Intake Bay Design Equations and Numbers Needs

[GBBUDD]

Idk my intake bay pulls all the floating crap into it, which is mostly plants that are getting ripped up by koi and those annoying helicopters seeds off maple trees this past spring. I do have those Aquascape power heads in the pond creating a circular flow near the surface, so surface debris gets pushed in the direction of the intake bay. Will say leaves aren’t an issue with my pond, as none really fall into it. Mostly went with intake bay over negative edge due to the turtles in my pond.

Agree that you can size a skimmer for a large pond, still use a skimmer at the far end of my pond by the bridge to feed one of the bogs. The other skimmer is abandoned at the moment, in favor of the intake bay, but May end up putting a pump of some sort in there if I add another water feature like one of the 4-5’ tall urns…..

With the intake bay as well, you can always add or remove rocks at the weir/entrance to the intake bay to create the desired effect. Ie widening/narrowing the weir, lowering/raising the depth at weir entrance even after the pond is done, if it doesn’t come out how you imagined.

I KNOW your pushing a lot of water. for the most part a 3 or 5000 gph pump i don't see it doing much pulling in from the surface . it will draw from all levels of the water column. i am just saying a negative edge or skimmer suck strickly from the surface where the newest items that fell in the pond can be drawn out the quickest

 

[jgell]

In one of the videos, John talks about 2000 gallons of water going over the hill if the power goes out. I may be misunderstanding something here but it seemed like in his example the water in motion was from the waterfall and the top 2 inches of water in the pond that would spill over the negative edge. So if the catch area of the negative edge were designed such that, in the event of a power outage, it would fill up with water to a height equal to that of the pond then the top 2 inches of pond water are eliminated from the equation. Thus leaving me with only the water in the water fall to worry about catching and holding until power is restored. Am I missing something? Is there a problem with allowing the the catch area to fill with water when the pumps aren't running other than debris back flowing into the pond? Negative edge ponds have a constant water level but are they designed to be able to hold another inch or two of before spilling there banks? If so then I would guess the pond itself could be the reservoir for the waterfall if pond had enough surface area and the water wasn't too big?

 

[GBBUDD]

Look at it this way if you have a pressurized 2" line that pushes out 8,000 gph and your spill way " negative edge allows for 2,500 gph to free flow one inch of water over the negative edge then your water level to the pond will rise until the necessary height is achieved to except the amount of flow so you would need three inches in height of water passing over the negative edge to come close to the pressurized water flow from the 2" line that is the water drop of the pond level. but while the power is on it stays a constant. as tot he falls i would make pools in the falls so i did not need to catch that much water from simply a water fall this will also allow for your plants along the falls to survive as they won't dry out. yes there will be some water no matter how you slice it i would just not build one that completely empties out when the power goes down

 

[Rashad]

I have an intake bay with just one aqua block and vault, Pump is 2000 gph, pond is about 1200 gallons, and I actually have a ball valve partially reducing flow to increase head so the pump isn't operating at full capacity, and the intake bay works great, but you have to be on it when you're having leaves fall. I didn't quite realize the toll cottonwood seeds were going to take on the pond. At the height of the season I could scoop out all the cottonwood fluff and an hour later the whole thing would be covered again. But if I had a skimmer they would be clogging up the skimmer so at least I think the intake bay is better in that regard. I agree negative edge would be even better if it's a possibility. I just wasn't up for it when I built my pond.

 

[GBBUDD]

THeres no perfect this is it ! this is the only way it works !.

 

[jgell]

So now I’m leaning towards negative edge. Immediately after the negative edge would be the catch area comprised of a few aquablocks topped with appropriate sized gravel. Then followed by a rectangular reservoir that would be capped with a duck pen. The duck pen would be modular so sections could be removed if ever the need to get into the reservoir. Basically I’m envisioning building a deck over the reservoir with duck pen on top of the deck. So the reservoir would have no need for aquablocks or a gravel top, if all goes accordingly no one would know the reservoir is under the pen. Here is my next question: how shear and deep can I make the walls of the reservoir if there is only water in the reservoir applying pressure to the liner and the dirt behind the liner? I was thinking about maybe making a box of treated lumber for a structure for the reservoir and a foundation for the deck. If I could get to 5x10x4 that would be a 1500 gallon reservoir and that should be enough.

