Rainbarrels and leveraging/repurposing existing irrigation system?

[jeromedawg]

Hi all,

I was thinking about our irrigation setup and how to leverage and repurpose it in conjunction with a rainbarrel (or two) that we would plan to install to catch the water from our gutters when it rains. I was specifically curious to know if we could just reuse the current irrigation lines that are connected to a manifold fed from the water main, capping off the zones on the manifold that we don't want to be sourced by the main and then tying those zones into the rainbarrels. It seems at that point we might have to consider using pumps right? Gravity seems like a great idea but I'm not sure if ALL of the irrigation plumbing runs fully downhill and graded (which is what I would anticipate is going to be best if relying strictly on gravity).

Has anyone done anything like this and can offer input or suggestions? I would especially be interested in figuring a way to get this working with a smart irrigation timer (Rachio 3).

[Abe]

Seems reasonable, but would work best with drip irrigation. Standard sprinklers will not get enough pressure to activate. Pumps seem like a lot of cost/effort. In SoCal I'd go with drip irrigation regardless.

Here I have rain barrels that have spigots at the bottom, and have drip irrigation hoses screwed into them. Those hoses run under the mulch in the flower beds. Just have to remember to manually open/close, but there are automated valves available that can be controlled by an app. My cousin uses those for the same purpose for no reason other than its cool (to him).

[jeromedawg]

Seems reasonable, but would work best with drip irrigation. Standard sprinklers will not get enough pressure to activate. Pumps seem like a lot of cost/effort. In SoCal I'd go with drip irrigation regardless.

Here I have rain barrels that have spigots at the bottom, and have drip irrigation hoses screwed into them. Those hoses run under the mulch in the flower beds. Just have to remember to manually open/close, but there are automated valves available that can be controlled by an app. My cousin uses those for the same purpose for no reason other than its cool (to him).

Oh we definitely plan on replacing the sprinklers with drip. I was just curious if we would still need to use pumps from tthe rain barrel in case any portion of the existing irrigation lines are bowed or not graded downhill. I figure as the rain barrel is more full its less of a problem versus if its less full as presumably there is less pressure pushing and forcing the water through.

[RetiredAt63]

Seems reasonable, but would work best with drip irrigation. Standard sprinklers will not get enough pressure to activate. Pumps seem like a lot of cost/effort. In SoCal I'd go with drip irrigation regardless.

Here I have rain barrels that have spigots at the bottom, and have drip irrigation hoses screwed into them. Those hoses run under the mulch in the flower beds. Just have to remember to manually open/close, but there are automated valves available that can be controlled by an app. My cousin uses those for the same purpose for no reason other than its cool (to him).

Oh we definitely plan on replacing the sprinklers with drip. I was just curious if we would still need to use pumps from tthe rain barrel in case any portion of the existing irrigation lines are bowed or not graded downhill. I figure as the rain barrel is more full its less of a problem versus if its less full as presumably there is less pressure pushing and forcing the water through.

If you have the rain barrel on a stand that will help with the pressure.

[birdie55]

A few years ago, I set up three rain barrels connected to my downspout.  I used this connector kit to connect the first train barrels, then used the tubing to connect them together.  When the first rain barrel filled, the overflow went into the second and then from the second into the third.  I put them on cinder blocks to help with gravity. 

https://www.homedepot.com/p/Good-Ideas-Rain-Wizard-0-29-cu-Diverter-Flex-Kit-RW-DIVFLX-BLK/317983943

I found one inch of rain filled them all and then I had overflow.  I live in California and it does not rain in the late spring and summer, which is when I needed the water.  So, since it only rains in winter, I didn't really need the water then.  I did store it, but had to wait until spring to use it.  I tried using a hose to water from the barrels which worked fine, but was slow.  So I mostly used buckets to take the water to the vegetable garden and watered each plant individually. 

IF you set up a series of barrels, consider what to do with the overflow.  One good storm and my barrels were full. 

[sonofsven]

A few years ago, I set up three rain barrels connected to my downspout.  I used this connector kit to connect the first train barrels, then used the tubing to connect them together.  When the first rain barrel filled, the overflow went into the second and then from the second into the third.  I put them on cinder blocks to help with gravity. 

https://www.homedepot.com/p/Good-Ideas-Rain-Wizard-0-29-cu-Diverter-Flex-Kit-RW-DIVFLX-BLK/317983943

I found one inch of rain filled them all and then I had overflow.  I live in California and it does not rain in the late spring and summer, which is when I needed the water.  So, since it only rains in winter, I didn't really need the water then.  I did store it, but had to wait until spring to use it.  I tried using a hose to water from the barrels which worked fine, but was slow.  So I mostly used buckets to take the water to the vegetable garden and watered each plant individually. 

IF you set up a series of barrels, consider what to do with the overflow.  One good storm and my barrels were full.

