Need some help in designing a rain catchment system

[madhen]

I have a 1500 gallon water tank that I recently replaced with a larger one. I'd like to use the old tank to catch and store rainwater for use in the garden, but I am stuck as to how to do so.

I can't put it near a gutter, because it is so large, it doesn't fit next to the house. Besides, I'd LIKE to put it near the garden, so it would be convenient to run a hose from it. But I can't figure out how to divert water into it, and I also can't figure out how to screen out twigs, leaves, etc.

The lid is a large circular one on the top of the tank. I have looked on-line to try to find a "conversion kit" to make it into a catchment tank, but everything I find is for 55-gallon tanks attached to house gutters.

[Judi Dial]

Try french drains? There's info here about doing your own drainage. Design info is almost the last item:
How To Design a Lawn, Garden, or Yard Drainage System

Judi

[madhen]

I'm trying to figure out how the French drains would apply, Judi, so I don't miss a good idea, but I'm apparently not putting 2 + 2 together. The water tank is about 8' high, and the lid is on the top of it (spigot on the bottom), and the water would have to be collected and enter the tank from the top, so I'm not seeing how the French drain would work. I like the idea of maybe a perforated container, however, with gravel or some other substrate to catch larger particles, set up over the intake area!

[Russ]

Madhen: Can you get me some pictures? Of the tank and location.

[madhen]

Here is the tank. The location is not fixed yet, but it will be on level ground and at least 15-20 feet away from any building/structure. Most likely, it will be near the garden area, so it can be used both for watering plants and as an emergency water supply for the goats/donkeys/chickens if my well goes out.

[Russ]

I assume you want this to work completely using gravity feed only?

[Russ]

Here ya go! Looks exactly like your tank too! (2nd photo)

Tiny House Design , Archive The Field Lab – Extremely Sustainable Homestead

I know you want it away from the house a bit so you will have to run more PVC pipe.

[madhen]

That's nice, Russ, but it would not be feasible for me to run PVC pipe from the structures. The tank won't be anywhere near the house and probably far enough away from the only other structure (chicken coop) to make running that long of a stretch of PVC problematic. I am looking for something a little more free-standing - maybe such a thing doesn't exist.

As for your earlier question, my preference would be gravity fed, but I don't have any objection to a small pump (manual or electric) that can be used optionally.

[Russ]

Without a surface area for the rain to run off of, I'm afraid the tank won't do much good.

You can ship it to me though.

[madhen]

That is the problem I'm trying to fix - creating a funnel or some sort of way to channel the water into the tank, but without the use of a roof. Otherwise, my only option is to have water tanked in and to fill it that way. I'm not opposed to that, but want to at least supplement that with natural rain water. (And not haul it by the bucketful from my house.)

[Ceashels]

You might need to fill it manually. A small pump and hose could be used to fill as needed then put away till next time. You might be able to make a small collection area above it like a small inverted tent to keep it topped off when it rains.

[Russ]

probably far enough away from the only other structure (chicken coop) to make running that long of a stretch of PVC problematic.

As for your earlier question, my preference would be gravity fed, but I don't have any objection to a small pump (manual or electric) that can be used optionally.

I think I would re-evaluate this. If you're willing to use a small pump why not place it near the coop? Just curious why you wouldn't?

[madhen]

It would be problematic because I have a run coming off the coop that is between the coop and the optimum place for the water tank. There are also a couple of trees near the coop that make placing the tank there impossible (and the trees are there to shade the coop, so they need to stay). Add to that the problem that most of the ground around the coop is sloped, as it sits on a hill. Potentially, I guess I could try to set up the pipe in such a way that it is attached to the run, giving it the extra support it needs. I'll have to re-evaluate the gutter and see if it would work that way. I was thinking more along the lines of building a frame around the tank with an inverted sloping funneled roof that fed directly into it, but maybe I'm overthinking the process.

[Judi Dial]

If French drains are what I think they are it's gravel on an incline with a perforated pipe in the middle to carry water. You should be able to route water I'd think?

What you're proposing to do is sort of like a rain garden too. Something equally low tech...

The rain garden guide here talks about how to route water to where you want it. See pages 6 on.

http://seagrant.oregonstate.edu/sgpu...ubs/h10001.pdf

Judi

[KeithBC]

Try an inverted siphon.

At the house, replace the regular downspout with a sealed pipe (like 2" PVC, where the joints are glued). The important thing is that the top of the pipe be higher than the top of your tank.

The bottom of the 2" PVC pipe connects to a horizontal pipe that can be on the surface or buried. It runs out to wherever the tank is. At the tank, it connects to the bottom drain connector on the tank.

Water will fill the vertical 2" PVC pipe at the house to the same level as the water in the tank. That is why you can't use regular downspout - the joints would leak. The water will flow through the horizontal connecting pipe to the tank. You need to make sure that the horizontal pipe can handle the flow of a heavy rain, or the vertical pipe will back up and overflow.