Water Collection System

The water collection system in the garage in its original configuration with a jet pump and pressure tank.
Fortunately, we were already primed to improve our water collection system. A few years ago, I replaced the shingle roof on the garage with a standing seam metal roof when I managed to get a good deal on surplus steel. This gave us an additional 600+ square feet of collection area, which has mostly been going to waste. Around the same time as the roof went up, we managed to secure several Intermediate Bulk Containers (IBCs) that had been used to ship corn syrup to a candy factory. IBCs tend to go for around $100/piece in our area, though we secured these six for $50/piece. The water pump I took out when we redid our household plumbing, a small pressure tank I had lying around and assorted other plumbing components — mostly scavenged or leftover from other projects — rounded out the parts list. One problem that remained was connecting the IBCs, with their bizarre threaded connectors, to more conventional household plumbing components. With calipers in hand, I was able to identify the thread as S60x6 and order the appropriate fittings from Global Industrial. I ordered six in order to bring shipping down from what it would be for four (yeah .. makes perfect sense) and so am ready to adapt the other two IBCs for future projects as well.

The downspouts on the back of the garage — future site of the greenhouse. The lower drain faucet and overflow junction can be seen on the central stack, with the upper faucet visible just to the side.
The solution to inflow came in considering outflow, in that I decided that I wanted to provide a powered option to pressurize water. This would allow not only the use of longer hose runs but would also open the possibility of emptying the system into our main cistern or even pumping it uphill into the currently unused water storage tank in our larger outbuilding. At the same time, there is great benefit to being able to gravity-feed water. Not requiring power every time you need to fill a watering can and being able to provide low-pressure water over long periods of time for irrigation systems are both appealing prospects. In the end, I split the system into top and bottom and provided a centralized junction where I could control the direction and nature of the water flow. The whole system, therefore, can be broken into three main flows: collection, pump-powered, gravity-powered.
Collection
Under each of the eavestrough outlets, I placed assemblies to collect the flow. The assemblies contain clean-out fittings on the bottom which can be removed in order to allow most of the water to fall straight through. This is useful in winter to avoid building up ice inside the system and also comes in handy any time I want to eliminate the majority of the collection flow. Knowing that the fittings for the clean-outs would be easy to misplace, I cut rings from 2″ ABS pipe and then cut out a slice from the rings so that they could expand to clip over the 1-1/2″ pipe used for the collection system. Using a file to rough up the surfaces followed by ABS solvent, I fused the clips to the backs of the clean-out fittings, allowing them to be snapped conveniently onto nearby plumbing so that they are always in reach when the system needs plugging. When the system is active, water is diverted out the side of the collection assemblies and down to a central pipe. The pipe contains a junction part-way up which acts as an overflow spout at the level of the top of the lower IBCs so that the system doesn’t overflow. The bottom of the pipe ends in a T fitting, with one side leading to a tap which can be used to empty the entire system and the other side heading into the garage and connecting to the lower IBCs through their lower fittings. In this way, 500 gallons of water can be collected in the lower IBCs through gravity alone.Pump-Powered

With the valve to the faucet off and the other two valves on, the pump can be used to fill the top two IBCs with rainwater collected in the lower two IBCs.

Out with the old, in with the … also old, but at least functional. The transfer pump plumbed into the system until a new jet pump can be scrounged.

With the valve to the top IBCs off and the other two on, the pump can be used to push water through the outside faucet.
Otherwise, the transfer pumps works in a manner similar to the intended use of the jet pump. By manipulating the valves at the junction point, the water from the pump can either be sent to the upper IBCs — preferably during off-peak electricity pricing hours — or to a faucet located on the exterior of the garage (soon to become the interior of the greenhouse).