Diverting rainwater away from pool

[Death Dream]

If the rain was coming at 2" per hour for the two minutes you describe, that means an area of about 18,000 - 45,000 square feet (depending on the surface material) is draining into your yard. 7 inches of rain over 18,000 square feet is 78,000 gallons of water. You aren't going to hold that with any wall. You'd have to build something three times as big as your pool.

You sir, are a math wiz. Lol. But I highly doubt 78k gallons of water went into my yard. My number are not 100% accurate like yours are. I will have to build some sort of wall, no doubt about it though.

Did you use a Realtor to purchase this home and if so was the a Property Disclosure?

I used a realtor. They owners never disclosed this but with those rail road ties, it would be hard to say they didn't know about this. Not really interested in pursuing a lawsuit. I love the house and where it is located. This is just the one flaw it has right now.

Pm me your email address and I can send you pictures of what we've done to date...the two upper drains are going in tomorrow after a failed attempt at an upper french drain. And our retaining wall is being extended. But I can show you what we are planning.

PM'ed

 

[sbcpool]

You sir, are a math wiz. Lol. But I highly doubt 78k gallons of water went into my yard. My number are not 100% accurate like yours are. I will have to build some sort of wall, no doubt about it though.

Don't be too surprised. 7 inches of rain on a 2,000 square-foot roof is almost 9,000 gallons all by itself. You could divert your gutters to your pool and get a free 50% water change.

 

[kimkats]

I am thinking that with some hard labor you can "fix" the problem.

-dig out all of the rocks/dirt/silt in the rock area.

-on the other side of the fence dig as much as you can to form a trench that will take the water towards the outside of the fence towards the road

-To lead the water to the area you are thinking of making the water go you need to redo the rocks having them at a good angle TOWARDS the fence to make the water go where you want it to go.

-build a solid wall to contain the rocks.

-replace the rocks in such a way so they do not go all the way to the top of the wall and again they are angled in such a way as they help the water go where you want it to. Rocks high where you do NOT want the water to go and low where you do.

I think the outside of the fence will be key to helping to keep it our of your yard. Talk to your neighbor about allowing you to do this.

I hope this make sense.

Robert I would love to see what you are doing. You never know but you might be able to help some one else if you post it here and explain your doing and thinking.

Kim

 

[diverminh]

Have you thought about putting in some deck drains? If it was me, I would consider removing the RR ties and rocks. Then I would cement the area but put in a good slope so that it's V shaped. At the bottom of the V, I would put in deck drains. Then trench a line to pull the water out to the area where you want to drain to. You will be burying ABS pipe in the trench. Connect the deck drains to the ABS pipe or solid drainage pipes. ABS is preferred, but it's also a lot more expensive ($30 vs $10 for a 10ft section).

Quaker Plastic Deck Drains- 4 Water Hog Deck Drain
Advanced Drainage Systems 4 in. x 10 ft. Triplewall Pipe Solid-4550010 - The Home Depot

Minh

 

[robertmee]

I have deck drains also in addition to everything else. I took some pics I'll post up in a little while to show what we did and plan to do.

 

[DaninFLA]

based on what I saw in your video (great work by the way), you are pretty limited in your options. your best option to me, based on the video, is to replace that railroad tie will a solid concrete curb. I would form/pour it in the same location, but wrap it around to the other side of your pool (opposite of house) so the water can divert around your pool and into the street. I would pour the curb 6" high, preferably 8" if you can. you will need to make sure the curb is set down into the ground at least 6" too or so that water wont undermine the curb and flow underneath. an open trench to move water around your pool is going to be much more efficient at getting water around. using pipes and/or drains will cause restrictions that could easily cause the water to overtop the curb. plus they are more expensive and you have to trench them in and give them somewhere to discharge.

- - - Updated - - -

Don't be too surprised. 7 inches of rain on a 2,000 square-foot roof is almost 9,000 gallons all by itself. You could divert your gutters to your pool and get a free 50% water change.

well 7" of rain in a lot of places in this country would be a 50 year of 100 year rain event, so not something to count on. most rain events are 1"-2" tops and those are substantial. and that 7" is over an hour or two. when designing the wall to divert the runoff, you aren't concerned with the total rain amount, you are worried about the flow rate. 1" of rain over 1 hour is a lot more than 7" over 24 hour.

 

[owkaye]

If the neighbors are not at fault for diverting their runoff onto your property, and if your property is higher than the nearest municipal storm drain and/or the street, you might get away with installing surface or near-surface storm drains that lead out to the nearest municipal storm drain, or just to the street. But if this is not allowed or does not work ...

You may need to get rid of the gravel and railroad ties, then dig a deep hole and install a big underground sump in that location. You'll probably have to custom-build the sump out of poured-in-place concrete to fit your narrow limited space. This deep new sump will temporarily store some of the huge volume of water that comes flooding in during a big rain storm.

HOWEVER ...

