Ideas needed to deal with run off ground water from driveway

[ShinDiors]

House we bought a year ago had this strange setup. In order to accommodate the addition of a 2-car garage and the sunroom above at the rear of original house, they carved the driveway into the original backyard, and now the driveway is downward, with the end of it enclosed by the retianing walls. The only route that the run off water from the driveway, and from neighboring lot, backyard is a grated channel with a 4inch pipe buried under garage floor connected to a sump pit at the corner of the garage. Currently I have a liberty LE50 sewage pump in the pit, which goes 8400 gph at 5ft, but the discharge tube that connects to it is half inch smaller than the pump's 2 inch port. That tubing is partially buried into the cinder block wall then goes underneth/around the house to the street side drain. Pump is hooked up to the backup generator, so the power failure was not too much of a concern. Here is the problem:

The grated channel + the sewage pump inside garage sometimes could not cope with the speed of water accumulation from crazy heavy rain plus the water seeping through the retaining wall (from neighboring yard, and my back yard), I'm discussing with neighbor to have a french drain behind the retaining wall on their side to divert part of the water.

Water cannot get pumped out quick enough when it rains heavy for long period of time, then accumulated, went into the garage and worse case into the house.

A few plumbers/landscapers have thrown the idea of adding 2nd pump. Idea was to put the pit at the corner of where gutter is at, and pump the water straight up and flow with that gutter water, but some concerns were brought up that the dirty ground water may clog the gutter's drain pipe. Now the idea became using separate pipes to go around that retaining wall (sitting on top of the wall, or sitting at the drive way) and then go to street. Pretty long distance to the street (drive way is at least 4-5 car length, plus the width of it). However, no one seems to think about the possibility of the external pump got busted/frozen during DC's winter.

Combined with the 2nd pump idea was to adjust the grated channel's position, length and depth, so that the channel will go past the garage doorposts (so the run off water would be go into the channel instead of hitting on the garage door post, got it rotten), also make the external pit the lowest spot, that the external pump taking the most burden, only overflown water drained into the original 4inch pipe into the sump pit inside garage.

I got a quote of $5k labor to finish #3 and #4, but unsure about two things

1. What type of pump I need? Looks like trash pump is the way to go instead of the sewage pump I have in the inside. Any recommendation of the pump model? Liberty, Zoeller do not have trash pump, it looks like. Maybe this ? https://smile.amazon.com/dp/B000PDU9...5&ref=aa_scomp (it works with a tethered float too)

2. How to avoid the potential frozen for the external pump or should I put it inside the garage (just across the door from the current thinking spot)

Any other ideas, alternatives? VA is a non-disclosure state, so seller did not have to disclose anything, plus the neighboring house was a tear down new built finished right about the time we bought the house. It could well be the case that this setup worked fine when neighboring house was a 50s rambler, but got worse with a 6000 sqft mcmasion.

 

[ShinDiors]

I also got some suggestion against putting an external pump because of the risk of frozen season. Instead, I was advised to reduce the number of right angle turns and also replace the 1.5 inch pipe to 2in or 3 inch all the way.

 

[Sponsor]

 

[Reach4]

Water cannot get pumped out quick enough when it rains heavy for long period of time, then accumulated, went into the garage and worse case into the house.

Does the water get into the sump quick enough to cause there to be enough water in the pit to keep the pump running without cycling during heavy water times?

If yes, you need a more powerful pump. You have a lot more than 5 ft head for your discharge.

Expanding your pit or putting a second pit adjacent with a big connecting pipe to the existing pit would make sense if the water can move to the pit quick enough. Then put in two pumps. This both gives you more capacity, and gives you some redundancy.

A trash pump is made to be able to pump big solids. You don't need that capability.

I think you are saying that the gutters have their own path to the curb and don't drain to a place where the gutter water contributes to the driveway water.

 

[ShinDiors]

Yes, the pit's water level goes up when the rainfall is crazy heavy, if more/faster, it actually overflows with pump kept running. But most of the rainfall, it cycled fine. I asked about the trash pump, because the run off water is dirty, there are sand, dirt particles, some times the leaves although I have chicken wire covering the grated channel.

I've experienced maybe twice the water level rising up and stayed up or overflow for the past year, after experimenting and excluding all other factors (went from a 0.3 hp zoeller sump pump, to the current 0.5 hp sewage pump, then found out the power outlet it was plugged into had issues that it randomly stopped, fixed that, but still got hit by the record high rain storm earlier last month (got about 4.6 inch with around 4 inch/hr). And also yes, the gutter has its own discharge route which did not contribute to the water collect by this grated channel+sump pit. The water here comes from the run off water from the doward driveway, plus the water from the neighboring higher lot + my own backyard (water seeping through the retaining wall).

