Planting Rain with Brad Lancaster Can You Plant Rain?

By Erica Browne Grivas

"A core aim of passive water-harvesting is to grow or enhance regenerative water-harvesting systems that get better with time, and which can repair and/or reproduce themselves because so much of these systems is alive. The soil and its vegetation is the living "tank;" and vegetation, mycorrhizal fungi, and other life are the living "filters" and "pumps" that then make that harvested and cleaned water accessible in the form of fruit, fodder, shade, shelter, beauty, habitat, erosion-control, medicinals, craft materials, lumber, and more." – www.harvestingrainwater.com

Working with neighbors Lancaster planted over 1,600 native food-bearing trees and hundreds of native understory plants mainly in the neighborhood's public rights-of-ways using curb cuts and cores to direct street runoff to street-side and in-street planting basins to irrigate the vegetation. Vaughn Lancaster dips a cup into the water.
Credit: Brad Lancaster

Can we transform water scarcity into abundance? As we look to increase available water reserves across the country, ecological designer Brad Lancaster offers intriguing solutions to not only gather existing rain but take a holistic landscape approach to amplify and store it in the soil and plants – what he calls "planting rain."

Lancaster's Tucson, Arizona, home is his laboratory and demonstration site, and he consults on residential and commercial projects and with state agencies. Lancaster has written several books, the latest of which is the updated Rainwater harvesting for Dry Lands and Beyond, Vol. 1, Third Ed.

Left: Shown in 1996 the streetside right-of-way is sterile and prone to shedding water. Right: In 2006, the transformed right-of-way is a destination.
Credit: Brad Lancaster

He says much historical design has focused on draining away the rain rather than utilizing it. His method asks how we shed our dependence on an imported, costly water supply by "using what's freely at hand, like rain, which is so much higher quality?" (In Arizona, the municipal water is often high in salt residue.)

"Before we plant any plants, we plant the rain," he asserts.

While active rainwater harvesting via rain barrels and tanks works, Lancaster says the harvest is limited by the size and cost of the tanks you can install, and he recommends starting with passive harvesting and supplementing if needed with cisterns and tanks.

Passive harvesting, using the natural dynamics of the site, takes many forms – from earthwork "berm 'n' basins" – mini rain gardens – to terraces and infiltration trenches as well as capturing and directing the rain from high points to the gardens. Diverting runoff lessens flood pressure and allows the stormwater to be filtered through the soil, lessening pollution in waterways.

His rain basins are of varying depth, some so wide and gradual you hardly notice them, while driveways and paths are raised and sloped toward the basins. Soil dug for the basins becomes the foundation of berms or paths. Downspouts are diverted, and sidewalk curbs are cut or drilled to harvest the rainwater lost in standard street design where the rain slides along the curb downhill, often missing the drains.

"You start getting the domino theory working with you," he says. As a result, Lancaster's system easily doubles the 11" of annual water received by the property.

His eighth of an acre and surrounding public right-of-way harvests 100,000 gallons of rainwater a year while the neighborhood public rights-of-way harvests over a million gallons within tree-canopied and rain garden traffic-calming spaces. [Source: harvestingrainwater.com/press-kit]

A sign details the rainwater-grown local bounty.
Credit: Brad Lancaster

He designs for efficiencies, stacking benefits as much as possible to maximize sustainability. His outdoor shower recycles greywater, hydrates the plants, and cools down his chicken coop. Berms can provide shade, support a raised path, or grow food or native plants. For seasonally wet places like the PNW, valved graywater systems can be turned off or redirected in the winter.

"Now all the water can be directed off-road to where it can be of service," says Lancaster. "You are finding spots where you can get maximum spreading of the water so you can slow down, spread out and infiltrate the maximum amount. The ground becomes a living sponge that rapidly absorbs that water, so you have more fertility and more flood control."

Lancaster's residence has an outdoor shower fed by greywater which hydrates surrounding food gardens and shades and cools the chicken coop.
Credit: Brad Lancaster

Washington Rain Garden Resources
Note: Always check on your local municipal and state codes
12000 Rain Gardens – non-profit promoting and educating about rain gardens and incentives; includes a professional directory.
Rain Garden Handbook for Western Washington, Department of Ecology State of Washington and Washington State University, 2013.
King County's RainWise program – learn about incentives available in your area.