Calling for ideas - new pond project

[AussieGardener]

Good morning everyone from coastal North Carolina (USA).

I am proposing to divert rainwater from our house and into a to-be-constructed pond. I have attached 2 drawings with my ideas here, along with the devices I have found that conceivably could be used to send water off to another destination.

The pond is only to provide a habitat for frogs, and we’ll also populate the pond with plants. We probably won’t bother with any filtering - my experience with naturally occurring frog populations is that they seem to thrive on filthy water - the more organic material/the stinkier - the better!

I am ‘abundant’ in 2” and 1 ½” Sched 40 PVC pipe, so intend to burn that up in the below-grade traverse between the downspout and the pond location (just finished a complete reworking of pool system; lots of used pipework left over). This is my first time attempting to manage rainwater. There is approximately zero debris entrained in water coming off the roof, so only very light filtering will be needed as the water is intercepted. I have a 10’ x 12’ pond liner ready for this.

Some questions :-

1. Starting with the downspout, which is 2 x 3 - are any of these illustrated fittings (attached) likely to be the best choice? My thinking here is to cut into the downspout 12” or so above grade, perhaps even higher. This way I can build a hydraulic head that will assist in moving the water thru relatively small diameter pipe, and also to get the flow up and over the lip of the pond.

2. Speaking of water being fed into the pond - I am assuming it is not a good build practice to attempt to enter the rubber pond liner below grade with the pipework? That would presumably involve a gasket and cement or solvent to make a water-tight connection. I am more inclined to run the pipe back up above grade and over the top, then covering it over with rocks. But I thought I would collect any other ideas.

3. Pond design - we’re only ½ mile from the ocean, so we’re dealing with straight sand. I am not clear on whether there is any way to build steps into the pond opening as I form up it’s shape. And even if I could manage to profile some of the pond in that way (would need to be quite wide to prevent collapsing), I suspect the first time someone waded in there to service anything, the shape would collapse quickly. There might be a known method using say build up steps of treated lumber - but I have not yet found anything relevant through my searches. Perhaps I can ‘pioneer’ something.

I am looking forward to seeing and implementing other people’s ideas. The motivation for this project comes from the fact that our pool was offline for months, turned green while we were away, and when we returned found that a vibrant frog community would gather around it each night - with the typical deafening chorus. I am willing them to be patient while I build their new home - now that the pool is circulating with fresh but salty and chlorinated water, I imagine them hiding in the leaf litter, confused…. !

 

[addy1]

I have my gutters feeding our ponds. We are on a hill ponds downhill from us.
I just put gutter ends into the 4 inch black drainage tubes. Buried the tubes, fed them over the edge into the pond.
Covered with rocks.
Non formal pond

 

[GBBUDD]

while sand seems to be a nightmare to work with and it can if you do not attack it correctly but it can also make things very easy once you know the tricks.
1. retaining walls or wood like you said or retaining wall blocks that would sit in the pond on layers of gravel or process. anything that will not wash away.
2 over dig your pond, get rocks just slightly taller than the shelf. pull the liner in over these rocks and back fill up to these same roacks whala you have a shelf once you throw the liner back. make the shelf as wide as you'd like and where ever the next rise is do the same with slightly taller rocks than the shelf would be.

a cistern is advisable your little pond will have huge water swings a cistern can provide stable water levels for the frogs. a auto water replenisher is not what frogs would love.

a 2inch pipe can not handle a the amount of water from a down spout fully . . downspouts are closer to two 2" lines
they sell simple strainers for collecting rain water . the first is close though it will aloow a lot of fines to make there way into the pipes and pond. we have all cleaned gutters it's amazing the amount of buildup there is

 

[AussieGardener]

Thank you addy1 and GBBUDD. I am going to add a little more of my thinking here - my experience with small ‘simple’ ponds (no inputs except for occasional rain landing directly on the pond) is that they get pretty dark and stinky over time. My first pond (apx 20 x 15 and built up with rocks) seems to be very successful for frogs and aquatic plants, even with the state of the water.

This time, I am thinking to allow for ad hoc recharge with rainwater events. With a rubber liner in place, the thinking is that the runoff will likely be enough to keep things topped off, allowing the excess to just discharge onto the surrounding sand. I have no interest in introducing fish - we’re often away from home for extended periods, and I don’t want to get involved with feeding, cleaning, etc. That’s the great thing about frogs in my opinion - they’re VASTLY entertaining, and they completely take care of themselves.

