Connected water tanks to gutter => Gutter overflowing in heavy rain?

Forums › Home Workshop DIY › Connected water tanks to gutter => Gutter overflowing in heavy rain?

1 | 2

BlargHonk

176 posts

Master Geek
+1 received by user: 131

#3192252 8-Feb-2024 08:55

Def put a leaf diverter in above the Marley twist. They will stop all the gunk getting into your tanks and provide an overflow point if required.

It might also pay to get up on a ladder and check out all the support clips for your gutter. Check they are all still attached and spaced at 500mm or less.

boland

559 posts

Ultimate Geek
+1 received by user: 87

#3192358 8-Feb-2024 11:37

tweake:

don't believe, measure.

sorry i don't have time tonight to look into it but can you get pic/measurements of the whole system. you mention both ends? got two downspouts? really need layout and size of roof feeding it etc. i notice the gutter is the higher flowing version. off the top of my head 80mm is probably ok if there is two, but the center should be the high point. it sounds like they have the slope the wrong way, maybe intended to have a single big downspout in the middle.

the adapter thing looks highly restrictive.

i would fix it asap.

Pipe size is indeed 80mm, there are two downsprouts. I checked with a level, but it's not accurate enough to tell if it's on the correct slope.

While I think the adapter is indeed restrictive, it still shouldn't overflow in the middle. Further to that, there is always a lot of dirt in that gutter. After ~6 months of not cleaning it even has plants growing in it.
Other gutters in the house are fine, I initially thought it was just the position as it's closed to the bush.

Replacing the adapter will probably help, but I think I can better spend the money on getting the gutter checked out & adjusted if need be.

First thing I want to do is install an overflow in the watertanks as that should increase the waterflow through the adapter using this

tweake

2641 posts

Uber Geek
+1 received by user: 1137

#3192574 8-Feb-2024 18:43

boland:

Pipe size is indeed 80mm, there are two downsprouts. I checked with a level, but it's not accurate enough to tell if it's on the correct slope.

While I think the adapter is indeed restrictive, it still shouldn't overflow in the middle. Further to that, there is always a lot of dirt in that gutter. After ~6 months of not cleaning it even has plants growing in it.
Other gutters in the house are fine, I initially thought it was just the position as it's closed to the bush.

Replacing the adapter will probably help, but I think I can better spend the money on getting the gutter checked out & adjusted if need be.

First thing I want to do is install an overflow in the watertanks as that should increase the waterflow through the adapter using this

the adapter has to go. you simply cannot have restriction especially as the 80mm is borderline (if i recall correctly).

i think the 200l tanks are to small to be useful. water requirements for the garden are pretty big.

i would have installed a 1000l maybe 2000l and used half of it as a detention tank. that also means you run the downpipe directly in and out of it.

leaf diverters, as you have a storm drain setup, putting leaf diverters in will lower the pressure you an push water into the storm system. that can mean your neighbors will feed into the storm drain but yours won't. whoever is lowest is worse off. if you had a detention tank, you can have the overflow go to your overland path and not pour water around your foundations. thats the problem i had, gutter and downpipes overflow and flowed water into the foundations (and into the garage). with the dentition tank that overflow is pipe to the lawn and goes down to the creek.

i would seriously look at how the whole storm water system for the house functions.

RunningMan

9186 posts

Uber Geek
+1 received by user: 4840

#3192577 8-Feb-2024 18:57

boland:

First thing I want to do is install an overflow in the watertanks as that should increase the waterflow through the adapter using this

That will do little if anything. The feed to that tank is trival compared to the rest of the downpipe, Those diverters that have a small bore hose to the tank present a significant restriction to the downpipe. They've usually got a 10mm lip or thereabouts around the inside edge of the pipe. Doesn't sound like much, but doing the maths on an 80mm pipe, that reduces the cross sectional area to just over 50% of the original which will have a massive impact on water flow.

boland

559 posts

Ultimate Geek
+1 received by user: 87

#3192607 8-Feb-2024 20:34

Thanks all for your input. Yeah, I'm not sure the overflow on the water tank will help.

I guess this goes beyond what I can fix myself, and I don't have the time at this stage. I'll ask a plumber to come over for a quote.

RunningMan

9186 posts

Uber Geek
+1 received by user: 4840

#3192614 8-Feb-2024 20:45

There's a picture on this listing of how those diverters work. They work because the water hugs the interior surface of the downpipe until there is a significant flow, but you can see how much they restrict flow.

You might find that removing one of those diverters is enough to fix the problem, but you're still going to be below the original design flow spec. You could just join those 2 water barells together off one diverter, or move them to a downpipe that has less flowing to it (sounds counter productive, but should still be enough to fill those small barrells quickly).

Samsung

Shop now on Samsung phones, tablets, TVs and more (affiliate link).

boland

559 posts

Ultimate Geek
+1 received by user: 87

#3192615 8-Feb-2024 20:52

RunningMan:

There's a picture on this listing of how those diverters work. They work because the water hugs the interior surface of the downpipe until there is a significant flow, but you can see how much they restrict flow.

