Water Conservation at the City of San Bruno

Xeriscape is a systematic concept for saving water in landscaped areas.
Xeriscape (pronounced zeer-eh-scape) is a combination of the Greek word Xeros, which means dry or arid, and the English word Scape, meaning vista. Xeriscape was originated in Denver, Colorado, in 1978 by a water conservation task force of the Denver Water Department (The term Xeriscape is a registered trademark of the Denver Water Department).

Xeriscape is NOT dry only
Limited areas of more highly-watered landscape are completely consistent with wise water use. For example, heavily-irrigated athletic field turf makes sense, since it recovers quickly from heavy use. However, areas around the edges could be replaced with ground cover, stepping stones or concrete.

Retrofit your Landscaping to a Xeriscape
The average home landscape uses as much as 50 percent of the water in a household. Even if you already have a well-established landscape, you can substantially reduce water use by following some simple steps.

Change turf areas on steep slopes, hard-to-water places and narrow mowing strips to low-water ground covers.
Use or update an irrigation controller for cycle and soak irrigation to minimize runoff from slopes and compacted soils.
Modify sprinkler systems to water only turf areas, not hardscapes.
A low pressure, micro-irrigation (drip) system can save water.
Like any plants, xeric plants require more water for establishment.

Survey Your Yard
Observe turf grass areas that are difficult to water and maintain. These include:

along fences;
on steep slopes where water tends to run off;
corners of lawns where it is hard to water without overlapping into other areas;
narrow strips of lawn between the house and sidewalk or driveway; and
irregularly shaped lawn areas that do not fit the normal pattern of most sprinklers.
If you have an underground sprinkler system, turn it on and see where the water sprays.

Adjust heads that are spraying concrete and other hardscape surfaces to water only plants. Relocate sprinkler heads near fences so water sprays towards plants, move heads further away so water doesn’t wet fences, or switch to drip (micro-irrigation).

Steep slopes, especially those on south and west exposures, waste water through runoff and evaporation. Utilizing or installing a control timer that allows for cycle and soak irrigation may solve the problem on gentle slopes. You could also convert these areas to perennials or ground covers that tolerate the exposure and thrive on little water. Drip (micro-irrigation) that slowly applies water over longer periods of time may further minimize runoff.

Study the areas in your yard to include play areas for children and exercise areas for pets. These could be left as turf that can take the wear. Other areas could be converted to shrub borders, flower gardens and non-turf ground covers that use less water. Paths could be altered to stepping stones or flagstones.

Turf prevents soil from moving into the air, streams and homes. It is the best filter of runoff and scrubs pollutants from water. It also builds soil for other plants and is one of the best means of urban fire control.

Drip (micro-irrigation) Systems
Drip or micro-irrigation systems can be a good way to water any type of plant except turf. Low pressure, micro-irrigation systems apply water slowly and close to the ground - this eliminates waste from water blowing off-target and reduces water use. The boundary between sprinklers and drip irrigation has blurred with advancements in micro-irrigation to include spray stakes. These systems allow you to water plants separately with emitters, or water groups of plants with micro-spray stakes or tapes that ooze water along their entire length.

What to Avoid
Do not group plants with different water needs together in the same irrigation zone. “Hydrozone” plants by grouping them together by similar water needs.

Keep rock or gravel areas to a minimum as they tend to increase air and soil temperature. Use weed barrier fabrics (geotextiles) available in garden centers. Geotextiles allow water penetration and air exchange. Cover landscape fabrics with mulch.

Use organic materials such as wood chips and chunk bark. They help retain moisture and hold weeds in check. Use mulch either with a landscape fabric to save water. Rock could be used to cover a steep slope where wood chips and gravel may wash away. Lay rock over a weed barrier fabric as if you were constructing a rock wall.