View Full Version : Draniage issue-possible rain garden??

08-26-2009, 10:30 PM
Talked to a new customer today and he has run off coming from his neighbor's driveway, his roof, and part of the turf in his front yard. See photos below. He has put out the ugliest stone possible (large gravel) through the area where the water flows.

He said some other guys said they could make a french drain into a gravel pit in the back yard, then sod it. Frankly, there is too much water for a small gravel pit to control the amount of water. If that were to work it would need to be a huge hole in the ground that would cost way more money!!

There is no good elevation change off of his property to the front or the back.

I was thinking of maybe putting down river rocks in the place of the ugly gravel and planing the area to make it into a rain garden area.

If the area is graded differently can this area just be sodded for control?

Any advice is always appreciated

White Gardens
08-27-2009, 10:18 AM
If you've got a place for the French drain to actually drain out, then that would be my suggestion.


08-27-2009, 11:35 AM
I'd also french drain/cutrain drain it, that wooded area to the rear appears unused, and though there is a risk to the trees with too much water if you pipe it into a sizeable pit that would be limited. Sometimes a smaller pit goes further than you think. Figure out how many sq ft of the neighbors drainage is affecting his property, then go to NOAA for average rainfall stats, take your sq ft number and multiply by the average rainfall to see how many cubic inches of "pit" you need to handle an average storm., depending on soil conditions and how well the pit will perc add a CYA percentage. Meaning if it's heavy clay go much larger than required, if it's loam and will drain well, not so much, but still enough to handle some heavy rain. This set-up and these calculations have served me well in this area. And now my disclaimer, I'm no engineer, geo,hydro or otherwise but was given this method and simple version of where an engineer would start with a formal drainage plan............

White Gardens
08-27-2009, 11:43 AM
One other thing that I thought of is that around here your property can't drain into the neighbor's property,

If there are codes similar to this in your area, then it might be the responsibility of the neighbor and not your client.

Just looked at the property on the other side of the issue and it looks to have a swail (SP?) or ditch in that area. You might want to talk to them also and see if you can trench through their yard to make the french drain exit without a catch basin or pit.

Solving the problem for one property might not solve the whole issue.

08-27-2009, 01:08 PM
Hey BTW whats a rain Garden?? And White raises a good point, if elevations were favorable I'd be inclined to pipe it to daylight at the curb. Since you say thats not an option you're looking at a drywell or cistern. Some towns around here want a drainage plan for any of this kind of work, I had one in Paramus where I could easily have daylighted gutters to the curb but town insisted on 1 1500 gal tank in rear and a 1000 in front for about 1800sqft of roof, no ground drains. Average rain about 1/2 inch per event. Total overkill and added thousends to the work, bigger machine, lots of gravel.....it was silly.

08-27-2009, 05:19 PM
There is no good elevation change to open it to day light at the curb and It won't work to day light it in the back where the trees are either. That would just move the problem, not solve it.

Rain Garden: A rain garden is a garden which takes advantage of rainfall and storm water runoff in its design and plant selection. Usually, it is a small garden which is designed to withstand the extremes of moisture and concentrations of nutrients. Rain gardens are sited ideally close to the source of the runoff and serve to slow the storm water as it travels downhill, giving the storm water more time to infiltrate and less opportunity to gain momentum and erosive power.

I'm surprised so many are unsure of what a rain garden is...

There is easily a few hundred sq. ft. of surface water coming from the neighbor's roof and driveway on the left. Look how the rocks on my client's yard goes right up to neighbor's driveway.

White Gardens
08-27-2009, 11:16 PM
Oh, I know what a rain garden is.

Even in the first diagram, there is still a large hole you would have to dig.

In your pics of the property, it appears that the neighbors have a lower elevation and ditch going into the tree line.

If you can, and if I'm correct, then you could cut your drain across the other property and make it exposed to daylight.

All you need is a 1 percent grade to accomplish this.

Not only could you make money off the needs of your current client, but you could up-sell the neighbors and get their business also.

Everyone wins, and when your done, you've added property value to all three houses.

08-28-2009, 02:20 PM
no one has mentioned a dry creek bed design... acts as filter system during heavy rains...most states now give rebates if you use rain harvesting on your yard