Small yard roof drainage question

by Kara
(Chicago)

I live in a large city and have a small fenced yard on the corner of two streets. I am in the process of grading my yard away from the house (years of erosion have made it grade towards the house. The backyard is done- graded away and I have noticed that water runs away pretty effectively.

But here's my problem. I have a flat roof that has one large gutter that runs all the water into the side yard (narrow strip along side the house about 6-7 feet wide). Because we live on the corner right now the water runs right on to the sidewalk outside our fence and makes a complete mess in the winter when it freezing (think major ice slick). We are trying to figure where to run all of this water (we can just drain it into the back yard because of the way our sidewalks in the yard are laid).

I don't want to run it too close to the house but I'm thinking of shooting the gutter alongside the house-slightly angled to sidewalk. Any ideas on how to maximize drainage? Should we sink the gutter into the ground and run a drainage pipe through the side yard? The problem is that most examples show that gutter coming out somewhere and we can't do that in our yard...

Any help would be much appreciated- i hope all of that made some sense!
Kara

ANSWER

Hi Kara,

When you want to lead water somewhere, it has to flow from a higher point to a lower point. Sounds obvious, right? But to have it work, you need to know your elevations, particularly in situations where the slope is minimal. This will tell you exactly what your options are.

I understand what you are trying to do and your obstacles. If you run the leader pipe along your house and angle it to the sidewalk, I don't know if this will solve the problem or just create the same problem elsewhere. In addition, you need enough pipe pitch.

If you lead it underground to your back yard, it must exit somewhere, and this exit point must be at a lower elevation. So this is possibly an option depending on what the pitch is in the back yard.

If you could get me some elevations, I can provide you with suggestions. If you can't do this, perhaps you can get a landscaper to do it for you. At the least, it would be best to have the grades at your house corner where the leader pipe extends in the photo, rear back house corner, and property line elevation straight out from the rear house corner. More grades would be even better, such as sidewalk elevations in various places.

I can then determine the pipe slope from the front to the back and see if there is enough pitch so that the water will flow. Also a photo of your back yard would be great.

An alternative solution would be a drainage pit, but this must be located far from your house, and if your property is small, I would not advise it.

You can always contact me via my Contact Form too for email correspondence.