backyard flooding with the rainwater collection system

[chandrika]

Hi There 

I have problem with my back yard- water collecting pit which overflow's during Rain and floods the sourrouding area . Our land is sloping to the back. Back yard pit is connected to the front via Pipe against the gradient. There is no pump at the back pit but there are two pumps in the main pit at the front,they pump out the storm water  from the front pit to the main road.

With heavy rain our back yard is very soggy and around the back yard pit water stagnates for couple of days.

Can not walk with out gum boots far end 1/3 of the back yard.

I have spent lot of money on plumbers to check the existing system ( scanning & ect....) just in the past 3 months. No proper solusion given.Out come is all pips are clear, front pumps are working well with their valves.

But there is  back flow the the back pit because it is pumping to the front pit without a pump   against the natural slope of the land. 

Please give me the best solusion 

1. install a pump to the back pit?? ( plumber says it is too small to have a pump ? 

2. install a Drain well ? at the far end of the land towards the slop??

3. french drains ??

Thnk you 

Deepa

[JacobZ]

Hi @chandrika,

Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Is it possible to get some photos of the backyard? While the plan you have provided helps, it is a bit hard to come up with solutions based on it alone.

It sounds like you might be dealing with some heavy clay soils which are inhibiting the water's ability to naturally drain away. A combination of french drains and a soak-away (drain well) might be the solution, but it is hard to tell.

Allow me to tag some of our knowledgeable members to see if they have some thoughts, @Dave-1, @Noyade, @Nailbag, @TedBear.

Once you've provided some images of your backyard and the pits you've mentioned, I'd be happy to offer more specific advice.

Jacob

[TedBear]

Hi @chandrika from what you describe, the connection between the front (higher) pit and the rear (lower) put will be adding to the problem, not solving it. It sounds like the water may be filling the front pit then flowing to the back pit. There is no way the water will flow from rear to front if it is against the gradient unless it is actually pumped. Without a pump, I'd suggest that you disconnect the front from the back pit, install a second pit (or drain channel) at the back area and connect those two together instead. Hopefully the two back area pits will cope with the water, especially if they are not also getting water fed into them from the front pit, which is what I am guessing is happening at present.

[Dave-1]

Afternoon @chandrika 

I am a little confused with the description of the water pits in the front and the backyard and the slope you have. The small pit is overwhelmed adn pumps to the big pits is how I am thinking it is?

Sorry I cant make out the small print on your picture 😕 

The small pump is trying to push water all the way against the slope to get to the big pits out front, If its trying to push 20m plus of water up a hill that would explain it. What is the slope of the yard? Does it drop 1m every 3m or 1m every 5m?

I have some ideas but will wait for some pics as I could be wrong what the issue is.

Dave

[Nailbag]

Hi @chandrika 

I used to live on the side of a mountain and suffered greatly from a similar situation. with massive run offs and, underground streams, which resulted in also flooding parts of my home. I'm with @TedBear on this and install an additional pump, even if it means swapping out the pit for a larger one to suit. I used a submersible one with an integrated float as opposed to any external one. As soon as the water level rose to around 50mm it was automatically pumping water. Inn y case it was about 90% successful, but still had the occasional issue in consistent heavy rain.

Nailbag