When we're on your property pressing block, we can also reshape the land around it. Swales, berms, and basins capture rainfall where it hits the ground instead of letting it run off — so every storm feeds your landscape instead of eroding it.
Passive water harvesting works on three goals: slow the runoff down, spread it out over a wider area, and let it soak into the soil instead of draining away. In the desert, rain isn't a nuisance to move off the property as fast as possible — it's the resource the whole landscape is short on.
A conventional lot is graded to shed water: hardscape and slopes push rain toward the street or a detention basin as fast as possible. Terraformed land does the opposite. Earthworks intercept that same water and hold it against the slope long enough for it to infiltrate into the root zone, turning runoff that used to leave the property into water your landscape actually uses.
A swale is a shallow basin cut across the slope; the berm is the raised bank on its downhill side, often built from the same soil removed to dig the swale. Together they catch water moving downhill and hold it in place to soak in.
Shallow, sunken planting beds positioned to receive runoff from roofs, driveways, or higher ground, directing water straight to the root zone instead of the storm drain.
Level shelves of soil built parallel to the contour of a slope, used to control erosion on steeper ground while creating flat, plantable area.
Permeable barriers placed across a drainage path to slow concentrated flow, reduce erosion, and redirect water where it's more useful.
A finishing layer that reduces evaporation, slows runoff further, and keeps infiltrated water in the soil longer once it's there.
A berm-and-swale retrofit on a 55,000 sq ft parking lot, installed by Watershed Management Group volunteers, redirects stormwater that used to bypass irrigation and drain straight to a detention basin.
Tucson was the first U.S. city to mandate rainwater harvesting for new commercial properties, requiring earthworks and catchment sized to meet half of landscape irrigation demand after plant establishment.
This isn't guesswork — there are real design rules behind a swale and berm that holds up in a storm instead of blowing out.
As a rule of thumb, the base of the berm should be at least four times as thick as its total height, measured from the bottom of the basin to the top of the berm. A berm that's too thin for its height is the most common cause of a blowout during a heavy storm.
How far apart swales and berms should sit depends on two things: how much water the basin can hold, and how much runoff the slope actually produces. Smaller basins on high-runoff ground need to sit closer together; larger basins on lower-runoff ground can be spaced farther apart.
Every earthwork also needs a planned overflow route — a wide, stable spillway — so that a storm larger than the system was sized for has somewhere to go besides through the berm.
We didn't invent this — we're applying documented, Arizona-tested practice. If you want to understand the design principles in more depth, these are the sources we build from.
Brad Lancaster's field guide is the standard reference for water-harvesting earthworks in arid climates, with step-by-step instructions for swales, basins, and planting design. harvestingrainwater.com
Publications AZ1564 and AZ1916 cover passive water harvesting design and landscape management for the low desert. extension.arizona.edu
A Tucson nonprofit running community earthworks installations across southern Arizona, including the Sierra Vista project referenced above. watershedmg.org
The Water Resources Research Center publishes ongoing research on passive water harvesting specific to Arizona conditions. wrrc.arizona.edu
When we're on-site pressing your compressed earth block, the same visit can include grading, swale cutting, and berm construction for your property. By the time your walls are up, the land around them is already set up to capture water instead of shedding it.