How to harvest rain for your yard
During recent winter storms, many Sacramentans had the same thought: How can I save some of that rain for later?
Forget buckets; instead, rethink your flow.
Traditionally, most of our home landscapes were designed for maximum runoff, whisking any excess water away from homes into streets, then rivers and out to the ocean.
Holding onto some of that rain can recharge soil moisture, cut down on outside water use and create lasting savings on irrigation. Which methods you use depends on space and how much you want to spend.
Rodger Sargent and Chris Lopez of Sacramento-based Grow Water create rain-harvesting gardens that maximize water efficiency. Among their designs was a Cal Expo demonstration garden at the 2015 State Fair. Last year, Grow Water’s workshops and projects added up to an estimated 78,000 gallons of harvested rainwater. They shared some of their favorite methods for holding onto nature’s gift: Free water from the sky.
“We’re mimicking nature,” Sargent said. “Did you ever trip on a sprinkler head in the forest?”
To maximize the benefits, Sargent and Lopez also recommend converting ornamental gardens to low-water-use native plants that can survive year-round without additional irrigation besides what they receive from rain harvesting. They also use several edible plants in their designs.
“We design with natural forces in mind – gravity, sun, wind and shade,” Lopez explained. “The more passive the system, the more benefit. You don’t always need a tank to store water; put it in the soil instead.”
These water-saving techniques can be added gradually or all at once, but the cumulative effect can create huge benefits for thirsty landscapes and make a life-and-death difference for plants in times of drought and water scarcity.
Remember: Rain goes away. Save some for those dry days ahead.
Rethink your flow
Look at existing places outside the home and how to repurpose them to collect rainwater.
1. Earthworks: Manage water where it falls or flows. Create berms and swales that hold rainwater and let it slowly percolate into the ground, recharging the soil with moisture. Make sure water doesn’t collect around a house’s foundation.
2. Rain garden: This planting design takes earthworks to the next level. It slows, spreads and sinks water into soil, providing longer-lasting moisture for plants. The lowest areas are covered with a “reservoir” layer of gravel that holds water as it filters down. That’s topped by organic mulch, compost or soil where plants that don’t mind occasional standing water may grow.
3. Mulch: An insulating layer keeps moisture in the soil longer. Rock mulch and cobbles in a rain garden suppress weeds.
4. Permeable pavement: Instead of solid concrete or asphalt, this hardscape allows water to seep into the soil underneath, cutting down on runoff and benefiting nearby trees or shrubs.
5. Roof and gutters: Your roof is ready-made to harvest rain, yielding up to 623 gallons per 1,000 square feet per inch of rain. Redirect gutters or gutter extensions to a rain garden or use a downspout diverter to fill a rain barrel or cistern.
6. Rain barrel: Hooked up to downspouts from rain gutters, this simple system allows for mosquito-free storage of captured rainwater. Typically, each barrel holds 40 to 80 gallons and costs under $200.
7. Cistern: This large tank can be above or below ground for storage of rainwater for later use. Holding 500 gallons or more, above-ground models cost $1 to $3 per gallon installed; underground cisterns cost $3 to $8 per gallon installed. They can be quite large; a 2,000-gallon cistern is about the size of a minivan. A 3,000-gallon tank is 8 feet tall and 8 feet wide.
8. Olla: An ancient idea, unglazed 2- to 5-gallon earthenware pots are buried in the ground and filled with water, which slowly seeps through the sides to irrigate nearby plants.