Our Rain Water Harvesting workshop was a success and the Bed-Stuy CSA Headquarters now has an awesome new RWH system that will be used to irrigate gardens (front and back yards), feed into their washing machine and water their chickens. The systems cisterns (700 gallon capacity) were built with salvaged materials, and the rest of the materials (PVC pipes, shallow well pump, etc) were made possible due to the support of the Citizens Committee for NYC.
photos by Anton A
Here is what the design called for:
Residents of the brownstone wanted to be able to have 15 gallons a day to water their front yard garden, and wanted to also have infrastructure in place to irrigate a roof top garden that they will plant in the coming year. They wanted 40 gallons a day accessible for washing machine use, and a minimal amount of water in the backyard for chickens and landscape. The challenges of this system were:
1) Both the roof and the 2nd Story balcony could not support very large cisterns
2). The roof is pitched to send water to the backyard (which happens to be the place where the least amount of water was needed.
3) The system had to be designed in a way that would allow possible adaptation once the roof garden was installed (i.e. adding more capacity) if needed.
Here is how the final design went…
Water falling off the roof travels down to the back yard and into the first flush. The purpose of the first flush (being constructed in this shot) is to divert the first bit of rainfall that hits the roof away from the cistern since it is usually full of pollen, leaves, bird droppings, and whatever else has fallen on the roof since the last rainfall.
After this initial bit of dirty was has been diverted, the rest of the rainfall is then directed to our main cistern. Consisting of (2) food grade 275 gallon totes (industrial liquid containers), the main cistern acts like a battery from which the other parts of the system can be fed. Since totes are meant to be stacked on top of each other, and since we are all about stacking functions, a tree fort was constructed on top of the totes ( tree fort pictures to come) to make sure that no space was lost in the back yard! The system is designed as a loop, and the totes are the starting and ending place for all water.
From the totes water is then pumped up to a 35 gallon food grade barrel on the roof. This barrel can then gravity feed down to the front yard, and also gravity feed to the roof garden (once it is installed). We used a Wayne shallow well pump for this job. It was considerably cheaper then any other pumps we could find that would fit the application. We’ll let you know how it works.
From the 35 gallon barrel on the roof, the water coming from the pump then overflows into a small (two 55 gallon food grade barrels connected together) cistern on a 2nd floor balcony. These barrels gravity feed to the washing machine. Rainwater washed clothes!
The overflow from this barrels then falls down back into the totes (main storage) in the backyard, completing the loop. The idea is that, one day, the pump will be hooked up to a solar panel, and whenever the sun is shining the pump will be circulating water throughout the entire system, making sure that water is available everywhere it is needed. For now, the pump will be run manually to replenish the system whenever necessary.
55 gallon food grade barrels can be obtained for free from soda bottling plants (they keep syrup in them), food shipping places (pickles, olives, marichino cherries all come in 55 gallon barrels) and overseas shipping companies. The totes (275 gallon stackable containers) were obtained from a soda bottling plant and can also be bought used (make sure they are food grade!) on Craigslist.
For connecting pipe to barrels we used:
a PVC male adapter (plumbing section of your hardware store) with a gasketed lock nut (electrical part of your hardware store) and sealed with a little silicon.
The lumber for building stands for the barrels was dumpstered or obtained from Build It Green NYC
Have questions about building a rainwater harvesting system for yourself? Email us at ExpeditionGowanus@Gmail.com