Rainwater is 100% soft water. Free of the salts, minerals, and chemicals that are found in municipal treated water, groundwater, and surface water, rainwater is pure hydration. Salts and chemicals build up in your soil over time and these residues are tough on plants. This effect is exaggerated in potted plants where the accumulation is more pronounced.
Rainwater is slightly acidic—naturally! Green gardeners know that most organically grown plants prefer soil pH levels between 5.5 and 6.5. This is on the acidic side of the neutral pH 7. Irrigate with rainwater and help keep your soil pH in perfect balance ongoingly!
Stored rainwater contains some organic matter. If collected from your rooftop, rainwater contains traces of organic material. While the water is very clean and should run clear, it has been exposed to anything on your roof. We’re not talking about chunks (these get pre-filtered out on their way into properly-designed rain barrels)–we’re just talking about contact exposure to leaf litter, pollen, bird droppings and the like (which perhaps not surprisingly are great for your plants). It’s like a light application of fertilizer every time you water!
Steward the Environment. The environmental benefits to collecting rainwater onsite are many! When you install a rainwater catchment system you are aligning with Mother Earth in a variety of ways:
Reduce your Draw on Stressed Systems: Aging water infrastructure is expensive to update, and groundwater and reservoirs are often overdrawn. When you supply a portion of your own water from the rain that falls on your roof, you reduce your draw on these stressed systems.
Restore the Hydrologic Cycle: In a natural landscape, approximately 50% of stormwater infiltrates into the ground, recharging groundwater. About 40% evaporates, and only 10% runs off. In developed landscapes by contrast (e.g. our neighborhoods!), only 15% infiltrates and a whopping 55% runs off! When you collect rainwater for use in your garden, you fix the broken hydrologic cycle by restoring the infiltration link.
Protect your Local Watershed: When rainwater infiltrates onsite, it is prevented from entering stormdrains and surface waters as polluted runoff. Left unmitigated, rainwater sheets off hardscapes collecting contaminants along the way.
Reduce your Carbon Footprint: There is a strong nexus between energy and water in our modern world. In the state of California, 20% of per-capita energy use is dedicated to treating, heating, and transporting water! By reducing your reliance on pumped and treated water sources, you are contributing to a collective savings in energy.