It is a very small opening where the pit is, grown man need to crouch all the time, so I'm not sure if someone would be able to dig another pit or dig the current pit deeper. I was suggested replacing all the 1.5inch piping that connected to the current pump with 2inch pipe and try to reduce the number of right angle turns in the tube routing. Combined it with a larger pump. Problem is the larger pump (by reputable brands like Zoeller or liberty) will run me $800-$1000, with all the associated work of pipe change etc, would it make sense to simply add an entirely separate pump+tube outside the garage (pipe will be exposed, so main work is to dig another pit outside+ maybe the same 0.5hp liberty pump). But concerns of freezing seems to be quite possible.

 

[Reach4]

Total head is the sum of the static head, due to altitude difference, and the dynamic head.

http://www.pressure-drop.com/Online-Calculator/ can let you predict the dynamic head. Note the Group drop-down which can let you add in for bends or changes in section.

Where on this curve do you think you are operating?

That is from https://www.libertypumps.com/Portals/0/Files/Engineering Specifications/LE50-Series.pdf

https://www.libertypumps.com/Portals/0/Files/Engineering Specifications/LE70-Series.pdf are 3/4 HP.

https://www.libertypumps.com/Portals/0/Files/Engineering Specifications/LE100-Series.pdf are 1 HP and would take 240 volts.

 

[LLigetfa]

Could you not place a second pump in the same hole above the existing? Of course you should run a second line out, not Tee the two into the existing line.

 

[ShinDiors]

It would be pretty difficult for me to do the calculation. Do I estimate first section (straight up pipe) then get the result (flow speed) and use that speed as the input flow speed for the 2nd section, so on so forth? Is the black section between the pump discharge port and the straight 1.5 inch pipe the "check valve" or just a reducer? Also the portion after the cinder block wall I don't know how long but it goes around the side of the house and into the storm drain (pretty long). There are six right angle turns in this routing, so I don't expect to see the results to be too good. But except the one I circled in red, which can be eliminated by lower the straight up pipe, I don't see too many turns that I can avoid. A lot of the 90 degree turns are used to route the pipe along the wall.

I would like to make use of the 0.3 hp zoeller sump pump in the same pit if possible. It has been sitting there. But if I need to buy a 3/4 hp liberty (that spot has 110v hooked with backup generator, so without having to do a 240v outlet), and the problem can be solved with the existing piping. That's the easiest solution for me.

BTW, the very original pump (which was bad during home inspection) was a 1 HP F&Q 50WQ0.75-2P sewage pump. http://www.fqpumps.com/50wq.html

I picked the liberty 0.5hp due to the budget restraint and the spec. (it has maybe 80-85% of the capacity, but I didn't have $1k to shed on a Liberty 1HP back then).

 

[Reach4]

Something like this could supplement when the existing pump is not doing the job due to deluge or power failure: https://www.championpowerequipment.com/product/66520-2-inch-semi-trash-water-pump/ This presumes you the pump could be in the garage with the door open.

 

[Toolaholic]

What You need a " Geotech " They get it right !

 

[WorthFlorida]

Before going all out on the pump fix, you should work on the gutter first. Just going to a larger pump maybe enough if the gutters are doing the best they can with water off the roof.

I would immediately start on the gutter and will not lay require whole lot of money to start. Do upgrade to a 6" gutter, if not already there is a 6" gutter, and more important at least 3" x 4" downspouts. From the picture it does look like they are 3x4. Someone should look at the hole at the drop outlet.
The most important part of this is the drop outlet. I find too many guys just punch a hole and then bend the gutter cut into the downspout. 1) the hole is never cut large enough this way and the hole overall is too small and easily catches debris. It's the cheap and a fast way, not better. 2) Insist on using the drop outlet that matches the downspout. You might look into a gutter company that does commercial work where the gutters and downspouts can be larger.

Where the existing gutter extends into the PVC pipe has to go. If that is the same pipe the pump discharges into on the side of the house, it probably is overwhelming the pipe. For the gutters connect to a proper 4" drain pipe and bring it as far back as possible. You might consider using two downspouts. It is obvious from the water damage that water is seeping back down that corner. Use this type of connection and a flex corrugated pipe and fittings just for the gutter system.

I live in Florida and we always get huge downpours especially in the summer and my 6" gutters work great but the number of downspouts is as import.

 

[ShinDiors]

Before going all out on the pump fix, you should work on the gutter first. Just going to a larger pump maybe enough if the gutters are doing the best they can with water off the roof.

