Rainwater Collection

At The Fruitful Field one of our goals is to promote environmental stewardship.  One of the ways we do this is through water conservation through the collection of rainwater.

 Our Setup

We collect water from the roof of the church using professionally-installed gutters.  By choosing a collection spot on the west side of the church we were able to utilize two downspouts to increase the amount of water we can collect.  The water is pumped from the collection site to an 1100-gallon cistern located approximately 120 feet away.  From there a second pump is used to send it to where we need it.

 Filtration

Once the water has fallen on the roof and is on its way down the gutter the first thing we need to do is filter out as much of the dirt and impurities as possible.  In between rainfalls lots of things can accumulate on the roof including leaves, dead bugs and the not so occasional bird dropping.

The first step in filtration is a Leaf Eater downspout filter.  The water falls out of the gutter and onto a tilted metal mesh filter.  Larger leaves and unwanted things that washed off the roof are caught in this filter while the water passes through.  Since the filter is tilted anything that collects on the filter is eventually washed off, and the filter cleans itself.  Inside the downspout filter is a smaller mesh filter to trap finer particles.

The next step is a first flush filter.  This filter is designed to get rid of anything that is too small to be caught in the downspout filter.  It will also filter out anything that can dissolve in water.  Once again think bird droppings.  This is accomplished by catching the first 50 or so gallons of water from each downspout.  By the time that much water has passed through the system most of the impurities will have washed off the roof, and the water will be mostly clean.

Collection

Once the water has been filtered we need to get it to where we are going to store it. At the Fruitful Field that is in an 1100-gallon cistern that is located about 150 feet from our gutters.  Since we can not just let gravity get the water there we need a  pumping system.  After the first-flush filter the water is piped to a 55-gallon barrel.  Inside the barrel is a sump pump capable of moving 1500 gallons an hour.  When the barrel starts to fill up a float switch turns the pump on, and the water is pumped to the cistern.

 Cistern

Our cistern is an 1100-gallon large plastic barrel.  One of our volunteers actually found it on the side of the road, and we fabricated a lid from plywood and two-by-fours.  The water from the 55-gallon barrel is pumped into the top of the cistern.  When the cistern is full an overflow takes care of the extra water so it will not run down the sides and erode the dirt that the cistern is sitting on.

Pump

A pipe from the bottom of the cistern goes through a mesh filter in place to remove any fine particles left in the water.  It then goes to a pump and bladder tank system.  When on this system will keep a pipe on the output pressurized similar to the faucet in a house.  Since the pump is stronger than the output requires it does not need to run all the time.  It pressurizes the tank and shuts off.  At this point the water is usable the same as it would be from a faucet.

Rainfall

Due to the large roof area we are collecting from quite a bit of water can be collected in a very short amount of time.  From what we have seen since setting up our system, we can fill our cistern with under an inch of rainfall.