Unless you are living in the desert somewhere you have probably experienced some problems with water over the last few months! We have spent so much of the last few years talking to clients about water harvesting and better water management, the shift to what to do with the excess is a bit of a shock!
Clearly any areas of standing water are likely to be problem, do take note of where the problems are – do you have wet areas in the lawns, or are parts of your patio knee deep at times? Are your plants drowning and failing (lavender, any grey leaved plants and yew in particular hate being wet)? Are there drains that simply can’t cope or are there no drains in the right places? Is the rain washing huge volumes of soil and debris onto your patios and paths, or gravel from your drive out onto the road? There are different approaches to these:
What to do about it
Well generically there are 4 options:
- Check existing drainage solutions are working:
- Ensure that all drains, grilles and slots are clear of debris, leaves and soil. If the water is going to a drain and then sitting there it is likely the drain is blocked or (in the case of a soak-away) it simply can’t cope with the volume of water in which case look at the options below
- Your hard standing areas should have been laid with a fall (i.e. a slope) towards either a drain or a free draining area – if not then you will almost certainly need to rectify this – water can’t flow uphill. A common problem is not having any drainage in sunken areas (fire-pits and sunken seating areas) – landscaping 101 is “where is the water going to go”. If this is the case for you then the first option is a soak-away, although in clay or high water table areas this will not work and you may need to consider a pumped solution depending on the geometry of the plot.
2. Divert all or some of the water elsewhere:
- Sometimes a simple gulley can take water from a slope across to a free draining area avoiding your drive/patio/house, a barrier/wall or bank might assist with this. If you have steep banks leading to a path or patio you can consider a raised edge to the patio to stop the run off, or plant more heavily to stabilise the banks – ground cover can be very effective and attractive too.
- Check water sources dropping onto your patio – sometimes downpipes and guttering are pouring huge quantities of water directly onto the surface that could be diverted to your normal rainwater system or to a free draining area – lawns and flower beds are your best bet.
- If water is being channelled by your paths, steps or driveway, see if an intercept gulley can be put in to take some of this off before it becomes a problem – slot drains are pretty invisible in hard surfaces and there are many different types available although easier to install at the time the patio goes in.
3. Create better drainage within the areas in trouble:
- In lawns the usual approach is to add land drains of some kind – usually a channel is dug to put in a slotted pipe that can channel water away – this is pretty disruptive but usually effective as long as there is somewhere for the water to go (a lower level to run off to or a soak-away)
- In flower beds or planted areas it can be a case of digging the affected areas to break up underlying clay and adding grit and organic material to the soil to break it up – this can be back breaking but is usually effective. I try to be selective about this – if preparing a new planting area then it may well be worth doing the whole bed (using a digger or rotavator if possible)
- If you have a clay layer that is preventing drainage you can sometimes perforate this with a spike – (anything will do – a road pin is good!) it’s a bit labour intensive but spiking lawns does almost always improve aeration and percolation and you can extend this into flower beds to
4. Work with the water creatively
- In permanently wet areas I aim to plant to suit – willows, gunnera, iris and a host of wonderful bog plants will be your friends! There are few things as amazing as a well thought out bog garden – if space allows add a natural pool, or if it tends to dry out in the summer put a liner underneath with some holes in it just to keep the moisture through the year
At the design stage
Its obviously easier if you are thinking about this before you have a water problem – part of any landscape design should be a drainage strategy – this doesn’t have to be complicated and should work with the drainage scheme for your existing or new house/extension.
Typically you need to plot in where the water is going to go across all the hardscaped areas, think about drain types (there are lots of options – slot drains don’t have to be an eyesore), all level threshold areas need some serious drainage to ensure you don’t get water in the house, all patios and hard paths need to drain to somewhere and any sunken areas need consideration.
Hiding drains already there or planned is another key part of landscape planning – manhole covers can be very conspicuous and can prevent planting where you wanted it so getting these planned in as part of the landscaping is a much better approach than working around them afterwards!
There are regulations now on what you can do on your front driveway to improve overall drainage and reduce the amount of water pouring onto our roads. See Susdrain national standards for sustainable drainage
In summary this is pretty simple – use permeable materials where you can – gravel is an easier option than a hard paved drive (and cheaper) but there are permeable block-paving options, and resin bound gravel is permeable too. If you can’t or don’t want to use a permeable material then you need to create drainage to prevent run off onto the road – slot drains, gulleys or similar will be required. These need not be unattractive. In the example below we used a gravel drive, but since it was steep and facing the house, we added a decorative cast iron grilled slot drain system between the drive and the front door paving.
If you have a gravel drive it needs to be edged – in the example above we used granite setts, but there are plenty of options – it is worth looking carefully at the edging as this sets the tone of the space – even when using very basic block work paving a sett edge make a massive difference. Even tarmac looks pretty good with a neat edging!
If your driveway slopes at all down towards the road you will want an apron of hard material of some kind to prevent the gravel washing out onto the road.
There are some creative approaches to water management, using natural swales (temporary streams and ditches) and bog gardens which are my personal favourite – the one below we created for a client who has multiple natural springs in his garden and needed a better solution than periodic flooding of a large chunk of space.
If you fancy something more creative than modern slot drains, this example of early 19th century drainage is rather splendid
Whatever the solution, it is worth thinking about before it becomes a problem if possible, but if you already have a problem do get in touch to discuss.
Cool Gardens are an award winning team of Garden Designers, Landscapers and Garden Maintenance Operatives working in Buckinghamshire. We are currently working locally, and welcome enquires for design, landscaping or garden maintenance. Contact us here