 

[Rashad]

How would you support the deck over the reservoir? Just way cantilevered out? That's going to get expensive real quick. Probably more expensive than just filling the reservoir with aqua blocks. You'll also need cleanout access to drop a pump down there to pump out gunk from the bottom periodically.

Also plan for overflow from the reservoir if you get a ton of rain.

 

[GBBUDD]

The idea is to dig your hole straight up and down walls the size of how many blocks you use. They determine the exact measurements . BUT YOULL WANT TO LEAVE SOME ROOM so you can get the two layers of fabric and one layer of rubber and preferably sand.

So dig the hole. Dry set the blocks if you need to to check the size fits in the hole. Line it with fabric . Install the rubber and a second layer of fabric over the liner. Place your matrix blocks and once thats done pull the fabric and liner in and cover the top of the blocks. This keeps dirt and such from falling in . But you want to leave one area open to have the water drop in. Backfill the remaining with sand that will hold up against collapse. . If your prefer you can install the liner like a pond and just rock over the top of the blocks.

 

[jgell]

How would you support the deck over the reservoir? Just way cantilevered out?

Starting with a level area I would dig a rectangular hole and put a deck over it which would be supported by a substructure outside of the hole on all four sides or by a box I build to support the walls of the hole. No need to cantilever.

The idea is to dig your hole straight up and down walls the size of how many blocks you use. They determine the exact measurements . BUT YOULL WANT TO LEAVE SOME ROOM so you can get the two layers of fabric and one layer of rubber and preferably sand.

Yes, this is the plan for the bog. What I'm attempting to do here is make a reservoir without using aquablocks. 1500 gallons worth of aquablocks is no small amount, I already plan to buy 64 blocks. I am just wondering how that can be done? I'm thinking I could dig my 5'x10'x 4' deep hole and set 4"x4"x6' treated posts around the sides set in 2feet of concrete below the floor of the reservoir hole and then build walls using 2"x12"s. Put the liner in the hole and over the walls. Use the walls and 4x4s as the foundation of the deck. The deck itself would add support to the walls of the reservoir. Build the duck pen on top of the deck so the space is used for something. Portions of the deck and pen would be designed so they could be removed for access to the reservoir below. Does this sound like something that could work?

 

[Jhn]

would not bury 4x4’s, 2x12’s in the ground unless you can get them rated for ground contact, otherwise they will rot out in short order. If it were me I would just dig the hole, as @GBBUDD suggested, walls straight down, and back fill Around it no need for reinforcing the walls. If you are going to deck it over sink 6x6 posts into the ground like a normal deck, no sense in cheaping out on 4x4’s instead of using 6x6’s .

 

[combatwombat]

If you want a really sturdy hole at a reasonable cost without matrix blocks, you could line it with the large format landscape retaining blocks before installing a thick underlayment like old carpet and then your liner. You could also just dig the walls of your hole at 15-30°. That will add a lot of stability.

For an unsupported wall, highly recommend ensuring runoff will move away from that area and not seep in and wet the wall.

 

[Lisak1]

I'm a little slow - are you planning a "reservoir" that's really just a pond under a deck?

 

[jgell]

I'm a little slow - are you planning a "reservoir" that's really just a pond under a deck?

You're not slow, I'm not good at explaining what I'm imagining in my head. But yes, that is what I'm planning.

 

[Jhn]

@jgell Okay, now I get what You are doing, as I said if you choose to reinforce the walls with wood, make sure it is rated for ground contact ( not all treated lumber is the same anymore) Also, watch using 2x’s on edge if you leave large enough spaces between the posts the 2x’s don’t have the structural integrity to hold back much over time. Would go with cw’s suggestion of blocks or you could use treated 6x’s stacked and pinned together at the corners, then just build the deck sitting in the top 6x.

 

[GBBUDD]

One and done go with concrete block .