both barrels and then the hose to drain the excess was gusing water into the middle of the back yard. Nothing the yard couldn't handle, and no water in the cellar. If you have any interest in gardening, or even in watering plants/yard for free, rain barrels might be useful. You can buy a bend-able spout thing to put on your drainpipe to aim the water into the barrel.
Posted by: mshook at April 22, 2009 1:39 PM
PS, catching the water in this way presumably helps lessen the pressure on the sewer system at these times and hopefully reduce flooding in other places, too.
Posted by: mshook at April 22, 2009 1:40 PM
We have been dealing with a similar problem since we moved into our brownstone 16 years ago. We also installed a check valve, which snaps closed when the street sewer water starts to back up - this was the recommendation by the City. Our downspout goes directly into the back of the house and into the sewer line (we are told that is the code requirement). When the trap shuts - we were having rain water back up into the garden level bathroom toilet and overflow. Like you, it is A LOT of water. When a check valve was placed inside to keep water from flooding up -- caps on pipes would blow and flood the cellar. We've had sump pumps put in (which cannot work until the rain stops because the trap is still shut), you name it. The latest suggestion is to install a diverter on the back downspout and have the water go out into the back yard - but this is actually against code, as it could flood our back neighbor's yard. I will be interested to hear other's thoughts...but it is a common problem when we get these hard, fast rains. The City has assured us that the City pipes are too small to accommodate the water rushing down the street during these...but that they will not be replaced in our lifetime.
To the above post: the trap slams shut when water from the outside is pushed up against it - there is nowhere for outgoing water to go.
Posted by: parkslopemom at April 22, 2009 1:52 PM
I thought code was to not have the rain gutters go straight into the drain, because it does overflow the sewers during rains like we had the other night.
Also RE the rain barrels: I like this idea, but wonder what you do about mosquitoes throughout the summer. Is there a fix for that?
Posted by: corolla at April 22, 2009 2:44 PM
I keep mosquito tabs in my rain barrels, birdbath, etc.
Posted by: Arkady at April 22, 2009 3:09 PM
We used those pellets last year, but did see tons of larvae in the water. I did recently read that those pellets somehow inhibit the larvae from maturing, so maybe that was ok, but we thought they weren't working. I did some more reading online and found that a layer of oil floating on top will prevent them, too, so we're trying that now and we'll see how it goes.... I also read that using those pellets in water you use for gardening may mean you kill friendly bug larvae (I think they are bacteria which eat larvae).
Posted by: mshook at April 22, 2009 7:36 PM
Thanks for all the ideas everyone. To the above commenter 'mshook', may I ask how large your roof is? I'm interested in the rain barrel idea, but as our roof is pretty large, maybe 18' x 40', I wonder if the barrels will fill up in a matter of minutes and then the yard has to handle the rest. It already tends to be a bit soggy in the wet weather.
Posted by: sourgrapes at April 23, 2009 8:36 AM
Assuming my math is correct (Big Assumption):
18' X 40' = 103,680 square inches
103,680/6 inches per 1" cube = 17,280 cubic inches
17,280 cubic inches ~ 75 gallons per 1 inch of rain.
Does this sound right?
Posted by: newsouthsloper at April 23, 2009 9:01 AM
Hmmmm.... I would have to be at home to give you a real measurement, but my estimate would be: garage roof - 35'x 13', house - 25' x 17', plus we don't know if our neighbour's roof also drains onto our garage (water collects and drains off the garage, and off the main roof down onto the same garage drain pipe). We have 2 60 gallon rain barrels, one of which was half full at the beginning of monday's rain. At least with the overflow hose we are now able to direct whatever there is that the barrels can't take. And the dog sure liked sticking her face in it!
Posted by: mshook at April 23, 2009 9:48 AM
1 inch of rain on a 1,000 square feet roof yields 623 gallons of water.
18' X 40' = 720 sq ft
(720/1000) * 623 gallons = 448 gallons of water per 1 inch rain.
mshook,
With 880 sq ft, your looking at almost 550 gallons per inch of rain. Your 2 barrels setup can only 'handle' 1/4 inch of rain. Anything more than 1/4" and your dumping it back into the yard.
The overflow really should be connected back into the sewer line and should be 3 inches. I've seen many designs where the overflow is simple connected to a garden hose. That's a flood waiting to happen.
I did a setup for a friend of the family that consisted of 4 60 gallon barrel connected in series for a total capacity of almost 240 gallons. They have a pretty large garden and wanted to harness the water for later use.
Here is a rough idea of what i'm talking about, http://www.aquabarrel.com/images/Double%20_Barrel_Kit/link_2barrelsIMG_0157.jpg
Posted by: Colonel Steve Austin at April 23, 2009 11:05 AM
Perhaps too expensive, but installing a green roof will dramatically cut down your storm runoff - the plants and growing medium soak up the water which takes a longer time to leach into the drainpipe, net of plant usage and evaporation.
Posted by: wyckoff at April 23, 2009 1:39 PM
A green roof is our next step. The extra run-off has not been more than our garden can handle, even when we only had one barrel.
Posted by: mshook at April 23, 2009 2:02 PM
Post a comment
Please be patient while your comment is published. It may take a moment.