At high enough levels this can cause injury to plants and those plants should not be consumed 1.
Is it safe to water a garden with roof runoff.
One exception was zinc and elevated levels could lead to build up of this element in soils.
The untreated runoff quickly killed the salmon while the fish in the rain garden treated water survived.
Gardeners often collect water in a rain barrel with little to no protection from the roof s first flush of runoff.
Locate a rain garden at least 10 feet from your house and at least four times that far from a septic system or steep slope.
The water flowing from a roof does pick up a small quantity of contaminants including chemicals from shingles and gutters possibly bird and animal waste tannins and other compounds from leaves in the gutter etc.
Unless the zinc content is particularly high it is safe to use on lawns and ornamental gardens.
In one study most of the metals tested the same in rain barrel water as in rain water before it hit the roofs so little to no concern there.
Use it to wash cars and outdoor equipment and to rinse patios.
Curiously in other countries the inhabitants are not so squeamish and roof runoff water is their main source of drinking water soil microbes and root hairs carefully filter materials entering the roots.
So watering the soil instead of pouring it directly on the veggies provides an opportunity for the soil to work some of its purifying magic before the water is taken up by the plants.
If your property slopes toward any buildings you will want to divert that water.
Limited studies have been conducted focusing on the safety of roof runoff for vegetable garden irrigation.
Using rain barrels to collect roof water runoff.
But could the runoff water contain harmful elements or chemicals that are leached from the roof and pose a hazard to plant life or even be capable of contaminating garden soil and crops grown for food.
But you can also learn by experimenting.
Steep slopes can however be a good thing for stormwater absorption.
So roof runoff is not considered safe for human consumption in most countries at least not without filtration.
Designing a rain garden to handle all of the runoff from a roof or driveway entails careful calculations.
So roof runoff is not considered safe for human consumption in most countries at least not without filtration.
Build one watch what happens after a storm and then enlarge it as needed.
Also micro organisms can proliferate in the reservoir itself.
Steep slopes can be good for runoff keep in mind the slope of the land while designing your stormwater friendly landscape.