Swales

Swales are level-bottom ditches that run along a contour line across a landscape. Swales slow water down, spread it out on contour and give it time to infiltrate into the soil. They are useful anti-erosion structures where there is significant sheet flow (uniform surface run-off) or concentrated sources of run-off (i.e. culverts, gutters, and hardscape shed points). Swales are primarily tree-establishment systems that will ultimately fill in over time as their function is taken over by a healthy belt of trees running across the landscape.

While not suitable to every landscape, swales are often very helpful in establishing tree belts and mitigating erosion while simultaneously providing a way for water to infiltrate into the soil (where it can be of great benefit) instead of running off the property.

Back to Water Implementation List

Earthen Drains

Unlike swales, drains are ditches that run slightly off contour (usually 1-2% grade) across a landscape and sometimes road surfaces. The function of a drain is to move water (usually as slowly as possible in the case of earthen drains) across a landscape to an area where it can be infiltrated into the soil or put to use.  Drains need to be  carefully surveyed to ensure constant grade in order to function properly. Drains with substantial grade changes will soon become erosion gullies or sediment basins.

Drains are useful tools to link catchment areas with infiltration zones. Depending on soil types and grade they may need to be armored (geologically, biologically, or both) to prevent erosion and failure.

Back to Water Implementation List

Infiltration Basins / Pocket Ponds

Infiltration and/or sediment basins are used to infiltrate seasonal concentrations of water, typically only present during larger precipitation events. Infiltration basins can range in size from small, backyard sunken rain gardens to football field or larger sized depressions graded to give extra water a place to collect, drop its sediment load if it has one, and infiltrate into the soil.

Infiltration basins are great for handling run-on from neighboring properties. In cases where there will be a known sediment load, deposition will occur, often yielding a source of nutrient rich material that can be dug out and re-used elsewhere in the landscape. Where sedimentation is known to occur we typically make the basins large enough to clean out with a tractor.

Back to Water Implementation List

Keyline Subsoiling

Keyline subsoil ripping utilizes a specially-designed non-inversion sub-soil ripper to create pathways for air to enter and water to infiltrate otherwise compacted or hardpanned soils. 

What does that mean? The soil is aerated and water is allowed to infiltrate without destroying soil structure or killing all of the soil microbiota (as happens with discing or soil inversion) because the soil is not exposed to sunlight and the open atmosphere.

The ripping generally runs slightly off-contour, from valleys to ridges, to help evenly distribute water throughout the landscape.

Back to Water Implementation List

Terraces

Terraces are level or just off-level benches cut into hillsides to create flat ground where previously there was none.

Terraces are excellent for creating more usable land, improving access, improving soil production and retention and serve as backbones for some of the most productive growing systems the world round.

Terrace systems can be set up for orchards, food forests, market production, grazing animals and much more – terrace size and spacing is dependent upon the nature of the system being installed, the existing terrain and soil type, and system management requirements.

Back to Water Implementation List

Ponds

Ponds are excellent ways to impound large amounts of water for later use or infiltration. Having water in the landscape also provide a whole host of ecological benefits and additional habitat niches.

In high-evaporation, long-dry season climates like central California, storing water in open bodies like a pond is not always the best choice. However, by constructing ponds to maintain cooler water temperatures (deeper), reduce wind evaporation (planted windbreaks and edges) and shading them (south and west facing shade trees) we can create ponds that will hold water for longer in the landscape and are less susceptible to evaporative loss.

Back to Water Implementation List

Headcut Repair Structures

Zuni bowls are geologically armored plunge pools that stop the up-valley migration of head cuts. Head cuts are particularly damaging to a landscape because once they form they continue moving up-watershed (kind of like unzipping a zipper, except they move uphill!) causing ever-worsening damage with each rain event large enough to create flow in the drainage.

The most effective way to take the erosive energy out of moving water is with standing water. Zuni bowls create an armored pool into which quickly moving water can drop and safely dissipate its energy before being directed onto contour (swales) or continuing on its course, albeit with less energy. Over time, these structures can be allowed to fill in as the watershed repairs itself and healthy flow patterns are restored.

Back to Water Implementation List

Flow Spreaders & Concentrators

Depending on where overland flow is located in the landscape, it can be advantageous to either disperse that flow or concentrate it.

One of the low-tech structures often chosen for this function is the media luna. Shaped like a crescent moon, its tips can either face downhill (“tips down”) or uphill (“tips up”). 

The arc of the crescent is set completely level so that any flow passes over the crescent at the same time. When “tips down” this concentrates flow, much like a drain pipe held just under the water’s surface – water will flow into the pipe evenly from both sides and be directed to the center. When “tips up” this spreads flow, much like filling a cup to overflowing – the water will overflow evenly around all sides of the cup, thus spreading the flow from the center.

Because tips down media lunas concentrate flow these structures are useful in halting upland erosion rills or runnels and for concentrating erosive upland flows before they reach the transport zone (steeper section of slow where interventions carry greater risk and cost). Tips up media lunas spread flow out and are placed below keypoints where the landform has transitioned from convex to concave and where spreading flows is once again desirable.

Back to Water Implementation List

Grade Control Structures

Grade control structures are used to transition water over sudden drops in vertical height that, if left unattended, lead to incision, gully formation, and large-scale soil loss and landscape dehydration.

Two common grade control structures are log-drops and rock mulch rundowns.

Log-drops are generally utilized in areas without a lot of rock available on-site but that do have straight trees available for felling and limbing. They are essentially an armored step down ramp that allows the water flow to transition the grade change without further eroding the soils underneath and continuing up-valley.

Rock mulch run downs are composed of knitted stone and create an armored trough for water to run down where previously it was falling vertically over an edge, creating headcut erosion.

Back to Water Implementation List

Aggradation Structures

Aggradation is a fancy term for raising the level of a gully bottom. This is generally undertaken to help with gully repair, enhance vegetation recruitment via sediment deposition and moisture retention, and to further slow and disperse erosive flows.

The most common structure we utilize for this function is the one-rock dam. A line of rocks one rock high (4-6”) and 6-10 rocks deep lain atop a keyed in splash apron in the bottom of a gully. This line of rocks backs up sediment and becomes an excellent location for new vegetation to establish, which further enhances roughness, slowing heavy flows and securing soil.

One-rock dams also help to secure the downstream edges of larger elements, like zuni bowls, log drops, and rock mulch rundowns by creating a still water pool / sediment drop zone just downstream of those structures, which further helps to dissipate erosive energy.

Back to Water Implementation List

Some of the enterprises and applications we have designed irrigation systems for include…

• Mixed-Variety Home Orchards And Small-Scale Commercial Orchards
• No-Till Market Gardens (overhead micro-sprinklers, drip)
• Swale-Based Tree Systems 
• Agroforestry Systems – Including Windbreaks And Shelterbelts
• Farmstead-scale Tree And Plant Nurseries (intermittent mist and air pruning bed propagation systems)
• Home Landscaping Irrigation Systems (drip, sprayers, sub-surface)
• Biological Erosion Control Systems (vetiver grass)
• Log-based Mushroom Production Systems (misters, sprinklers)
• Off Grid Solar Powered Irrigation Timer + Manifold Assemblies
• Completely Off-Grid Systems For Pumping From Creeks And Pressurizing Water

Back to Water Implementation List