If the sump is not large enough to contain all the storm water, you will also need a very high capacity automatic pump that can remove water from the sump faster than it's coming in. Then the storm water won't be able to overflow the sump and pour into your pool again.

 

[DaninFLA]

If the neighbors are not at fault for diverting their runoff onto your property, and if your property is higher than the nearest municipal storm drain and/or the street, you might get away with installing surface or near-surface storm drains that lead out to the nearest municipal storm drain, or just to the street. But if this is not allowed or does not work ...

You may need to get rid of the gravel and railroad ties, then dig a deep hole and install a big underground sump in that location. You'll probably have to custom-build the sump out of poured-in-place concrete to fit your narrow limited space. This deep new sump will temporarily store some of the huge volume of water that comes flooding in during a big rain storm.

HOWEVER ...

If the sump is not large enough to contain all the storm water, you will also need a very high capacity automatic pump that can remove water from the sump faster than it's coming in. Then the storm water won't be able to overflow the sump and pour into your pool again.

sump is not the answer, you cant build one big enough. OP has issues with larger rain events, a sump isn't going to help with that. only option is divert the runoff around the pool and into the street on the other side of his property. based on the video, this is the natural path anyway. adding pumps, etc is just another item to fail. he has adequate fall from the two ends of his property, so easiest thing is to just let gravity do the work for you.

 

[DaninFLA]

OP - if you PM me with your email address, I can sketch up what i described. only concern i have is the width between the fence and pool deck on the long side of your yard. may need to use a pipe for that area. im an engineer that deals with drainage all day anyway

 

[sbcpool]

An open trench to move water around your pool is going to be much more efficient at getting water around. using pipes and/or drains will cause restrictions that could easily cause the water to overtop the curb. plus they are more expensive and you have to trench them in and give them somewhere to discharge.

Open trenches have a way of ruining the landscaping. Also, rushing water tends to erode trenches unless they're lined with concrete which would make them double plus ugly. Restrictions are not a necessary result of using pipes or drains, otherwise sewers would be pointless.

well 7" of rain in a lot of places in this country would be a 50 year of 100 year rain event, so not something to count on. most rain events are 1"-2" tops and those are substantial. and that 7" is over an hour or two.

If you are building something to protect you against rain, why would you engineer it so that it's guaranteed to fail in exceptional rain events - the very time you most need it to work?

when designing the wall to divert the runoff, you aren't concerned with the total rain amount, you are worried about the flow rate. 1" of rain over 1 hour is a lot more than 7" over 24 hour.

My suggestion was to design for the NOAA's 100-year 30-minute rain rate. I don't think anybody was suggesting designing a system based on the storm total without regard for the rain rate.

 

[DaninFLA]

your trying to be argumentative without reading the context on my full post. secondly, transmission systems are never designed for a 100 year event, the highest is usually 25 year and more commonly the 10 year events. this is a private homeowner, so I don't think trying to come up with some mega designed and elaborate design is warranted. the easiest solution is just to divert the water around the pool and let it go to the road. the curb i suggested, along with the trench (or pipe) along the long side of the pool accomplishes this. if he gets a 50 or 100 year event and it floods again, well then oh well, stuff happens. that's not a common occurrence though and no need to design for it. would be cheaper to just drain the pool and refill if he gets that type of storm event than it would be to try and design to protect the pool.

and yes, pipes and inlets create additional losses/restrictions and another area to fail (i.e. debris accumulates on top of the inlet and it cant handle the flow - very common)

 

[Death Dream]

I think the outside of the fence will be key to helping to keep it our of your yard. Talk to your neighbor about allowing you to do this.

My neighbors seem nice, but they have a HUGE garden on my fence. Doubt they will let me go tearing that up unfortunately.

based on what I saw in your video (great work by the way), you are pretty limited in your options. your best option to me, based on the video, is to replace that railroad tie will a solid concrete curb. I would form/pour it in the same location, but wrap it around to the other side of your pool (opposite of house) so the water can divert around your pool and into the street.

Building a concrete curb to replace the RR ties sound interesting. I don't think it would be possible for me to build the curb on the fence line opposite of the house though. There isn't much wiggle room there. If I wrap it around over by the deck, or even possibly under the deck, might be a better option. That way it catches the water that comes back from the filter area as well. Could hide the curb afterwards with a nice brick wall or something fancy at a later point once it is known to work.

I have deck drains also in addition to everything else. I took some pics I'll post up in a little while to show what we did and plan to do.

Robertmee, just as a heads up. Not sure if you sent an email already or not, but I have not seen anything come through.

 

[sbcpool]

your trying to be argumentative without reading the context on my full post.

My apologies if it came across that way. I am not trying to be argumentative, but to clarify the reasons for the the suggestions I gave.

secondly, transmission systems are never designed for a 100 year event, the highest is usually 25 year and more commonly the 10 year events.

I don't know the practices around the country, but in the Los Angeles area storm drains are engineered for a 10-year frequency with the caveat that they must be able to handle a 50-year event without causing excessive or serious damage (meaning the can overflow if doing so will not cause a lot of damage). But, how municipal storm drains are designed isn't relevant to OP's situation - the goals and objectives are different.

this is a private homeowner, so I don't think trying to come up with some mega designed and elaborate design is warranted.

