Browse Forums Landscape & Garden Design 1 Dec 06, 2010 3:24 pm Hi all, I'm looking for some advice with regards to drainage, whether a garden bed will be suitable to "retain" water if need be or if I need to incorporate plan B. I've attached a very basic layout of the yard (sorry, best I could do with the time!) and will try my best at an explanation. To assist with the explanation...grey is driveway/path/footpath, brown is currently clay with weeds but will be garden beds and green is some nice new turf. There is very little slope on the property and about 100mm of turf underlay beneath the turf. With the driveway/path and turf both at a higher level, rainwater tends to pool in the garden bed making an impromptu water feature. The driveway on the left slopes downhill, so no dramas there; there's a small path which leads to the front door of the house and it slopes to the south-eastern corner and currently empties into the garden bed; and there's a minor slope on a portion of the turf towards the gardedn bed (which I could attempt to fix with topsoil over time). My thoughts so far...most of the pooled water is probably run-off from both the path and turf, so building up a garden bed will not only help absorb some of the water, but help move the surface water to another area if I design it correctly. However, my question is that if I dig out some more of the clay and put in about 200mm of decent soil, will the garden essentially "soak" up the water and put it to good use or will it remain a soggy mess and destroy any plants I put in there? I don't particularly want water pooling around the driveway/path and house because I'd hate to think what that will do to a clay foundation over time. So if it comes to drainage, this then creates another problem...I can't connect any piping to my existing stormwater system because it's charged (positive pressure), and the outflow to the street is essentially horizontal - cutting a hole in it will only make the flood worse. I had thought of placing some ag pipe and moving the water over to the eastern boundary, but if there's a lot of it then it will most likely pour into the neighbour's property and that's not an option. The only other solution I can think of is a stormwater pit at the lowest point of the garden bed - it wouldn't be connected to anything, it just simply becomes a big hole! So to make a long story short, I need some helpful advice and recommendations! Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Drainage options vs. Garden bed 2Dec 07, 2010 7:57 am I'm certainly not an expert but you definitely want the water to drain away from the house. Usually whatever is the lowest is where the water will sit/run to. Most people have raised garden beds which means the rain will run to the lower portion (e.g. lawn). Wet lawn is no problem as long as it doesn't get water-logged (needs air at the roots) and it shouldn't be walked over when soggy or it will quickly tear it up and make a big mess. Our block is dead flat in Melbourne and from the recent rains we had a mini swimming pool in the back yard where our turf is soon to be laid. It was gone in 24hrs so I'm not concerned that it will be an issue. Being in Sydney you shouldn't have too much dramas with too much water, but then all of the weather patterns seem to be changing. Second Time 'Round Re: Drainage options vs. Garden bed 3Dec 08, 2010 8:07 am I've noticed that while the water won't completely drain within a 1-2 hours, the majority of it does disappear overnight so I might go with the option of filling the beds with organic soil and have them raised above the level of the lawn. I've done some reading on drainage beneath a garden bed and while it would be beneficial in times of continued rain (such as the past week in Sydney), more often than not I don't think it will be required and may end up doing more harm than good to the plants. I will most definately remove some of the clay to create a slope away from the house, driveway and path and try to level the entire bed so that the water is dispersed over a larger area. Re: Drainage options vs. Garden bed 4Dec 09, 2010 8:35 am C&C, We had a similar problem with rain spilling directly from a downpipe at the front of our house. I built a garden bed there hoping that it would just run into the soil and disappear, just as you are contemplating, but the amount of water that came out of the downpipe stunted the growth of the plants that I had planted there. In the end we got a small 2700 L tank fitted to the side of the house and had the problem down pipe cut of and sealed and instead had the water run from the opposite end of the gutter into the tank. Problem is now solved and plants are growing quite happily. I'm sure you have a lot of water running into that problem area but it doesn't sound like half as much water as what we had, so I would go for building the raised bed. But when you take out some of the clay, I would make sure that the bottom of the bed is sligtly sloped toward the front of the bed, rather than clearing it out and making it all nice and flat. For extra measure, I would fill the bottom of the bed with 20mm road base (perhaps 5cm high?). We have massive drainage issues in our yard as we're not connected to the town storm water system and our block isn't big enough for a 20,000 litre tank. Best of luck getting your problem sorted out. My blogs: http://www.movingtotasmania.com.au - a resource for those considering relocating to Tasmania http://www.sarahandtim.com - my daily life and renovation blog Hi HomeOne, I'm in the midst of landscaping a cat run down the side of my house, and the recent rains have me wondering if I need to install some sort of drainage. I've… 0 12279 2 5842 I would find out how deep your clay base is and depending on the depth install a cut off drain which is more than a normal agi drain. Where the neighbouring walls is… 2 3147 |