Need drainage and landscaping suggestions for side and backyard

[lijithwv]

I am seeking suggestions for a landscaping and drainage project around my home. I am at the very initial stage so as to have a plan in mind and then cater it with any special requirements during the home build. I have seen a few articles in this community with people struggling with water pools in their side and backyards.

My site is classified as P with underlying site reactivity as H2 - very highly reactive clay. So as much as I love to have a lush green outdoor space in whatever limited area I can have, I am also concerned about having proper drainage around landscaped portions in this clay site to avoid water pooling and subsequent slab damage. The site has a slope towards the front where the stormwater connection to the property is situated.

Here are the detailed specifications:

1. **Layout and Dimensions:**
- The side yards are each 1.2 meters from the fence.
- The backyard is 3.2 meters from the fence.
- I aim to lay a concrete apron around the home with a preferred width of 1 meter.
- Additionally, I plan to reserve 0.2 meters of ground along the sides for planting hedging plants to cover the fence (lilly pilly or a similar variety that doesn't grow excessively tall) or star jasmine on a trained wire frame *I am inspired by the star jasmine article in the community workshop  
- Similarly, I'd like to reserve 0.2 meters of ground along the back fence for hedging plants and ground cover, and allocate the 2 meters between the concrete apron and the hedge for a vegetable garden, fire pit area, etc.

2. **Drainage Considerations:**
- Given the concrete apron layout, it's crucial to ensure proper drainage to prevent water pooling or runoff issues.
- I need advice on how to incorporate effective drainage solutions into the landscaping design, especially considering the proximity of the concrete apron to the house foundation and property boundaries.
- Suggestions for drainage systems that can capture water on the surface itself (spoon drains or grated drain) rather than sub-surface drainage (french drain or agi pipes) would be preferred. Digging a trench for agi pipes might be difficult in the sides following standard widths and offsets? Also don't want a situation where this trench is overflown by some reason and the very thing that I am doing to protect the foundation will end up doing more harm!

3. **Plant Selection and Maintenance:**
- I prefer low-maintenance plants for the hedging and fence cover, particularly those that offer aesthetic appeal without requiring excessive pruning or care.
- Can you recommend specific varieties of lilly pilly or star jasmine or other plants that fit these criteria and thrive in the Melbourne climate conditions?

- The orientation of the house is south facing. So all of the fences will have mixed sun exposure

4. **Functional Spaces:**
- In the 2-meter space between the concrete apron and the hedge in the backyard, I envision creating functional areas like a vegetable garden, a fire pit etc.
- Advice on layout design (considering the orientation of the house), soil preparation, drainage and any additional considerations for these functional spaces would be invaluable.

I know it's a long post but thanks in advance.

[MitchellMc]

Welcome to the Bunnings Workshop community @lijithwv. It's wonderful to have you join us, and many thanks for your question about drainage and landscaping.

There is plenty to consider, and it sounds like you put a significant amount of thought into your plans. I recommend focusing on the individual elements while keeping the whole project in perspective.

I have concerns about running with surface-only drains as although they'll be great for collecting the runoff from the aprons, they will not assist with subsurface collection. A buried agi pipe not only collects surface water that drops through aggregate into it, but it'll also help drain any water that is subsurface. If you do go with surface drains it's important to ensure that these drains are properly sloped to facilitate water flow and prevent overflow. Regular maintenance to keep them clear of debris is also essential.

Allowing 200mm for your plantings is not really sufficient for plants like Lilly pilly's. If you like the look of Star Jasmine climbing over the fence, I would suggest that's a much more appropriate option. Apart from that, I would be looking at smaller plants to add interest to the space or container growing. You might like to read through How to plan a garden makeover, How to choose a screening plant and How to choose plants for your garden.

Another great place for inspiration is our Top 10 most popular side yard projects.

Given the clay-based soil, I'd recommend you consider container planting and a raised garden bed would be an excellent choice for your vegetable garden. Container gardening removes all the issues you'll experience with your current soil.

Please let me know if you have any questions.

Mitchell
 

[lijithwv]

Thanks for the response @MitchellMc .

Swapping out lilly pillies for star jasmine (at least on the sides) and container planting is a great idea. The vegetable garden in my plan was always in a container just because of the amount of irrigation it might require. But even the plants on the side yards can also be in a container as you suggested to minimise watering the clay soil underneath. 

I assume your concern with surface-only drains and sub-surface water is from factoring in the water from irrigation of plants, from neighbouring property and potential overflow of surface drains.

In that case what will be the best option for the side yards?

Option1:

Given the apron has to be 1m, have an agi pipe and trench in the next 200mm, fill it up with rumble and top it off with maybe some pebbles along the boundary. Then few containers evenly spaced with star jasmines that can grow on the fence.

This option will cover both surface water and sub-surface water from my land and even sub-surface water that might come from neighbouring property.

Option2:

Full width concrete up to fence on the sides with grated drains maybe at 900mm from the house and sloping on concrete towards these drains from both sides. Then few containers evenly spaced with star jasmines that can grow on the fence.

This option will cover only surface water but there is no possible sub-surface water from my side yard as it is fully concreted. Potential sub-surface water might come from neighbouring property which is not dealt with.

Which drainage option will be better in the long run in terms of maintenance?

[MitchellMc]

You're correct about my assumption, as I'm concerned that your soil could become saturated without subsurface drains from runoff from adjacent properties and rain hitting the area directly, @lijithwv. I think either of those options would be suitable.  However, those aprons must be graded sufficiently away from the house so water does not pool on them. Maintenance-wise, the surface drains are quite easy to clean out, but if there are overhanging trees, they could become quite the burden, whereas subsurface agi lines rarely need to be cleaned out.

Mitchell

[lijithwv]

Thanks @MitchellMc . I will keep the option1 with apron and agi drain as the primary solution. Only thing I am doubtful about is the limitation of space for all these in the sides given there will be fence posts along where I intend to put the agi drain. 

[MitchellMc]

100mm agi-line with a 100mm wide gravel-filled trench would be ideal @lijithwv. Or, if space is limited, you could drop it down to 65mm agi-line. 

Mitchell

[lijithwv]

Thanks @MitchellMc . I will keep this thread updated with how I go and if any further questions. 👍