This was basically my experience as well; I had seven barrels set up for garden watering, but it was not enough to use exclusive of my tap water to get through the end of summer dry season, so I was just supplementing my tap water usage.
I pay ($53.75) for a set amount per month, plus extra if I go over that amount. I found with careful watering I don't go over that set amount so the barrels were deactivated.
I kept two just so I could use them with a drip setup with a timer in case I was out of town during watering season, but I've never done that. I just call on helpful friends and neighbors, and really, I hardly go anywhere in the summer anyway.

[Abe]

Seems reasonable, but would work best with drip irrigation. Standard sprinklers will not get enough pressure to activate. Pumps seem like a lot of cost/effort. In SoCal I'd go with drip irrigation regardless.

Here I have rain barrels that have spigots at the bottom, and have drip irrigation hoses screwed into them. Those hoses run under the mulch in the flower beds. Just have to remember to manually open/close, but there are automated valves available that can be controlled by an app. My cousin uses those for the same purpose for no reason other than its cool (to him).

Oh we definitely plan on replacing the sprinklers with drip. I was just curious if we would still need to use pumps from tthe rain barrel in case any portion of the existing irrigation lines are bowed or not graded downhill. I figure as the rain barrel is more full its less of a problem versus if its less full as presumably there is less pressure pushing and forcing the water through.

If the rain barrels are elevated then it won’t be an issue. You may notice it takes more time to water the same amount of soil to the same moisture level (since pressure will drop a bit), but as long as the height of the stand is higher than the yard’s highest point you won’t need pumps.

[jeromedawg]

Seems reasonable, but would work best with drip irrigation. Standard sprinklers will not get enough pressure to activate. Pumps seem like a lot of cost/effort. In SoCal I'd go with drip irrigation regardless.

Here I have rain barrels that have spigots at the bottom, and have drip irrigation hoses screwed into them. Those hoses run under the mulch in the flower beds. Just have to remember to manually open/close, but there are automated valves available that can be controlled by an app. My cousin uses those for the same purpose for no reason other than its cool (to him).

Oh we definitely plan on replacing the sprinklers with drip. I was just curious if we would still need to use pumps from tthe rain barrel in case any portion of the existing irrigation lines are bowed or not graded downhill. I figure as the rain barrel is more full its less of a problem versus if its less full as presumably there is less pressure pushing and forcing the water through.

If the rain barrels are elevated then it won’t be an issue. You may notice it takes more time to water the same amount of soil to the same moisture level (since pressure will drop a bit), but as long as the height of the stand is higher than the yard’s highest point you won’t need pumps.

Makes sense. I guess at that point the only other consideration is what the flow rate is and if that flow rate changes depending on the amount of water that's in the barrel. If the flow rate does change, and this can be integrated into a timer system like the Rachio, I do wonder how to account for that. I figure any given timer used you're setting the time to run based on the flow rate so if the flow rate changes that might complicate things a bit. It may not be enough to be that big of a deal though...

[chemistk]

If you did want to use your existing sprinklers, you could always get a super cheap sump pump, tie the outlet into the sprinkler inlet, and run it when you've got enough water to run the sprinklers for however long you need them.

[YttriumNitrate]

Rain barrels are great. At my old house I had about 2,000 gallons of capacity thanks to some rather large IBC totes in system. That being said, I see two issues with your potential setup. First, raising up the rain barrels adds roughly half a PSI of pressure per foot raised. That means unless you are going to be using a pump you'll be using 1-3 PSI water. That's probably not enough to run the current system. The second issue is that the water you collect isn't going to be nearly as clean as the water supplied by the city. Your plants won't mind the pollen grains and other stuff in the water, but it can be an issue when trying to push water through a small opening like an irrigation emitter.

[jeromedawg]

Rain barrels are great. At my old house I had about 2,000 gallons of capacity thanks to some rather large IBC totes in system. That being said, I see two issues with your potential setup. First, raising up the rain barrels adds roughly half a PSI of pressure per foot raised. That means unless you are going to be using a pump you'll be using 1-3 PSI water. That's probably not enough to run the current system. The second issue is that the water you collect isn't going to be nearly as clean as the water supplied by the city. Your plants won't mind the pollen grains and other stuff in the water, but it can be an issue when trying to push water through a small opening like an irrigation emitter.

If you did want to use your existing sprinklers, you could always get a super cheap sump pump, tie the outlet into the sprinkler inlet, and run it when you've got enough water to run the sprinklers for however long you need them.

Yea, I'm a bit worried about the pressure running these through longer lengths of 3/4-1" PVC even if I raise them. So I may very well need a pump. I think there are ways to tie the pump into the Rachio so it aux powers the pump when operating the relevant zone. I haven't researched that part a ton but it sounds like it's possible just reading around a little. As far as the rain barrels collecting slightly dirty water, I've seen people putting multiple filters on them (both at the point of collection as well as using a filter on the spigot). This seems to help ensure that your lines won't get all clogged up.