Why should I harvest rainwater?

The benefits of rainwater harvesting at your home go far beyond your property. Utilizing rainwater reduces the energy and chemicals needed to sanitize and pump water, limits the need to draw from groundwater sources, and retains water in the watershed in which it fell. Rainwater harvesting also halts the negative effects stormwater can bring, such as erosion, water temperature fluctuations in streams, and pollution. Rainwater harvesting is a key component of sustainable living.


Is the water clean?

Yes, rainwater is free of the contaminants found in municipal water (ie pharmaceuticals, fertilizers, and pesticides). Off the roof it’s non-potable (not for drinking) and best used for irrigation. With a well-designed rainwater catchment filtration system your rainwater will exceed EPA standards.


How much rainwater should I harvest?

This depends on what you want to use the water for. Contact us at [email protected] or call us at 503-922-3583 for further information and estimation.


Do different types of roofs have different efficiencies for capturing rain?

According to HarvestH20.com:
· For a tile/metal roof assume a 95% runoff efficiency
· For a concrete/asphalt roof assume a 95% runoff efficiency
· For a gravel roof assume a 70% runoff efficiency
· For a bare soil roof assume a 75% runoff efficiency
· For a grass roof assume a 17% runoff efficiency


How much does a system cost?

The cost depends on many different factors including: size of system, uses of water, location of downspouts, etc. Please check out our website store for basic pricing without installation costs or contact us at 503-922-3583 or [email protected].


What is the warranty on your tanks?

We carry two different brands: Norwesco and Bushman. For information on Norwesco, go here and for Bushman go here.


Is the color of the tank significant?

Yes. The most important thing is that your tank is opaque. You do not want to use clear rain barrels or cisterns. This will increase the risk of algae growth.


What is the maximum temperature the cisterns/barrels can withstand?

120° Fahrenheit. At this temperature, your storage tank can be compromised.


Can I leave my tank outside in freezing temperatures?

The tank does not have a minimum temperature restriction. If you expect freezing temperature, we recommended you allow room for expansion to prevent cracking.


What type of foundation do you recommend for a cistern?

We prefer 1/4 minus gravel (found at your local sand and gravel retailer) to fill, a minimum of four inches deep depending on tank size and native soil characteristics.


What about mosquitoes getting in the tank?

Our barrels and cisterns have screening with prevent mosquitoes from entry.


Can you hook two tanks together to get larger capacity?

Absolutely. Depending on your space, we can accommodate many different needs to ensure you can capture as much rain as possible.


How do I maintain my system?

We recommend you inspect and clear debris from roofs, gutters, screens, and first flush diverters every three to four months.


What happens when my tank is full?

Your rainwater system must include an overflow pipe. This prevents back up in the storage tank and allows the water to flow into the watershed in which it is placed. The overflow must drain to a location approved for storm water by DEQ. This could be your existing drain tubes or a rain garden that complies with municipal code regulations.

Portland Purple Water LLC 503-922-3583 CCB#: 187045 WA#: portpw913ob