Basin sizes for stream/waterfall feature

[Joe113]

hello!

When building a stream/waterfall feature using a pump you have an upper basin and a lower basin.

Can the upper basin be larger than the lower basisn which is where all the water ends up before being pumped back up the hill? At the current time my upper basin is larger than the lower bottom and I even have a middle basin which is larger than both the upper and lower, but the lower is the smallest. Will this still work? I'd like to know before I invest in a pump.

The way the situation is laid out, it's really not possible for the bottom basin to be larger than the top or midddle.

Thanks for any help!

 

[sissy]

Not really because when it drains down to the smaller pond it will cause it to overflow

 

[Joe113]

Not really because when it drains down to the smaller pond it will cause it to overflow

That's what I was thinking while I was digging, it came to me, how could this work without overflowing. Thanks, this mission will be aborted.

 

[Lisak1]

Well, actually you could have some catch basins along the way - areas where the water pools up but stops overflowing once it goes below a certain level. Depending on how many and how deep, you could "store" some extra water that way.

 

[Meyer Jordan]

Well, actually you could have some catch basins along the way - areas where the water pools up but stops overflowing once it goes below a certain level. Depending on how many and how deep, you could "store" some extra water that way.

?????
How would one access this "stored" water?

 

[Lisak1]

Let me explain that better. Our pondless waterfall has a top waterfall that spills into a first pool which holds about 30 gallons of water. That pool, once filled, spills into a second pool which holds another 40 gallons. When we turn off the waterfall, those two pools continue to spill water UNTIL they fall below the level of the "lip" which contains the water within the pool. The two pools stay full up to that level. So the whole system holds 170 gallons - 100 underground and another 40 in those two pools.

A pondless stream could be built the same way, with pools along the stream that will contain water when the system is shut down. The real math comes in knowing how much total water you need your system to hold when it's shut down.

 

[Meyer Jordan]

Let me explain that better. Our pondless waterfall has a top waterfall that spills into a first pool which holds about 30 gallons of water. That pool, once filled, spills into a second pool which holds another 40 gallons. When we turn off the waterfall, those two pools continue to spill water UNTIL they fall below the level of the "lip" which contains the water within the pool. The two pools stay full up to that level. So the whole system holds 170 gallons - 100 underground and another 40 in those two pools.

A pondless stream could be built the same way, with pools along the stream that will contain water when the system is shut down. The real math comes in knowing how much total water you need your system to hold when it's shut down.

I am at a loss as to what you are trying to explain. Any water in these step pools is contained to the overflow level and is not going anywhere. I fail to see how this applies to the controlling any overflow on the lowest pond. What needs to be considered here is actual total volume of transit water vs volume of the lowest pond. Any water contained in any upper pool below overflow is not considered transit water.

 

[sissy]

Meyer has a good point how big will your catch basin will be and how will you access it .The top would have to be sturdy in case something walks on it but easy to open in a small area to service the pump .Little catch basins would be full also as it comes down and in the end each would over flow to the bottom pond and only way that would work is if one catch basin was empty and had some type of diversion for the water to only fill it when the pond was shut down .Like a dam you open and divert overflow water to it .Or each time the other way you would have to add water to the catch basin

 

[Lisak1]

So maybe I'm an idiot, but the original poster asked if his top basin could be larger than his bottom basin without being concerned about an overflow and further said he has a middle basin which is even larger than both top or bottom.

So my point was, he would not have an overflow concern IF he could calculate how much water the system would drain to the bottom basin when it was turned off. The top and middle basin would hold their share of the water. I understand that the whole volume isn't considered "transit" water, but it's still water that's needed to fill the system before it would even begin to flow - you can't run the stream or waterfall without those two basins first being filled. In my illustration, I need 70 gallons of water to fill those pools before the water even starts to flow. My reservoir holds 100 gallons - I can keep 170 gallons circulating in my system because I don't have to concern myself with the reservoir being able to hold the extra 70 gallons.

It makes total sense to me! But I have also been sampling my bourbon mashed sweet potatoes all morning so...

 

[Waterbug]

Lisak1 has it right.

Pools will store water unless of course you add some drain scheme at the bottom of each pool. That is very rare to add.

Although hard to see sometimes. Assuming the pools are all "full" with the pump off...when you startup the pump you will notice water flowing into the top pool but it will take a little bit of time for that pool to overflow. Same for the next, and so on. Same thing happens in streams. This happens because of surface tension and a few other things.

Same thing happens when the pump is turned off except in reverse. Turn off the pump and slowly the top overflow will reduce, then the next. The bottom pool has to have enough room to take that amount of water that still goes over each waterfall or that bottom pool will overflow.

I call this "extra" water the "charge". Meaning when you start the pump there is a certain amount of water that has to be added to the falls/stream to get it going, you charge the system.

The amount of water a system needs to charge depends on the amount of water being pumped, width of each falls, the height of the falls, surface material, shape of pools, wind, etc... First two are really only a factor in backyard systems.

Now, to the actual question...your bottom most pool can be the smallest, question is though how small and what the effect will be.

If super small and you have a very large pump that bottom pool can run dry before water is able to make its way back down. You can overcome this by turning on a water hose to add to that bottom pool while waiting for water to make its way down. If your hose can't keep up you can fill buckets ahead of time and dump those in as needed. If you run the system 24/7 it will continue to run. But if you needed to do this then the bottom pool will likely overflow when the pump is turned off.

