Marin Master Gardeners
University of California
Marin Master Gardeners

Fire-smart Landscaping - Water

How your landscape is irrigated makes a difference.  Too much water, too little water or watering at the wrong time of year will damage a plant.  Watering more than necessary can encourage excessive growth, increasing fuel load on your property.  Your landscape and irrigation system should be designed to work together.

Water quick check list

  • Consider seasonality. Give plants the water they need, when they need it, to thrive – no more, no less
  • Keep your watering routine steady
  • Do not wet down your property on Red Flag warning days. Irrigate as normal.  Over watering on Red Flag days depletes the water tanks that the fire departments rely on should a fire occur.
  • If you irrigate often and for a short duration, consider watering less frequently but more deeply.
  • Adjust your irrigation according to the seasons.


  • Learn about the water needs of plants in your landscape, and make sure they are watered accordingly
  • Divide your garden into low, moderate, and high water-use areas (hydrozoning). If you install an in-ground irrigation system, make sure that plants with different watering regimes are served by separate water lines and control valves so each group can be irrigated appropriately.
    • High water-use areas are lawns and other water-loving plants. This zone should be kept as small as possible. Limiting the size of your lawn is probably the biggest, single, water-saving action you can take.
    • Moderate water-use areas are the transition zones between high and low water-use areas.
    • Low water-use areas contain local “native” plants and Mediterranean-type plants adapted to our environment. Irrigation is needed in the summer while new plants are getting established (the first 2-3 years), but once established they need little, if any, additional watering.
  • Watering to the root depth of your plants creates a healthier and more efficient garden. Watering more than necessary can encourage excess growth, which adds to the fuel load.
    • For lawns in clay soil, this means applying ½” of water to moisten the soil to a depth of 6 inches.
    • Lawns in sandy soils will require less than a ½” of water but more frequent applications.
    • Shrubs must be watered even more deeply, but less frequently.
  • Use drip irrigation whenever possible. Drip irrigation applies water much more accurately and at a lower rate than overhead spray. Drip irrigation is best for areas where plants are widely spaced, since watering open areas between plants will encourage the growth of weeds. Conventional or subsurface drip irrigation is often best for slopes, where sprinkler irrigation may cause runoff and erosion.
    • Some plants in some situations may be best irrigated with sprinklers.
    • Slow, accurate application to the plant roots prevents spraying unneeded areas such as walks and driveways.
    • Assess the efficiency of existing irrigation systems; ensure proper watering with a drip irrigation system through the use of timers.
  • Clearly mark all emergency (and other) water sources
    • Create easy firefighter access to your closest emergency water source
    • Store an extra hose or two with emergency supplies.
    • Keep hoses accessible for firefighters.
    • If your water comes from a well, consider purchasing an emergency generator to operate the pump during a power failure.

Reference Materials for further reading

Water Use, Irrigation and Water Conservation:

Ten Tips for Water-Wise Gardening:

Firescape: Landscaping to Reduce Fire Hazard:

Efficient Water Management:

Drought - Gardening Tips:

Drought - Irrigation Tips:

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