If you're going to be trenching for drainage pipe, what makes placing enough to handle a 50-year event a "mega designed and elaborate" design? It's only a matter of adding about 20% more capacity.

the easiest solution is just to divert the water around the pool and let it go to the road. the curb i suggested, along with the trench (or pipe) along the long side of the pool accomplishes this. if he gets a 50 or 100 year event and it floods again, well then oh well, stuff happens. that's not a common occurrence though and no need to design for it.

A 50-year flood has a 20% chance of happening twice in ten years. Everyone's tolerance for risk is different, but if I were going through the trouble of protecting my pool from runoff I wouldn't want the system to have a significant potential for failure twice in ten years. The OP was posting about an unprecedented event in his area and how to address the resulting runoff, I think it's fair to assume that he would like to avoid problems in the event of another historic rain event.

We also do not know the particulars of Death Dream's situation. It may, or may not be, that diverting water around the pool will cause other issues (like draining towards the house, or into the neighbor's yard). It's difficult to perform an armchair evaluation and design.

would be cheaper to just drain the pool and refill if he gets that type of storm event than it would be to try and design to protect the pool.

Drain pipe isn't that expensive around here. Adding a 4" pipe would cost about $40.

and yes, pipes and inlets create additional losses/restrictions and another area to fail (i.e. debris accumulates on top of the inlet and it cant handle the flow - very common)

Atrium covers are a better design for drains. A flat drain cover is asking for trouble. That's why dams use trash racks (like an atrium drain cover).

 

[Death Dream]

Have you thought about putting in some deck drains? If it was me, I would consider removing the RR ties and rocks. Then I would cement the area but put in a good slope so that it's V shaped. At the bottom of the V, I would put in deck drains. Then trench a line to pull the water out to the area where you want to drain to. You will be burying ABS pipe in the trench. Connect the deck drains to the ABS pipe or solid drainage pipes. ABS is preferred, but it's also a lot more expensive ($30 vs $10 for a 10ft section).

Quaker Plastic Deck Drains- 4 Water Hog Deck Drain
Advanced Drainage Systems 4 in. x 10 ft. Triplewall Pipe Solid-4550010 - The Home Depot

Minh

This looks like it would work if the guards were not so restricting. This is what makes the curb idea appealing, could catch the water then angle it away.

 

[sbcpool]

This looks like it would work if the guards were not so restricting. This is what makes the curb idea appealing, could catch the water then angle it away.

Is the slope right so that the diverted water will not go into your neighbor's yards or near your house? If so, that's the easiest solution.

 

[engrav]

Am no hydrology / drainage expert but

Have struggled with French drains, curtain drains, dry wells, sump pumps on 3 different properties.
Based upon those struggles…

See if previous owner(s) or city permit office or neighbors have any knowledge on
1) did it ever work? and
2) how was it built?

and
I vote for the duraleigh idea.
Start by cleaning out / diagnosing/ restoring the old system. Could be that it is so debris filled and broken that it is no drainage system at all anymore. Simply a dirt slab from their garden to your pool. Also might add new bulkhead filter fabric on the upside to keep the garden dirt out of the rocks.

 

[owkaye]

sump is not the answer, you cant build one big enough.

That's precisely why I said he needs a high-capacity pump to go along with it.

 

[Yev]

A french drain will not fix your problem for the monsoon season. What you want is called a Trench Drain.

Trench Drain Systems | Pool Trench Drains

You would put it in place of the railroad ties or right before the water gets to the railroad ties. Because it has an open grate on the surface it will catch teh water that is moving. YOu then ties the end fo the trench drain pip to other piping, and run it off to the street, storm drain, etc.

I have one, it works fantasticaly

 

[krazykrames]

Open trenches have a way of ruining the landscaping. Also, rushing water tends to erode trenches unless they're lined with concrete which would make them double plus ugly.

Look up a product called Scourstop, does a nice job of eliminating erosion plus if installed correctly grass grows through it and you won't even see it.

I believe the most simple and effective solution would be a grassed swale. Clean out the rock area, reset the ties or some kind of curbing.

 

[robertmee]

Here are two pictures showing what we have and will have.

Have: Partial Retaining Wall
Will Have: Extend all the way to wood fence

Have: Deck Drain
Will Have: No Change

Have: Lower Catch Basin
Will Have: Move Lower Catch Basin in front of Retaining Wall

Have: Upper French Drain
Will Have: Replace with Trench Drain

Have: Down Spout Drains
Will Have: Add Catch Basin where water collects from two yards

Blow Up Pictures to see notes

http://i195.photobucket.com/albums/z217/robertmee/Pool/20150731_074335_zpsesbcueb0.jpg

http://i195.photobucket.com/albums/z217/robertmee/Pool/20150731_074453_zpsjispf7dh.jpg