Rainwater collection: what can you tell us?

I am interested maybe in doing some rainwater collection. The usual uses: gardening: car washing, are things we don't usually do here, and i'm wondering what else it could be used for.

for drinking, what's required? I understand this is widespread in bermuda (if i am thinking of the right island)
we don't really have any droughts here and are on city water, but.. you know.. Just curious :)


  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: Rainwater collection: what can you tell us?

    I have done it in the past for outdoor stuff, but never drinking. If I were to drink it I would R/O and somehow sanitize it, maybe Chlorine? I believe in Hawaii it is quite common to collect the rain water for domestic use. I remember being on a helicopter tour of the volcano flying over the big island and asking the pilot why everyone had small pools in their back yard, then he told me those were rain water collection tanks.

    I can't remember but someone linked to a nice rain gutter collector that got rid of most of "junk" but kept just the water. When we would collect it simply ran in to a big 250 gallon tank on the high side of our property and then gravity fed down. It was just a simple overflow to keep from over filling. It is amazing how much water you get from even a light rain and how much “junk” you would get in the tank.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • BB.BB. Super Moderators, Administrators Posts: 32,008 admin
    Re: Rainwater collection: what can you tell us?

    I believe that I have read/seen places (Florida Keys/Caribbean islands) where simple catchments are used for drinking water--and (IIRC) people not used to drinking it (i.e. visitors) can get (mildly?) sick from drinking it. Boiling your drinking water would probably take care of those issues (for example in Taiwan--even city water is still boiled before drinking).

    The short answer is that you probably use 10 to 1,000 times more water for bathing/flushing/washing/irrigation/etc. than for drinking. Using highly cleaned/processed drinking water for watering the lawn and flushing the toilet is probably a good use for rainwater catchment.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sodamosodamo Solar Expert Posts: 54 ✭✭✭
    Re: Rainwater collection: what can you tell us?

    OK, guess I might qualify for this one :) We call it a catchment system and is very common here in our piece of paradise

    Our current living situation includes a 3000 gallon poly tank for storing the rain water collected from our metal roof. Off the shelf Home Depot gutters feed into 3 inch PVC to the tank. From time to time I add about a cup of bleach to kill off any possible little criiters. Water is pumped through 3 filtration stages, the last being a carbon filter to remove the chlorine.
    A few pics at: http://travel.webshots.com/album/198517619KSTabh?start=0. We use the water just lke municipal, although it is probably cleaner as it doesn't get supplemented with treated waste as in some cities.

    The system at the new house isn't hooked up yet, but will be a bit different - 4 poly tanks @ 4000 gallons each, totalling 16000 gallon capacity. Will use similar filtration, but larger units and finally pass thru a UV treatment. Again, this will be our only source of water at the house.

    Although a few years old, Patricia Macombers guide is probably still the best consolidation of information on the topic. You can see or download from this link: http://www.ctahr.hawaii.edu/oc/freepubs/pdf/RM-12.pdf

    Feel free to ask any questions.

    10.04 KW panels
    3- FM80 CC
    4- FX3048T Inverters
    12 - 1350ah Rolls Surette 4v
    24kw generator (Chinese, built in Az)
    10kw MEP803A backup generator
Sign In or Register to comment.