You might find that removing one of those diverters is enough to fix the problem, but you're still going to be below the original design flow spec. You could just join those 2 water barells together off one diverter, or move them to a downpipe that has less flowing to it (sounds counter productive, but should still be enough to fill those small barrells quickly).

Thanks for your insights, makes sense. Yeah, just removing the diverters is not sufficient. We only have them for emergency storage and for gardening, but I'd like them to stay topped up in case of an emergency or if we run out of water here in Wellington.

On one end I already have two tanks connected, I could put one there.

But you're right, the original issue stays: It overflows in the middle.

RunningMan

9186 posts

Uber Geek
+1 received by user: 4840

#3192620 8-Feb-2024 21:01

Unfortunately the best technical solution is also a little more expensive and difficult. The entire 80mm downpipe goes directly into the tank, which then has an equal or larger overflow back to the stormwater drain.

mattwnz

20515 posts

Uber Geek
+1 received by user: 4795

#3192625 8-Feb-2024 21:30

tweake:
boland:

Pipe size is indeed 80mm, there are two downsprouts. I checked with a level, but it's not accurate enough to tell if it's on the correct slope.

While I think the adapter is indeed restrictive, it still shouldn't overflow in the middle. Further to that, there is always a lot of dirt in that gutter. After ~6 months of not cleaning it even has plants growing in it.
Other gutters in the house are fine, I initially thought it was just the position as it's closed to the bush.

Replacing the adapter will probably help, but I think I can better spend the money on getting the gutter checked out & adjusted if need be.

First thing I want to do is install an overflow in the watertanks as that should increase the waterflow through the adapter using this

the adapter has to go. you simply cannot have restriction especially as the 80mm is borderline (if i recall correctly).

i think the 200l tanks are to small to be useful. water requirements for the garden are pretty big.

i would have installed a 1000l maybe 2000l and used half of it as a detention tank. that also means you run the downpipe directly in and out of it.

leaf diverters, as you have a storm drain setup, putting leaf diverters in will lower the pressure you an push water into the storm system. that can mean your neighbors will feed into the storm drain but yours won't. whoever is lowest is worse off. if you had a detention tank, you can have the overflow go to your overland path and not pour water around your foundations. thats the problem i had, gutter and downpipes overflow and flowed water into the foundations (and into the garage). with the dentition tank that overflow is pipe to the lawn and goes down to the creek.

i would seriously look at how the whole storm water system for the house functions.

If the leaf Divertors are put directly under the gutter level I can't see it reducing pressure much it at all.

RunningMan

9186 posts

Uber Geek
+1 received by user: 4840

#3192755 9-Feb-2024 07:02

Just another thought. The gutter overflowing in the centre could be due to incorrect installation of the new diverters. If the downpipe above the diverter has been pushed vertically up during installation, that might affect the slope of the guttering that it is conected to.

This could cause the fall to be in the wrong direction, and worsen the problem during heavy rain events.

tweake

2641 posts

Uber Geek
+1 received by user: 1137

#3192926 9-Feb-2024 17:36

mattwnz:

If the leaf Divertors are put directly under the gutter level I can't see it reducing pressure much it at all.

yes, however usually see them install down a fair bit. you want easy access to them as they need cleaning. its just something to keep in mind.

Lenovo

Shop now for Lenovo laptops and other devices (affiliate link).

tweake

2641 posts

Uber Geek
+1 received by user: 1137

#3192929 9-Feb-2024 17:40

RunningMan:

Just another thought. The gutter overflowing in the centre could be due to incorrect installation of the new diverters. If the downpipe above the diverter has been pushed vertically up during installation, that might affect the slope of the guttering that it is conected to.

This could cause the fall to be in the wrong direction, and worsen the problem during heavy rain events.

no, because the hangers won't move. you might push an end up a bit which means it will overflow next to the end, not way out in the middle.

my guess here is they sloped the gutter for a center downspout, which is a common setup, but then installed downspouts at the ends.

RunningMan

9186 posts

Uber Geek
+1 received by user: 4840

#3192931 9-Feb-2024 18:03

tweake:

no, because the hangers won't move. you might push an end up a bit which means it will overflow next to the end, not way out in the middle.

You're assuming they are installed correctly, which as you've already pointed out they may not be.

tweake

2641 posts

Uber Geek
+1 received by user: 1137

#3192932 9-Feb-2024 18:08

RunningMan:

tweake:

no, because the hangers won't move. you might push an end up a bit which means it will overflow next to the end, not way out in the middle.

You're assuming they are installed correctly, which as you've already pointed out they may not be.

sadly thats true.

builders don't build houses, lowest paid sub contractors do.

MadEngineer

4591 posts

Uber Geek
+1 received by user: 2570

Trusted

#3193070 9-Feb-2024 23:37

RunningMan:
Unfortunately the best technical solution is also a little more expensive and difficult. The entire 80mm downpipe goes directly into the tank, which then has an equal or larger overflow back to the stormwater drain.

That’s what we’ve got a the back of our house with a leaf diverter above it, even though there’s generally no leaves on that part of the roof. We have a small ~200L tank purely for watering the garden with collected rain water and also for a fish tank.

You're not on Atlantis anymore, Duncan Idaho.

1 | 2