- WATER HARVESTING -

When the skies open and the wonderful rains fall to earth,
life is waiting to drink it in.

What if the majority of urban landscapes actually used plants that were well adapted to the region, and content with the average rainfall of an area?

What if these landscapes were consciously designed to mimic the natural world that existed before the city's development?

What if we consciously used rainwater to enhance these landscapes, rather than using precious desert water for our landscapes?

How would these simple changes impact our quality of life? How would these impact the biological diversity of the urban environment? How much water would we conserve?

These are intriguing questions to consider, and for us, they lead our design.
In designing "landscapes for life" we:

- use regional native plants
- consider the elements of creating habitat
- consider both the diversity of species and of the natural structure we are creating
- employ passive systems that increase water infiltration into the soil
- design active systems that store water for use during extreme times of the year

 

 

Passive Systems

- A passive rainwater catchment system could be as simple as running the guttered roof water out to planting areas and using infiltration trenches for water storage in the soil.
- Another method is using terraces on sloped areas -- which reduces the speed of runoff, allowing the water to soak down into the soil. This allows the soil to act as a water bank.
- Using a layer of mulch on the surface will slow rainwater runoff and retain the moisture longer by keeping the soil cooler and reducing the evaporation rate.
- If a new plant catches the runoff from the slope above with an eyebrow berm, the water is channeled toward its root system, significantly increasing the water available to the plant. "Eyebrow" berms are easy to create, and blend into the landscape (see In My Garden article).

With passive rainwater management, the establishment time of new plantings can be shorter and the health of existing plants can be enhanced. This is great, but the best thing is, you've created a permanent supplemental watering system.

 

Active Systems

You can also store rainwater in water harvesting tanks. These tanks can be installed above or below ground. Above-ground systems usually rely on gravity to disperse the water and serve smaller areas. The in-ground system requires a pump but can provide water throughout the site. In either case active systems bring a great advantage -- water can be stored and used when the soils are dry (instead of soaked from the same rain that filled your tank).

Keep in mind that a one inch rain on 1000 square feet of roof will produce 630 gallons of rainwater. Picture 630 one gallon milk containers packed together in your yard. This is a lot of precious water to store. It only makes sense, in our xeric environment, to enhance plantings with pure, sweet rainwater collected off of your own roof during the times they need it most.