Make most of monsoon season by harvesting rainwater
After years of prolonged drought and seeing dried and dead trees and shrubs along our trails and roads, our current monsoon season is a welcome relief.
Yet, as we are relieved from the specter of wildfires and struggling plants, we also see the destructive power of water when it flows unhindered across our parched landscape, through dry washes, and down our streets.
As a homeowner, I see the properties up the street shedding their runoff from roofs driveways, and yards onto the properties down the street increasing flooding, erosion, washing away topsoil and mulch, while depositing unwanted debris.
Why do we try to quickly get rid of water that falls on our land when it can be a valuable resource? At the end of July our series of rainstorms gave us more than four inches of rain. That translates to 60 gallons per 100 square feet per inch of rain, so four inches of rain on a 2,000 square-foot roof produced 4,800 gallons of runoff.
With that same quantity also falling on the rest of our property we received an abundant gift of water that we essentially threw away, or let cascade away with destructive force.
Harvesting rainwater does not rely on having tanks that capture rainwater off our roofs, although that is a small part of it. With the quantity of rain during a monsoon storm, a rain barrel or tank would quickly overflow.
To harvest rainwater it is important to slow down the runoff, and harvest it in our landscape before it reaches the street.
To do this we need to create areas where rainwater can pond up and sink in the soil. Living in an arid region, we can take cues from nature, and imitate it in our landscape.
A landscape that harvests water has depressions that can host plants that benefit from occasional deep watering, or are fairly dormant until rainfall awakens their life.
Low spots, or deep mulch “sponges” can become seasonal wetlands, hosting trees, shrubs, wildflowers and native grasses.
Many homeowners create rock-lined channels taking the shortest route to deposit their runoff in the street. Even these could be made to mimic a desert arroyo that meanders and has some check dams along the way.
Such a landscape will slow the water and keep much of it on your land. Behind check dams topsoil and mulch will be deposited.
These valuable garden amendments can be harvested or they can become places where seeds can germinate.
Just like our high desert, we can develop a resilient landscape that improves the soil, retains water, and helps native and non-native plants thrive.
By harvesting the water that falls on our own land we can reduce runoff that would potentially create destruction “downstream” from us.
One way to reduce the impact of a long drought is to save as much rainwater as we can during those times that we do receive it.
Visit www.gardensforhumanity.org to learn more about resources we offer to help plan a resilient and productive garden.