I will learn as I go, but if the 2” pipework can’t handle all flow coming down from the roof, the excess will just overflow out of the top of the downspout adaptor fitting. This is straight sand and the discharge point if away from the exterior wall of the house, so I don’t have any concern about water causing issues with the house. In future, I could arrange for the overflow to be directed to one side to maintain a rain barrel.

Does this then sound like a good approach? I looked up cisterns and realized that they are probably used to quiet the water and encourage solids to settle. I really don’t think we have an issue here. The gutters are generally very clean when I inspect them - the trees don’t get tall enough here to make it easy for leaf matter to get up on the roof. (first time I have not had to deal with regular gutter maintenance). Some of the fittings I showed in the first post do allow for deflection of some debris anyway.

I have one more question : I roughed out an aprox location and shape for the pond, and then bought a 10 ft x 12 ft liner. How does one shape the dug out area so that most of the liner is being used? Of course, the deeper you go, the more of the liner will be used up and therefore not available to provide as much for the sides. I guess I can dig, test fit, and backfill as needed. Because I am digging for frogs and plants only, I am not going to bother going deeper than a few feet - say 3 ft?

 

[GBBUDD]

3 feet deep will give you a max of 3 feet wide if your just doing frogs id do 18 inches deep , deep enough to hold enough water through a dry period yet deep enough to give them a home in winter where they won't freeze

 

[sissy]

I can't have my downspouts feeding my pond because of shingle roof . I do have them going into a under ground tank that I drop my extra pond pump down into to water my lawn . The gutters off the carport and all 3 sheds and the carport are metal so I use rain barrels on them with spigots nstaled and window screening on the top to keep bugs and any stuff that falls from the trees out . I make manure tea in them to fertilize the grass . But this summer all we have had is rain . My ziosa grass has never been so green . I go to North carolina to the Eden flea market . Bargains are great there . I got 2 nice lilac there 4 feet tall for 5 dollars each .

 

[sissy]

Do you get off shore storms . I know my one brother lives in KILL DEVIL HILLS NC and he can get some really bad storms and flooding

 

[addy1]

We have a shingle roof. Never has bothered the ponds. The run off from the roofs.

 

[GBBUDD]

because of shingle roof

what type of shingle roof are you talking about? there's only a copper roof i would not use rain water from

 

[sissy]

asphalt shingle . There is grit that comes off of it . I had to clean it out of my underground tank with a sump pump . This roof is new as of last year but all those roofs let some of the grit loose . Especially in heavy rain storms . The house was built in 2004 and GAF roof only lasted 24 years and you could see it was brittle . I had to keep pumping water into the under ground tank to stir up all the grit to remove it all . It also smelled horrible .

 

[AussieGardener]

Thanks all. 18” sounds good, and I think this will also make the ‘shelf issue’ (to stage aquatic plants) easier to handle. No concerns here about the shingle roof - at least not in the planning phase. If I somehow see grit making it to the pond, I will arrange some sort of trap with cleanout.

Sissy, I am just a few miles from KDH. Does your brother also have ponds, or interest in ponds?

 

[addy1]

Yeah grit comes off. Still had never caused a pond problem.
Fish frogs etc healthy.

 

[Lisak1]

A cistern is also to store water - you may find that during large rain events you lose a lot of water to runoff. If you're able to store it underground you have a more reliable source of water to keep the pond topped off. With our 1000 gallons underground, we have only had to top off once since April and we're having a relatively dry summer thus far. If we relied on rainwater alone, we would lose a lot during major rainstorms.

 

[GBBUDD]

asphalt shingle . There is grit that comes off of it . I had to clean it out of my underground tank with a sump pump . This roof is new as of last year but all those roofs let some of the grit loose . Especially in heavy rain storms . The house was built in 2004 and GAF roof only lasted 24 years and you could see it was brittle . I had to keep pumping water into the under ground tank to stir up all the grit to remove it all . It also smelled horrible .

The grit your referring to is stone it's crushed stone. That's what gives the color.

 

[GBBUDD]

A cistern is also to store water - you may find that during large rain events you lose a lot of water to runoff. If you're able to store it underground you have a more reliable source of water to keep the pond topped off. With our 1000 gallons underground, we have only had to top off once since April and we're having a relatively dry summer thus far. If we relied on rainwater alone, we would lose a lot during major rainstorms.

There's another big advantage to underground cisterns they are an air conditioner for the pond as underground is 55 degrees and in the wi ter it helps to provide a little warmth.
They do collect some debris in the bottom yes that is for sure. But never had a spike of any kind. I'm sure there's a entire eco system at work down there. More surface area and more settling chambers. The more water the more o2 the more your pond wull not fluctuate quickly