I would immediately start on the gutter and will not lay require whole lot of money to start. Do upgrade to a 6" gutter, if not already there is a 6" gutter, and more important at least 3" x 4" downspouts. From the picture it does look like they are 3x4. Someone should look at the hole at the drop outlet.
The most important part of this is the drop outlet. I find too many guys just punch a hole and then bend the gutter cut into the downspout. 1) the hole is never cut large enough this way and the hole overall is too small and easily catches debris. It's the cheap and a fast way, not better. 2) Insist on using the drop outlet that matches the downspout. You might look into a gutter company that does commercial work where the gutters and downspouts can be larger.

Where the existing gutter extends into the PVC pipe has to go. If that is the same pipe the pump discharges into on the side of the house, it probably is overwhelming the pipe. For the gutters connect to a proper 4" drain pipe and bring it as far back as possible. You might consider using two downspouts. It is obvious from the water damage that water is seeping back down that corner. Use this type of connection and a flex corrugated pipe and fittings just for the gutter system.

I live in Florida and we always get huge downpours especially in the summer and my 6" gutters work great but the number of downspouts is as import.

Valid points. Not a 6inch gutter, and there is one spot right above the left side entry door, where the roof angled together and the water would overflow outside the gutter guard and pour down to the driveway, other than that, I checked my gutters downspouts during the rain storms, seems no overflowing. The gutters all drained into the street side with underground pvc pipes, so it may have not caused too much pressure on the driveway run off water.

I asked this question at a few places and it seems that no one is a fan of having an external pump because of the potential winter freezing season. Instead, I was advised to re-route the discharge pipe from the pump, using 2 inch pipe (math the 2 inch discharge port and check valve) then reduce the number of right angle turns (the current routing has about six right angle turns until it finally reached the spot above at the wall where it should go straight towards the side backyard. One suggestion is to put the 0.3 hp sump pump i initially put in on top of the current 0.5 hp liberty, discharge both into a 3 inch pipe to accommodate heavy storms where the water lever in the pit rise up and trigger the upper 0.3 hp. Instead of hashing out 1k for a 1 hp pump. I'm leaning towards this idea more now. What do you guys think?

 

[Jadnashua]

Every change of direction in the pipe adds to the dynamic friction, and will reduce the maximum flow. The area of the pipe opening is pi*r^2, so going from 1.5^2 to 2^2 you get 4/2.25, or almost twice the potential flow. A larger diameter pipe will decrease the friction, and give you the option of a larger pump, if needed. Go larger on the pipe and minimize the elbows.

 

[WorthFlorida]

Go with the pipe diameter the maximum size the pump can handle. If the pump is 1.5", do not increase the pipe size to 2". Whoever did this installation did use drain elbows (better), not vent elbows that have hard 90 degree bends. In general every 90 degrees is equal to three feet of pipe. If you go the two pump route, I would in the same pit put two pedestals pumps, one 1/3 hp as the secondary and the primary 1/2 hp. Just set the float switches differently. Do run both pumps with their own pipe all the way. Where the ground slopes away from the house and you extend the pipe further from the house, that is where you can increase the size of the pipe.

Another two pump scenario is a second pump at the garage floor level, right about where the lawn mower is. Just need another plastic pit tub sitting on the floor. The existing one would pump into the garage level pit which is about 5 ft of head, and the second pump would be pumping about 6 ft of head. As long as the second pump can pump more water than the lower pump it should work.

Your current pump is a sewage pump which are ruggley made and may be able to handle sand and dirt than can drain into the pit from the driveway. Have you ever removed the pump to clean the bottom of the pit to remove sediments? You want nothing under the pump for the best water flow.

As I said earlier, get the drainage fixed and gutters upgraded and change the pipe to 2" for the pump before going to a second pump setup. KISS formula always.

https://www.sumppumpsdirect.com/stories/1496-How-to-Easily-Size-a-Primary-Sump-Pump.html

 

[ShinDiors]

What I have right now is a Zoeller M53 0.3hp sump pump (with a 1.5 inch discharge) that was replaced by the current Liberty LE50 (with 2 inch discharge). Is there a way of using these two together (with Zoeller on top)? I understand that it would be beneficial for each pump to have their separate discharging pipe, but in my set up, adding another pipe might involve extensive labor (breaking more cinder block and digging). It may or may not be much extra considering the labor involved for replacing ALL the current 1.5 inch pipe (including those behind that cinder block wall). Maybe I should replace/reroute the pipes with 2 inch all the way with the current liberty pump? If water still comes in the garage, then spend the money for the 1hp one (same 2 inch discharge port size) so no need of pipe change?

I understand the importance of a good gutter and downspouts, but in my case, is that the most critical part of solution compared to the piping/pump? Again that's from budget restraint point of view, so far I have not noticed too much of water overflowing from gutter to the ground, and the downpouts are all buried underground and routed to the street side, separately from this pump. Ideal case scenario, a 6 inch gutter plus new downspouts would be nice, just not sure if the bang for the buck is there in this case.