How to Prevent Outdoor Flooding Plus Tips on Living Below a Retaining Wall That Floods

How to Prevent Outdoor Flooding Plus Tips on Living Below a Retaining Wall That Floods

Protecting your home from outdoor flooding is not just about choosing a house that doesn’t stand in a flood zone. Your outdoor plumbing needs to be maintained and inspected to prevent flooding around your home.

With summer on its way, the end of winter and spring is the perfect time to inspect your outdoor plumbing to ensure it’s ready for summer rains and storms.

how to prevent outdoor flooding

1. Ensure you have adequate outdoor plumbing to protect your land and house.

When QLD had their unusual weather event with cyclone Debbie earlier this year, which travelled down the south east coast and turned into a huge rain event (causing flooding all QLD schools to be closed for two days), I did a Facebook live video. In the video I told followers if they had concerns about the outdoor plumbing of their home and their stormwater needs, use their phone to take a video of where the water pools and travels around your home. This video can give a plumber vital information about the stormwater needs to your home and help the plumber design a system that will prevent outdoor flooding around your home.

2. Maintain the existing storm water drainage at your home.

Maintaining your existing storm water drainage should be a bi-annual job. This involves cleaning your gutters of leaf debris, chucking your hose down each downpipe and blasting away any back log of debris stuck in the downpipes. Remove the grates from your storm water drains and clear them with a hose as well. If you find the water builds up and you can’t get a good flow down the pipes, you will need to call a plumber with a jet rodding machine which will have more power than your hose.

3. Ensure all stormwater drainage is connected to a lawful point of discharge.

This means, the stormwater pipe needs to connect to a drain (make sure it’s stormwater, not sewerage) to prevent nuisance flooding and flooding to surrounding neighbours.

Living below a retaining wall

If your property is below a neighbour’s retaining wall, their stormwater drainage (which is mandatory when the retaining wall is built) must discharge into a lawful point of discharge. The drainage can not and should not overflow into a neighbouring property unless it’s from an unusual weather event. The drainage is usually installed at the time of the installation of the retaining wall. The owners must ensure their drainage system is maintained, following step 2 above.

If you are the neighbour below the retaining wall, it’s your responsibility to have adequate drainage for any water flowing onto your property. That can be rain, a rare weather event and even run off from other properties. The same can be said when living on a hill. If the run off of water flows down from the hill into your yard, it’s not the land owner’s responsibility to ensure drainage, it’s yours. It’s your responsibility to have adequate storm water drainage to prevent your yard turning into a swimming pool.

But here is where things can get tricky and disputes between neighbours can occur.

If a neighbour has adequate drainage (where the stormwater discharges into a a legal stormwater drain), that neighbour is not deemed liable for the water run off if it ends up running onto your property and causing damage. If it’s a continuous problem, you need to discuss the issue with your neighbour. The council deem retaining wall run off as a civil dispute. You can read more about what the council advise you to do here.

In Brisbane, you can call you local council if you and your neighbor can not come to an amicable agreement. But this complaint will be dealt with Built Environment and they will simply issue a letter to both parties.

If you are the neighbour affected by flooding from retaining walls, this is how I’d approach the situation:

1. Ensure your house has adequate storm water drainage to catch the overflow of water.

2. Video the water running down the retaining wall during a rain event to show as evidence to your neighbours.

3. Have a friendly chat to your neighbours about the situation. They can get defensive and claim it’s not their problem, OR they hopefully will look at their own drainage system and ensure it’s adequate.

4. Ensure you have the right flood insurance for your property. Read the fine print and make sure you are covered for all types of flooding – including run-off, rainwater and storm.

5. If your property gets flooded and damaged from the overflow, ensure you have those videos to send to your insurance company as part of your claim. This is where your neighbour will need to be concerned. Insurance companies can be ruthless. They will pay out the cost of damage to your property, but they will use those videos and possibly pursue your neighbour if it’s found they are at fault for the flooding.

6. If you are the property owner of a retaining wall where the run off is affecting your neighbour, do all that is necessary to prevent the civil dispute becoming a legal battle. The costs involved will outweigh the money spent on getting the drainage right.

Even after adequate drainage is installed, rare weather events can cause extreme run-off and flood damage. Understand this is part of living where you do with retaining walls. If you want to avoid all the above, buy a property on flat land, with no need for a retaining wall.

Have you ever had to deal with flooding caused by stormwater or a retaining wall?

If you enjoyed this post, you can read my post on how to prevent indoor flooding in your home.

10 Ways to Protect Your Home From Water Damage Caused By Internal Flooding