Rainwater Harvesting

Hi warren, Austrailians lead the world in rainwater Harvesting and storage. They is a lot on the Internet on the subject. Can you please give us some pointers from your perspective as to what works, and what doesn’t?
Thank you.

Chuck, I have two collection sites, the House which has a pretty big roof and the workshop shed out the back which has an enormous roof. Both these are 5,000 gallons and fill pretty quickly if we have good rain fall. I have added a pic of some water storage tanks available here in Oz, there are slimline versions so they can be put along side the house for space saving.

Thanks Warren. We installed a 300 gallon barrel last year and you’re right, it fills very quickly. A quarter inch of rain filled it off of about 500 sq ft of roof. I have to find an inline electric pump to help distribute it as gravity feed is insufficient. The water flow is low at best and there is a very slight uphill grade over the length of the back yard which is enough to stall the flow about half way out. It’s been good for the bonsais on the patio, though.

Kim a lot of the companies selling these big tanks around $2000 Aus have packages where an electric pump is thrown in as the deal.
Cheers Warren

Thanks, Warren. They may here, too. Mine was but a fraction of that price.

Here in the Gulf Islands we have total watering bans most summers, and are encouraged to gather rainwater. I have 2x 2500 gallons just downhill from the house and shed. We use a pressure pump that works on demand, pumping the water back up to where the gardens are. It works pretty well- I have three taps attached to the system that stay pressured up, so it’s just like using water off the mains.

I’ve noticed a change in the weather there on the prairies. The winters are milder and less snow.
The summers are dryer, with less predictable longer dry periods and huge down pours of rain over short
periods. Last summer it became a question as to water the baby roses, or the vegetables.

I’m looking at putting in a drip irrigation system using stored rainwater.
Warren, Don and Kim and others who harvest rainwater. How do you keep the water from going stagnant?
Do you First Flush Diverters to keep bird droppings and debris out of the system, especially if you are
using some of the water for potable use.

Not sure what you mean by stagnant- water in tanks is by definition stagnant, isn’t it? Some people put a bit of bleach in every once in a while to keep the algae growth down, but I have fully opaque tanks. The water has never gotten smelly or anything. I screen the top of the tanks with fine mesh to keep bits of organic stuff from getting in, and also to keep the mosquitoes out. They will breed like mad in water tanks.
If you want to drink it, you should filter and have UV sterilization- there are home kits out there. There is some risk of giardiasis and salmonella from poop on the roof.
I don’t use flush diverters- I just have two grades of screen, coarse and fine, that all the water passes through. I just need to keep the screens (and eaves) clear.
There are good calculators out there to estimate your supply vs your use. Premierplastics.com is who made my tanks- they have a lot of info on their site.
I imagine on the prairies you’d need to bury the tanks to use them year-round. That can get expensive. Or just use the tanks seasonally.
I really love my tank system- this summer in the middle of serious drought we were able to water fairly liberally. It’s amazing how much water falls from the sky- the trick is capturing it.

Mine has only been full about a year. The tank is dark green and there are several feet of hose between the rain gutter and top of the tank. The roof there remains free of debris but not blowing dirt/dust. The water coming from the spout is clear with no smell nor visible particles. It’s only water pressure that seems at issue.

I have a 1200 gallon tank I want to use but it is clear plastic. I’m going to paint it and build a shed around it to keep out light.
Donald, what ratio of chlorine bleach can you safely put in the holding tank?
I need this system to manage itself. My fear is that the drip lines would become plugged with algae.

Re bleach- there’s guidance online- the consensus seems to be maybe 1/4 teaspoon per gallon, but I would do a bit of research.
Re: algae in the drip lines- you can get in-line filters. Recommended.

Instead of bleach, why not use hydrogen peroxide?