Ready to pipe overflow to street...questions

[anonapersona]

After we bought this house over a year ago, we found out that the pool overflow was a fake. We want to connect 2" PVC to the overflow pipe that goes nowhere and extend it to the street out front.

I have a few questions;

1) should there be anything added that would keep critters from taking up residence in that overflow pipe? I'd expect that frogs, snakes, or rats might like that long pipe.

2) is there some way that I can partially plug the overflow in order to raise the pool level just a bit? I don't want to impair flow in case of a hurricane but I find that the difference between the overflow grate and the pool level at which the skimmers suck air is pretty close. I am wondering if we can simply use silicone caulk and a bit of acylic or something to dam the overflow inside the grate cover. Even a 1/2" dam would help the water level.

3) if the overflow pipe is simply evenly sloped from the pool to the street it seems to be that we would have created a large reservoir of water connected to the pool that rarely gets chlorinated and would tend to hold algae. Is there a trap of some sort that should be put in to keep the water held there to a minimum?

Some details; The grate in the pool attaches to a pipe that runs about 2 feet then attaches to a corrugated pipe that leads UP into landscaping. So, when the pool is high with rainwater it will slowly seep out at the connection between those pipes, leaking into the dirt surrounding the pool shell. Or if there is enough rain, like 6" or 8" depending on the starting level of the pool, the pool overflows at the edge. When it overflows, it does flow first at the left side, away from the house. However, the difference between the height at the left and the height facing the back doors is so small, maybe 1/8", that in a storm debris could easily clog the left side and water could rush towards the house. The pool seems to be slightly above the threshold of the back door so this worries me. If we are home and have power, we can use the hose bib attached to the filter piping to draw water off the pool. But that is slow, and if we get a hurricane you can't plan on being around and with electricity when that is necessary.

Anyhow, the fellow who will be doing this work does irrigation and drainage, not pool work. He will know how to work with PVC and get the slope correct, but if there are any things specific to pool drains I doubt that he will know it. So, what do I need to know about this?

 

[PaulR]

I wonder if you'd need to connect the overflow to the sewer, rather than just dumping onto the street to go into the storm drain. Your MUD or water department should be able to tell you about the rules for draining pools; it's a common requirement.
--paulr

 

[fuzzy_dba]

I have a few questions;

1) should there be anything added that would keep critters from taking up residence in that overflow pipe? I'd expect that frogs, snakes, or rats might like that long pipe.
You can have it go into a "popup" valve toward the street. The popup valves are for 3, 4, or 6" lines and are green, usually circular. The pressure from the water causes the valve to "popup" or open then without water pressure it closes by gravity. Lowes has them.

2) is there some way that I can partially plug the overflow in order to raise the pool level just a bit? I don't want to impair flow in case of a hurricane but I find that the difference between the overflow grate and the pool level at which the skimmers suck air is pretty close. I am wondering if we can simply use silicone caulk and a bit of acylic or something to dam the overflow inside the grate cover. Even a 1/2" dam would help the water level.
Use a PVC bushing that has a screw in adapter, and a flat PVC/brass piece attached to the screw-in adapter? Lowes again?

3) if the overflow pipe is simply evenly sloped from the pool to the street it seems to be that we would have created a large reservoir of water connected to the pool that rarely gets chlorinated and would tend to hold algae. Is there a trap of some sort that should be put in to keep the water held there to a minimum?

Some details; The grate in the pool attaches to a pipe that runs about 2 feet then attaches to a corrugated pipe that leads UP into landscaping. So, when the pool is high with rainwater it will slowly seep out at the connection between those pipes, leaking into the dirt surrounding the pool shell. Or if there is enough rain, like 6" or 8" depending on the starting level of the pool, the pool overflows at the edge. When it overflows, it does flow first at the left side, away from the house. However, the difference between the height at the left and the height facing the back doors is so small, maybe 1/8", that in a storm debris could easily clog the left side and water could rush towards the house. The pool seems to be slightly above the threshold of the back door so this worries me. If we are home and have power, we can use the hose bib attached to the filter piping to draw water off the pool. But that is slow, and if we get a hurricane you can't plan on being around and with electricity when that is necessary.
If there is only a 1/8" difference then ou would be asking for problems in a storm; you are correct. Is the concrete decking between the pool and the house solid? If so, you may wan to have a slotted cover installed in the concrete that drains into 4" lines that drain away from the house... Just a thought...
Where do your guttering downspouts drain to?

Anyhow, the fellow who will be doing this work does irrigation and drainage, not pool work. He will know how to work with PVC and get the slope correct, but if there are any things specific to pool drains I doubt that he will know it. So, what do I need to know about this?
This is normal drain-type work. Most landscapers understand the need for it and he should be able to handle it.

 

[anonapersona]

I wonder if you'd need to connect the overflow to the sewer, rather than just dumping onto the street to go into the storm drain. Your MUD or water department should be able to tell you about the rules for draining pools; it's a common requirement.
--paulr

Good point and we did check into that. The Homeowner Association rules are very clear that rainwater related overflow from pools may go to the street.

OTOH backwash from a sand filter would be different. Since we have a cartridge filter, that does not apply.

 

[257WbyMag]

We have ours plumbed into the rest of our 4" PVC drainage system and this system empties via pop-up in the front yard by the street and the sidewalk. I will say this...if you have a sidewalk in your front yard, I would probably see if you were able to get a right-of-way permit from the city, and just have the drain empty through a hole that has been bored through the curb (if you have curbs), rather than a yard pop-up. We have had problems with soil erosion under our sidewalk due to the pop-up being there and washing it out. Had we known about this, we would have opted for the ROW permit to allow draining directly through the curb and into the gutter on the street.