If the pool is large enough to supply the pump while the system charges you will likely see the water level in the bottom pool has dropped. This drop can be a lot and the amount of that drop will actually be the system's charge amount. Most people don't like seeing that bottom pool being low so they add some water which, just like above, when the pump is turned off the bottom will overflow.

One more interesting thing, and what causes the biggest problem, is all evaporation will show up in that bottom pool. Takes a little thought - the upper pools are always being topped off so they're always full (while pump is on). But water still evaporates from the entire system. All that loss appears in that bottom pool. The smaller that bottom pool the more dramatic the loss will appear. Seen it many times where people come out the next day and see that bottom pool almost empty and freak out thinking they have a leak. They go online and get "great" advice on ripping their system apart to find the leak, and all kinds of goops to put everywhere making the feature look bad...all to find a leak that doesn't exist.

This is also why auto fills are added to the bottom pool.

 

[Meyer Jordan]

So maybe I'm an idiot, but the original poster asked if his top basin could be larger than his bottom basin without being concerned about an overflow and further said he has a middle basin which is even larger than both top or bottom.

So my point was, he would not have an overflow concern IF he could calculate how much water the system would drain to the bottom basin when it was turned off. The top and middle basin would hold their share of the water. I understand that the whole volume isn't considered "transit" water, but it's still water that's needed to fill the system before it would even begin to flow - you can't run the stream or waterfall without those two basins first being filled. In my illustration, I need 70 gallons of water to fill those pools before the water even starts to flow. My reservoir holds 100 gallons - I can keep 170 gallons circulating in my system because I don't have to concern myself with the reservoir being able to hold the extra 70 gallons.

It makes total sense to me! But I have also been sampling my bourbon mashed sweet potatoes all morning so...

Yes, but the volume of 'transit' water and only the transit water will determine if the lower pond will overflow and how much when the pump is turned off.

 

[RichardSJPonds]

It's doable, just make sure the basin can hold the water that will drain down or it'll overflow when the pump goes off.

 

[sissy]

True pump size does matter and how far the water has to travel up to the top .So I guess there can be a lot of thinking done on this and experiments on what you want .If the bottom is a pondless pool that yu only see gravel a mistake may be made not know how much water is down in the pump vault .Or if you want a little water above the rocks for birds to frolic in and a drink for butterflies and other critters

 

[Meyer Jordan]

Lisak1 has it right.

Pools will store water unless of course you add some drain scheme at the bottom of each pool. That is very rare to add.

Although hard to see sometimes. Assuming the pools are all "full" with the pump off...when you startup the pump you will notice water flowing into the top pool but it will take a little bit of time for that pool to overflow. Same for the next, and so on. Same thing happens in streams. This happens because of surface tension and a few other things.

Same thing happens when the pump is turned off except in reverse. Turn off the pump and slowly the top overflow will reduce, then the next. The bottom pool has to have enough room to take that amount of water that still goes over each waterfall or that bottom pool will overflow.

I call this "extra" water the "charge". Meaning when you start the pump there is a certain amount of water that has to be added to the falls/stream to get it going, you charge the system.

The amount of water a system needs to charge depends on the amount of water being pumped, width of each falls, the height of the falls, surface material, shape of pools, wind, etc... First two are really only a factor in backyard systems.

Now, to the actual question...your bottom most pool can be the smallest, question is though how small and what the effect will be.

If super small and you have a very large pump that bottom pool can run dry before water is able to make its way back down. You can overcome this by turning on a water hose to add to that bottom pool while waiting for water to make its way down. If your hose can't keep up you can fill buckets ahead of time and dump those in as needed. If you run the system 24/7 it will continue to run. But if you needed to do this then the bottom pool will likely overflow when the pump is turned off.

If the pool is large enough to supply the pump while the system charges you will likely see the water level in the bottom pool has dropped. This drop can be a lot and the amount of that drop will actually be the system's charge amount. Most people don't like seeing that bottom pool being low so they add some water which, just like above, when the pump is turned off the bottom will overflow.

One more interesting thing, and what causes the biggest problem, is all evaporation will show up in that bottom pool. Takes a little thought - the upper pools are always being topped off so they're always full (while pump is on). But water still evaporates from the entire system. All that loss appears in that bottom pool. The smaller that bottom pool the more dramatic the loss will appear. Seen it many times where people come out the next day and see that bottom pool almost empty and freak out thinking they have a leak. They go online and get "great" advice on ripping their system apart to find the leak, and all kinds of goops to put everywhere making the feature look bad...all to find a leak that doesn't exist.

This is also why auto fills are added to the bottom pool.

Which all supports having the lowest pond larger than any and all of the upper ponds. This is especially critical if a peripheral skimmer unit is employed on the lowest pond. Replenishing the needed amount of transit water when power to the pump is resumed may quickly result in cavitation, overheating and pump failure.

 

[Joe113]

So, would it be correct to say that in a simple pond/creek/waterfall, that if you had 900 gallons on your top basin and 300 on your bottom basin, you would have 600 gallons that would have to be accounted for in middle basins?

For myself it was easier to abandon this idea and try it somewhere else that I have space that I can have a much larger bottom basin. Make it more simple.