Of course, your municipality may not allow that. Some locales, as was mentioned above, are pretty picky about pool water. Ours is not, but the permit and the addition of this type of drainage would have cost an extra $500 more than going with the pop-up.

Another thing that you can do is consider teeing it into your sewer clean out.

ETA: We also have a cartridge filter and actually have our equipment plumbed to where we can send water to "waste" through a line teed into our sewer clean-out. Makes it nice if you want to change water out.

 

[Lershac]

Our municipality requires pool water go into the sewer. I just finished pre-plumbing for our future pool by putting in a cleanout into a vent stack that runs about a foot away from where we will have the equipment.

 

[anonapersona]

If there is only a 1/8" difference then you would be asking for problems in a storm; you are correct. Is the concrete decking between the pool and the house solid? If so, you may want to have a slotted cover installed in the concrete that drains into 4" lines that drain away from the house... Just a thought...
Where do your guttering downspouts drain to?

Ah, yes, if we had 4" PVC for the gutters already it would be so simple. That is something we are looking at. Not sure if we want to or have to. We are hoping that controlling the pool overflow will let us sidestep some of that.

I see that a 2" PVC pipe with gravity flow will handle 3300 GPH. Since 1" rain over 100 sf area = 62.5 gallons [edited as per correction noted in next post], and my pool area is maybe 700 sf, I may see about 875 GPH in a 2"/hr rain. So, if the overflow is connected to the street we should be fine even in rains exceeding 2"/hr.

One bid had the single gutter on that side of the house connected to the line that would be the pool overflow, but having roof water potentially wash back into the pool had me nervous. Seems cleaner to just have that line go to the street, and 2" is way cheaper than 4".

The pool decking does not extend to the house, there is a small wooden deck, then a bit of brick topped patio. The wooden deck and the brick topped patio are nearly level with the threshold of the door. And of course there is wood flooring just inside that door. (Side rant: in an area that can get excess water from hurricanes so easily, I don't understand why everyone puts in wood floors over concrete slabs. Just asking for trouble. No way to know when the under layment has gotten wet until the whole floor curls up.)

I don't know what happens under the wooden decking. In a hard rain I see rainwater come towards the house off the pool decking and then stall at the junction of the concrete and the wood deckings. It may run through the beds there, that bed was full of these huge river cobble rocks (6" - 15") and we have just removed most of that.

So, there is an opportunity to put in something at the back of the bed, along the edge of the wooden deck that could catch and carry away water. I suspect that cutting the concrete decking and inserting the slotted thing there would be best, just sounds expensive so I'll skip that if I can.

And "Carry the water to where?" is a question.

I am still conflicted about taking the rainwater to the street. Our area is about to convert to surface water instead of aquifer supplies and water is about to get at least twice as expensive as before. Not to mention the $5-8K bids we have seen.

Right now, we have dry stream beds that direct most of the excess rain to the street eventually, but there are swales along the way that hold some water. In the winter those holding areas mean that there is water oozing down the side yards for months but in the summer that same water really helps keep the trees alive. Water never stays there long enough to breed mosquitoes.

Unfortunately, in the gap between the house and the wooden deck, there is no good path for water to take to get to the dry stream beds. We just cleared out the huge river cobble the prior owners had in that gap. For now we have planted ferns there with the expectation that it might all be pulled out if we go to PVC. We have not had a good rain since we did that work to let us see how things look in the rain.

I may want to go price that slotted stuff at the irrigation store. It could run alongside the deck toward the start of the dry stream. That could also go in the fern bed to catch what comes off that gutter, and the overflow from the proposed rain barrel. (Side issue: has to be ON the wooden deck.... ugh. Sounds like trouble.)

 

[Lostuzer]

Since 1" rain over 100 sf area = 625 gallons

I hate to pick up on an old post but anyone reading this might get confused. I believe a typo occurred with the results. I believe it should read: 1" of water over 100 sf = almost 62.5 gallons.

Yes it's raining like mad down here and I (after a year and a half in this home) am lucky enough to have an overflow built in to the skimmer. I just realized it and haven't been able to find it yet but it has to be there.

Regards,
Bob

 

[anonapersona]

Thanks for the correction, yes it is better to keep these things straight, losing a decimal can be a problem!

I hope that you do locate where that overflow from the skimmer goes, hopefully it does not just sit open ended in dirt as mine did.

Meanwhile, the contractor is SUPPOSED to come tomorrow to do this piping of the overflow to the street. We did decide to connect one gutter downspout to the piping and I still worry that high volume from the roof could head toward the pool. I will be inspecting the connection quite closely to be certain that no flow towards the pool can occur.

We did resolve the rest of the drainage issues nicely. We created a small rock lined swale on both sides of the flower bed that separates the pool deck from the wood deck that adjoins the house. The small rock lined swale that takes the first downspouts water along the side of the wooden deck connects to the flower bed swales and then joins the dry stream bed that winds around the house taking all the downspout water out to the street. We've had a few really heavy rains and it all works just as designed. There are a few areas that hold water along the way. I thought that we'd need that to slow velocity but that was dumb and so we really need to raise those a bit to not hold water quite so long.

Next step, install the two large rain barrels we found online at Home Depot. I think they look nice, like huge stone pots, but my husband calls them the Big Carrots. Positioning them so as to not hide a window but still be accessible is tricky since they need to be really close to the downspout for the connection to work properly. One of these days I'll post a photo of all this when it is completed/